#410 ‒ The biology of pregnancy: physiologic adaptation, gestational diabetes, preeclampsia, childbirth, and long-term maternal health | Kathryn Gray, M.D., Ph.D.
117m 54s
Pregnancy is a unique and extreme physiological state that places significant stress on a woman’s body, reshaping her cardiovascular, metabolic, and hormonal systems. This transformation, including expanded plasma volume and insulin resistance, can uncover underlying genetic predispositions to conditions like gestational diabetes and preeclampsia. These conditions are not isolated events—they reflect a deeper biological vulnerability, with strong links to long-term risks of type 2 diabetes, cardiovascular disease, and kidney dysfunction. Research shows that women who develop gestational diabetes or preeclampsia have a substantially increased risk of future metabolic and cardiovascular disease, driven by shared genetic architecture. Despite advances, many women remain unaware of these links, and obstetric history is often underreported in medical records. Effective long-term care requires seamless communication between obstetric and primary care providers, ensuring that insights gained during pregnancy are translated into actionable preventive strategies. Key interventions, such as lifestyle modifications, regular screening, and early detection, can mitigate future disease. While the exact mechanisms of some complications—like HELP syndrome—are still being studied, the consensus is clear: pregnancy acts as a powerful diagnostic window into a woman’s lifelong health trajectory. This underscores the importance of comprehensive, patient-centered care that extends beyond childbirth.
Hey, everyone. Welcome to The Drive Podcast. I'm your host, Peter Attia. This podcast,
my website, and my weekly newsletter all focus on the goal of translating the science of
longevity into something accessible for everyone. Our goal is to provide the best content in
health and wellness, and we've established a great team of analysts to make this happen.
It is extremely important to me to provide all of this content without relying on paid
ads. To do this, our work is made entirely possible by our members, and in return, we
offer exclusive member-only content and benefits above and beyond what is available for free.
If you want to take your knowledge of this space to the next level, it's our goal to
ensure members get back much more than the price of a subscription. If you want to learn
more about the benefits of this content, please visit our website at www.thedrivepodcast.com.
To learn more about our premium membership, head over to www.peterattiamd.com forward slash
subscribe. My guest this week is Dr. Katie Gray, a physician scientist and maternal fetal
medicine specialist at the University of Washington School of Medicine, where she
serves as division chief of maternal fetal medicine and the director of research in MFM.
Katie's clinical work and research focuses on high-risk pregnancy and pregnancy complications,
with particular expertise in preeclampsia and stillbirth. I wanted to have Katie on because
pregnancy is one of the most remarkable physiologic challenges the human body undergoes, and yet
I realize there's a lot about this that I certainly don't understand. So we start with
the basic physiology of pregnancy and work our way through many of the complications
that can arise, from gestational diabetes and preeclampsia to stillbirth and actual
complications of delivery. Through this conversation, we talk about many things like how pregnancy
changes and how it affects the quality of life, and how it affects the quality of life
as a woman's cardiovascular system, metabolic system, and hormone physiology. We talk about
nutrition during pregnancy, fetal development, and the importance of nutrients such as folate.
We talk about gestational diabetes, why it develops, how it's diagnosed and treated,
and what it can mean for both mother and child later on. We talk about preeclampsia,
including the role of the placenta, why it can become so dangerous, and how it's managed.
We talk about HELP syndrome and other severe complications of pregnancy.
We discuss stillbirth and its potential causes, and why so many cases remain unexplained even after
extensive testing. We discuss the trade-offs between C-sections, vaginal delivery, and how
clinicians think about the risk and trade-offs of each, and how pregnancy complications can affect
a woman's health well beyond pregnancy, including her future risk of metabolic,
cardiovascular, and kidney disease. And it's this last issue in particular that has me curious,
as I've been reading more and more literature about what occurs in a woman's pregnancy can be a
window into her health later in life. So without further delay, please enjoy my conversation with
Dr. Katie Gray. Katie, thank you so much for coming out. It's awesome to meet you and I'm
super excited about what we're here to talk about. Yeah, me too.
Give folks just a little bit of a background in your, maybe what you're doing today,
but also kind of the trajectory that got you here.
You're a physician-scientist, an MD-PhD. What led you to this field?
I guess that's a good question, but I think I've always been interested in science,
and I was an undergrad, and I really liked all my classes and all the science classes,
and I was thinking of just going to medical school. And then I had this one advisory
meeting with our, that was required at the University of Wisconsin, where in this one
meeting, this professor sat down and said, "Well, my daughter went to medical school and she really
enjoyed it, but I thought she would have been so much happier if she also did a PhD. Have you ever
heard of that?" And I was like, "No, I've never heard of that." But because of that one conversation,
I investigated that further, and I thought that that was fascinating and super interesting,
and that was the beginning of me pursuing all the rest of the steps that happened after that.
And so just briefly, what did you focus on during your PhD?
Yeah, so I technically have a PhD in immunology, but what we really did was
take this benzodiazepine that was found from a drug screen, and it had been shown by a previous
student in the lab to help treat autoimmune lupus, disease in my soul lupus, but they
didn't know how it was working. So my PhD was focused on understanding the molecular mechanism
of this novel benzodiazepine and where it bound and how it actually induced apoptosis
in cells. And so basically, I took a lot of cow hearts and isolated mitochondria and did a lot
of biochemical assays to show that it acted on the mitochondrial ATPase. So that is what I spent my
time doing. Did that end up having human clinical benefit?
Actually, the drug itself is not very soluble, so it was hard to make into like a readily
absorbed drug. However, a derivative of that has actually become a treatment that's in trials,
for inflammatory bowel disease, because it can act just in the gut, so.
Interesting.
Yeah.
And I assume you did your PhD in the sort of normal MSTP fashion, where you did the two years
of pre-clinical, you went off to the lab, and then you came back for your rotation. So you come out
of your PhD, you've got a couple of years left of medical school. What drew you to obstetrics and
gynecology?
Yeah, I had always been really interested in women's health. I did all the clinical rotations
as a third-year medical student. I really didn't want to go into obstetrics and gynecology,
I really liked everything. I liked medicine, I liked surgery, but I really liked pregnant
patients and deliveries. And I thought it was such a unique patient population to take care of,
because I found people were uniquely motivated about their health during that time in a way that
you didn't find in other parts of medicine. And thinking with the research, half of my interest,
I also was fascinated that we didn't understand anything. Like, why do people go into labor?
Why do people have preterm labor? Why do people have preeclampsia?
The answer was, we don't know. And so I thought it was a great area of medicine to go into.
Well, let's just jump into it then. Really, the first place I kind of wanted to start was
understanding the sort of physiologic stress test that is pregnancy. Obviously,
I have no personal experience, but certainly watched my wife go through it three times,
actually more unfortunately, but three successful pregnancies. And I shared with you some personal
stuff that I probably wouldn't have been able to tell you about, but I think it's really important
to share with you. And I think it's something I probably won't disclose on the podcast about.
I've seen the most extreme sides of it. I have to be honest with you. There's a part of me that
thinks, how did our species propagate? I don't understand how all the women and children didn't
just die. I know we talk about how infant and maternal mortality was such a huge driver of short
life expectancy prior to the modernity of medicine. I'm still surprised it was as successful as it was.
In whatever way you want to address it, just maybe talk us through the unbelievable
demands that are placed on the women in this species as they have to deal with this essential
challenge of our reproduction. Yeah. I mean, I think that's, and I'm also amazed that it ever
goes well, pregnancy that is. So just for how many ways that it can go wrong. But I think you take a
look at the way that the fetus is developed. I mean, I think that's a really important thing. I'm
not sure if you can see it, but I think that's a really important thing. And I think that's a really
important thing. this developing fetus. And so there's great expansion of the blood volume, great alterations in the
endocrine and metabolism. And those are extremely dramatic and persist throughout the whole pregnancy.
So it's hard to pick just like one thing, but I think it's a
cardiovascular stress test because the plasma volume expands so much. It is a metabolic stress
test because there's increased insulin resistance, especially in the second part of pregnancy.
It causes some people to have gestational diabetes, and it often can unmask future
predisposition to disease through this process. Well, I want to talk about all of those,
but maybe we can just start with the beginning. So shortly after
conception, what is sort of the first physiologic interruption that occurs in the woman's body? And
I mean, we could think of this through the lens of, for a woman who is not planning to get pregnant,
is the first observation typically the menses, the missed period, or is it morning sickness?
Like in your experience, what is the first sign that a woman's pregnant?
Yeah, I think for people who have regular periods, like the missed period is often
the first sign before others. Before an actual symptom.
Yeah. Okay. We don't need to explain
why that happens. I think that's pretty self-evident, but let's now talk about how
the physiology is changing in that first four to six weeks. So the implantation has taken place,
obviously the placenta is starting to grow. What's happening in her endocrine system, for example?
Yeah. I mean, I think there's certainly different phases of, at first the ovary is actually
supporting in the. Yeah. endocrine way,
the development of the pregnancy. And then as the placenta develops, the placenta itself starts to
secrete the hormones that support the pregnancy. And when does that transition take place?
Between like, you know, eight to 10 weeks of pregnancy. So that's why when people have IVF
and they kind of shut down your own hormone system for that process, that supplementary
hormones are given for the first several weeks of pregnancy because there isn't the natural
hormones being produced by the ovary. Okay. So the ovary before that transition
is primarily making estradiol as the dominant estrogen?
And progesterone. And progesterone. Okay. And then what's happening with HCG
during that period of time? Yeah. I mean, that starts to,
you know, it goes from being zero to increasing dramatically.
And what's the purpose of that? I mean, I know it's basically luteinizing hormone,
but is it basically the pituitary's way of
taking the hormones that support the pregnancy?
Telling the ovary to make more of these hormones? Is that why it's rising?
That's a good question. I haven't thought about that in a while. So, yeah.
Is the rise in HCG part of what's driving the morning sickness or the nausea? Do we know
what's causing that? For a long time, people actually thought that. But actually, for people
who have extreme nausea and vomiting of pregnancy, so hyper-emesis gravidarum, we have very poor
treatments for that. And interestingly, genetics is something that gave us a great insight about
that, which is when they studied folks who had hyper-emesis, they found a signal that flagged
the GDF-15 gene is really important in driving who developed that condition. And so that's actually
now a developing target for therapeutics in that area and suggests that we haven't
really gotten it correct as to why people have that. So it's not,
that well understood.
Is it correlated with anything else? For example, is it correlated with
a person who easily gets sick being in a car or on a boat?
I don't think all the time that that is the case.
Is it also something that is predictive of subsequent, I mean, if it has a high genetic
component, I assume the answer is yes. But is it necessarily the case that if a woman's
sick during her first pregnancy, she's probably in store for this going forward?
We often see people who have hyper-emesis.
Hyper-emesis in all their pregnancies if they have it with their first. So yes.
Okay. So again, we don't know why it's happening. Is the biggest risk of that simply nutrition? Is
it that it makes it more difficult to get enough nutrition during that period of the pregnancy?
Yeah, I think so. And I think it's more maternally risky. So usually the fetus at
that stage will take what it needs from the mother. And so the biggest risk is dehydration and lack
of nutrition during that time. Yeah.
Do you have a rough sense of the prevalence of how often it becomes maybe something that would
even require a brief hospitalization or even a medical intervention? And by the way, are your
standard anti-emetics safe during pregnancy? I can't remember, Zofran and things like that,
can they be used during pregnancy?
Yeah, they can be used during pregnancy. There's various,
we could get into the data on that, but in general, we do have some tools and anti-emetics that can be
given, but oftentimes they're not helpful enough for folks. And they do end up in the hospital
needing IV hydration and even IV nutrition sometimes during pregnancy.
All comers, what's the prevalence of that intervention?
I think it's pretty rare, like less than 1% of folks, but obviously for the folks that have it,
it's very severe. Okay. Now I don't remember my embryology well enough to remember exactly what's
happening in the fetus at every week. Obviously we all had to know that in medical school,
but the first trimester,
the fetus isn't huge, right? It's a pretty non-linear growth pattern is one of my recollections,
but a lot of incredibly important things are happening, albeit at a small scale.
So you talked about plasma expansion in the mother. How much of that is occurring in the
first trimester? It starts immediately and kind of
peaks at being total, it increased by 50% by 28 weeks. And so it's pretty, it starts immediately
and it's pretty linear up to the, and really accelerates in the second part of the second
trimester and then kind of levels, levels off. So that's pretty remarkable. A 50% increase in
plasma volume by 28 weeks. Yeah. Now does, is that accompanied by a 50% increase in oxygen
carrying capacity? Is the, is the hemoglobin concentration expanding to, to compensate for
that? Or is there a relative anemia that's forming? It's a relative anemia that's forming due to that
expansion.
Okay. Again, I suppose because women are young when they have pregnancy, we don't have to worry
about things like CHF, but a 50% plasma increase would, would kill some people.
Correct. And that there are folks for, who have severe enough cardio or pulmonary disease that
they are unable to tolerate that. And then the recommendation is really to, to not be pregnant.
Wow. So there are women whose heart and lung function is poor enough that an abortion might be
necessary to save the mother's life. There's, you, in other words, you couldn't just give them
diuretics and treat them the way you would treat someone with CHF because then that would be
ineffective. That would be effectively causing the abortion as well.
Right.
Yeah. That's, and, and presumably is that a failure of the medical system in the sense that
that woman should have known that she was that high risk before? How, like that, that seems like
a difficult position for someone to be in. Well, it's, it's complex, right? 50% of pregnancies
aren't planned. Oftentimes,
folks affected by the most severe medical disease often lack other resources, insurance,
access to care. So there's a lot of, there's a lot of barriers. Sometimes disease remains
undiagnosed until someone- That uncovers it.
It is pregnant. So, yeah. Okay. You talked about this switch from
the ovaries providing the sex hormones to now the placenta. You said that takes place,
did I, did you say about eight weeks? Okay. Are they-
Are they just continuing to go up? Estrogen, progesterone are continuing to rise.
What is their function? How does it differ between a male versus female fetus?
There aren't a lot of differences for the, in that, in, for a male or female fetus.
And so the estrogen and progesterone, what are they doing to support the pregnancy specifically?
Yeah, I think we're, we're in the domain of the reproductive endocrinologist here and not the
maternal fetal medicine doctor.
But, but, you know, they, progesterone has many important functions in pregnancy, especially
in maintaining the uterine quiescence, right? So it doesn't contract and continuing to support
the development of the placenta itself. Yeah. And how often do women complain of
symptoms from the estrogen rise? Because we know from later in life, so when you think about women
who are undergoing hormone replacement therapy, they can become very symptomatic from the estrogen,
but they don't- Yeah.
the estrogen that's given during peri and post menopause is much lower than presumably what
she's experiencing in pregnancy. And yet they can still have symptoms like horrible breast
tenderness, headaches, and things of that nature. So how often are those occurring in pregnancy as
a result of this enormous surge in estrogen? Yeah. I mean, I think with the dramatic change
in the beginning of pregnancy, lots of those symptoms are common, like breast tenderness and
associated estrogen related symptoms. But they abate? Does the-
You know, different,
everyone experiences it different, but I do think that there is some adjustment. But that also,
the hormones often also drive the other physiologic changes in the mother across
pregnancy as well. At what point during the pregnancy does the mother's appetite usually
start to increase? Well, I mean- I mean, I guess it's complicated because you, let's take out the
case of a woman who's got horrible morning sickness. And more, I'm asking this through the lens of
when does the demand, when does the metabolic demand of the fetus warrant increased intake by
the mother? Well, I think that's more like in the second half of pregnancy when the actual
amount that the fetus is growing is the greatest. There's also increased nutrient demands, which is
why, you know, we have folks taking prenatal vitamins and also that didn't contain iron
because that will also support like the developing blood expansion as well. So there are increased
nutrient demands. So let's talk just specifically about them. I know that many folks probably know
what the prenatal stack looks like, but just, and maybe we can just state it, what are the most
important vitamins and minerals during, from the moment a woman is pregnant or even planning to
get pregnant? Right. Folic acid is really the, one of the things we've really thought about and
focused on a lot of having adequate levels prior to conception. So that's part of the reason we
tell people to take a prenatal vitamin prior to conception, because there's good evidence that
folic acid deficiency increases the risk of having a neural tube defect in the baby. And by the time
you recognize the pregnancy, it's already kind of too late to bring up folic acid levels if they
have been deficient. So that's one of the most essential things early on.
Now you said 50% of pregnancies are unplanned, which suggests that prenatal vitamins should be
recommended to all women of childbearing age, correct? Well, or a healthy diet. So,
I think if you have a well-balanced diet and a lot of the food is now supplemented with B vitamins,
and folic acid and things that you want to be replete in with pregnancy. So I think a lot of
folks will have adequate levels if they're eating a well-balanced diet with fruits and vegetables
and whole grains. So what is your patient population like? You're in Seattle, but you're
at a university hospital, so you serve a very broad population. How often do you today see a
neural tube defect? Well, we're a referral center. You're a tertiary center, so it's concentrating
there. Right. Yeah. So we see case of neural tube defects every month that come to our center,
but we have, again, we have a wide catchment. Explain to folks what that is, actually. We're
taking that for granted. Yeah. Well, it's a category of defects in any part of the neural
tube where it doesn't form correctly. The most common would be myelomeningocele, where at the
base of the spine, commonly, the. Spinal cord is actually exposed, so the overlying skin doesn't form properly and the part of the
spinal cord is exposed. And so when that is diagnosed, is there anything that can be done
in utero, or is it now just a case of knowing what to expect at delivery? Yeah, this is one of the
areas where there have been developments in doing in utero surgery. So I'm not a fetal interventionist,
but there are qualifications.
Yeah, there are qualifications that make people eligible or not eligible to have in utero repair. So for some folks, that is done. In the right cases, it can help improve long-term ambulatory, like lower extremity function, bowel and bladder function of the child. So that is why it is done sometimes.
And classically, without an intervention, if a child is born with a neural tube defect of the type you described, how does that impact their life?
Well, it is very variable. There can be mild effects or pretty severe effects. Again, I'm not a pediatrician either, but there can be a lot of effects on walking, lower extremity strength and function, bowel and bladder function, and also problems with accumulation of fluid in the brain and need for shunting of that fluid lifelong.
Now, this is taking another very, very extreme example, but it's one of the ones I really remember from medical school is this condition anencephaly.
Is that something that is not seen typically today, or are there still cases of that?
No, we still have cases of that. We have had two this year in our practice that I'm aware of.
Can you tell folks what it is?
Well, it's also on the spectrum of neural tube defect, but it's the most severe where the brain and cranium does not form at all.
And so those are, and I don't think today with the prenatal care that is available to women, children are born.
In that condition, although again, in medical school, we saw countless examples of this in textbooks and things like that.
What determines in the context of a folate deficiency, why one woman might have anencephaly versus, which is obviously not survivable, whereas another woman might have a baby that has a small neural tube defect down at the other end of the spine, which could be completely survivable.
Is that a random chance thing, or does it speak to some other factor?
The overall answer would be that we don't understand.
There are cases of these malformations that are associated with underlying genetic syndromes in the baby, but there are also cases that are sporadic where there's no underlying genetic defect identified, and we don't know why.
What are some other very important milestones for the mother and fetus during the first trimester?
Well, another really important thing that's happening entirely in the first trimester is formation of all the organs.
So by the time the first trimester is done, that's basically complete.
So the heart has four chambers, the pancreas has considered its little ventral bud rotation, all of that stuff has happened.
And approximate size of the fetus at the end of the first trimester?
I mean.
So for those who are listening to us, basically an inch and a half, two inches.
How many grams?
I couldn't tell you the number.
A few almonds.
Yeah, yeah.
So it's miniature, but it's perfectly formed.
Yeah.
Which is unbelievable.
Yeah.
Okay.
At this point, on average, the mother has gained how much weight?
Zero to 10 pounds.
Yeah, so it's relatively small.
Yeah.
There's huge variability, as you might imagine.
Yeah.
Okay, so now we enter the second trimester.
We are, let me do my math.
We're about halfway to that expansion of plasma volume.
So we'd be roughly at 25% plasma expansion.
Tell me what's happening.
Yeah.
So we're at 25% plasma.
for both like screening and identifying people who are at risk or have developed gestational
diabetes and having the most impact from treatment. Tell me, the diagnosis is made
with an oral glucose tolerance test, done at fasting, and then two hours. What's the criteria?
So the way it's done is the one-hour glucose test with 50 grams of glucose doesn't have to
be a fasting test. So you just come in, you drink 50 grams of glucose, you have your blood drawn
an hour later and tested for the glucose level. If you don't pass that test, so your glucose is
above 130 or 140, depending on which cutoff you're using. That's actually not that high, Katie.
No. Because I'm just, the way I'm thinking about it is we always do OGTTs on our patients,
but they're fasting. Now we're using 75 grams of glucose instead of 50. So I'm not sure it's
apples to apples, but I can imagine a scenario where a woman comes in from a lunch where she
pasta for lunch, her glucose is already 120 or 130, which would be perfectly normal post-prandially
an hour after 50. I would be surprised if she was back down to 130 or 140. So you could
potentially get into these false positives? Yeah. So yes, of course. So we do a follow-up
three-hour glucose test where they do have to come in fasting and then drink a larger glucose
load and then get tested at one, two, and three hours after that. And then what's the criteria on
that? Is that 75 grams you do for that one? Yeah. And then there's a range for each one of
those values of what is normal. So if your fasting's elevated from that test, you automatically
are diagnosed with gestational diabetes. And is elevated 110 in that fasting state or 100?
Or do you. The good news is you are going to get credit. You don't have to take your
next board exam. This podcast is the exam. It's okay. So just. We'll put this in the show notes. Don't worry. Anything you don't know the answer to,
just say, we'll put it in the show notes. Yeah. We're going to put the values there for you.
Okay. So there's a threshold at zero, one hour, two hour, three hour. But relatively speaking,
do these compare to what we would use on a person who we're trying to diagnose type two
diabetes in if we don't want to just rely on the A1C? Is it that high?
Yeah. Well, if you ever are over. If the one hour is over 200, you don't do the three hour.
Yep.
So I think that's similar to outside of pregnancy. And then there are ranges for each of the other
ones. And you have to have two elevators to actually be diagnosed if the fasting is normal.
So what is standard of care in this situation? So a woman shows up, I was going to say passes
the test, but fails the test, however we want to say it. What is first line? What is second line?
When do we ever rely on insulin? And I'm assuming this is in a woman who is not a type
two diabetic outside of pregnancy. So we can put that category to the side for a moment. But this
is someone who was metabolically healthy prior to and now is not. Are you going right to. Are you
trying to do this with nutrition first? Are you saying, no, we're going to go straight to metformin
or some other agent? Yeah. No. First line is actually to do dietary modifications, meet with
nutrition, monitor the glucose levels, fasting and postprandial. And with these modifications,
see if the glucose is well controlled.
So like fasting under 95, one hour postprandial, like, you know, less than 140. And so then we
monitor that at first. And then we go to medications when more than half the values are
above where we'd like to see them. Insulin is really first line. So that's different than
outside of pregnancy. With type two diabetics, there may be some differences in management,
but in general, we often just go next to insulin.
And what's interesting is if you're doing this test at 28 weeks,
you also have to be very quick. I mean, you're not going to give lifestyle that long. You're
not going to say, well, let's do this lifestyle thing for three months because no, in three months
you're having the baby. So how much time are you giving that first lifestyle intervention? Is that
two weeks basically? Yeah. I mean, it depends on the patient, right? If everything is elevated in
the first week, you're not going to keep going for another week. But yeah, you have close follow-up
and lots of communication about what the values are.
Is the reason you go to insulin as first line because of time, or is it because there's concern
that drugs could have a negative effect on the fetus? Yeah. Well, there's not good data on a lot
of the medications for both efficacy and safety. So metformin we think of as fairly safe in pregnancy
and potentially helpful, but really insulin is most effective and we have good safety data and
it has the best influence on the fetus. So it's not good data on a lot of the medications for both
efficacy and safety. So metformin, we think of as fairly safe in pregnancy and potentially helpful,
on improving the neonatal outcomes. How long after delivery does this metabolic pattern return
to normal? In other words, if a woman is actually initiating insulin, how long does she have to
continue this post-delivery? Does it fix like that? Yeah. If you diagnose them with potentially
having undiagnosed type 2 diabetes, this might not be the case. But if you really think it's
gestational diabetes, then once they deliver, it seems to, for most folks, be resolved. So we
usually check a finger stick while they're still in the hospital. And then the recommendation is
also at the six-week postpartum visit to do another two-hour glucose test to screen for type
2 diabetes, because some people will have type 2 diabetes. And then they should also be surveilled
for type 2 diabetes more closely following a pregnancy, because they're at higher risk.
Is it an oversimplification?
It's an oversimplification to say that every woman, to some extent, has to become insulin
resistant during pregnancy, because that's the adaptive response to preferentially direct
nutrients to the fetus. There are probably genetic factors that amplify this in some women.
And then there are going to be environmental factors that would also amplify it. And that
could be stress, sleep, nutrition, et cetera. Is that the risk of oversimplifying it? Is that
sort of the point? No, I think that's a great framework for it.
So if a woman is. Diagnosed with gestational diabetes, goes through treatment, et cetera, et cetera.
Would you counsel her prior to her next pregnancy and say, look, you don't have to go through this
again? You might, because we don't know how much each of those things was a contributor. It might
be that your genes overwhelmingly made this happen, and you're destined for it. But let's
see if we can avoid it by doing A, B, and C. Or is it basically the case that once it happens
during a pregnancy, you almost assume it's going to happen with subsequent pregnancies?
No, interestingly, it doesn't always recur.
In every pregnancy. And I don't think we fully understand it. Like almost everything in medicine,
if you've had it before, you're more likely to have it again. But not everyone gets it again.
Okay. Let's talk about preeclampsia. This is obviously a big one. You mentioned it already,
but do you mind just defining it again? Yeah. So preeclampsia is a pregnancy-specific
condition where folks develop new onset high blood pressure or hypertension after 20 weeks gestation,
and often accompanied by a preeclampsia. And so preeclampsia is a condition where folks develop
by proteinuria, so protein in the urine, and also accompanied by other severe, what we would
call like severe features, but sometimes other symptoms like right upper quadrant pain, vision
changes, headaches. And this is obviously screened for because most hypertension is asymptomatic. So
that's something that has to be caught during your routine visits, correct? Yes. And actually,
the initial schedule for prenatal care was really set up to detect developing preeclampsia in
pregnancy. And so preeclampsia is a condition where folks develop new onset high blood pressure,
which is why you see like accelerating, you know, closer visits at the end of pregnancy
compared to early pregnancy is really screened for like blood pressure. And is this defined as
blood pressure like 135 over 80? Is that the threshold? Where do we consider that? So for
systolic, it's 140. And for diastolic, it's 105 to 110 to qualify as having. Okay. And is the diagnosis
made in office or do we accept that there's some white coat syndrome and we have the patient monitor
at home? So we're always looking at the whole picture, but a lot of times people will have
some elevated in the office and we will send them home with a blood pressure cuff and have them
monitoring more. Sometimes people present more robustly with like very severe blood pressures
from the get-go and other symptoms. And then sometimes they go straight to being admitted to
the hospital. So it can have very different correlations. And I think that's a really good
way to look at it. And I think that's a really good
course for different folks. Like some people will have hypertension for weeks that doesn't
seem to be getting so much worse and other people will present just in a very severe format from the
very first time they present with hypertension. And does the diagnosis require both hypertension
and proteinuria or is one of them, if significant enough, warrant the diagnosis?
Yeah. So they've changed the definition over time. So it used to be that to have preeclampsia,
you needed to have both elevated blood pressures at least two, six hours apart,
and then also proteinuria or another severe symptom. Now they've sort of changed it to say
like with severe range blood pressures and other, you know, you can get the diagnosis without
necessarily having overt proteinuria. All comers, what is the incidence of this?
About 5% of pregnancies, 5 to 7%, depending on your patient population in the U.S.
And then how does that change if we stratify by age?
So if we were to limit it to, okay, just women in the 20s versus women in their 40s,
does that change things? Well, the highest risk individual
are those folks who are having their first pregnancy and people who are very young or very
old. So I picked the worst demographic to compare. Yeah. So first of all, why is that?
I think we don't know. There's lots of reasons why people like there's lots of reasons why folks
think that the first pregnancy is at highest risk. There may be some degree of one of the reasons
people wonder is if there is less exposure of the mother to the paternal antigens and it's in
and there's some autoimmune response. It's not autoimmune. I'm sorry. But there's yeah, there
may there is can be and there's a thinking that there can be an immune component to it. But it's
not it's not just that. But we don't fully understand. So that would explain the early
pregnancy. And then presumably there's a sensitization with a subsequent pregnancy
tolerance. Yeah. OK.
I'm talking.
I'm talking to an immunologist. I have to be careful. I mean, I'm not really. No, no, I'm just
easy. I mean, but that. So then what do you think explains the other end of that barbell, which is
the women over 40, for example? Yeah, I think women over 40 have just increased cardiometabolic
disease slash intolerance to more cardiovascular demand. So I think it's really maternal
physiologic changes by the time that you're that age that really drive the increased incidence.
Because the plasma.
The plasma volume alone could drive the hypertension, although I don't know that that would
drive the proteinuria. Right. That seems to be like. I mean, yeah. Tell me more about why that's
happening, because we see that in kidney disease. I mean, that's what we're monitoring is for GFR.
So how do we tie those two things together that don't necessarily seem obviously related?
Well, that has to in pregnancy, both the hypertension and proteinuria have to do with
angiogenic imbalance. So classically.
The classic model of preeclampsia, which may not be true for everyone, is that the early in
pregnancy, the placenta, the placental trophoblasts, which should invade into the maternal spiral
arteries and allow them to become wider and lower pressure vessels to supply the placenta with
adequate blood flow. If that is not adequate enough, then the placenta has some degree of
hypoxia. And the placenta itself then.
Releases this anti-angiogenic factor called S-flit into the maternal circulation. And that
molecule soaks up the VEGF, an important growth factor for maintaining vessel endothelial cell
function. And that affects both the endothelial cells of the maternal vessels and the endothelial
cells in the glomerulus of the kidney. And so that connects like the what's happening
physiologically. Super interesting. I had never heard that before. So
that makes sense. When was that level of understanding brought to the field? Is that
something in the last 25 years or? Oh, the timing.
Like something you learned during your career? Or did you know that from was that taught in
medical school and I just missed that day? Well, Ananth Karamanchi, who was a nephrologist
at Beth Israel in Boston, was very interested in preeclampsia. And he actually went around
collecting folks' placenta. And he said, well, I don't know. I don't know. I don't know. I don't
who had preeclampsia and did microarrays on them looking for upregulation of different genes that
might be involved in this syndrome. And what he found was this incredible upregulation of S-Flit.
And then, you know, they did a lot more experiments to show that what was happening with that protein
and why it could be causally involved in the trajectory of preeclampsia. And so I always
thought that story was fascinating and worked in very, you know, Ananth was one of my early mentors
in Boston. And I really like, he's just, was always so inspirational in thinking about the
science in this area. Yeah. It's just a great example of why we just must have scientists
working alongside physicians. Otherwise we just don't learn. Like we can't, we can't learn this
stuff. And of course, Judah Folkman was also at Harvard working, of course, on anti-VEGF for
cancer, which is kind of another way to tie that together. So what is the natural history of
preeclampsia if left untreated? So in other words, before we knew what the heck was going on,
how did this manifest itself? So pregnant people would develop severe hypertension
that would progress to seizures and even death and other maternal complications like stroke and
organ, organ failure. Wow. So in other words, this is a totally different type of
hypertension because, you know, in my practice, for example, if somebody shows up with hypertension,
it could be, they may have had it for 10 years already and they clearly have some renal compromise
as a result of it and some coronary artery disease as a result of it. But, you know, it wasn't going
to kill them in nine months. So there's something about this degree of hypertension that is far more
accelerated and far more extreme if it's producing this type of outcome. The treatment option is to
give preeclampsia to antihypertensive agents? For the hypertension, when women present with
preeclampsia, we do give antihypertensive agents. That can help us expectantly manage a lot of
patients, meaning that they can present with hypertension at 30 weeks and we can treat their
hypertension and monitor them closely. And they may get several more weeks in the pregnancy. But
ultimately, it won't go away until the baby is delivered. There's nothing that we can do besides
that to actually. cure it.
So, what is the, I don't want to say the earliest because there's always going to be some edge case,
but what would you consider to be a very early presentation of preeclampsia and therefore
potentially risky case because it's, you have to wait longer till you get to the point where you
can deliver the fetus to ultimately render the cure. Would 25 weeks be considered very early for
this to show up?
Yeah. So the earliest we think of it as showing up
is 20 weeks. It is very rare to see it at that point of pregnancy. So we consider early onset to be preeclampsia that shows up before 34 weeks, because most of it will show up in the third trimester. And actually most of it shows up near term. So. And sorry, just to do my math, third trimester starts around 27 weeks, right?
Yeah, like 28 weeks.
Yeah. So it's like halfway into the third trimester would be the sort of standard case of preeclampsia
where your tech, you could, if the woman got into trouble, you could induce and safely deliver a
fetus at 33, 34 weeks, right?
Yeah. I mean, we have, it's not the gestational age of the fetus per se that drives when we decide
when to deliver somebody. It has to do about the severity of their disease. So we do make different
decisions about delivery, balancing the maternal and the fetal risks based on where they are in
gestation. But like a term, we would always deliver somebody who was showing up with even mild
hypertension. That would be the recommendation.
And is term considered 36?
37 weeks and greater.
Okay. Are you ever making this decision based on the severity of the proteinuria
for fear of renal damage? Or is it always based on the hypertension?
We don't make decisions based on the proteinuria. We often make
decisions based on the severity of the hypertension, but there's also lab abnormalities
that can go along with preeclampsia, like elevated liver function tests and low platelets. There's
also fetal concerns that can develop. So the fetus is more likely to be growth restricted. It might
have abnormal testing. So sometimes we get into a space where like the mom is doing okay, but the
baby's testing is not reassuring and we need to deliver. So there's many reasons why we stop
expectantly managing and move towards delivery. And so all those things have to be considered
when we're making that decision.
Is the mother ever at risk for residual or lasting kidney damage?
Yeah, that's a good question. For patients who start out with normal kidney function,
they generally have recovered their kidney function after the pregnancy is done. However,
people who have experienced severe renal failure, they're not going to be able to do that.
Severe preeclampsia have a longer term risk of kidney disease as well as
cardiovascular disease. So long term-
Which I want to come back to this topic because it's become a very interesting
recent discussion, which we should spend some time on. LFTs, platelets, boy, this sounds a lot
like HELP syndrome. So I don't remember what HELP stands for. I just remember it's really,
really bad. Can you remind us what it is?
Yeah. So HELP syndrome is where the pregnant patient presents with,
it stands for hemolysis, elevated liver enzymes, and low platelets. Some folks think it's on the
spectrum of preeclampsia, like it's this very severe version of preeclampsia. Other folks
think that it may have a completely different underlying biology, but have overlapping
features with preeclampsia. Patients with HELP syndrome may present with severe hypertension,
like we described for regular preeclampsia, but they also might have just mild range blood pressures and
then very severe lab abnormalities. So we see it present both ways.
And it can become pretty scary if it occurs, you know, in the 20 weeks, not 20, but in the 20s,
right? If it's at 28 weeks, 29 weeks, because you're really balancing the
maternal health with maximizing the viability of the fetus. And as you said, the fetus could
be compromised based on growth. I mean, this gets very complicated very quickly.
Yeah. Help syndrome is one of those conditions where we often give beta-methazone to help mature
the baby's lungs and we wait 48 hours and then we deliver because we don't expectantly manage
somebody who has help syndrome. How often do women get that diagnosis
prior to when they need. In other words, is that something that can be. I guess by definition,
you're saying help syndrome implies diagnosis to delivery is a very short window.
Yeah. As long as that's actually what's going on, but yes.
Okay. What's your best guess for the etiology?
Great question. We do not know what causes help syndrome.
If we assume that preeclampsia is something distinct,
or even if we assume that preeclampsia is something distinct,
if it's not, do you have a sense of the. I mean, we explained the mechanism of preeclampsia,
but do we think that this is somewhat genetic, largely genetic, somewhat environmental,
not environmental at all? Yeah. Good questions. Well,
preeclampsia is heritable, meaning that there is definitely a genetic component.
And it comes from both the fetus and placenta, which are considered to be the same,
relatively the same genetically and the maternal genetics. So they're both important.
So there's been a lot done in the past, you know, eight years or so that's come out about
the underlying genetics of preeclampsia. It was a really understudied field when I started
working in this area myself. There were like no big cohorts that had genetic data and had
had the same type of genome-wide association studies that had been done for many other
complex diseases. And so it was really unknown what factors across the genome might contribute.
But in the past eight years, there's been a lot more information that's come out of that.
Which I think is really great and fascinating because genetics can really help you get at the
underlying causal biology behind something. So when you really don't understand what's causing
it or what pathways might be important to target with therapeutics, then genetics can really help
you understand that. Going back to management of preeclampsia,
if you're going to use antihypertensives, what are the agents of choice? Yeah. What you'll see
used most is not only the preeclampsia, but also the preeclampsia. So if you're going to use
nifedipine and libidool, because there's good data about safety in pregnancy. There are other
hypertensives that we use sometimes, but those are two mainstays. So interesting because, I mean,
we just don't use those outside of pregnancy at all because they're not that good. So does that
mean we do not know or we do know that ACE inhibitors or ARBs, which would be first line
in someone who's not pregnant, do we know for sure that those are not safe in pregnancy? And
is that why they're not chosen? Correct. We know for sure that they're
not safe in pregnancy. Yeah. So they have a negative impact on the fetus, presumably.
Correct. That's right. Got it. Yeah. But they're good agents postpartum when we're
working to control maternal blood pressure. So we often will utilize them after delivery.
So when we were talking about gestational diabetes, you pointed out that the woman could be
off insulin by the time she goes home. Oh, yeah. That's how quickly it resolves. But what you just
said makes me think the same is not necessarily true of preeclampsia and the hypertension. Yeah,
that's correct. So-
Some people will have their hypertension resolve like very quickly after delivery,
but many women need antihypertensive medications for several weeks after delivery. It can take
like six, 12 weeks to kind of come back to more of a baseline. And there are other women who will
have persistent hypertension after delivery that never quite resolves. And lots of women who will
come back and develop hypertension within the next five to 10 years.
Wow. Does the proteinuria respond or resolve quickly? And I assume that's checked until it
does?
You know, we don't check it, and that is because it resolves.
And is that sort of just be- Is that because once the placenta is out, you've sort of solved
the problem that's driving that?
Yeah.
Yeah.
Yeah. So unless someone, when we screen their metabolic labs, has evidence of renal dysfunction
other, you know, in elevation of their creatinine.
Then we would be monitoring that. But most folks just have the proteinuria. And for folks without
kidney disease, that resolves.
By the way, does the creat- If a woman has significant proteinuria,
does she also have a bump in her creatinine or cystatin C during the pregnancy?
Not in- We don't check cystatin C, but the creatinine tends not to bump. But when it does,
if it does get elevated with preeclampsia, then that's also a severe feature of the disease.
So this is probably a good window to now,
talk about what you alluded to already, which is something that I was unaware of until,
I don't know, nine months ago, 12 months ago, which was this idea that in cohort studies,
preeclampsia, or more specifically, hypertension during pregnancy, even if it resolved,
was predictive of later life atherosclerotic cardiovascular disease.
How long has the field of medicine known this? And what do we think is the best explanation other
than-
The obvious one, which is there's a strong genetic component to it,
and therefore that same genetic component doesn't go away.
Right. So good questions there. Actually, this has been known for quite a while. I just think it
hasn't really-
I'm just late to the party, which is often the case, I can assure you.
Hasn't translated well out of the obstetrics field into primary care and other fields of medicine,
like it should have, really.
It should be a question you would ask. We now ask this question, but you should ask this question
during a history and physical of any patient, right? You should say,
oh, I noticed you had three kids. Did you have preeclampsia during those pregnancies?
Yeah. The obstetric history is relevant and often not asked about. And in fact,
that inhibited genetic studies because people would do these large cohort studies and never
ask about obstetric history. If it wasn't recorded, the data wasn't there.
In terms of why, when we've looked at these genetic studies on the maternal side,
one of the strongest shared genetic architectures between preeclampsia and preeclampsia is essential
hypertension, both systolic and-
diastolic. Hypertension is, if you have a higher genetic disposition to that,
you have a higher risk of preeclampsia. In the very first maternal GWAS of preeclampsia,
genome-wide association study, the top hits that were genome-wide significant were some of the top
hits in genome-wide association studies of hypertension. So we do know that folks who
develop hypertension or preeclampsia are much more likely to have an underlying
genetic disposition to hypertension. So that's definitely part of why they have a higher
long-term risk. And pregnancy unmasks that predisposition. There's still a component of
the exposure to the hypertensive pregnancy that people think may add on top of the underlying
genetics to the future risk. So I think that's an active area of research that people are engaged
in. Like, does the pregnancy itself increase the risk? And if so, how? And then, of course,
there's other factors like social factors, like otherwise, like other health conditions that
are associated to those risks. So it is a multifactorial contributor as to long-term
disease.
Remind me, you may have said this and I just missed it. Do women who develop gestational
diabetes also have a higher risk for type 2 diabetes? Is that predictive?
Yes. So 50% of patients who have gestational diabetes will develop type 2 diabetes.
50%?
Yeah.
Interesting. Have there been any intervention studies that have been done? And this would be a
because it would take a long time. So the answer is almost assuredly no. But where you take women
who develop gestational diabetes and then you manage them aggressively, you would randomize
them to one intervention versus the other to see if you could delay and or just outright avoid
type 2 diabetes. Yeah. I think that the recommendation is that they have frequent
follow-up for diabetes screening and also should be very much advised on any lifestyle changes that
they could make that would impact the. risk of type 2 diabetes. So we know that healthier diet and appropriate body weight and regular
exercise all are very important there. So it's even more critical for folks who have a history
of gestational diabetes to be counseled about that to decrease their risk.
So is that sort of the message you're delivering to a woman? Because you're in a very interesting
role as a physician in that you play a profound role in the care of her,
and her baby. But once that baby's gone, you're not the one that gets to take care of her. And yet
you learned something really profound about her because, as you said, you saw her during a very
high physiologic stress test that gave you an enormous insight into what the rest of her life
has in store for her vis-a-vis metabolic health, cardiovascular disease at a minimum. I mean,
by the way, we might discover that there are other diseases we're learning about that are predicted
through pregnancy. But you're not the one that gets to take care of her. And yet you learned
something really profound about her. So what is the relationship between a high risk or any OBGYN and the long-term health of the patient
to say, look, this is not, your genes are not your destiny, but you need to, we need to really stay
on top of managing these things aggressively. And by the way, you should live a normal life
as a result of the privilege of modern medicine that we wouldn't have been able to do this 50
years ago. Yeah. I mean, I think the counseling is really important. And as a high risk,
high-risk obstetrician, some general OB-GYN,
might see a patient for their pregnancies and then also for their GYN care and have
more of a primary care relationship with a patient. With our high-risk obstetric practice,
we will only see the patient back in general if they have another pregnancy. And so that
transition to a primary care provider with that information transmitted is really essential. And
I do think lots of patients who are young and taking care of kids and often don't follow up
a lot themselves between pregnancies. And so stressing the importance of having a primary
care provider and following is really important. But certainly there could be, you know, we can
continue to enhance like both education and the communication. I mean, electronic health records
have helped some, right? Because we can often see now like records and, you know, if somebody is
tuned into that, they can get out what happened, but they have to know that it's important.
So if we did nothing,
else today, if we accomplished only one thing, and it was that women and their primary care
doctors were really tuned into what was unmasked during pregnancy and use that for aggressive
treatment and prevention, that would be a win. Yeah, for sure.
Okay. Do you have a sense of, well, I mean, it sounds like it's a bit of a mixed bag in terms
of what's recognized there. Okay. So the other thing I wanted to ask you about is C-section
versus vaginal. What are the
trends? What are the trade-offs? This is an area where I feel like I have heard so many differing
stories. I can't tell what's real. So let's kind of walk through what is known and let's
acknowledge what is not known. So what, first of all, I don't, from a historical perspective,
I assume it wasn't until the late 1800s, we were doing the first cesarean sections. I hope we were
at least waiting until we had modern anesthetics. These are also good questions that I don't know
all the answers to. But,
certainly, even now, there's many parts of the world where people don't have great access to
surgical intervention during labor and delivery. And that can really drive a lot of both stillbirths
that people have during the intrapartum phase and long-term maternal complications like fistulas
and other complications from prolonged labor. So C-section is certainly a needed and helpful
intervention because not every baby is going to deliver vaginally.
And do we just have a sense of, again, and I don't expect you to know the answer to this,
so don't worry, not on the boards, prehistoric times, right, or ancestral times, you know,
go back a thousand years. Do we have a sense of what the frequency was of a stillbirth? And
was the stillbirth necessarily going to lead to the maternal demise? Like if you can't get
a dead fetus out of a woman, she's going to die of an infection, correct?
Um, I, yes, I think like, um, I think you often will eventually,
deliver the demised fetus, but you know.
But, but you can't possibly, I mean, maybe you could, but it would seem to me that you would
be leaving behind some placenta or there, there would be some dead tissue that would remain,
wouldn't there?
I mean, I wouldn't think of that happening, but like a retained
pregnancy is certainly going to be risky for the patient.
Yeah. Okay. So C-sections have obviously become important. What, what do we know about the,
uh, I don't know what the right word,
I think of it as a prevalence or usage or nump, you know, in whatever metric you would use to
determine what percentage of deliveries in the United States are vaginal versus C-section.
How has that number changed over the last 50 years?
Yeah, it's dramatically increased, you know, so we've, we've gone from, you know, like 10%
C-section rate, say like, I don't, I don't have all the exact numbers in my head to like,
oftentimes practices have like in an academic medical center, like a 30% C-section,
and that's all comers, right? You're like accounting for people who've had like previous
C-sections and people who can't have a vaginal delivery by, because it's not safe for whatever
obstetric reason. So, but it has increased, increased dramatically.
And what is driving that 3X increase?
I think there are different drivers. The pregnancies are, are higher risk than they
used to. Once you have one C-section, you're more likely to have another one that the health of,
the, the, the patient matters. A lot of people think that maternal obesity increasing has
increased the number of women who have like either larger fetuses or feel like labor that
doesn't progress normally and therefore leads to a C-section. You know, we went from a time when we
were not doing continuous monitoring, so fetal monitoring during labor to where we monitor in
most hospitals, the babies being monitored during the active phase of labor continuously. And we're
when the tracing is not reassuring, we move to a C-section. So I think it's, it's a complex
issue to understand. And, you know, there is a lot of focus on trying to
decrease that number or avoid it getting higher than it is now.
Why is that? Why would we be concerned if it's getting too high?
Yeah. So I think the one consequence, and it's not the only one, but for folks who have
prior C-sections, multiple prior C-sections, they're,
at higher risk for abnormal placentation in the next pregnancy, meaning that specifically
placenta accreta spectrum. So the placenta can invade abnormally into the, to the uterus during
pregnancy. And then when it's time to deliver, the placenta does not come out after the baby.
Is that the main reason why once you have a C-section, your probability of another C-section
goes up because of the placenta, or is it because of the pressure on the fascia from,
that would be required during the exertion of a vaginal delivery?
There's a couple of different things. So there's a couple of different kinds of C-sections. So
meaning where you cut on the uterus. So if you cut, if you cut low down on the uterus in a
transverse fashion, so that's called a low transverse C-section. That is in the, is not
in as muscular of a part of the uterus. And so in general, it's thought that you are fairly safe to
labor in a future pregnancy. It would like a one,
percent risk or less than 1% that the, that old scar might come apart during labor. So that's
called a uterine rupture, which is obviously an emergency. And that's a surgical emergency. Now
you're going. Yeah. However, if you have had prior surgery on your uterus, either because you had a
big fibroid and you had it removed from your uterus, or if you had a prior C-section, that
was what we call a classical C-section where you cut up and down on the uterus, then that cuts
through the,
musculature of the uterus. And, um, that type of incision is much more likely to rupture during
labor. They say like 10% for someone who've had a classical C-section, which is too high to even
too high. So we've saved folks in that group, not labor. So they remind me why the choice is made
between those two incisions in the first place. We try to do a low transverse C-section and in
term patients, you almost always can. But if you need to deliver somebody preterm, for example,
this is one of the,
most common reasons we would do a classical C-section. The uterus is not big enough that it expanded
enough that they, the lower uterine segment is not developed and you may not be able to make an
incision down in the lower part of the urine segment and safely deliver the preterm baby through
that. So if, if it's too premature, we often have to do a classical C-section. Sometimes there's other
reasons like surgical complexity. Someone's had multiple C-sections. You can't get around the scar
tissue. Other reasons why we can't, but. Yeah. And you're not entering the peritoneum when you
do this, correct? You're doing this all outside of the abdomen? No, it's in the abdomen. You are,
you don't, you don't separate the fascia and keep the uterus outside. Okay. When you, okay. So I'm
trying to think of reasons where it was a non-negotiable. So a breach delivery would,
you wouldn't ever try to deliver a breach vaginally if you, I mean, I assume you know this.
We generally don't because the biggest, the recommendation by ACOG is that we generally
don't. And it's because the biggest part of the baby is the head and it comes last and, and a head
entrapment, meaning the head, the rest of the baby comes out and then the head doesn't is,
is very dangerous. So for a singleton, we generally recommend a C-section. If the baby's
breached, there's an opportunity to potentially turn, try to turn the baby before labor. That's
called an external cephalic version. So sometimes we can turn the baby to cephalic and then the
patient can. And how like you would do that in the days leading up to. Yeah, we try to do
it closer to 37 weeks because if somebody actually goes into labor or breaks their water, then,
then you really can't turn the baby anymore. How successful is that procedure? 50%.
Painful, I'm guessing. Yeah, it can be. You can get anesthesia for it.
I'm going to guess the answer is we have no idea why some babies are breached.
Yeah, in general, we don't. There are cases where, there are cases where like the head might be
very big and it makes sense that the baby was in that position the whole time.
Sometimes we do a delivery and we find out the cord was wrapped around the neck like four times
and then it made sense that the baby couldn't really turn around. So sometimes we see things
that, you know, make us kind of think that's why it was, but a lot of the time we don't know.
How often does the cord wrap around the neck at all?
Well, like a third of the time the baby comes out with a cord around the neck. It's very common.
It usually doesn't cause a problem.
When does it cause a problem?
Well, you can't predict when it's going to cause a problem. It can be,
very tight sometimes in certain stillbirths we think
it might have been the cause, but we don't really know. More common of something we would see is
that, you know, we're monitoring this fetal tracing during labor. We have patients sometimes
who have like recurrent big like variables or like a type of deceleration on the fetal heart rate.
And then they come out and we discover that there was a cord around the neck. So sometimes it just
causes like stressful, non-reassuring fetal heart tracings, but doesn't really ultimately
cause any problems. What's the frequency of stillbirth in the U.S.? One in 160. That much?
Yeah. I thought you were going to say one in 106,000. One in 160 is startling. It's pretty
common. And just to make sure, the definition of a stillbirth implies it went to near term?
No. Stillbirth means any fetal demise after 20 weeks gestation. So it can be any time after 20
weeks. Okay.
But after 20 weeks, you've largely, I assume, eliminated a lot of the really
lethal trisomies, the trisomy 18 and things like that. Those probably,
we've already taken care of those. So these are usually chromosomally normal fetuses?
I mean, it depends. I mean, there's many, there's patients who don't do testing. There's patients
who choose to continue their pregnancy. But you're right that like a lot of people who
have choice and access to those choices do.
Terminate their pregnancies earlier. But there are many patients carrying pregnancies with various
anomalies and other genetic conditions.
Hoping that things will work out, but maybe they don't. So what would you say are the
most common drivers of a still pregnancy?
Yeah. I mean, I think there's different categories, but many of them remain unexplained. At the time
of delivery, the things that help give us the most information about what might have happened was
doing pathology of the placenta.
Doing a fetal autopsy and doing genetics. So those are the three most useful tests.
Also like describing like the baby and the placenta at delivery, like just what you see
in terms of, you know, you might see a big abruption, like the placenta came off the
uterus. There might be like a really tight cord there. So there might be things that you actually
see in the delivery room that, you know, help you. But even with the standard workup, we don't
understand what's going on. So I think there's a lot of things that we can do. I think there's a lot
of things that we can do. I think there's a lot of
component of placental insufficiency, but it doesn't really explain, like that might've been
the proximal cause of then what, why the baby passed away, but it doesn't really explain like
what causes that and why that happened at the end of pregnancy, you know, and everything had
looked okay up until that point. Because I'm just trying to understand one of these late stage
events. So let's just say a woman's had normal prenatal care. She's not high risk, but she's
still doing all the normal stuff. Every time she goes in for an ultrasound, you obviously see the
heartbeat. Presumably you can tell that the placenta is still attached to the uterus. Is it
standard to also do duplex on placental blood vessels or is that not, we wouldn't do that level
of inquiry? We're only doing like Doppler monitoring on ultrasound when the baby is growth restricted.
So when we know that there's fetal growth restriction or there's a few other indications,
then we monitor blood flow through the umbilical cord. But we don't do that in general because it's not been shown
to be a helpful like test otherwise. So it's just mind boggling to me that they're, they're from a
tragic standpoint that a couple could come in to think everything is fine. Would their labor pains
and labor signs and symptoms under stillbirth conditions resemble that of non-stillbirth?
Yeah. So let's talk a little bit about that. What triggers labor? Why, why, what is happening in the
body? How does the body know it's time? We don't know. Really?
Yeah.
We, so tell me, tell me what is actually happening? What, what is the, what's happening with prolactin
and oxytocin and all these other things? Even if we don't know why it's happening, do we, do we at
least have a sense of those things? A little bit, but you know you know, people have tried to look
at the changes that directly precede labor and there's some, but it's hard to predict, right? Like
you monitor somebody like every day to see what's going to happen up to delivery. So we, we really don't have
a great sense. We think something's changing with the HPA axis that's triggering this quiescent state
where progesterone is maintaining the uterus not to contract to actually contract, but we really,
really don't have, have a good sense of, of what's happening.
Is the contraction of the uterus the first sign? Is that the first thing a woman is actually feeling?
Yeah.
And tell me how you coach a woman through that. Like if, let's say you're seeing her in your office and it's what,
you believe will be the last time you see her prior to her admission to the labor and delivery
ward. It's her first pregnancy. She doesn't know what to expect. Her partner is equally clueless
and they're scared senseless. What are you saying?
Well, with every third trimester patient, we're saying like, you know, monitor like how you're
feeling the baby move. Let us know if it's different. Look out for leaking fluid and
vaginal bleeding. If you have any of those things come in. And then if you start to have contractions,
time, how frequently they're coming. And if they're coming closer than five minutes apart for
more than an hour, or they're increasing in pain and intensity or accompanied by any of those
other things I just described, then you should come in to get checked out.
Okay. So that's, that's a pretty logical list. Having experienced contractions yourself. What,
what does this, what does this thing feel like? What does a contraction feel like? Does it
feel like a muscle flexing?
Contractions might kind of be like, or, you know, Braxton Hicks, like practice ones might be like
having a really bad period, like a really bad menstrual cramp, but like real contractions,
probably more painful than anything else that, you know, I've experienced before.
So it's not subtle. A woman is not, there's no, she's not thinking to myself, is this a contraction?
Well, that often comes up and there are patients who have very
high pain tolerances or experience it differently who come in, who are quite
dilated without a lot of pain. But I think most people experience it as a pretty painful process.
How, so I explained to the listener what you mean by dilation and what is the, what is the amount
of dilation that you would see commonly and not be concerned if there still hasn't been any
contraction? Well, I think that's a complicated question to answer, but so the, what, what I mean
is that, um, you know, at the, at the lower part of the uterus inside, inside the vagina is the
cervix and the cervix is what we're actually monitoring for whether it's dilated or not in
pregnancy. In early and mid pregnancy, you don't want the cervix to be dilated. If it is, that's
like a sign of premature cervical dilation or preterm, it can be preterm labor, but say you're
at term, it would be very common for people to have a cervix that gets thinner and softer and
they start to dilate some, that's the body getting ready for labor. And then we digitally check how
dilated the cervix is to understand like if somebody is in labor and how labor is progressing,
it's what we use to monitor the progression of labor when somebody is in the hospital ready to
getting ready to deliver. And how many centimeters of dilation is when you start to say, okay,
you're not, we're, we're sitting here until this baby comes out. Well, it's, it's,
it's not just the dilation by itself. It's also the frequency of the contraction. I mean,
people can sit around at three to four centimeters dilated for weeks and not be in labor. There can
be other people who come in four centimeters dilated, who are contracting painfully every
three minutes. And they're definitely an anatomic difference. Is that a function of the anatomy of
the cervix? Or is that another mystery of, we don't fully understand the whole process of
delivery? Well, it's not, it's not the same in everyone, right? It's not like there's this, then
there's this, then there's this. Like in some people, the water breaks first and other people,
they, you know, that's a smaller percentage of people, but that can happen before any labor.
And then, then you either, then they either go into labor or you help them go into labor.
And the quote unquote water breaking is the placental fluid coming out because that,
that membrane at the cervix opens the, like what's actually happening when the water breaks?
Well, the amniotic sac gets a hole. So it can be at any part of it. It's often at the part that's
lower uterine segment or, or near where the cervix is opening, but it's that the, the fluid in the
amniotic sac gets released. And it's clear fluid, clear yellowish? Usually it can contain baby's
poop, like meconium staining at term. So, or it can be bloody if there's a placental abruption,
but it's like, ideally it's clear. Okay. If it's not, if it has blood in it
and the placenta has just started to separate,
that's not a problem necessarily.
It just means you got to get on with things.
It may be or it might not be like if it stays, if the majority of it stays attached long enough for the labor to progress, which it often does quickly if that's what's happening, then you potentially can have a vaginal delivery.
But if it continues to progress, you know, you're monitoring the baby's heart rate tracing closely and the bleeding closely.
So if things become non-reassuring, you may have to move to a C-section.
What is the clock? There's a clock that sort of starts once the water breaks because there's a risk of infection, correct?
Yeah. I mean, you're mindful of how long it's been.
What do you start to say is too long?
Well, there's a few steps. Like one, when somebody's water breaks, we do recommend that they come in even if they're not contracting because of that risk of the longer the water is broken.
We're talking like in a term patient also here.
If the water is broken and we don't help induce the.
In labor, then there's the risk of infection.
So we recommend coming in, getting started on some Pitocin and helping the labor progress.
We want to see like labor and progression and ideally delivery within like 24 hours.
But there's no absolute clock.
Like if everything's fine, there's not an infection.
The mom's fine. The baby's fine. Labor's progressing.
It's not like we just stop it.
So what do you do if the or how often does the water break before a woman is?
I don't know, like when she's in 28 weeks or something.
That's called P-Prom, like premature, preterm rupture of the membranes.
So people who have P-Prom, they will come into the hospital.
About half of patients who have that will deliver in the next seven days.
They will go into spontaneous labor a lot, like a fraction of them.
Some people will not.
They will sit there with their membranes ruptured and we will monitor them in the hospital all the way up until 34 weeks if everything looks reassuring.
Reassuring.
And you are, your highest concern is an infection, I assume?
That's one of the concerns.
Infection is a high concern.
Progressing rapidly into labor once the bag of water is broken is, can be very common.
If the patient is not cephalic, so not head down, there's a risk of like cord prolapse or another body part, like the cervix dilating and then some part of the pregnancy or cord starting to come through the cervix, which can be an emergency.
And I guess I'm still confused.
How, if a woman comes in in this situation, does she still retain or just make more amniotic fluid, but she's just now making it at a high rate and it's leaking?
Right.
There's, they will often continue to have quite low fluid for the rest of the pregnancy, but they will continue to make the fluid and leak the fluid.
Got it.
Do you ever give antibiotics in that situation or is that a no-no?
We do.
So it's not continuous.
So the recommendation is to give antibiotics.
The antibiotics at the time they present, and that's because it helps prolong latency.
It doesn't, it doesn't ultimately necessarily present, prevent all infections, but it helps prolong the duration of the pregnancy in that situation.
So we do give some antibiotics at the, at the start and then like no more after that.
Going back to the C-section versus vaginal discussion.
Again, my vague recollection is one of the advantages of a vaginal.
Delivery is related to the bacterial transfer between mother and fetus.
Is that real or is that something that gets over extrapolated?
There's a lot of attention to that for how much we really know about it.
I would say there's probably something there, like the microbiome is important.
Like there's certainly influences and importance across different areas of medicine, but I think like there's a lot of popular press about that without probably a lot more of the.
Of the basic medical.
There seems to be a lot of fear mongering about it, quite frankly, which is almost like shaming women that have C-sections into believing like you have failed to deliver the appropriate gut biome to your child.
And so is it safe to say that there's the science is not suggesting that?
Well, I'm not saying that there's no helpful component of that, but I would say of all the things that help determine your health and your baby's health, that's probably not the thing to stress about.
Is there some epidemiologic data that suggests, which of course would be confounded by a hundred other things, but is there some on-off kids that are born via cesarean section are more or less likely to have some gut related?
No.
Not to my knowledge.
Okay.
Yeah.
Not.
Yeah.
Standard application of social media there.
Let's talk about breastfeeding a little bit.
So, again, one of the things I do remember from medical school is the importance of IGA, if I recall.
Yes.
And so notwithstanding the obvious example of why breastfeeding mattered evolutionarily when we didn't have formula and things like that, what percentage of women are unable to, for some physiologic reason, breastfeed?
I mean, pick a duration to answer that question, like after X number of weeks.
I mean, it's such a complicated question, right?
Because most people, unless they have had like substantial breast surgery or other endocrine disruptors themselves.
Have the physiologic capacity to produce breast milk.
There's a lot of breastfeeding is complex, right?
It's like a both a maternal and neonatal like partnership.
So for people who have very premature babies, for example, who might not be able to like latch and actually breastfeed, the mom would have to like pump and produce breast milk, which is always less effective than the baby actually like directly breastfeeding in terms of effectiveness.
And stimulation and also the ability for like a mother to keep keep doing it over time.
And, you know, then, you know, a breastfeeding mom will have to, you know, be responsible for expressing breast milk every few hours for many, many weeks and being present with with the baby, which may or may not be possible for for any given mother.
So what's driving that from the endocrine system?
You mean the production of milk?
Yeah.
I mean, it's again, it's a complex.
It's a complex hormonal interplay.
So and in theory, a lactating woman is going to have a harder time ovulating.
I mean, that was generally viewed as one method of birth control.
Correct.
But you only have to miss one feeding to make it not be a good form of birth control.
Really?
So, yes.
That's an important message.
It is.
Don't rely on this for birth control.
Definitely not.
So it's true that like a lactating woman will have very suppressed levels of estrogen.
And progesterone is often doesn't lactate when they're but if they skip any of the feeds, then they stop that suppression of the of their cycle.
I want to talk about a couple of things you would counsel patients on during pregnancy with respect to three things.
So sleeping position, any nutritional things outside of managing, you know, are there any real big do's and don'ts of what you make want to make sure people are eating versus not eating and then exercise?
What restrictions?
Do you place on exercise?
So maybe we'll start with exercise.
Yeah.
I mean, I think exercise is really important.
The more data we get, the more we know, like bed rest is bad.
People do better when they exercise.
You know, we tell people not to start like a new intensive program during their pregnancy.
So if they weren't that physically active prior to pregnancy, it's not the time to like start to try to run a marathon.
But having like regular activity like walking or low weight, weightlifting.
Was is fine for patients who've been doing exercise program.
They're generally if everything in the pregnancy is going fine, it's like generally fine for them to continue it, including resistance training.
If it's like if they're used to strenuous resistance training.
Yeah.
You would be OK with that until what point in the pregnancy?
Well, I think the main risk is like the center of gravity changing the risk of getting injured or hurt by whatever you're doing.
So you just have to do all the things.
You're doing in a safe way.
So, you know, we don't recommend downhill skiing in the second part of pregnancy.
You know, we, you know, horseback riding or or, you know, things where you might incur trauma to your abdomen or are not good.
But but a Valsalva, a bearing down during a, you know, lifting something heavy is OK if a woman's used to that.
Yeah, we haven't.
You know, if she's having like a healthy pregnancy now for people who have threatened preterm labor or a short cervix or other things going on, we may tell them to abstain.
We may tell them to abstain from like heavy lifting and things and during a short cervix presumably means you have less resistance to the intra abdominal pressure.
Yeah, presumably.
I'm not sure our data is great, but there's just like there are certain things where we tell people to have some restrictions.
What about running?
So if you had a woman who's a runner, lifelong runner, loves to run, it's one of her favorite forms of exercise.
What restrictions do you place on her during pregnancy?
I wouldn't say that we would.
So run to your heart's content and just be mindful of everything you said at some point.
Your center of gravity is going to move.
Don't overdo it.
Try not to fall.
Stay well hydrated.
Right.
Like maybe take it a little easier than you sometimes would.
But yeah, no, we would.
OK.
People who can.
It might be uncomfortable for people at that and they might desire to stop.
Yeah.
Yeah.
And then what about sleeping position?
At some point it starts to become pretty uncomfortable.
I would imagine side sleeping is probably ideal.
Any truth to this idea that you want to sleep on your lap?
The left side so you don't compress the vena cava on the right side?
Yeah.
I mean, it's the end of pregnancy when the fetus is pretty big.
Yeah.
I think to lay completely flat on your back is probably not the best position.
So to have some tilt if you're laying towards your back would be good because there is that part has some truth to it.
But I think people sometimes come in panicked that they woke up on their back and, you know, I'm like, it's going to be OK.
OK. Yeah.
I know that you're not the one as the obstetrician who's taking care of the mom months and months following her pregnancy.
But what's your understanding of postpartum depression?
How often is it showing up even in the hospital?
What's our what's our understanding of what's driving that?
Yeah. So so postpartum blues are really common, like having dramatic changes in the mood in the first two weeks after delivery.
There's just the most tremendous collapse of the estrogen and progesterone levels, which are sky high during at the end of pregnancy and then drop to like extremely low levels.
And also a lot of, you know, changes that are going on in the HPA axis.
And so those things really do cause emotional changes in most patients.
But postpartum depression is when those like baby blues like persist beyond that short term and, you know, lead to depressive symptoms for weeks afterwards.
We do have standard screening that's recommended during, you know, both during pregnancy for depression and postpartum.
And so we.
Really do work hard to do that at the postpartum visit.
And we identify patients who might be at higher risk of postpartum depression due to social stressors and other things and try to hook them up with resources and social work.
But I think as we all know, across all of health care, like the mental health system is stretched thin.
People often don't have providers or the access that they need.
Obviously, mothers who are caring for newborns like don't don't have a lot of time.
They may have difficulty.
Getting to appointments, they may have hesitancy to ask for help.
They may be told that their feelings aren't normal.
So it's definitely can be very serious and under recognized and under treated for all those reasons.
And do you think that the biggest source of under treatment is the failure to differentiate between what is maybe normal in this short term response to what becomes maladaptive and or persist in an abnormal way?
And then it just sort of gets.
Turned into like there's so much going on that this kind of gets, you know, shoved under the rug.
Yeah, I mean, I think it might be a lot of mothers instincts just to focus on the baby and not like necessarily take care of great care of themselves.
So we need a lot of advocacy and encouragement for, you know, mothers to like present to care, get help, like not feel shame and guilt that, you know, I think a lot of that goes in like I have a new baby.
Like society tells me I should be really happy and excited and I feel terrible.
Like so then people don't present to care because of feelings that, you know, they're it's somehow their fault that they're feeling this way.
Let's go back to the other end of the pregnancy, which is on the sort of genetic screening side of things.
So IVF is becoming much more common these days.
And with IVF comes prenatal screening.
But for for couples not undergoing IVF who are showing up with a spontaneous pregnancy, what is the current state of the art in screening?
Is it mostly done through sampling amniotic fluid?
Is that still viewed as kind of an aggressive thing that you wouldn't really do unless you needed to?
How do you think about that?
Yeah.
So the the number of diagnostic or invasive procedures that we're doing that include amniocentesis and then chorionic villus sampling, which we can do even earlier in pregnancy, have decreased.
And one of the primary drivers of that is how screening for chromosomal disorders like Down syndrome has improved with the advent.
Of cell free DNA screening.
So just a tube of the maternal blood, we can find fragments of the placental DNA and therefore screen the pregnancy for chromosomal conditions.
That test is best at screening for trisomies 21, 18, 13 and the fetal sex.
It's less good for for other other things.
And you can do that within how many weeks of pregnancy?
As early as nine or 10 weeks of pregnancy.
So very early on.
Is that considered routine?
Yeah.
So it is recommended to be offered to all pregnant patients for screening now.
Okay.
So presumably that takes away a lot of the incentive that was present for amniocentesis, correct?
Right.
So previously we had what was called a serum screen that looked at three or four protein markers in the maternal blood.
And if that screen was positive, meaning that the levels of those proteins.
For the gestational age were consistent with an increased risk of a chromosomal disorder, then an amniocentesis was recommended.
But in those cases, only five, the positive predictive value of a positive test was 5%, meaning that for everyone who screened positive for potentially having a baby with Down syndrome or trisomy 21, only 5% would actually be carrying a baby with Down syndrome.
Now, is that because the prevalence was too low?
Or because the sensitivity and specificity were too low?
It's because the sensitivity and specificity were too low.
Got it.
And so cell-free DNA has dramatically improved both the sensitivity and the specificity of that testing.
So fewer people feel inclined to also pursue a diagnostic procedure.
And when the screen is positive, they're not 100% guaranteed to have a fetus with that condition, but they're much more likely to have one.
What do you think?
What do you think is the biggest gap in this type of testing?
Where would you like to see things in a decade with respect to prenatal screening or in utero screening, for that matter?
Yeah.
Well, there's different kinds of screening.
There's ultrasound, which is developed a lot, so we can actually look structurally at the baby.
And then there's genetics.
Chromosomal disorders that I mentioned that we are currently screening for from cell-free DNA only represent a very small percentage of all the genetic disorders that can exist in a baby.
And so we're missing many serious and devastating conditions on that cell-free DNA screening.
So sometimes people think they've been screened for everything, and it's really only these three things, basically.
So I think the entire genome is represented in the cell-free DNA in the maternal blood.
So potentially we could detect—
So what's the limit?
Do we just not have enough of it?
Why aren't we doing a whole genome sequence on it for the—or at least screening for 27 genes?
Different, you know, metabolic diseases that are quasi-common?
Yeah.
Well, there's many reasons.
But when you're thinking about a prenatal screening test, you have to think about what the cost is and what the implications are in the prenatal space and which things you should be calling out during pregnancy versus, like, what things are only important later in life.
To really look at all the genes in the whole genome and—
Well, let's simplify it.
Let's look at, like, say, the inborn errors of metabolism.
Which would present early in life.
Yes.
There would probably be value in knowing that during the first trimester, right?
Correct.
So for serious conditions like that, folks are working on creating, like, panels of disorders that might be helpful to screen for.
It's still complicated because for any given condition, take, like, cystic fibrosis as a good example.
There might be tons of different genetic variants that a patient has that could—
That could cause disease.
So our ability to understand which genetic changes cause disease in a given gene and which ones don't is essential because there's no other phenotype that we can see prenatally for many of these conditions, right?
So for an inborn error of metabolism, the baby within the mom is generally, for most of those, or it's doing just fine.
There's no signs.
There's no ultrasound features.
There's nothing else that we're testing.
So we're getting—
We're getting this genetic result, but if we don't really know with confidence that, like, which things actually cause disease, then it can be really, really tricky and stressful to counsel a patient about that in the prenatal space where they're trying to decide if they should continue the pregnancy or what the implications of that are.
So I think there's a big gap between what we can do from a technology standpoint and our framework for how we decide which things—
things to screen for and then the resources of the healthcare system that it will take to actually counsel people about these conditions and their screening results.
So what is the most difficult thing you have to do in your role as a physician?
What is—what's the thing that just is so challenging, either because of the resources that are brought to bear or just, quite frankly, the emotional toll it takes on you?
Or, you know, you can answer that in any way.
It makes sense.
Yeah.
There's some really hard things that we, you know, deal with as physicians.
I think from a medical standpoint, when we see things in pregnancy, you know, people who are—who we have to inform of devastating diagnoses, whether it be, like, an underlying genetic condition, severe fetal anomalies, a stillborn baby, when you have to, like, deliver that news and the implications that it has.
for a given family and trying to walk them
through that, those are really tough conversations. I also see, like, it's just the different
resources that people have that bring them to us or that they go back to, I think, are very
impactful for me to think about, too, like patients that we treat and then don't have somewhere to
stay or, you know, have really complex other situations that, you know, they're dealing with.
So I think there's often feels like you can't do a lot about that, but you can see,
you know, with your own patient how much impact it has on them and their own health.
Have you ever had the privilege to go and visit another country where the resources are far less
and participate in childbirth in a place like that?
Yeah, I haven't participated in childbirth in another country myself. I spent a lot of time
in our own country and in the Appalachian Mountains as a high schooler on a service
project where we go for a week every summer and fix people's homes. And it was really like being
somewhere very different than how I thought of at the time, like how our country is. And I wasn't
participating in childbirth at that time, but I've certainly like seen a lot of folks who live in
very, you know, across many circumstances.
What percentage of women in the United States use a midwife for delivery as opposed to an
obstetrician?
You know, I don't know the exact statistics and it really, there are definite trends by
state and rural versus urban and area of the country. So there's big variations. There is a
lot of midwife care prevalent throughout the country. Midwives do a great job providing
obstetric care. They provide, you know, a lot of care for the midwives. And I think that's a
great access in many places where patients don't have other access and they, their training is a
bit different. So folks often, they can often reach patients who are otherwise like skeptical
of the medical system or really don't prefer to have a physician taking care of them. So I think
they're really important, you know, component of obstetric care.
I assume a midwife doesn't have the other tools with, I'm going to say her because I'm just
going to assume most of them are women, but to say, pivot to a C-section if something goes wrong
in the pregnancy, or is there ever a scenario where a midwife is there with an anesthesiologist
should something change?
I mean, usually most practices are set up so that if a surgical procedure is needed, then the. There's a backup.
Yeah.
I see. Okay. Got it. So it's not like, because how often does a woman come in for a delivery? So
let's just assume it's a woman who's been under your care for the entire pregnancy. She's not
high risk. You are therefore expecting to do a
vaginal delivery. And one of the many factors we've talked about today, that just either there's
some rapid deceleration, you'd realize the placenta is a little bit detached, the cord is
wrapped three times, any of those things, what percentage of those are converting to your
surprise to a C-section? Yeah. I mean, if anticipated vaginal deliveries, about 20%
end up going to C-section. Wow. So that would imply that even for a woman who's been under great care
wants to go and have a baby at home with a midwife, there's at least, because I would say it
might even be higher, but at least a 20% chance that they're going to need to call in for a backup
surgical plan. Yeah. And well, there's different reasons why people, if they're delivering in a
birthing center or even at home with an attended birth, might need to transfer to the hospital.
One is that it's thought that a surgical delivery is needed, but another might just be that
the more pain control is needed or the more. That just augmentation with oxytocin is needed to help the labor progress. So we definitely see
different things. So how does that work if a woman is having her baby in a place that's very
remote? Because you mentioned one of the benefits of midwives is they can access patients that don't
have great access to a hospital. So how does that work? Well, I mean, I sort of meant that in the
outpatient setting. I mean, we really do try to encourage people to deliver in a birthing center,
or a place with access to other types of medication. And there are obviously patients
who do choose to have home births, but it's not our recommendation. For this reason, presumably.
Well, and you can't know when things are going to go wrong. So hemorrhage is a big problem. And
often things can change in a second and then you're very far away from where you need to be to get care.
So different obstetrical emergencies can happen. And usually, mostly they don't. But the risk to
the baby is higher at home deliveries and to the mom. You alluded to something earlier when
referring to contractions and saying that it's the most painful thing you've ever experienced.
That's actually kind of surprising to me. I naively assumed that the most painful part
of the delivery was actually the vaginal expansion necessary to get the head out.
But is it the actual contraction itself that is causing the majority of the pain during labor?
Well, most of the labor is contractions. The delivery of the head is like a 30 second part
of the whole thing. So you have something goes on hours, like not to be too crude,
but I had a nurse describe it once as like trying to make a husband understand like who didn't want
his wife to have an epidural. And she's like, it's like having your balls slammed in a drawer
again and again and again. Think of it that way. That's how painful it is.
Want her to have an epidural. Right. I see. So she was sort of saying,
I'll make you a deal. If you let me slam your balls in the door for four hours without an
epidural, you can, you can do this to me. Right. Yeah. Yeah. Got it.
But I mean, it's, I only say that to say like really people don't understand.
All kidding aside, that's describing a very deep visceral pain.
Right. That's how it is. That's, that's what I, cause yeah, every guy listening to this has been
kicked in that region. So they know what that feels like. Yeah. Yeah. No, it is. And it goes on for so
long. Right. So yes, the, the delivery of the head is like very, very painful. I mean, I had,
I had an epidural with all three of my labors and on the third one, they were trying out this new
thing where the medicine was more dilute and it was supposed to spread around better to give you
better coverage. But apparently there was no coverage like right at the perineum. So I was
fine, fine, fine. And then the head was about to come out and it was my third delivery and,
and I could feel everything.
And it was like the first time you'd experienced that because right. Like in the sense that that
was, yeah. So let me ask another question about a term that I've heard. I don't know what it means,
which is called back labor. Yeah. What, and is that because, well, anyway, explain what it is.
Well, it's just that, um, it, that we have many patients who in the first part of labor,
especially, or, or even throughout labor may feel more, a lot of pain in their back in addition,
or, or instead of feeling a lot of pain in the front where the, where the uterus is,
so that's not uncommon. I think menstrual pain can commonly be both in the, in the front and the
back. And I think for patients whose babies might be facing like sunny side up that there seems to
be like more pain in the, in the back during labor. So normal delivery is head out first,
face down, correct? Right. That's the most common position. Yeah. Does the mother's body make
or other pain suppressing molecules endogenously to help make you have amnesia? Yeah. Yeah. Well,
it's, it's kind of a joke, right? Which is, it's, it's described as the single most painful thing
a person can undergo. And yet women are, it seems that that pain immediately vanishes when that baby
is out. And then to your point, there's a little bit of amnesia as you say, I can't wait to do this
again. I'm not sure most of us think that right away, but yeah.
Yeah. That's a good question, but maybe you should interview an anesthesiologist about it.
Yeah. Interesting. When you, when you sort of reflect on this field, it's, they're probably,
I need to think about this because I don't know if it's entirely true. I mean, medicine has made
so much progress over the last hundred years, but I would be hard pressed to think of a field that
has had a greater improvement in mortality in the last hundred years than your field, right?
I mean, it's had, I think it's had the single biggest impact on the population's longevity has
been fewer mothers and babies dying during this unbelievably hellish process, right?
Yeah. I think that's, that's pretty fair to say.
So despite that, the United States still doesn't quite stack up to other OECD nations in this arena.
This has been a topic that's come up.
I had this discussion with a gentleman, a physician, Sam Sutaria, when we talked about
some of the mortality statistics in the United States. And this is a big drag down on our overall
mortality, our survival numbers or life expectancy numbers. There's all the obvious reasons for it.
You've talked about many of them today. Do you, do you hold out much hope that there there's a day,
you know, in, in 10 years, in 20 years, the United States,
is leading the world in, uh, maternal fetal health?
Doesn't feel that way right now.
honestly. I think there's some pretty low hanging fruit that would help. I think insurance access is
a big deal. You know, for states that expanded Medicaid, where, you know, patients came into
pregnancy with better health were more willing to come to prenatal care or able because they were
able to get insurance through Medicaid who had extended Medicaid postpartum for care,
which is when a lot of mothers die. You're saying Medicaid previously
stopped once you left the hospital? It's been like 60, 60 days. So there's
states who in recent years have, you know, really expanded access longer postpartum,
which is really, really impactful for families. But, you know, I think overall, one of the reasons
that our health is poor is because insurance access is piecemeal and it's not guaranteed.
And so, you know, I think it's a big deal. I think it's a big deal. And health care is expensive, even for those who have insurance.
What's typically not covered? Like if someone was going through
the Affordable Care Act, buying their own insurance through the program,
what's the sort of surprise that they end up getting, potentially financial surprise,
where they're saying, hey, I bought my health insurance. I showed up. This is all taken care
of. And then they get a bill that says, actually, we covered this, but not this.
Yeah. I mean, the system is so complicated that I think most physicians can't
answer that question because it's so unpredictable. And there are, it changes every year with any
health plan. As we all know, it's like, you know, to have this plan, you have this amount of
deductible or you have this other plan. And then these are the charges, right? It's so complex that
it's really, really hard to understand. But you can't even help a patient
navigate the system and try to cater your care to their coverage.
No, it's incredibly frustrating and difficult. And it feels, you feel very powerless because you would like to be able to do it.
To provide information, that's like part of our job. But like, there's so many differences between
so many different plans that it's quite difficult. Which is interesting because that would seem to me
an issue that anyone, everyone on both sides of the aisle could agree that it's a bad thing to have
moms and babies not cared for. And nobody should, nobody should really incur bankruptcy-inducing
health care bills. And everybody's very frustrated with the payers, for sure. It really,
really is the, it is the Achilles heel of the U.S. health care system that does not appear in single
payer solutions. Now, again, the challenging thing is there are so many wonderful things about the U.S.
health care system that are the result of a two-payer system. But at the same time, there are
so many things, and this is a classic example. I wasn't aware of the, for example, the Medicaid not
necessarily extending post. So, well, I don't mean to end it on a downer, but that's, this has been a
super fascinating discussion.
Katie, again, I think this idea that what happens during pregnancy gives you a window into your
future health. I think if we, if, again, if the listener, both male and female, for the, takes
nothing but that, which says, use this opportunity to learn what your susceptibilities and risks are
in the future. Any other really big messages you want to make sure people take away from this as
far as improving their health? Well, I mean, I think, I think in the
pregnancy space, we still really lack interventions and treatments because of lack of investment in
research in this area. And we haven't spent a ton of time talking about that today. But I think that,
you know, it's been a neglected area in research. It's been an underfunded area of research.
Even at the NIH level? Yes, even at the NIH level. And, you know,
the branch of the NIH, the NICHD, the National Institutes of Child Health and Development,
nothing in that word has the word pregnancy in it. So there, like, that has been the institute.
That's the closest pregnancy gets to the 17 different branches of the NIH.
Right, exactly. So, like, that branch has funded the most pregnancy-related research of any branch
of the NIH. And yet, like, it's, it's, it's a title that indicates it's about child health,
not about the, the mom. So. Why do you think that is? It seems obvious. I mean,
sorry, what seems obvious is that it should address pregnancy. Do you, I mean, what's,
what's the hypothesis? I know that the NIH has areas where it's just doubled down and spends
endlessly. Right. And then there are gaps, presumably. I mean, there are, I'll give you
a gap in my world is the investment in geroscience is, it's, it's literally basis points of NIH
budget. So that's another area that is just completely ignored. Prevention is another area
that gets very little funding. Yes. So I guess we can add pregnancy to that list, unfortunately.
Yeah. And I think it's the recognition of its importance in the whole lifespan,
has really, has expanded some, you know, funding opportunities. And so I think there is more
recognition of it now, but really there's need for continued investment in this area because it
still remains like understudied and under-resourced to really help people the most, most we could if
there were more resources. So if there were philanthropists listening to this now who are
saying, look, I want to, I'm very interested in funding biomedical research, but I, I like to fund
things that are not otherwise crowded. This is an area.
What would their next steps be? How would they find the right scientists and investigators
who are asking the questions that can be answered? Yeah. I think there's some groups that have come
around trying to advise or advocate for funding. So AGOS as the American Gynecologic and Obstetric
Society, they've put together this women's health collective to try to advocate for women's health
funding. And they, lots of the key players in leading in this space,
across OBGYN are involved in that society. So you can contact leaders of these organizations
and they can help direct people. Various folks have different, sometimes people have areas of
very specific interest in giving money to sometimes, you know, there's, there's lots
of ways to make investments that make a big difference for people. So I think.
But going to that organization is a place where you could find the investigators and basically
figure out who's doing the work you're interested in. Well, Katie, thank you so much. I appreciate
it. And I apologize.
For the board exam, but on the positive side, you don't, you get to sit the next year's out.
Thanks.
Thank you for listening to this week's episode of The Drive. Head over to peteratiamd.com
forward slash show notes. If you want to dig deeper into this episode, you can also find me
on YouTube, Instagram, and Twitter, all with the handle peteratiamd. You can also leave us
review on Apple podcasts or whatever podcast player you use.
This podcast is for general informational purposes only, and does not constitute the
practice of medicine, nursing, or other professional healthcare services, including
the giving of medical advice. No doctor patient relationship is formed. The use of this information
and the materials linked to this podcast is at the user's own risk. The content on this podcast
is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users
should not disregard or delay in obtaining medical advice from any medical condition they have,
and they should seek the assistance of their healthcare professionals for any such conditions.
Finally, I take all conflicts of interest very seriously. For all of my disclosures and the
companies I invest in or advise, please visit peteratiamd.com forward slash about where I
keep an up-to-date and active list of all disclosures.
Podcast Summary
Key Points:
Pregnancy is a profound physiological stress test that dramatically alters the mother’s cardiovascular, metabolic, and hormonal systems.
The placenta takes over hormone production around 8–10 weeks, replacing ovarian hormones and driving key changes like increased plasma volume and insulin resistance.
Gestational diabetes arises from pregnancy-induced insulin resistance and is diagnosed via oral glucose tolerance tests; it often resolves postpartum but increases future risk of type 2 diabetes.
Preeclampsia is defined by new-onset hypertension after 20 weeks, often with proteinuria, and is linked to placental dysfunction and an imbalance in angiogenic factors like sFlt-1.
Pregnancy complications like preeclampsia and gestational diabetes reveal underlying genetic predispositions to long-term cardiovascular and metabolic disease.
Conditions like HELP syndrome—hemolysis, elevated liver enzymes, and low platelets—remain poorly understood but are associated with severe maternal and fetal risks.
Women with a history of pregnancy complications have a significantly elevated risk of future cardiovascular and kidney disease, emphasizing the need for lifelong monitoring.
The transition from obstetric to primary care is critical, as clinicians must share pregnancy-related insights to guide long-term preventive care.
Summary:
Pregnancy is a unique and extreme physiological state that places significant stress on a woman’s body, reshaping her cardiovascular, metabolic, and hormonal systems. This transformation, including expanded plasma volume and insulin resistance, can uncover underlying genetic predispositions to conditions like gestational diabetes and preeclampsia. These conditions are not isolated events—they reflect a deeper biological vulnerability, with strong links to long-term risks of type 2 diabetes, cardiovascular disease, and kidney dysfunction.
Research shows that women who develop gestational diabetes or preeclampsia have a substantially increased risk of future metabolic and cardiovascular disease, driven by shared genetic architecture. Despite advances, many women remain unaware of these links, and obstetric history is often underreported in medical records. Effective long-term care requires seamless communication between obstetric and primary care providers, ensuring that insights gained during pregnancy are translated into actionable preventive strategies.
Key interventions, such as lifestyle modifications, regular screening, and early detection, can mitigate future disease. While the exact mechanisms of some complications—like HELP syndrome—are still being studied, the consensus is clear: pregnancy acts as a powerful diagnostic window into a woman’s lifelong health trajectory. This underscores the importance of comprehensive, patient-centered care that extends beyond childbirth.
FAQs
Preeclampsia is a pregnancy-specific condition defined by new-onset hypertension after 20 weeks gestation, often accompanied by proteinuria or severe symptoms like headaches or vision changes. It is diagnosed when blood pressure is ≥140/100 mmHg and either proteinuria or other severe features are present, though recent guidelines allow diagnosis with severe hypertension even without proteinuria.
Pregnancy involves dramatic changes including a 50% increase in plasma volume, increased insulin resistance, and elevated hormone levels. These changes stress the cardiovascular, metabolic, and endocrine systems, with the body adapting to support fetal growth, though they can reveal underlying health risks in the mother.
Folic acid is crucial for preventing neural tube defects in the developing fetus. It is recommended that women take prenatal vitamins containing folic acid before conception and early in pregnancy, as deficiencies during this time can significantly increase the risk of birth defects.
Gestational diabetes is diagnosed via a one-hour glucose tolerance test (50g glucose), with a level ≥130 mg/dL indicating abnormal results. Confirmation comes from a three-hour oral glucose tolerance test. Management starts with dietary changes and monitoring, with insulin being first-line therapy if glucose levels remain uncontrolled.
Yes, approximately 50% of women with gestational diabetes will develop type 2 diabetes in the future. This highlights the importance of ongoing lifestyle monitoring and regular screening postpartum.
HELP syndrome (hemolysis, elevated liver enzymes, and low platelets) is a severe pregnancy condition with overlapping features to preeclampsia but distinct lab abnormalities. It can present with mild or severe hypertension and is often associated with fetal compromise, requiring urgent delivery.
Chat with AI
Loading...
Pro features
Go deeper with this episode
Unlock creator-grade tools that turn any transcript into show notes and subtitle files.