Transcript episode #40:The TRUTH ABOUT OBESITY AND PREGNANCY
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In today's episode of the podcast, I am talking about how obesity affects pregnancy.
Welcome to the All About Pregnancy and Birth Podcast. I'm your host, Dr. Nicole Calloway Rankins, a board certified ob gyn physician, certified integrative health coach and creator of The Birth Preparation Course, an online childbirth education course that will leave you feeling knowledgeable, prepared, confident, and empowered going into your birth. Quick note, this podcast is for educational purposes only and it's not a substitute for medical advice. See the full disclaimer at www.ncrcoaching.com/disclaimer.
Hello, welcome to another episode of the podcast. This is episode number 40 and I'm so glad you are here with me today. On today's episode of the podcast I am talking about how obesity affects pregnancy, and this idea actually came from one of my Instagram followers. Now I know that weight in general can be a really sensitive topic, but it's something that we need to discuss, because it's important and it affects quite a few women during their pregnancies. So in today's episode you're going to learn what exactly obesity is, the definition, how common it is for reproductive age women, the effects that obesity has on pregnancy, also how it affects babies, and then how your pregnancy care changes if you're obese. Now I know that some of the information today may feel like a lot, it may feel a little bit overwhelming at times, maybe even a little bit depressing, but we have to understand the facts about how obesity affects pregnancy, because without those facts, you don't have the information you need to have your very best pregnancy and birth. So we are going to tackle all of that information today.
All right, now before we get into the episode, a quick listener shout out, this is to NicoleANC. And she left me this review in Apple podcasts. The title of it is, I finally found it. And it says "I wanted to take advantage of my commuting time each day with a podcast that will prepare me for birth and baby as well as helpful tips through pregnancy. Until I came across this, I found most podcasts in this subject area to be way too specific on obscure topics or just too much fluff. This one is exactly (in all caps), exactly what I was looking for. Dr Rankins breaks it all down so well and I find all the episodes relevant to what I want to learn about." Well thank you so much NicoleANC. I am so glad that I can help you take advantage of your commuting time and there are plenty more episodes to come so you'll have lots of stuff to listen to on your commute.
Also, let me take a moment to remind you about my free live online class, How to Make a Birth Plan That Works. This is a great class to give you a step by step process on how to make a birth plan that works for you and your birth. Now, due to my work schedule, I have to cut back on how many times I can offer the class over the next couple of months. So if you're interested, then definitely go ahead and sign up. It's www.ncrcoaching.com/register to sign up and I'll put that link in the show notes. You can be at any point in your pregnancy to take the class, so don't feel like you have to wait. And if you can't make the time of the class, go ahead and register anyway and I will send you the replay video. So that's www.ncrcoaching.com/register and if you're looking for childbirth education, which I strongly encourage that everyone does, then the birth plan class is a great way to get a feel for my online childbirth education class, The Birth Preparation Course. And The Birth Preparation Course is my lovely program, amazing program that gives you comprehensive childbirth education. So you are knowledgeable, prepared, confident and empowered to have the birth you want. You can learn all the details about the birth preparation course at www.ncrcoaching.com/enroll and that link is in the show notes as well.
All right, so let's get into today's episode. And the first thing we're going to talk about is what is the definition of obesity? And we define obesity as something called body mass index and that is where you take your weight and your height and you put it in this formula and it spits out a number. And a BMI of greater than or equal to 30 kilograms per meter squared is defined as obese. And the reason we use kilograms per meter squared is because those are more standard definitions internationally.
Now we also divide it even more into a class one, a class two, and a class three obesity. Class one obesity is a BMI between 30 and 34.9, class two is the BMI between 35 and 39.9, and class three obesity is a BMI of 40 or greater. We also sometimes refer to that class three obesity with a BMI of greater than 40 to be morbidly obese. Now, just for some real world examples, if you're five feet three inches tall, for example, and you weigh 175 pounds, then you would be considered obese. And if you're five feet three inches tall and you weigh 225 pounds, then you would be considered in that class three category or morbidly obese. Another example, if you're five feet five inches tall and you weigh 185 pounds, then you would be considered obese. And 240 pounds will put you into that class three obesity category. The definitions for obesity when you're not pregnant don't really adapt that well to pregnancy because during pregnancy women gain a fair amount of weight in a short period of time. So usually what we do is classify you as obese or non obese based on your pre pregnancy body mass index or BMI.
As far as how common obesity is, different studies find different numbers but the national center for health statistics, which is part of the Centers for Disease Control, they estimate that for women between the ages of 20 and 39 roughly 34% of those women are obese. It's higher for African American women, that number is 57%. And when you look at women who actually give birth, roughly 26% are obese. So that's about one in four. Now obese pregnant women are at an increased risk, for quite a few problems both for themselves and for their baby. And I'm going to talk about those things later. And those risks go up with increasing levels of obesity. So the more weight you have the higher your chances of having pregnancy issues are. And it's actually estimated that a full 25% of all pregnancy related complications are directly related to being overweight or obese. Also, babies born to obese mothers are at an increased risk of having issues and I'll talk about that later as well.
So how exactly does being overweight and having that extra fat cause problems? Well, it's because adipose tissue or fat tissue, it's actually an active endocrine organ. And what that means as an endocrine organ is that fat actually secretes hormones and other products directly into our blood. And when that fat is present in excess and those hormones and other products are secreted into our blood, it can have negative effects on metabolism. It can create what's called an inflammatory state in the body and have effects on the vascular system too. And we think that these are the things that lead to those concerning pregnancy outcomes.
So we think, for example, that obesity related insulin resistance and abnormalities and things like what's called inflammatory pathways can affect the placenta and can lead to the development of preeclampsia. So again, those endocrine functions of fats secreting those hormones can have excess negative effects. And then as far as how maternal obesity affects the babies, what we get concerned about is that the baby in the uterus is exposed to increased levels of blood sugar, insulin, fat, and then those inflammation factors and those effects inside of the uterus may cause either transient or potentially permanent changes in metabolism that can lead to adverse health outcomes for those babies as they become adults.
All right, so now what I'm going to do is talk about the effects of obesity during pregnancy, during labor, and during the postpartum period, and I'm just gonna kinda run through them all. So when you look at the overall risk of what's called severe morbidity and mortality, and severe morbidity and mortality, well, mortality is death, but severe morbidity includes things like hemorrhage that requires transfusion, serious heart problems, lung problems, liver problems, kidney problems, stroke, blood clots, severe infection, kind of lumping all those things together. For a woman with a normal BMI, out of 10,000 women, about 143 will have either a severe morbidity or mortality event. And with increasing weight, that number goes up. So for a woman with a normal BMI, it's 143 out of 10,000 women. If you're overweight, it goes up to 160, class one obesity that said BMI of 30 to 34 the number goes up to 168, class two obesity, that BMI of 35 to 39 then the number goes up to 178 per 10,000 women. And then class three obesity, the highest level of obesity, it goes up to 203 per 10,000 women that'll have a severe morbidity or mortality event.
And if you look at women who have a BMI greater than 50 then they have a very high chance of having an adverse maternal event or adverse event for their child. So when you look at some of the impact or things that obesity can do, and we kind of break it down to before pregnancy, one of the things that we see is that obesity, can slightly increase the risk of early pregnancy loss, it's not a lot, but it does increase it enough that it's notable and again it's thought to be to that hormonal factor and the fat. So creating hormones and it creates potentially an unfavorable environment inside the uterus. It also may create a higher inflammatory state that can make it harder for our pregnancy to continue. Obesity is related to diabetes outside of pregnancy and that's certainly the case within pregnancy as well. So sometimes women are first discovered to have type two diabetes during pregnancy. Maybe they hadn't been screened before or maybe they haven't seen a doctor recently and because of the way we take care of women slightly differently who are obese in pregnancy, we test you earlier and I'll talk about some other changes that happen in prenatal care in a little bit. So very often women are discovered that they have had type two diabetes. They discovered that during the first part of their pregnancy. Also gestational diabetes, which is diabetes that is specific to pregnancy, it's more common among obese women than in the general OB population. And again that risk increases with increasing levels of weight.
Hypertension or high blood pressure issues during pregnancy are also more prevalent for women who are obese and that's both hypertension and preeclampsia. We don't exactly understand why that happens. We think it may just be because we know that obesity in general is not good for your cardiovascular health, so we think it's related to that. Another thing that obesity increases the risk for is having what's called a medically indicated preterm delivery and that's usually because of developing high blood pressure or diabetes that moms need to be induced early and sometimes preterm. We don't know for sure whether or not being obese increases the risk of having what's called a spontaneous preterm delivery. The evidence is kind of mixed on that, but it definitely increases the risk of needing to be induced earlier because of problems with the pregnancy. Obesity in moms also increases the risk of a pregnancy going post-term or past the due date. Again, this is not something that we understand why this happens. Part of it is maybe thought to be due to the fact that it's a little bit harder to estimate gestational age in women who are obese. Periods are irregular, so if an early ultrasound wasn't done, then maybe the dates of the pregnancy aren't exactly right and even if an early ultrasound is done, it technically can be harder sometimes to do ultrasound in obese women. So that may be part of the reason. Another theory is that the hormone changes outcome with the increased fat interfere with the normal hormone changes that initiate labor, something that we don't entirely understand. So that's just kind of a theory.
A couple of other things that we know are increased for women who are obese are sleep apnea. We know that sleep apnea is worse when you're obese outside of pregnancy. It's the same during pregnancy and during pregnancy it can potentially become worse and having sleep apnea during pregnancy may increase your risk of gestational diabetes, preeclampsia, as well as respiratory problems after a C-section.
All right. Now during labor, obesity does have a little bit of an impact on how labor progresses, and this is really for the period of active labor like getting from 4 centimeters to 10 centimeters. So when you look at women who are normal weight, the median duration to get from 4 centimeters to 10 centimeters is roughly 6.2 hours. So that's roughly a little more than a centimeter an hour. For an overweight woman, that goes up to 7.5 hours. And then for an obese woman that's 7.9 hours. So almost two hours longer to get from 4 to 10 centimeters for obese women. Now the good news is the second stage of labor, which is the part of labor from being completely dilated to delivery of the baby, so the part where you push that part does not appear to be affected by increase in BMI. As far as induction, obese women are at an increased risk for needing their labor to be induced like I talked about earlier. Usually it's because of pregnancy related issues like hypertension or diabetes and then once they are induced they are at an increased risk for having a longer induction and also for the induction failing. There was one study that showed that obese women were about twice as likely to have a failed induction compared to normal weight women and that risk increased with increasing classes of obesity.
Obesity is also a risk factor for having an emergency cesarean delivery, and again like many of the other things that I've discussed, the risk increases with increasing maternal weight. There's also concerns after cesarean delivery of an increased risk of wound infection, blood clots and infection of the uterus and I will have to be honest, c section, when a woman is obese from the obese perspective, it is a technically more difficult and challenging procedure to do. It's more physically demanding. There's an increased amount, when you have that increased amount of fat, it just creates that much more that you have to go through in order to get to the uterus and get the baby out. And getting the proper visualization and what you need to see, can be challenging. Sometimes we even have to tape up a woman's belly in order to really have the best chances of being able to see and get to the uterus to get the baby out as safely as possible. There are even companies that have designed special taping devices to help like pull the belly up specifically for obese women related to a c section. If you are obese and you have a c section and you want to attempt a vaginal birth the next time, unfortunately obese women are less likely to have a successful VBAC. And when you look at some of the calculators that look at your chances for success with VBAC, BMI is going to be one of the things that they take into account.
And then another issue is anesthesia. When you get an epidural, you get the needle placed in your back, the catheter in your back, and the way the anesthesiologist places that catheter is by feeling some bony landmarks in your spine so that the needle can go in exactly the right spot in order to get the catheter in the right place. So as you can imagine, if there's more fat there and the more fat that's there, then it's much more challenging to feel the right place in order to put that epidural needle and catheter or the spinal needle. So obese women are at a higher risk of having multiple attempts at getting an epidural or spinal, at an increased risk of having the needle get put into the wrong place and they're at an increased risk of the epidural or spinal not working at all. Again, it's related to that extra tissue there and the challenges with getting the needle in the right place.
And then finally, during labor and birth, there are some issues potentially related to having a big baby or macrosomia, which is a birth weight greater than 4,000 grams. I talked about that in a recent episode of the podcast. I can link to it in the show notes. The truth about having a big baby, but having a big baby is more common in obese women, and that increases the risk of shoulder dystocia, dysfunctional labor pattern where things don't progress like we expect, higher risk of vaginal tears, higher risk of postpartum bleeding as well.
All right. And then when we look at the postpartum period, pregnancy in and of itself increases the chances of having blood clots in the legs that can potentially travel to the lungs and obesity further increases that risk. And again, that risk goes up with increasing levels of weight. There's also an increased risk of infection no matter what type of delivery it is. So there's an increased risk of if you had a vaginal tear an infection may develop in that vaginal tear or if you have a c section incision, a wound infection or endometritis, infection of the uterus and again that risk is there regardless of vaginal delivery or C-section or whether or not we use antibiotics.
We suspect that it is a result of the fact that fat tissue doesn't necessarily have good blood flow to it and that can kind of create a situation where infection can more easily develop. Now when looking at babies of women who are obese, obese women are at an increased risk for having a baby that has congenital anomalies, specifically things like neural tube defects, which affect the spine and how the spine develops, part malformations, cleft lip, cleft palate, and the risk again increases with the increasing degrees of weight. We don't exactly understand how this happens, but yeah, like the other things we think that it's related to the hormones. We also think it may be related to potentially the nutritional environment that the baby has had developing.
The other issue with congenital anomalies is that quite frankly, they're just more difficult to see if there are problems with the baby on ultrasound. Ultrasound uses sound waves, the sound waves go through the belly and they bounce back to the transducer to give the pictures and if there's a longer distance, so there's more fat, if there's more fat that the ultrasound waves have to travel through, then it can make the pictures have lesser quality. So it's estimated that the ability to detect problems with babies on ultrasound is reduced by at least 20% in obese women compared to women who are of a normal weight. There's also unfortunately an increased risk of stillbirth, an increase risk of death during labor and increased risk of death within the first 28 days, neonatal death and an increased risk of infant death, so in the first year of life among women who are obese. This tends to be more pronounced in black women when compared to white women. And it increases with increasing levels of weight.
Now, because obese women are more likely to need to be induced for issues related to pregnancy, sometimes even when the baby is premature, then they have babies that are more likely to be premature and have those problems as well. And on the flip side, mom being obese can lead to babies who are bigger when they are born. I talked about some of the issues related to that with the shoulder dystocia and issues during birth, it also predisposes those babies to being obese later in life. As a matter of fact, when you have one mom or I'm sorry, one parent who is obese, it increases the risk of obesity for that child by two to three times. If both parents are obese, it can increase the risk of obesity for that baby as an adult for up to 15 times. And we think that mom being obese is of particular concern because we believe that environment that the baby is in inside of the uterus contributes to this environment that predisposes them what we call an obesogenic environment so it can change their metabolism. That really increases the risk of childhood obesity and then obesity to continue as an adult and then the resulting conditions that can happen from that, like diabetes, hypertension and heart disease.
We also think that obesity in moms can contribute to programming in the baby's brain in a negative way. There is a growing body of evidence that suggests that exposure to mom being overweight can lead to increased risk of autism spectrum disorders, attention deficit hyperactivity disorder, anxiety, depression, schizophrenia. These things are kind of developing, but we're discovering more that those can be a concern and we think that again, it's related to the dysregulation and insulin, blood sugar and those inflammatory properties as well.
Now, as far as what we can do or what we do do for women who are obese during pregnancy, actually let me first back it up and talk about what we can do before women get pregnant. And I would highly suggest that if you are thinking of getting pregnant and you are obese, that you undergo preconception counseling and evaluation, that you have a discussion with your healthcare provider before you get pregnant. So you can plan your pregnancy as best you can as possible. And you need to understand how that your weight may be affecting your fertility. You need to understand the potential pregnancy complications like I talked about, you need to be evaluated for some other things that may need to get under better control, like if you have high blood pressure or diabetes, and then talk about the possibility of weight loss before you get pregnant. Really, if you can lose, and it's actually not that much weight, if you can lose 10% of your BMI, which amounts to usually about 20 pounds or so, if you can do that before you get pregnant so you don't have to get down to a normal weight necessarily, but just even 20 pounds can reduce the risk of preeclampsia, reduced gestational diabetes can reduce having to have a preterm baby early can reduce stillbirth by at least 10%. And then if you lose a little bit more, so 30 pounds or so, then we can reduce that even more. So you don't necessarily, I think some women think, oh my gosh, I have to get down to a normal weight before I get pregnant. No, even if you can lose 10% of your BMI, then you can have better pregnancy outcomes.
Now for some women, depending on your weight, then you may even need to discuss something like bariatric surgery. For women who are very obese, so in that class, three obesity or morbid obesity range, bariatric surgery may be the best option for you. It's one of the things that we know works best for people who are very overweight, but that requires some definite intense planning because there needs to be a good bit of time between when you have the surgery and when you get pregnant.
Now, during pregnancy, there are a few changes in the way you have prenatal care. In the first trimester, it's not terribly different. Probably the biggest change is that you will undergo screening for diabetes in the first trimester, whereas we don't do that for normal weight women. Your care team will also probably be expanded a bit. In addition to seeing your regular Ob doctor, you will probably at some point be sent for a visit to a high risk pregnancy specialist as well. You may also see a dietician and if there are concerns about anesthesia, you may see an anesthesiologist too definitely for sure when you're on labor and delivery. One more thing about the first trimester, there should be a discussion about weight gain and I'm actually gonna talk about that next week's podcast episode, but women who are obese really should not gain more than 20 pounds the entire pregnancy, so 20 pounds the entire pregnancy. Some people actually recommend pregnant women losing weight during pregnancy, but that can increase the risk of the baby being small, so you gotta really be careful about that.
Now, during the second trimester, many obese women well benefit from starting to take a daily baby aspirin in order to prevent preeclampsia. Baby aspirin is one of the things that we know in certain populations it works well to help reduce your risk of preeclampsia. So if you have several risk factors, then this may be something that you need to talk with your doctor about. And some of the risk factors are obesity is one, some other risk factors include if it's your first baby, if you have a family history of preeclampsia, either your mother or your sister. If you're black, if you are what's called advanced maternal age, so 35 years or older, then you may benefit from taking aspirin during your pregnancy. So if you're obese, then definitely talk to your doctor early about whether or not you should be on a daily baby aspirin. Don't start it without talking to them because you may, you know, maybe they decided on based on your other factors that the risk outweigh the benefits. But definitely bringing the conversation up.
In the second trimester, you'll also get like a regular ultrasound, like every pregnant woman gets around 20 weeks or so to look at the baby's anatomy. But some people will also do what's called a cardiac echo. So an echocardiogram for the baby that looks at a more detailed view of the baby's heart. Certainly maybe more likely to do that if you have diabetes. Not every doctor will do this, but you may end up having that echocardiogram just because obese women are at an increased risk for their baby having heart problems.
And then in the third trimester you often have regular ultrasounds every four weeks or so in order to assess how your baby is growing. Normally we can tell pretty well how a baby is growing based on fundal height. When we measure the top of the uterus with the measuring tape and centimeters should correlate roughly with how many weeks you are in pregnancy. However, if you're obese and you have extra weight, it can be challenging, if not impossible in some instances to really feel the uterus. So the only way that we have in order to know whether or not the baby is growing well is to do regular ultrasounds. And we don't typically do ultrasounds any sooner than every three to four weeks because we need that amount of time to assess for growth. So you may be getting those regular ultrasounds towards the end of pregnancy. Some doctors also do increase what's called antinatal surveillance with putting you on the monitor with non-stress test to monitor your baby's heart rate or BPPS biophysical profiles, do a quick ultrasound to look for some things on ultrasound. But that hasn't necessarily been shown to improve outcomes for obese women. So your Dr. may or may not recommend it and they may recommend it depending on if you have other things. They may not recommend it for just obesity alone, but if you have obesity with hypertension or diabetes, then they probably will.
Now during labor and delivery, some of the challenges that we encounter for women who are obese, it can be more challenging to monitor the baby's heart rate. The Doppler that we use to measure the baby's heart rate, again, is sound waves, and if there's more fat tissue to go through, then it's just harder to get to the baby's heart rate to hear. So sometimes we have to do internal monitors where we put monitors inside the uterus or on the baby's scalp in order to listen to the baby's heart rate and track the contractions better.
As far as timing for delivery, then most folks recommend induction or delivery by due date for women who are obese in order to reduce the risk of stillbirth. So most doctors again will recommend induction by that time and it doesn't seem to increase the cesarean delivery rate. And then the last thing during labor and delivery, if the anesthesiologist feels like it's going to be particularly difficult to do your anesthesia, then they may recommend doing an epidural early and trying to do it under the most controlled circumstances possible so that it's there in case they need it and they're not having to struggle if there's an emergency situation.
Now postpartum, a couple of things may come up. If a cesarean section was done, there's an increased risk of surgery complications related to that infection. Sometimes respiratory problems, so that can be a concern. Also sometimes obese women have a little bit more trouble breastfeeding. So you definitely see a lactation consultant before discharge from the hospital and maybe even after you leave the hospital. And then some other things that your doctor will touch base about if you had diabetes during pregnancy, you need to be retested afterwards. And that's actually for anybody that has gestational diabetes during pregnancy. And then there needs to be a discussion about weight postpartum, so how to manage weight loss and lose that pregnancy weight or postpartum weight gain. But again that's a discussion that really we need to have with all pregnant women after they have a baby.
All right, so that is for this episode. I know that was a lot and a lot of it may be felt overwhelming. I talked about a lot of negative impacts that obesity has on pregnancy. Now I know obesity and weight is a sensitive topic and I hope I conveyed the information in a way that was just the facts and without judgment, cause I'm certainly not judging here. I know how challenging weight can be. I also have to be honest about the seriousness of it because it is serious. Obesity can cause some very serious and negative things to happen for moms and babies. I've seen it time and time again. So if you are obese and pregnant and you haven't already done so, it is not too late for you to start making some changes to your health that will benefit you and your baby not just during your pregnancy but after your baby is born and for the rest of your life. So ask your doctor if you can see a dietician, talk to them about how to start an exercise plan. It doesn't have to be anything major. It can be as simple as a walk three or four times a week. I don't want this to be terribly stressful for you. Every little bit counts and every little bit of change adds up. And if you're not yet pregnant then focus on reducing your weight, notice I didn't say get to a normal weight. Just focus on reducing your weight by 15-20 pounds. That bit of weight loss can make a big difference or your pregnancy.
Now if you are obese and pregnant or you were obese during your pregnancy and you were able to successfully make some changes to improve your health, then I would love to have you come on the podcast and share your story of how you were able to do that. You can DM me on Instagram. I'm on Instagram @drnicolerankins and tell me about your stories to see if you're a good fit to come onto the show. Then be sure to subscribe to the podcast and Apple podcast or wherever you listen to podcasts and of course I would love it if you leave a review, an Apple podcast. It helps the show grow, it helps other women find the show and I can leave you a shout out. And don't forget about the free online class on how to make a birth plan that works. Because of my work schedule, I can't do the classes often, so go ahead and hop on in and grab your spot. It's not too early to take the class. It's www.ncrcoaching.com/register. If the date and time don't work for you, register anyway, and I will send you the replay video.
Next week on the podcast, I am continuing the discussion about weight and I'm going to talk about the recommended guidelines for weight gain during pregnancy, as well as some basic kind of nutrition stuff for pregnancy. So I'm going back next week and until then I wish you a healthy and happy pregnancy and birth.
Today's episode is brought to you by Women's Wellness Coaching by Dr. Nicole Calloway Rankins. Head to www.ncrcoaching.com to check out my free one hour mini course on how to make your birth plan as well as my comprehensive online childbirth education class, The Birth Preparation Course with over eight hours of content and a private course community. The Birth Preparation Course will leave you knowledgeable, prepared, confident and empowered going into your birth. Head to www.ncrcoaching.com to learn more.