Ep 41: What You Need To Know About Weight Gain During Pregnancy

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Do you know what the recommended amount of weight gain during pregnancy is? Or what the relationship is between weight gain during pregnancy and pregnancy outcomes? The truth is, a lot of women don’t know all the in’s and out’s of weight gain during pregnancy, because there isn’t a lot of time during your Ob appointments to really dig into it.

In Episode #40: The Truth About Obesity And Pregnancy, we talked about how obesity affects pregnancy and now, we’re going to talk about weight gain during pregnancy. Listen in to see how weight gain affects pregnancy outcomes and the recommended weight gain targets.

Learn the optimal amount you should gain if you’re underweight and how you may not need to gain any weight if you’re obese. Find out how pregnancy weight is distributed throughout your body, as well as the steps you can take to meet the ideal weight gain.

In this Episode, You’ll Learn About:

  • How weight gain affects pregnancy
  • What the recommended weight gain target is for good pregnancy outcomes
  • Where all the weight you gained during pregnancy go
  • IOM recommendations for weight gain during pregnancy
  • The relationship between weight gain and pregnancy outcomes
  • How we deal with care during pregnancy in relation to weight gain
  • The importance of preconception weight
  • What we do when pregnant women aren’t meeting the guidelines for weight gain and pregnancy
  • The importance of preconception weight

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Speaker 1: On today's episode of the podcast. I am talking about weight gain during pregnancy.

Speaker 2: Welcome to the All About Pregnancy & 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 class 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.

Speaker 1: Hello, hello, hello. Welcome to another episode of the podcast. This is episode number 41 and as always I am so glad you're here with me today. So last week on the podcast I talked about how obesity affects pregnancy. That was episode number 40 and I'll link to that in the show notes. And in continuing with the theme of how weight affects pregnancy, this week I'm talking about weight gain during pregnancy. So on today's episode I'm going to cover what the recommended weight gain targets are, and it's based on your pre pregnancy weight, and also how weight gained during a pregnancy affects pregnancy outcomes.

: Now before we get into the episode, let me give a quick listener shout out. This is to Cat5367 and she left me this review in Apple podcasts. The title of it says love this podcast and then the review says "Love this podcast. Very informative and I like that she has other people on the podcast to share their real birth stories." Well, thank you so much for that review, Cat5367. Just like you, I also love having women come on the podcast and share their birth stories. It kind of gives me a window into the birth experiences that I don't typically get as an OB GYN. I so love, love, love, birth stories, and if anyone out there wants to share their birth story on the podcast, you can always go to www.ncrcoaching.com/birthstory and submit your story. I'll include that link in the show notes too.

: What I also love is helping women make a birth plan and I do that through my free live online class, How to Make a Birth Plan That Works. I do this class like three or four times a month. It's actually going to be a little bit less towards the end of the year here, but you can go to www.ncrcoaching.com/register to sign up and grab your spot. Women love this class and every single class I have more and more people join. It's getting bigger and bigger, so you definitely want to come check it out. It's www.ncrcoaching.com/register to sign up for the next class. If the time doesn't work for you, I always send out the replay video and you can catch it after that. So check out the free live online class, How to Make a Birth Plan That Works.

: Okay, so let's get into today's episode. Now, why do we even care about weight gain during pregnancy? Well, last week I talked about how obesity can affect pregnancy and it can increase the risk of gestational diabetes and preeclampsia and cesarean birth. Well, it turns out that gaining too much weight during pregnancy can also have a similar effect and add to that gaining too much weight during pregnancy also have some implications for the postpartum period, particularly with holding on to extra weight and the risk for obesity later in life. So that's why we pay attention to weight gain during pregnancy. Now that's the side of gaining too much weight during pregnancy.

: On the flip side, for women in particular who start pregnancy and they are underweight and if they don't have enough weight gain during pregnancy, then they're at an increased risk for delivering a baby that's too small. So that's kind of a broad overview of why we care about weight gain in pregnancy because gaining too much has implications, not gaining enough has implications.

: So where exactly does all that weight go when you gain weight during pregnancy? What I'm going to do is just kind of go through like roughly the estimates of where that weight goes and this is for when you're full term. So towards the end of pregnancy and it kinda gets divided between some for the baby and then most of it for you.

Speaker 1: So here's how it works. So the baby, and this again is at full term, roughly on average will be anywhere from seven to eight pounds. You will gain between six to eight pounds of increased fat. Your actual blood volume, the amount of blood circulating through your body is going to increase by three to four pounds. And that's because of the increased demands of blood flow to the uterus that are required to grow a pregnancy. You also have some increased fluid outside of your blood vessels and what's called the extra vascular space. And that's two to three pounds. So that's fluid circulating through your fat and through, you know, like around your muscles and other body parts, like why your legs may get swollen, that kind of thing. So that's two to three pounds. Amniotic fluid weighs about two pounds. Your breasts will gain between one and three pounds of weight. Your uterus itself will gain about two pounds. And then the placenta weighs roughly one and a half pounds. So when you total all those things up between the baby, the increased blood, the increased amount of fat in your body, amniotic fluid, the increased weight in your breast, your uterus, the placenta, that total is roughly 30 pounds or so on average.

: Now we base our recommendations for weight gain during pregnancy, it's primarily based on some recommendations that were made in 2009, so 10 years ago. And the 10 years ago piece is going to become important as I talk a little bit more in the episode, but we base this on recommendations from 2009 from the Institute of Medicine. That's part of the National Academies of Science, that's the national government organization and the recommendations are the same for everybody, at least in the United States. So it doesn't matter how old you are, whether it's your first baby or second baby, it doesn't matter your race, your ethnic background. The recommendations are the same for everyone and that is largely due to the fact that at the time these recommendations were made that there just wasn't a lot of data available to decide if different people needed different types of recommendations. So they made the recommendations on the best available evidence that they had at the time.

: So let me just run through the evidence for you. So this is divided into your pre pregnancy weight or I should say it's based on your pre pregnancy weight. So how much weight you should gain is based on your pre pregnancy weight. And actually more specifically your pre pregnancy BMI. So body mass index body mass index takes into account your weight and your height. You put it into a calculator and it spits out a number and based on that number it classifies you as underweight, normal weight, overweight or obese.

Speaker 1: So if your BMI is less than 18.5 you're considered underweight. And then in that case you should gain between 28 and 40 pounds during your pregnancy. That's the Institute of Medicine recommendation, IOM recommendation. If you're a normal weight where your BMI is between 18.5 and 24.9 then it's recommended that you gain between 25 and 35 pounds. So not that much less than if you're underweight. If your BMI is between 25 and 29.9 you're considered overweight and you should gain between 15 and 25 pounds and if you are obese where your BMI is greater than or equal to 30 then the recommended weight gain is between 11 and 20 pounds, so as you have more weight, then you should gain less weight during your pregnancy.

: The recommendations are slightly different for twins. If you have twins and you need to gain more weight, they actually don't have a recommended weight gain. For someone who is underweight and then what their weight gain should be for twins, there's not enough data to make recommendations, but if you're a normal weight, overweight and obese and you have twins roughly for each of them, you need to gain an additional 20 pounds. That's kind of a rough estimate if you have twins. As I said, these guidelines in 2009 by the IOM at the time, there wasn't necessarily a lot of robust data in order to determine if we needed to make different recommendations for different people. One of the particular criticisms was not having different recommendations for women who are obese because there's something different about women who have a BMI of 30 versus women who have a BMI of 40. I talked about in the last episode about the more weight you have, the increasing levels of complications you have. So it's thought that there should be different recommendations based on your weight as you get above that BMI of 30.

: So in 2019, so just this year there was a study that came out from the Life Cycle Project, maternal obesity in childhood outcome study group and they did another look at data looking at over almost 200,000 pregnancies between Europe and North America to try to get a better sense for what amount of weight gain is associated with lowering the risk of having bad outcomes. And the bad outcomes that they looked at were preeclampsia, gestational diabetes, cesarean birth, preterm birth, and then having a baby that's either too small or too big. And what they found is different than the 2009 Institute of Medicine guidelines. So they found that for underweight women there was a decreased risk or a lower risk of adverse outcomes if they gain between 31 and 35 pounds, that's compared to the Institute of Medicine, which says 28 to 40, so not a huge difference. For normal weight women, they recommend a weight gain of between 22 and 40 pounds. That's actually not that much different from Institute of Medicine. And then overweight and obese is where things start to get a little bit different. So whereas the Institute of Medicine recommends a weight gain at between 15 and 25 pounds, this newer data showed that a weight gain of between just four pounds for overweight women up to 35 pounds was considered.

Speaker 1: Okay. And then for obese women, the weight gain was a lot stricter. So as where's the Institute of Medicine says 11 to 20 pounds, this newer data suggests less than that. So for a BMI of to 34.9 the best outcomes were associated with the weight gain of just four to 13 pounds. If your BMI is 35 to 39.9 a weight gain of just either no weight gain at all up to nine pounds was associated with better outcomes. And then for those with the BMI, greater than 40 a weight gain between zero and 13 pounds was considered associated with better outcomes. So a bit more restrictive than the Institute of Medicine. Another key finding from this newer data is that it was actually pre pregnancy weight or prepregnancy BMI is most strongly associated with whether or not you have adverse outcomes during your pregnancy as opposed to gestational weight gain. So it's really how you start your pregnancy that has a bigger influence on whether or not you have bad outcomes as opposed to how much weight you gain during pregnancy. This is just another reason why we need to do a lot better in our society of helping women be the healthiest that they can when they start pregnancy because that really makes a difference.

: All right, so what exactly happens? What's the relationship between weight gain and pregnancy outcomes? So let's break it down first into weight gain. Above the Institute of Medicine targets and I'm using the Institute of Medicine because even though we have some newer data, we still kind of use that 2009 data in our recommendations. We haven't quite caught up in changing our recommendations yet, so that's sort of an ongoing thing. So gaining weight above the Institute of Medicine targets has been associated with a few things. So it's associated with an increased risk of having it big baby also associated with a higher risk of cesarean birth. It's associated with a higher risk of pregnancy related high blood pressure and also gestational diabetes. Interestingly, gaining more weight than recommended is associated with a lower risk of preterm birth and as you might suspect, a lower risk of having a small baby cause remember it's the opposite. It also is not associated with an increased risk of stillbirth. Now in the postpartum period, also weight gain during pregnancy or excessive weight gain during pregnancy has some implications postpartum and that's because it makes sense if you gain excessive weight during pregnancy, then you have a higher chance of holding onto that weight after you deliver.

: As a matter of some data has shown that for women who gain more weight during pregnancy than the recommended guidelines, about 60% of those women will have an additional 10 pounds postpartum that they hang on to and then another 40% will hold on to an additional 20 pounds and you can see how over time, especially if you have multiple pregnancies, so you have a pregnancy, have some extra weight, have some trouble getting rid of that extra weight and then you go into another pregnancy and then because you gained excessive weight the first time, it puts you at an increased risk of gaining weight excessively the next time and then it sort of can spiral into a problem with obesity as you get older.

Speaker 1: I don't think I'm describing anything that anyone isn't familiar with. I think we've all heard those stories of how that weight gain during pregnancy is hard to get off and how it kind of compounds as you get older and have more babies. As a matter of fact, I'm thinking that I want to have somebody come on and talk about specifically weight loss in the postpartum period. If anybody has any ideas or suggestions for somebody who specializes or focuses on weight loss in the postpartum period, definitely shoot me a DM on Instagram. I'm @DrNicoleRankins on there.

: Okay, so let's talk about the flip side. If you gain weight below the target, so you don't gain enough weight, this is really only a concern for women who start off pregnancy underweight. So if you start off pregnancy underweight and you don't gain enough weight during pregnancy, then you have a higher risk of preterm birth and you have a higher risk of your baby being small. On the flip side, you're going to have a lower risk of your baby being large. That makes sense. And there's no difference in cesarean birth. Now, gaining weight below the recommended guidelines does not have any bad effects for women who are overweight or obese. It doesn't have any negative effects on the baby's growth or anything like that. Based on this newer evidence that we've seen. So we've seen that women who gain as little as four pounds or like I said, even no weight, which is below the Institute of Medicine guidelines, they still have good outcomes. And I'm saying that to say is that you may hear if you are overweight or if you are obese, your Dr. may actually be telling you, you know what, you probably don't need to gain any weight during pregnancy. You just want to focus on kind of maintaining a steady weight during your pregnancy as opposed to gaining any weight. And then as far as not gaining enough weight during pregnancy, obviously that means that after you have the baby, you're less likely to hold on to extra weight. But that's not a reason not to gain weight during pregnancy. You still want to gain the appropriate amount so your baby grows healthy and well.

: So how do we deal with care during pregnancy as it relates to weight gain during pregnancy? Let's back up for a minute and talk about again the preconception. So before you even have a baby, I have to put another plug in that really that's the best opportunity to optimize your weight. Whether you're underweight and actually about 5% of women in the US are underweight before they get pregnant. So if you fall into that category, then ideally you want to get closer to a normal BMI before you get pregnant. So you don't have that risk of having a baby that's too small.

Speaker 1: We know that the flip side is more prevalent in the US about even up to 50% of women are overweight or obese. And in that case you want to focus on just getting as healthy as you can. I talked about it in the last episode, how even just dropping 15 pounds or so can make a huge difference for the outcomes for your pregnancy. So really just optimizing your health as best you can before you get pregnant is key and ideal to having the best pregnancy outcomes.

: Okay, so during pregnancy in the US we monitor weight at every prenatal visit so that we can see or track if you're gaining too much weight. And not enough weight. Are you sorta right on target and then we can make interventions as needed. This is actually not the case everywhere. I believe in the United Kingdom, they only weigh women who they think are at risk for issues for weight gain during pregnancy, so it's not necessarily normal that women get weighed at every single visit.

Speaker 1: Now, what ideally should happen is in the beginning of your pregnancy, we should sit down and we should explain what the ideal amount of weight gain is because it's actually, again, not that much roughly. If you say 30 pounds for normal weight women, when you think about it, when you first get pregnant, you tend to be six, seven weeks along, somewhere around there, maybe a little bit earlier or maybe a little tiny bit later, and a normal pregnancy lasts up to 40 weeks, so between 6 weeks and 40 weeks, that's 34 weeks. If you need to gain a total of 25 pounds, 30 pounds, then you really only need to gain about a pound a week. And if you're overweight or obese, then it really should be less than that. And this should be close to half a pound a week.

: So I'm saying that to say that we have to get rid of that myth of eating for two, that is completely a myth. It only takes an extra 300 calories a day to gain one pound a week, so it's just a little bit of extra and the 300 calories is like an apple and some peanut butter or some cheese and crackers. It's not a whole lot extra that you need to eat in order to maintain a good weight during your pregnancy. And I'm going to talk about nutrition more in another episode of the podcast, Nutrition in Pregnancy. Now, as much as I say that's not that much to gain weight during pregnancy, it's actually hard to do that in practice. When we look at data and we look at where women hit their targets, roughly 32% of women meet the guidelines, the Institute of Medicine guidelines, for weight gain in pregnancy, about 47% of women gain more weight than is recommended in pregnancy. And then 21% of women don't gain enough during pregnancy.

Speaker 1: And it's actually overweight and obese women who are more likely to gain more than what's recommended and underweight women are more likely to not gain enough weight. We think some of that is probably due to OB GYN are not counseling women as well. Not really explaining the importance of weight gain during pregnancy and how to maintain and pace yourself for your weight gain during pregnancy. There's definitely some studies that show that women report that they don't receive much education or any education at all regarding weight gain and pregnancy. So what do we do when women aren't meeting those guidelines for weight gain in pregnancy?

: So I'm going to break it down into women who are overweight and then women who are underweight and I'll start with women who are underweight. So if someone is underweight and they are not gaining enough weight and their weight gain is not adequate, then yeah, we really need to like sit down and think about why. Is it because they have terrible nausea and vomiting so they have trouble eating and keeping the pounds on? Is it because they have an eating disorder? Is it because they have food insecurity and they just have difficulties or trouble getting food? So we need to figure out and make sure that she has access to all of the things that she needs. Sometimes it involves getting a dietician involved to help them understand the types of foods that will help them to gain appropriate weight. Now for underweight women who gain more then the recommended Institute of Medicine guidelines. Then really there's not anything that has to be done. These women are just, I shouldn't say lucky because you know that's not necessarily the case, but if you're a prepregnancy BMI, you're underweight and you gain more than the recommended guidelines, then it typically doesn't end up causing any problems. You'll just have a normal wegiht baby. You don't have the same sort of risk or outcomes as a normal weight or overweight or obese person who gains more then recommended during pregnancy.

Speaker 1: Okay, so let's talk about if you fall into the overweight or obese category and how weight gain or how we manage weight gain during pregnancy. I actually fell into the overweight category myself for my first, but not my second. So if you're overweight or obese and you gain above the Institute of medicine recommendations. Okay, so we see that if you're trucking along and it looks like your weight gain may be excessive, then we just kind of sit down and we say, hey, let's talk about what you're eating. Let's talk about the choices that you're making and try to see if we can prevent the weight gain from getting any worse, so to speak. We certainly do not do anything like dieting or trying to lose weight, anything like that. It's more of if you're gaining too much weight in pregnancy, let's kind of stop, look at everything, maybe see a dietician and kind of see what we can do to keep it from getting any worse.

Speaker 1: That may mean adding an exercise program as well. Nothing major, but again, just to kind of get your body moving. We've tried, there certainly have been lots of studies to try to find the best method to help women limit weight gain during pregnancy or keep it kind of at a steady state. But honestly there hasn't been a lot of success. A lot of good results are good methods that we know are tried and true that help women keep their weight gains steady during pregnancy. I wish I had a better method to report, but unfortunately we just don't have great methods or recommendations. Now what about if an overweight or obese woman gains below the Institute of Medicine recommendations? Now, like I was saying earlier, there's some newer data that shows that if overweight and obese women don't gain as much, so if they gained less than the Institute of medicine recommendations, even as much as like gaining no weight during pregnancy, then it doesn't necessarily have bad outcomes.

Speaker 1: So if it looks like the baby is growing well on ultrasound, things look good. If you're not gaining those Institute of Medicine recommendations, then we don't make any changes. We don't say that, hey, you have to eat more. You have to do some things so you can gain some more weight. Because we've seen that outcomes can still be very good. Even if you fall into the overweight or obese category, there are some doctors who recommend for women who are very obese to even consider losing some weight during pregnancy. The data's kind of mixed on whether or not that's a good strategy. I think really what you should focus on is just kinda holding steady with your weight during pregnancy.

Speaker 1: Okay, so that brings us to the end of this episode. So just to recap, if you are underweight, if your BMI is less than 18.5 then you should gain between 28 and 40 pounds during your pregnancy. If your BMI is between 18.5 and 24.9 that's normal weight, then you should gain between 25 and 30 pounds. If you're overweight and that's a BMI of 25 to 29, there's so many numbers in this episode, then you should gain between 15 and 25 pounds. And if you're obese, then you should gain between 11 and 20 pounds or even less. I would even argue that if you're overweight or obese that you could gain less based on that newer data. You don't have to lose, but you could gain less or not gain any weight at all. Now, although I want you to be mindful of your weight during your pregnancy and your weight gained during your pregnancy, don't obsess over it. I have seen some women who no matter what they do, they just gained 40 pounds. It just kind of how their body works.

: So what you should focus on instead is just overall good habits. So overall eating healthy, not overeating, making good food choices for yourself and these are things that'll prove useful for you, not just during your pregnancy but also after your baby is born. And remember you only need just an extra 300 calories or so a day even less if you're starting off pregnancy overweight and obese. So focus on that overall eating healthy, not so much the number on the scale. If you focus on overall eating healthy, then you're doing the best that you can and then move your body, focus on moving your body, taking a walk during your pregnancy, prenatal yoga also a great thing. So do those things. Do the best you can and just kind of focus on those healthy habits as opposed to the number on the scale. Because like I said, they're just going to be some women who no matter what they do, they're just not gonna gain the weight necessarily that they want to gain or they're going to gain too much.

: Okay, so that is it for this episode. Be sure to subscribe to the podcast in Apple podcast or wherever you listen to podcasts and I would love it if you leave reviews so I can give you a shout out on the show. It also helps the show to grow and helps other women find my show. And don't forget about my free live online class, How to Make a Birth Plan That Works. Go to www.ncrcoaching.com/register for the next class. Checking out my free class is a great way to get a feel for my online childbirth education class, The Birth Preparation Course. That is my comprehensive online class that leaves you knowledgeable, prepared, confident, and empowered for your birth. You can learn more about The Birth Preparation Course at www.ncrcoaching.com/enroll.

: Now next week on the podcast, I'm gonna wrap up this series on weight and guys, I feel like this has been a little bit of a tough one for me. Weight is always a sensitive topic, so I would love your feedback on how you feel like the episode or the information has been for you. I'm trying to present it in a way that's useful for you guys, but gosh, I feel like it's been a little bit tough. Anyway, I'm going to wrap up this series talking about weight by talking about nutrition next week and just kind of some basic facts about nutrition in pregnancy and the nutrients that you need and ideas to meet your nutrition needs during pregnancy. So come on back next week. And until then, I wish you a healthy and happy pregnancy and birth.

Speaker 2: 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, competent, and empowered going into your birth. Head to www.ncrcoaching.com to learn more.