Declining Heart Health in Most Pregnant Women with Sadiya Khan, MD, and Natalie Cameron, MD

Erin Spain, MS: This is Breakthroughs. A podcast from Northwestern University Feinberg School of Medicine. I'm Erin Spain, host of the show. One of the many changes to a woman's body during pregnancy is the extra burden put on her heart and blood vessels. Changes like extra blood circulation requires her heart to work harder. This can create a challenging situation for many pregnant women in America. That's because about 60 percent of women in the U.S. have poor heart health before becoming pregnant. That's according to a new Northwestern Medicine study published in the journal Circulation. Study authors Sadiya Khan and Natalie Cameron join me to share results of the study and what can be done to help more women protect their heart health before, during and after pregnancy. Dr. Khan is a Feinberg assistant professor of medicine in the Division of Cardiology, and Dr. Cameron is an internal medicine specialist and instructor of medicine here at Feinberg. Welcome both of you to the show. Dr. Khan, tell me about this special issue of circulation where this study is published.

Sadiya S. Khan, MD, MSc: It's really exciting that we were able to have our work in this themed issue for the Go Red for Women campaign. This campaign was developed by the American Heart Association in 2004, particularly to raise awareness about heart disease risk in women, which is the leading cause of death for women.

Erin Spain: What are the common heart conditions seen in pregnant women and which are the most serious?

Sadiya S. Khan, MD, MSc: Many new conditions can develop during pregnancy because of the extra stress put on one's heart. Oftentimes pregnancy is referred to as nature's stress test for women. High blood pressure, diabetes and other complications such as heart attack, stroke or heart failure, can develop for the first time in previously healthy young women.

Erin Spain [00:02:06] But there are many women who already have at least a few risk factors. Tell me about those and what are the most common?

Sadiya S. Khan, MD, MSc: Risk factors that develop before pregnancy are likely to increase risk for experiencing complications during pregnancy. These are common risk factors like having extra weight, being overweight or having obesity, having high blood pressure or even pre hypertension, or diabetes or prediabetes.

Erin Spain: So there is a thing that we call optimal heart health. What is that? And what is it for pregnant women and why is it so important that pregnant women try to reach that optimal heart health before becoming pregnant?

Sadiya S. Khan, MD, MSc: Having optimal heart health includes maintaining a healthy weight and not having hypertension or diabetes. And part of the reason that it's so important to optimize heart health before becoming pregnant is because oftentimes the risk of pregnancy begins even before conception. Risk factors such as obesity, hypertension or diabetes can even affect the placenta, one of the earliest changes happening during pregnancy, before someone might even know that they're pregnant.

Erin Spain: Dr. Cameron, cardiovascular disease is the leading cause of pregnancy related deaths in the U.S. and the number of these deaths has gradually increased since the 1980s. And according to data from this recent study published in "Circulation," there is no sign of this trend slowing down. What did the study find?

Natalie A. Cameron, MD: In our study, we defined favorable cardiometabolic health as entering pregnancy with a normal weight, not having diabetes and not having high blood pressure. We then looked at the percentage of women who entered pregnancy with favorable cardiometabolic health overall, and then also in each U.S. state from 2016 to 2019. And what we found was that only about 40% of women entered pregnancy with favorable cardiometabolic health - so having a normal weight, no diabetes and no high blood pressure. And there were also substantial differences among U.S. states. From 2016 to 2019, the percent of women entering pregnancy with favorable health declined by about a total of 3%, about 1% per year, which we actually found pretty concerning because if we continue along that trend, it's just going to be less and less women entering pregnancy with favorable health.

Erin Spain: What was the geographical differences?

Natalie A. Cameron, MD: There, in general, was a lower percentage of individuals who entered pregnancy with favorable cardiometabolic health in the Southern and Midwestern states compared to the Northern and Western states. And specifically it ranged from about 30% of women in Mississippi to about 50% in Utah.

Erin Spain: Was there a difference in ages when it comes to maternal age?

Natalie A. Cameron, MD: Oh, that's a really great question. So we did break it down by different age groups for women entering pregnancy. And, unfortunately, even among women who are about 30 to 34 years old, and even younger in their twenties, only about 42% of them entered pregnancy with favorable cardiometabolic health - so really not that different from women who were in their forties.

Erin Spain: There used to be a theory out there that because women were having children a little bit older, that that was kind of driving some of these numbers, but that's not the case.

Natalie A. Cameron, MD: Not the case, no. We've done a lot of work in this area, actually breaking down trends in cardiometabolic health and adverse pregnancy outcomes in different age groups and we keep finding that there have been increases in adverse pregnancy outcomes and worsening cardiometabolic health prior to pregnancy in all age groups.

Erin Spain: Now, you talked about this drastic difference in geography. So, what's going on in Utah versus Mississippi that you would tell the numbers are so much better than Mississippi?

Natalie A. Cameron, MD: We were alarmed about the geographic differences as well. So, in our study, we looked at two factors that may be related to these geographic differences. We looked at educational status and health insurance. So, in general, we found that in states with lower percentages of women with favorable cardiometabolic health, there tended to be more women with less than a high school education and more women on Medicaid during their pregnancy. Maybe these are two factors that are contributing to these state level differences, but there's a lot of other factors that may be at play. And these would most likely relate to upstream determinants of health that have to do with, like, social, economic and policy-level factors. We didn't have the data in our study to specifically look at all of those different factors.

Sadiya S. Khan, MD, MSc: One of the reasons that we were so interested in looking at the state level was we know, with the rising maternal mortality crisis, that individual states have put together state maternal mortality boards, where, at the state level, groups are reviewing and assessing rates of maternal death and pregnancy related death. So we're really hoping that this is informative and helpful to those public health groups that are looking at this at the state level and trying to understand why their rates are high or what are potential ways to address it.

Erin Spain: Being overweight or obese was the most common reason for poor heart health before pregnancy. That's what you found. And the obesity epidemic is so difficult to address, not only here in the U.S., but other westernized countries with similar diets. Is there anything that women can do once they're pregnant to reduce the risk, even if they are overweight or obese? Does eating a better diet or exercise during pregnancy make an impact on their risks, or is the damage already done?

Natalie A. Cameron, MD: During pregnancy, eating a healthy diet, reducing sugary food and salty foods will help you prevent getting diabetes and high blood pressure during pregnancy, even if you enter pregnancy with excess weight. And staying active during your pregnancy too, will also help reduce your risk of those conditions as well.

Erin Spain: Dr. Khan, it's not just the mother that we're concerned about. It's the babies too. Poor maternal heart health is related to poor outcomes for babies at birth too. Tell me about that.

Sadiya S. Khan, MD, MSc: Absolutely. We've been talking a lot about the complications that can happen during pregnancy, like high blood pressure or diabetes. These can affect the baby as well. So babies that are born to mothers with poor heart health are more likely to be born at a low gestational weight - so having a low birth weight - or maybe born early. Both of these can have long-term impact on that child's health and development throughout their life.

Erin Spain:Tell me a little bit about the data and how you collected it and looked at it. Where did it come from?

Natalie A. Cameron, MD: Sure. So we use data from the CDC natality files, which contains information on all live births in the United States. The data is obtained from birth certificates, which contain information on both maternal and infant health, both before pregnancy, during pregnancy, and then at delivery. The data itself was collected by the attendant at birth who got information from the mother and also from chart review.

Erin Spain: Dr. Khan, something important to bring up is that Black women are over three times more likely than white women to die of cardiovascular related pregnancy complications. Tell me about this disparity. How is it currently being addressed?

Sadiya S. Khan, MD, MSc: This is a really important part of the maternal health crisis and, unfortunately, is one that has been longstanding. In fact, this is one that has been persistent for hundreds of years in the United States. And unfortunately we haven't seen much change in recent years. In fact, we've seen increasing rates of maternal mortality, or death related to pregnancy, in recent years in the United States. And it's one of the only countries in the world where we're seeing increasing rates. On top of that, Black women face an even higher risk of dying during pregnancy. And it can be up to three to four times higher during pregnancy. There are many reasons why this may be the case, particularly structural or systemic barriers, such as racism, less likely to have health insurance, or more likely to have pain or symptoms disregarded, and being treated unfairly, importantly.

Erin Spain: Tell me about some of the work that the American Heart Association is doing to address this disparity.

Sadiya S. Khan, MD, MSc:  The American Heart Association is really focusing on policy approaches to improve maternal health outcomes and has really put together a concerted effort, publishing a call to action around maternal health and saving mothers that was published earlier this year in "Circulation." A large proportion of maternal deaths are related to cardiovascular disease, and even more complications, such as severe maternal morbidity complications that happen during pregnancy, are associated with heart health prior to pregnancy or before pregnancy. So focusing on provider education, better reporting prevention, education, and awareness, and funding research such as this, to make sure that we can better understand what steps are needed to be taken to improve heart health equitably across the nation.

Erin Spain: We talked about, some of these conditions can appear during pregnancy and some of them could become lifelong conditions for these women. Is that right?

Sadiya S. Khan, MD, MSc: That's a great question. We know that maternal health during pregnancy can be linked to heart health years down the road. And so, while having high blood pressure during pregnancy like preeclampsia or having gestational diabetes used to be thought of as just a pregnancy specific problem, we now know that it can be linked to health problems down the road. And a lot of times pregnancy is referred to as a window to future cardiovascular health. We know that women who have high blood pressure during pregnancy, even if it resolves, are much more likely to develop hypertension or high blood pressure five to 10 years after the delivery.

Erin Spain: Dr. Khan, how can society better support mothers and pregnant women to achieve optimal heart health?

Sadiya S. Khan, MD, MSc: One of the most important parts of this research is to try to understand what the structural and societal and community supports that are needed so that we can support pregnant and young mothers. We know that there are significant gaps in providing resources for having available green spaces to be able to do physical activity, having access to healthy foods while providing education and awareness about heart health on the individual level is important. We know that there are larger policy level changes that are needed to be able to support this for all women.

Erin Spain: The American Heart Association does make a big point that people should know their numbers, right? Is that true also before going into pregnancy? And you talked about this a little bit already, but what are those numbers that people should remember or that should be top of mind when they're trying to get in optimal shape for pregnancy?

Natalie A. Cameron, MD: So the American Heart Association identifies seven health factors and behaviors that they use to measure cardiovascular health. So, those include your weight, if you have diabetes, high blood pressure, your cholesterol, and whether or not you use tobacco as well as your diet and physical activity levels. So the numbers that you can be really aware of is your weight, which is standardized with the body mass index. So something between about 18.5 and 24.9 is ideal. Staying below 30 keeps you out of that obese category. For blood pressure, you want to be below, about, you know, 130 over 80 or so. And then for diabetes, you want to make sure you get your sugar checked. There's a lot of different ways to check for diabetes so I'd talk to your doctor about that. But those are really the numbers that you should be aware of. In terms of physical activity and diet, you want to try to get it about 150 minutes of physical activity where you're getting your heart pumping in about a week. So that's about 30 minutes a day.

Erin Spain: You suggest people should work with their physician before they get pregnant if they know that that's something that's going to be in their future and what the next six months to 12 months. How far in advance should someone start preparing if they do have some of these risk factors?

Natalie A. Cameron, MD: I would encourage women to get to their primary care doctor or whoever they see really for their general care, as soon as they can. The younger you start, the better. We know that heart health early in life is linked to heart health later in life. So optimizing risk factors early as possible is really ideal. And, you know, if you do have these risk factors like obesity or diabetes or high blood pressure, it takes time to manage these conditions. We're really trying to start lifestyle changes and forming new habits can take a very long time and, um, we want to start as early as possible.

Erin Spain: Thank you so much, Dr. Cameron and Dr. Khan for coming on the show and explaining this new research to us. We really appreciate it.

Sadiya S. Khan, MD, MSc: Thank you for having us.

Natalie A. Cameron, MD: Thank you so much.

Erin Spain: Thanks for listening and be sure to subscribe to this show on Apple Podcasts or wherever you listen to podcasts and rate and review us. Also, for medical professionals, this episode of Breakthroughs is available for CME credit. Go to our website, feinberg.northwestern.edu, and search CME.