NIH-supported research provides a broader understanding of the manifestations of cardiovascular disease risk after pregnancy.
Body mass index, adverse pregnancy outcomes, and risk of cardiovascular disease Background: Obesity is a well-established risk factor for both adverse pregnancy outcomes (APO) and cardiovascular diseases (CVD). However, it is not known whether APOs are mediators or markers of the obesity-CVD relationship. This study examined the association between body mass index, APOs, and postpartum CVD risk factors. Methods: The sample included adults from the nuMoM2b Heart Health Study (Nulliparous Pregnancy Outcomes Study: Follow-up of Expectant Mothers) who were enrolled in their first trimester (6 weeks to 13 weeks and 6 days of gestation) from 8 sites in the United States. . Participants had a follow-up visit 3.7 years after delivery. Adverse pregnancy outcomes ( APOs), including hypertensive disorders of pregnancy, preterm birth, small-for-gestational-age birth, and gestational diabetes, were centrally adjudicated. Mediation analyzes estimated the association between early pregnancy body mass index and postpartum CVD risk factors (hypertension, hyperlipidemia, and diabetes) and the proportion mediated by each APO adjusted for baseline demographics and health behaviors, psychosocial stress factors and levels of CVD risk factors. Results Among the 4216 enrolled participants, mean ± SD maternal age was 27 ± 6 years. The prevalence of overweight in early pregnancy was 25% and obesity 22%. Hypertensive disorders of pregnancy occurred in 15%, preterm birth in 8%, small for gestational age birth in 11%, and gestational diabetes in 4%. Obesity early in pregnancy, compared with normal body mass index, was associated with a significantly higher incidence of postpartum hypertension (adjusted odds ratio, 1.14 [95% CI, 1.10–1.18]), hyperlipidemia (1.11 [95% CI, 1.08–1.14]) and diabetes (1.03 [95% CI, 1.01–1.04]) even after adjustment for baseline levels of risk factors. risk of CVD. APOs were associated with a higher incidence of postpartum hypertension (1.97 [95% CI, 1.61–2.40]) and hyperlipidemia (1.31 [95% CI, 1.03–1.67]). ). Hypertensive disorders of pregnancy mediated a small proportion of the association between obesity and incident hypertension (13% [11%-15%]) and did not mediate associations with incident hyperlipidemia or diabetes. There was no significant mediation by preterm birth or small for gestational age birth. Conclusions: There was heterogeneity among adverse pregnancy outcome (APO) subtypes in their association with postpartum CVD risk factors and mediation of the association between early pregnancy obesity and postpartum CVD risk factors. However, only a small or non-significant proportion of the association between obesity and CVD risk factors was mediated by any of the APOs, suggesting that APOs are a marker of CVD risk before pregnancy and not a predominant cause of postpartum CVD risk. |
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Being obese before and during early pregnancy appears to be a strong risk indicator for developing future cardiovascular disease and was significantly associated with adverse pregnancy outcomes, such as high blood pressure, preeclampsia, and gestational diabetes, according to a study published in Circulation Research . which was funded by the National Institutes of Health.
Researchers know that obesity is a risk factor for cardiovascular disease and blood pressure-related pregnancy complications. However, they didn’t know which factors—obesity or pregnancy complications—played a larger role in influencing a person’s risk of cardiovascular disease years after pregnancy.
Although adverse pregnancy outcomes were associated with an increased risk of cardiovascular disease during pregnancy, complications accounted for a small percentage of the increased risk of cardiovascular disease in the years after pregnancy for people with obesity.
“We are finding that certain pregnancy complications are unmasking and then increasing the risks of cardiovascular diseases, such as obesity, that were already present. “This study provides information about the potential timing for interventions in overweight or obese people who are considering pregnancy,” said Victoria L. Pemberton, RNC, study author and researcher in the Division of Cardiovascular Sciences at the National Heart Center. the Lungs and the Blood. Institute (NHLBI), part of NIH.
Researchers analyzed data collected from the nuMoM2b Heart Health study from more than 4,200 new mothers, about half of whom were overweight or obese. They compared the participants’ pregnancy experience with their health two to seven years later. They found that mothers who were overweight or obese during the first trimester of pregnancy had about twice the risk of developing gestational diabetes or having a pregnancy complicated by high blood pressure, compared to participants with a normal body weight. These mothers also had higher risks of developing cardiovascular disease after pregnancy.
In comparison, pregnancies complicated by high blood pressure explained only 13% of the future risks of developing high blood pressure if a person was obese. Likewise, gestational diabetes explains only 10% of future diabetes risks.
"We want to do everything we can to support a person’s heart health, but especially during pregnancy: before, during and at the beginning of pregnancy," said Sadiya S. Khan, MD, the study’s principal investigator, a preventive cardiologist. and associate professor of medicine at Northwestern University Feinberg School of Medicine in Chicago. "That includes achieving and maintaining a healthy body weight, knowing your heart health numbers, and finding ways to stay physically active."
For some complications, the researchers found that body weight does not influence the risks. For example, people who were overweight or obese did not have increased risks of having a premature birth or a low birth weight baby. Additionally, the researchers found that among all participants, those who had premature births had higher risks of having high blood pressure, high blood sugar, or high cholesterol a few years after pregnancy. Having a low birth weight baby was not found to increase the risks.
"Looking for ways to support and optimize a person’s cardiovascular health remains of utmost importance if someone has had an adverse pregnancy outcome," Khan said. "However, if we really want to make a difference in improving cardiovascular health and preventing these pregnancy outcomes, we need to move into the pre-pregnancy and early pregnancy space."
