Obesity Raises Pregnancy Complications and Cardio Risk

Obesity during and during early pregnancy appears to be a powerful predictor of future cardiovascular disease and has been associated with unfavourable pregnancy outcomes such as high blood pressure, preeclampsia, and gestational diabetes, according to a study.

The findings of the study, which was supported by the National Institutes of Health, were published in Circulation Research. Obesity has long been recognised as a risk factor for cardiovascular disease and pregnancy difficulties caused by high blood pressure. They didn't know which factors influenced a person's cardiovascular disease risk years after pregnancy - obesity or pregnancy problems.

While having adverse pregnancy outcomes was linked with increased cardiovascular disease risks during pregnancy, the complications accounted for a small percentage of increased cardiovascular disease risks in the years following pregnancy for people with obesity.

"We're finding that certain pregnancy complications are unmasking and then increasing cardiovascular disease risks, such as obesity, that were already present. This study provides insight into potential timing for interventions for people with overweight or obesity who are thinking about pregnancy," said Victoria L Pemberton, RNC, a study author and researcher in the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute (NHLBI), part of NIH.

The researchers analyzed data collected from the nuMoM2b Heart Health Study of more than 4,200 first-time mothers - about half of whom were overweight or obese. They compared the participants' pregnancy experience to their health two to seven years later.

They found mothers who were overweight or had obesity 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 normal body weight. These mothers also had increased risks of developing cardiovascular disease risks after pregnancy.

In comparison, pregnancies complicated by high blood pressure explained just 13 per cent of future risks for developing high blood pressure if a person is obese. Likewise, gestational diabetes explained only 10 per cent of future risks for diabetes.

"We want to do everything we can to support a person's heart health, but especially around the time of pregnancy - before, during, and in early pregnancy," said Sadiya S. Khan, MD, the study's lead investigator, a preventive cardiologist, and an associate professor of medicine at Northwestern University Feinberg School of Medicine, 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 body weight did not factor into risks. For example, people with overweight or obesity did not have increased risks of having a preterm birth or a baby with a low birthweight.

Additionally, researchers found among all participants, those experiencing preterm births had increased risks of having high blood pressure, high blood sugar, or high cholesterol a few years after pregnancy. Having a baby born with a low birth weight wasn't found to increase risks.

"Looking for ways to support and optimize a person's cardiovascular health is still of the utmost importance if someone has had an adverse pregnancy outcome," said Khan.

"However, if we really want to make a difference in improving cardiovascular health and preventing these pregnancy outcomes, we have to shift to the pre-pregnancy and early pregnancy space."