Obese Mothers are Twice as Likely to Have a Baby with Congenital Heart Defects

Obesity doesn’t just increase health risks for the mother, based on a recent study that found obese pregnant women are twice as likely to have babies with serious congenital heart defects. Findings were published in the Journal of the American College of Cardiology and highlight the importance of maintaining a healthy weight before pregnancy.

Using a national health registry in Sweden, this study analyzed data from more than 2 million births between 1992 and 2012. The goal was to see whether maternal weight has any impact on a baby’s risk for congenital heart defects.

Congenital heart defects refer to problems with the heart that are present at birth. They’re the most common type of birth defect and affect roughly 8 in 1,000 births. Studies suggest that congenital heart defects are more common in babies with overweight or obese mothers. However, data is sparse, and the association remains unclear, according to authors.

In the recent analysis, researchers found that serious heart defects occurred in 1.4% of 2,050,491 Swedish births. Complex heart defects included a number of conditions including tetralogy of Fallot, transposition of the great arteries, atrial septal defects, aortic arch defects and single-ventricle heart.

After analysis, researchers found that severely obese women were twice as likely to have babies with congenital defects compared to women who were a healthy weight. Overall, risk of certain defects increased with maternal weight, suggesting that the more overweight or obese women are, the greater the risk of having a baby with a congenital heart defect.

In this study, researchers categorized women as normal, overweight or obese based on their first prenatal exam. As authors explain, the appointment usually occurs early enough in pregnancy and provides a general idea of women’s pre-pregnancy weight. In this study, obesity was defined as having a body mass index (BMI) of 30 kg/m² or greater, while severe obesity was defined as a BMI greater than 35 kg/m².

What findings show, according to authors, is that risk of having a baby with congenital heart defects increases with obesity. This is a finding that is especially concerning, given drastic rises in obesity rates over the years.

Obesity is generally considered the most important preventable risk factor for pregnancy complications. In Sweden alone, the proportion of pregnant women with obesity nearly doubled between 1992 and 2014. Experts worry about the potential impact of maternal obesity on pregnancy outcomes, such as congenital heart defects.

With additional research, authors hope to better understand the association between obesity and pregnancy outcomes. Authors also emphasize the importance of maintaining a healthy weight, especially for women considering getting pregnant. Achieving a healthy weight before pregnancy can help reduce risk of complications and promote better health for the baby.