Obese Pregnancy Ups Kids Heart Risk

BETHESDA, Md.The more obese a woman is when she becomes pregnant, the greater the likelihood that she will give birth to an infant with a congenital heart defect, according to a study conducted by researchers at the National Institutes of Health (NIH) and the New York state Department of Health.

The researchers found, on average, obesity increases a womans chance of having a baby with a heart defect by around 15 percent. The risk increases with rising obesity. Moderately obese women are 11 percent more likely to have a child with a heart defect, and morbidly obese women are 33 percent more likely.

Researchers analyzed data in the New York State Congenital Malformations Registry, a repository of case reports on children born with birth defects in New York state, excluding New York City. Using 1.53 million births that took place in the state over the course of 11 years, the researchers compared the records of mothers of 7,392 of children born with major heart defects to those of more than 56,000 mothers of infants born without birth defects.

 The researchers calculated the mothers body mass index (BMI), and found obese mothers were 15-percent more likely than mothers with normal BMI to have children with heart defects. Women classified as morbidly obesewith a BMI of 40 or higherwere 33 percent more likely than women with normal BMI to have children with heart defects. The risk of heart defects increased sharply at a BMI of 30 and was progressively higher with each increase in BMI.

On average, women who were overweight, but not obese had no increased risk. However, the researchers saw the chances of having a child with a congenital heart defect increase for obese women, and increase sharply for morbidly obese women.

"The current findings strongly suggest by losing weight before they become pregnant, obese women may reduce the chances that their infants will be born with heart defects," said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that conducted the study.

In a press release, NIH noted previous studies have shown obesity also increases the risk for pregnancy-induced hypertension, preeclampsia (a serious form of hypertension during pregnancy), gestational diabetes and cesarean delivery. Infants born to women who were obese during pregnancy are themselves at increased risk for overweight and type 2 diabetes later in life. Previous research by NICHD scientists and others has also shown an association between maternal obesity and birth defects, such as neural tube defectsserious malformations of the spinal column.

The findings were published online in the American Journal of Clinical Nutrition.