Obesity Before Pregnancy Puts Women and Infants at Risk

NEW YORK (MedscapeWire) Feb 27, 2002 — A new report says that simply losing weight and being in shape before pregnancy could increase both maternal and infant health.

The March of Dimes Task Force on Nutrition and Optimal Human Development presented a report on Monday showing that women who are overweight or obese are 30% to 40% more likely to deliver a baby with a major birth defect such as those that affect the brain, heart, and digestive system.

"It's an area where weight matters more than we think," says Richard Deckelbaum, MD, chairman of the task force and director of the Institute of Human Nutrition at Columbia University in New York City. "People don't really understand the effect on the babies."

He says it's more difficult for women to get pregnant when they are overweight, and if pregnancy does occur, the risk of complications during pregnancy and problems for the baby after birth increase dramatically.

Overweight was defined as being 10% to 15% heavier than recommended for a woman's height, or having a body mass index (BMI) of 25 to 30. Obese was having a BMI of 30 or more.

The report shows overweight or obese women are at increased risk of having complications during pregnancy such as gestational diabetes, preeclampsia or eclampsia, and hospitalization. "The risk of the mother being hospitalized during pregnancy goes up 4 times if she's overweight. If her BMI is over 35, the risk goes up by 6 to 7 times," says Deckelbaum. The risk of perinatal mortality also increases as maternal BMI increases. Deckelbaum says most doctors -- as well as their patients -- are unaware of this connection even though the risks are well documented by research. He says the public seems to understand the importance of other things women can do to ensure a healthy pregnancy and baby, such as folic acid supplementation, but the message about being in shape before pregnancy has been lost.

In light of the US surgeon general's declaration that the country is facing an "epidemic of obesity," experts agree that pregnancy problems associated with maternal overweight and obesity will increase. According to the task force, the percentage of women aged 20 to 29 years who are obese has more than doubled from 7% in 1960-1962 to 17% in 1988-1994.

"It's an issue that's going to grow in importance," says Martha Werler, ScD, associate professor in the school of public health at Boston University in Massachusetts. Werler was the author of a 1996 study, published in The Journal of the American Medical Association, that found women who were overweight before pregnancy were more likely to have children with neural tube defects, including spina bifida.

"There are definitely pregnancy complications that come with obesity," says Werler.