Overweight and obese women suffer more pregnancy complications and their babies have more medical problems at birth, according to a position paper of the Public Affairs Committee of the Teratology Society.

Among women aged 20 to 39, more than half are overweight and nearly a third are obese, and they face increased risk of infertility and problems during pregnancy, including hypertension, gestational diabetes and thromboembolic events and are more likely to need a cesarean section, the committee said.

One French study found that overweight women had higher prenatal medical costs, and spent more time in the hospital recovering from childbirth. In addition, the babies of obese mothers are more likely to be admitted to neonatal intensive care units. They also have a higher incidence of neural tube defects.

"The literature suggests that compared to normal weight women, women whose body mass index (BMI) is greater than or equal to 30 have approximately double the risk of having an affected child," according to the Public Affairs Committee. The increased risk cannot be explained by folic acid intake, or by maternal diabetes.

"The Public Affairs Committee views obesity as a pregnancy risk factor and supports the public health initiatives identified by the FDA and the research initiatives identified by the NIH," the Committee writes. The national agencies are addressing the problem of obesity and acknowledging pregnancy as an important subject of further study.

The paper suggests that weight reduction efforts should be made well before conception is attempted, and dieters should avoid pregnancy. "Adequate nutrition is important for pregnant women and women planning pregnancy," the paper says. The committee recommends that clinicians counsel pregnant women about appropriate caloric intake and exercise.

The committee also recommends that all parents be educated about appropriate childhood nutrition, including the value of breastfeeding, which has been shown to have a protective effect against childhood obesity.

"Prevention of childhood obesity is expected to be important in the prevention of obesity during the reproductive years," the paper concludes.

Other sources: Teratology Society