RESTON, Va., Feb. 3 - Obesity should be classified as a pregnancy risk factor alongside smoking, drinking alcohol, and an insufficient intake of folic acid, according to recommendations issued today by the Teratology Society here.
The recommendations suggest that obese women who intend to become pregnant be given counseling about the health risks that obesity may pose to their developing child.
For example, a review of the literature suggests that the infants of women with a body mass index of 30 or greater have about double the risk of neural tube defects, said Anthony R. Scialli, M.D., of Sciences International in Alexandria, Va.
This increased risk can not be explained by folic acid intake or maternal diabetes, Dr. Scialli and co-authors said in a position paper from the society published online today by Birth Defects Research Part A: Clinical and Molecular Teratology.
Infants of obese women are also at greater risk for other congenital abnormalities, including macrosomia and shoulder dystocia, the authors added.
In addition, obese women have a greater risk of infertility and pregnancy complications, including hypertensive disorders, gestational diabetes, thromboembolic events, and the need for cesarean birth, they said.
Despite these risks, obese women who are pregnant should not attempt a diet or other weight-loss program, the recommendations said, because this is likely to cause inadequate intake of calories and nutrients necessary for a healthy pregnancy. Rather, the authors suggested that these women should be offered prenatal testing for congenital abnormalities.
Ideally, obese women should be counseled to lose weight and successfully do so before becoming pregnant, the authors said. "Weight-loss programs are best completed prior to conception, and pregnancy avoidance can be counseled for women who are dieting," they wrote.
The recommendations did not endorse bariatric surgery for obese women intending to become pregnant, but the authors noted that recent evidence suggests that weight-loss surgery improved pregnancy outcomes.
"Because some weight loss procedures can result in nutritional deficiencies, it appears reasonable to recommend that pregnancy be delayed until surgery-related weight loss has stabilized," they added.
Among women ages 20 to 39, 54.5% are overweight and 29.1% are obese, according to National Health and Nutrition Examination Survey (NHANES) data from 1999-2002, the recommendations noted.
Counseling about the importance of appropriate caloric intake and exercise during pregnancy should receive similar emphasis to the advice about the risks of smoking, alcohol, and insufficient folic acid intake that clinicians routinely make to women who intend to become pregnant, the authors said.
Finally, breast feeding should be encouraged because of evidence that it protects against childhood obesity as well as confers other health advantages, the recommendations stated.