Women who are obese during their pregnancy may nearly double their risk of giving birth to a baby with a spine- or heart-related birth defect, researchers report in the Journal of the American Medical Association.
The study's authors pooled data from many other studies of mothers' weight and baby health to look for weight-related birth defects. They focused on women who were obese before and during pregnancy, defined as having a body mass index over 30 (calculate your BMI here). Those mothers were roughly twice as likely to have a baby with spina bifida or other neural tube defects. Their babies also more likely to be born with heart defects, cleft lips or palates, anal and rectal deformations, hydrocephalus and small or missing limbs. The babies had a lower risk of abdominal wall problems, however.
While the risk was very different, the researchers stressed that the change was not big in absolute terms. It would add a neural tube or serious heart defect to about 1 in every 2,000 babies born to obese women. Since about a third of childbearing women are obese, however, that would add up over the population. And the study implies that obese women who slim down before getting pregnant may be able to limit risk to their babies, though more studies of the weight-birth defect link are needed to see if this is true.
- Andy Dworkin, firstname.lastname@example.org