Obesity in pregnancy increases risk of NTDs

Being overweight or obese increases the risk of having a pregnancy affected by neural tube defects, with the risk for severely obese women triple that of normal weight women, according to a review published in the June issue of the American Journal of Obstetrics and Gynecology.

Sonja A. Rasmussen, MD, of the Centers for Disease Control and Prevention in Atlanta, and colleagues conducted a meta-analysis of 12 studies on the relationship between maternal obesity and the risk of neural tube defects (NTDs). Compared to normal weight women, overweight, obese, and severely obese women were 1.22, 1.70, and 3.11 times more likely, respectively, to have a pregnancy affected by NTDs, the researchers found.

“The reasons for this association are unknown. This quantitative estimate of the risk adds to our understanding of the total public health effects of obesity among women of reproductive age and provides additional information for appropriate interpretation of trends in neural tube defects prevalence,” the authors write. “Future assessments of trends in neural tube defects prevalence might benefit from taking into account the effects of the changing prevalence of maternal obesity.”

Rasmussen SA, Chu SY, Kim SY, et al. Maternal obesity and risk of neural tube defects: a metaanalysis. Am J Obstet Gynecol. 2008;198:611-619.