Earlier studies have found higher risks for neural tube defects (NTDs) among infants of obese women. With increasing obesity prevalence, it is important to know if this relation is true in recent years. We examined self-reported maternal pre-pregnancy body mass index (BMI) (kg/m2) and NTDs in infants born during 1993-1997 in Atlanta to underweight (BMI < 18.5), average weight (BMI 18.5-24.9), overweight (BMI 25-29.9), and obese women (BMI ³30). We studied 44 infants with NTDs (12 with anencephaly, 22 with spina bifida, and 10 with encephalocele) and 340 control infants without birth defects. After adjusting for maternal race, age, education, smoking, alcohol use, fever, dieting, and periconceptional vitamin use, we found that obese women were more likely than average weight women to have an infant with anencephaly or spina bifida (ASB) (odds ratio [OR]=4.8, 95% confidence interval [CI] 1.8-12.9). The OR for ASB was 1.2 (95% CI 0.4-4.1) for underweight women and 1.6 (95% CI 0.6-4.1) for overweight women. The OR for obese women was higher for spina bifida (OR=7.1, 95% CI 2.3-21.6) than for anencephaly (OR=2.9, 95% CI 0.7-12.8) and was not elevated for encephalocele (OR=1.0, 95% CI 0.2-4.9). The five-fold increase in ASB risk among obese women was higher than that in previous studies, and if confirmed, is of concern, especially given increasing obesity prevalence. If the relation is causal, 79% of ASB among obese women and 9% of ASB in the general population may be due to maternal obesity.
Learning Objectives: To identify the magnitude of the risk for neural tube defects (NTDs) among infants of obese women and to describe the importance of this finding given the rising obesity prevalence
Keywords: Birth Defects, Obesity
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.