Maternal obesity and the risk of neural tube defects in offspring: A meta-analysis

Objectives: The aim of this was to access maternal obesity and the risk of neural tube defects (NTDs) in offspring, and establishes a nonlinear dose-response relationship between maternal body mass index (BMI) and risk of NTDs in offspring. Methods: PubMed and Web of Science were systematically searched. We compared NTDs risk difference in maternal obesity group vs. normal weight group + overweight group, and maternal obesity group vs. normal weight group. We also examined the dose-response relationship between maternal body mass index and the risk of NTDs in offspring. Results: A total of 22 studies with 1,758,832 patients included in the meta-analysis. The results showed obesity maternal obesity is an important risk factor for NTDs in offspring. When maternal obesity group compared with normal weight group + overweight group, the summary OR of NTDs was 1.632 (95% CI 1.473-1.808; Z = 9.37, P < 0.00001); when maternal obesity group compared with normal weight group, the summary OR was 1.682 (95% CI 1.510-1.873; Z = 9.44, P < 0.00001). No publication biases were found. Dose-response meta-analysis showed statistically significant association between maternal BMI and risk of NTDs in offspring (model chi(2) = 41.49, < 0.00001). In linear model, the OR of NTDs in offspring was 1.040 (95% CI 1.027-1.051) for every 1 kg/m(2) BMI increase in mother. In spline model, the OR of NTDs in offspring risk increased rapidly along with maternal BMI, especially when BMI >30 kg/m(2). Sensitivity analyses by only included the studies reported adjusted OR showed the result was robust. Conclusion: Our meta-analysis indicated that maternal obesity is an important risk factor for neural tube defects in offspring. (C) 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.