OBJECTIVEDietary factors that could potentially be related to the risk of birth defects are still unknown in Shanxi province, a region with high prevalence of neural tube defects(NTDs) in China. The main aim of this study was to evaluate the association between NTDs and local dietary factors.

METHODSA population-based case-control study was conducted during 2003-2005 in four selected counties of Shanxi province with 363 NTDs cases ascertained and 523 control babies without any external birth defects.

RESULTSBy multivariate logistic regression analysis, we found the NTDs risk was significantly associated with low consumption of meat and legume, high consumption of pickled vegetables, noncentralized supply of drinking water and drinking tea after adjusting for maternal education level and birth defects history. A significant dose response trend was found between the NTDs risk and the lower frequencies of meat and legume consumption and higher frequency of pickled vegetable consumption, with population attributable risks (PAR) of 69.4%, 22.0% and 18.5%, respectively. Mothers who got their drinking water from river or pond during periconceptional period were more likely to have a NTD-affected pregnancy [OR = 3.42, 95% CI: 1.44-8.09, population attributable risk (PAR) = 4.7%] compared with those who utilized tap or well water. Those who drank tea everyday had an elevated risk of having a NTD-affected pregnancy compared with those who didn't (OR = 4.65, 95% CI: 1.41-15.36, PAR = 2.6%).

CONCLUSIONHigher intake of meat and legume protects a woman from having a NTD-affected pregnancy, and consumption of pickled vegetables, drinking water from river or pond and drinking tea everyday increase the risk of having such a pregnancy in the study population.