Maternal periconceptional consumption of pickled vegetables and risk of neural tube defects in offspring

Background Maternal exposure to nitrate, nitrite, and N-nitroso compounds from drinking water or diet has been associated with an increased risk of neural tube defects （NTDs） in some studies. Pickled vegetables contain relatively large amounts of nitrite and N-nitroso compounds. We examined the association between maternal periconceptional consumption of pickled vegetables and NTDs in Shanxi Province of northern China. Methods Data were derived from a population based case-control study of major external birth defects in four counties of $hanxi Province. Participants included 519 NTDs cases identified between 2003 and 2007 and 694 healthy controls. Exposure information was collected within 1 week after delivery. Multivariable non-conditioanal Logistic regression model was used to estimate the adjusted odds ratio （OR） controlling for potential confounding variables.