Maternal and paternal occupational exposure to agricultural work and the risk of anencephaly.

Aims: To evaluate the association between parental occupational exposure to agricultural work and the risk of anencephaly in three Mexican states. Methods: A paired case control study (1:1) was done based on records of the Epidemiological Surveillance System of Neural Tube Defects in Mexico; 151 cases of anencephaly of more than 20 weeks’ gestation were selected between March 2000 and February 2001. Controls were selected from the same maternity services as those of the cases and were born alive without congenital malformations. Information was obtained from both parents by means of a general questionnaire, a food frequency questionnaire, and a specific questionnaire on occupational exposur…