Maternal occupational and hobby chemical exposures as risk factors for neural tube defects

In a case control study, we investigated whether occupational and nonoccupa tional (hobbies) chemical exposures to women in the periconceptional period increased their risk for having neural tube defect-affected pregnancies. W omen were asked about occupational tasks and hobbies performed during the 3 months before through 3 months after conception. Based on her reported occ upational tasks and hobbies, an industrial hygienist assigned a priori defi ned exposure categories to each task and hobby. The exposure categories inc luded 74 chemical groups, 9 "end-use" chemical groups, and organic solvents . Face-to-face interviews were conducted with mothers of 538 (88% of eligib le) infants or fetuses with neural tube defect and mothers of 539 (88%) ran domly selected, nonmalformed, live born infants from a population-based 198 9-1991 cohort of California births (N = 703,518), Our results suggested tha t maternal exposures in the periconceptional period to a variety of chemica ls associated. with occupational and nonoccupational activities did not con tribute substantially to risk of neural tube defects in offspring. We obser ved no effect estimate greater than 2.0 for maternal exposures to the chemi cal agent groups studied. We did not observe substantially elevated risks a ssociated with maternal exposures to any of the end-use chemical groups or to organic solvents, Considering occupational exposures only among women wh o worked did not substantially alter results. Adjustment for maternal vitam in use, race/ethnicity, or education level also did not substantially alter the observed associations.