Assessing combined chemical exposures as risk factors for neural tube defects.

摘要: Abstract Many studies have investigated whether chemical exposures early in pregnancy increase risks to women of delivering offspring with congenital anomalies. We periconceptional chemicals combination increased having neural tube defect (NTD)-affected pregnancies. Women were asked about occupational tasks performed during the period. These assigned by an industrial hygienist a priori defined exposure categories. The categories included 74 groups. Two population-based case control analyzed. Information on was obtained from mothers 538 NTD cases and their 539 controls one study, 265 481 another study. used data first study identify clues. Specifically, we estimated for maternal all possible pairs, triplets, quadruplets Chemical combinations revealing elevated these “clue generation” analyses then second case-control contribution risk NTDs. computed odds ratios each total 192,374 comparisons identified that produced 5 or more. A 5-fold criterion revealed 53 combinations. reflected various exclusive 12 Analyses did not 2.0 greater groups resulted Despite use labor-intensive method categorize exposures, unable substantiate clues associated combined large as factors