Maternal occupational pesticide exposure and risk of hypospadias in the National Birth Defects Prevention Study

Hypospadias is a common congenital malformation among men in which the urethral opening is ventrally displaced. Pesticide exposure has been suggested as a possible etiologic factor, but previous epidemiologic studies have produced inconsistent results. Methods: We used data from the National Birth Defects Prevention Study (NBDPS), a population-based case-control study, to examine maternal occupational exposure to fungicides, insecticides, and herbicides among 647 hypospadias case infants and 1496 unaffected male control infants with estimated delivery dates from October 1997 to December 2002. Periconceptional (1 month before conception through the first trimester of pregnancy) pesticide exposures were assigned by an expert rater, assisted by a job-exposure matrix (JEM), from a job history completed by mothers during a telephone interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with multivariable logistic regression, and adjusted for relevant covariates. RESULTS: Maternal periconceptional occupational exposure to any pesticides (yes/no) was not associated with an increased risk of hypospadias (OR = 0.78; 95% CI = 0.61-1.01). Maternal occupational periconceptional pesticide exposure type (insecticides, fungicides, and herbicides) and estimated quantity also showed no significantly increased risk of hypospadias and no evidence of a dose-response relationship; however, the estimated pesticide exposure levels in this population were low. CONCLUSION: Using broad classes of insecticides, herbicides, and fungicides, we found no evidence that low intensity maternal periconceptional occupational pesticide exposure was a risk factor for hypospadias.