Alcohol binge drinking during pregnancy and cryptorchidism.

BACKGROUND Recent studies have suggested gestational weeks 8-14 as a time window of particular importance to the intrauterine development of the male genitalia, and prenatal exposure to alcohol is under suspicion as a risk factor for cryptorchidism. We examined if prenatal exposure to alcohol, and especially binge drinking, during the suggested programming window is associated with an increased risk of cryptorchidism. METHODS The authors used data on 41 268 live born singleton boys of mothers who were enrolled into the Danish National Birth Cohort in 1996-2002. During early childhood, 1598 cases of cryptorchidism were identified and 398 of these were orchiopexy verified. Maternal alcohol consumption including number and timing of binge drinking episodes was assessed in two computer-assisted telephone interviews around gestational weeks 17 and 32. Adjusted hazard ratios (HRs) of cryptorchidism were estimated by Cox regression. RESULTS Average weekly alcohol consumption as well as frequency of binge drinking at any time during pregnancy was not associated with risk of cryptorchidism. Binge drinking in gestational weeks 7-15 was associated with a slightly increased risk of cryptorchidism with adjusted HRs between 1.03 and 1.66. CONCLUSION Prenatal exposure to alcohol-measured as average intake as well as frequency and timing of binge drinking-was not associated with cryptorchidism. Our findings, however, do not rule out that binge drinking during the suggested male programming window may increase the risk of cryptorchidism.