MATERNAL AND NEONATAL RISK-FACTORS FOR CRYPTORCHIDISM

We assessed risk factors for cryptorchidism in a prospective hospital- based cohort study at Mount Sinai Hospital in New York City. We examin ed at birth 6,699 singleton male neonates who were delivered between O ctober 1987 and October 1990. Follow-up examinations were undertaken a t 3 months and 1 year for those diagnosed as cryptorchid at birth. We calculated prevalence ratios and adjusted odds ratios according to sel ected maternal and neonatal characteristics for those who remained cry ptorchid at the 1 year assessment. We found elevated risks for materna l obesity [prevalence ratio = 2.42; 95% confidence interval (CI) = 1.1 1-5.27], for infants delivered by cesarean section (adjusted odds rati o = 2.17; 95% CI = 1.29-3.65), for low birthweight (adjusted odds rati o = 2.29; 95% CI = 1.12-4.70), for preterm birth (adjusted odds ratio = 2.25; 95% CI = 1.16-4.35), and for infants with congenital malformat ions (prevalence ratio = 13.97; 95% CI = 1.27-26.67). We observed a se asonal effect, with a peak in births of cryptorchid infants during Sep tember through November and a smaller peak during the months of March through May. We found no evidence that young women, white women, or pr imiparas were at increased risk.