Population-based case-control study of oral ketoconazole treatment for birth outcomes.

The objective of the study presented here was to check the effect of oral ketoconazole treatment on fetal development. Ketoconazole has been given a teratogenic classification of C by the US Food and Drug Administration, but human controlled epidemiological studies of the treatment's effects have not been reported. The occurrence of ketoconazole use in the second to third months of gestation was compared between cases with congenital abnormalities and their matched controls in the large population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. Birth weight and gestational age were evaluated in control newborn infants born to mothers with or without ketoconazole treatment. The case group comprised 22,843 cases with congenital abnormalities, while the control group contained 38,151 newborn infants without any defects. Six infants (0.03%) and 12 controls (0.03%) had mothers who had received oral ketoconazole treatment (prevalence odds ratio: with 95% confidence interval: 0.8, 0.3-2.2). No group of infants with congenital abnormalities had mothers with a higher incidence of use of the drug. The mean gestational age was somewhat longer while birth weight was somewhat larger in controls with ketoconazole treated mothers. Our study failed to demonstrate a higher rate of congenital abnormalities in infants with mothers who had received oral ketoconazole treatment during pregnancy.