Oral Contraceptives and Birth Defects

Abstract
We reviewed the birth certificates and hospital records of 7723 infants whose mothers had reported using oral contraceptives. The overall frequency of malformation was 4.3 per cent for infants whose mothers terminated use of oral contraceptives shortly before conception, as compared with 3.3 per cent for infants whose mothers did not take oral contraceptives during the three years before conception. The 90 per cent confidence limits for the prevalence ratio were 1.0 and 1.7. No difference was apparent for major malformations. For specific malformations the most notable difference was for undescended testis, but this excess, like the overall excess, could be explained by sampling variability. Despite the slightly greater rate of minor malformations in the short-interval group, a reasonable interpretation of these data would be that oral contraceptives present no major teratogenic hazard. (N Engl J Med 299:522–524, 1978)