Are female sex hormones teratogenic?

An analysis of available epidemiologic data leads the present reviewers to conclude that the use of exogenous hormones during human pregnancy has not been proved to cause developmental abnormality in nongenital organs and tissues. This conclusion is further supported by the animal laboratory data. The preponderance of evidence at this writing indicates a lack of causal association between hormonal use during pregnancy and nongenital malformation of the offspring. The quality of the epidemiologic data does not, at this time, permit a definitive conclusion that sex hormones during pregnancy may not, under as yet to be defined conditions, have some adverse effect on human prenatal development. If there are increased risks of nongenital malformations associated with the administration of certain sex steroids, the risks are very small, may not be causal, and are substantially below the spontaneous risk of malformations. In spite of the present degree of uncertainty, the clinical, epidemiologic, and laboratory data do permit the formulation of a rational approach to handling problems related to sex steroid usage and exposure in pregnant women.