Congenital malformations among offspring exposed in utero to progestins, Olmsted County, Minnesota, 1936-1974.

Comparison of a cohort of 988 offspring exposed in utero to exogenous progestins with a matched cohort of unexposed offspring did not result in detection of an association of congenital anomalies with exposure. The conclusions are based primarily on outcomes of pregnancy with exposure to progesterone and 17 alpha-hydroxyprogesterone caproate, and may not apply to androgenic progestins. Offspring exposed to combinations of progestins and estrogens were excluded from this study and may have a different distribution of anomalies.