Evaluation of the teratogenic potential of delalutin (17 alpha-hydroxyprogesterone caproate) in mice

Swiss Webster female mice weighing 25-30 gm were injected subcutaneously on days 6-15 of gestation with the synthetic sex steroid Delalutin (17 alpha-hydroxyprogesterone caproate). Treatment was given daily in doses ranging from 42 to 833 mg/kg body weight, or 10, 100, and 200 times the human therapeutic dose. On day 18 fetuses were removed from the uterus and examined for malformations and other fetotoxic effects. Prenatal treatment with the two higher doses resulted in 8 and 13% maternal deaths, and all doses resulted in a slight increase (4-12% above control) in resorption frequency. Treatment with Delalutin did not significantly affect intrauterine growth, sex ratio, or malformation rate of the offspring. The results of the present study confirm other reports that Delalutin is not androgenic, and that it, like progesterone and certain other sex steroids, does not alter the development of nonreproductive organs.