Potential teratogenicity of gonadotropin treatment for ovulation induction in the mouse offspring.

The teratogenic effects of induced ovulation were studied in mice by using three different doses of pregnant mare's serum (PMS)/human chorionic gonadotropin (HCG) (2.5, 5, or 10 IU) at two different stages of the estrous cycle. The PMS/HCG treatment induced high incidences of external congenital anomalies in the offspring in a dose-dependent manner. This was especially so when the treatment was "out of phase" to the naturally occurring ovulation schedule. The predominant malformations were open eyelids and cleft palate. The problems of extrapolating these findings to humans are discussed.