Polyovular follicles in the ovary of immature mice exposed prenatally to diethylstilbestrol.

Polyovular follicles (PF) occur in the ovary of 30-day-old offspring of ICR/JCL mice given 4 daily subcutaneous injections of 20-2,000 micrograms diethylstilbestrol (DES)/day from days 15 to 18 of gestation. PF containing 2-9 oocytes per follicle in the prenatally DES-exposed mice are increased 33- to 112-fold as compared to controls. In 5- to 25-day-old offspring of mothers given injections of 2,000 micrograms DES/day, PF are observed 17-65 times more frequent than in controls.