Cleavage of unfertilized eggs after repeated administration of human chorionic gonadotrophin to hamsters

The proportions of unfertilized eggs in the oviducts, showing abnormal cleavage, were examined in hamsters given single or repeated doses of 30 i.u. human gonadotrophic hormone for the induction of ovulation. In control animals (n = 7), 1.7% of the total ovulated eggs were morphologically abnormal unfertilized eggs showing cleavage. The proportions of unfertilized eggs that were abnormal in the groups of seven hamsters treated with one, two or three doses of the gonadotrophin were 20.4%, 19.4%, and 30.4%, respectively. The proportion of unfertilized eggs showing abnormal cleavage thus appeared to increase with repeated administrations of gonadotrophin.