Biology of Reproduction, Vol 6, 281-287, Copyright © 1972 by Society for the Study of Reproduction

Vaginal Stimulation and Progesterone in Relation to Pregnancy and Parturition

¹ Department of Anatomy, University of Hawaii School of Medicine, Honolulu, Hawaii 96822

The significance of vaginal stimulation and progesterone at the time of insemination was studied in relation to the initiation of pregnancy and parturition in the golden hamster. While both are capable of supporting the initiation of pregnancy, vaginal stimuli at the time of estrus is seen crucial for the maintenance of normal pregnancy and for parturition to occur. Vaginal copulatory stimuli are seen involved in initiating mechanisms inhibiting gestational ovulation and recurrent estrus as well. Progesterone may support an apparently normal pregnancy but without vaginal stimulation normal parturition is rare. Vaginal stimulation given simultaneously with progesterone at estrus may compensate for some adverse effects of the exogenous hormone.