Sexual Satiety Diminishes the Capacity of Novel Males to Disrupt Early Pregnancy in Inseminated Female Mice (Mus musculus )

Male mice (Mus musculus) are sexually aroused by previously inseminated females and can disrupt intrauterine ova implantation. In Experiment 1, females were mated with males of their own genetic strain (CF-1) and then exposed for 5 days to novel males of the same or a different heterogeneous strain (HS). Half of these males had just mated with other females. HS males disrupted pregnancy more than did CF-1 males, with a nonsignificant trend toward greater influence of unmated males. In Experiment 2, HS males mated with 2 ovariectomized females that were made sexually receptive by injections of estrogen and progesterone, whereas other males lacked this exposure. Inseminated female CF-1 subjects were then housed near such males for 4 days. Unmated males disrupted pregnancy more often than did mated males. These data suggest that sexual satiety can diminish the capacity of novel males to disrupt pregnancy, by reducing sexual motivation, pheromonal emissions, or both.