Reproductive Development and Functions in the Rat after Repeated Maternal Deprivation Stress

The present study examines whether interruptions of maternal-neonatal behaviors may alter the maturation of reproductive organs and functions, thereby potentially confounding the interpretation of toxicity data with stress-induced responses. Sprague-Dawley rat neonates were removed from their dams for 6 hr daily beginning on Day 4 of postnatal age and continuing until Day 21. Vaginal opening and preputial separation were monitored as indices of puberty. Sperm production in the male rats, estrous cycles in the female rats, and reproductive tissues were weighed when the animals reached sexual maturity. In addition, rats were mated for the evaluation of pregnancy outcomes. Maternal separation stress in itself did not appear to alter these parameters, although potential interactions of stress responses with a toxicant should still be considered.