Fetal and neonatal action of a polycyclic hydrocarbon (benzpyrene) or a synthetic steroid hormone (allylestrenol) as reflected by the sexual behaviour of adult rats.

Allylestrenol or benzpyrene, given either between the 15th and 19th days of fetal life or from birth to the postnatal 7th day, caused dramatic decrease in the sexual activity of adult female rats. Allylestrenol, given in fetal life, resulted in a profound increase in the sexual activity of male rats. Given in newborn conditions, a decrease of sexual activity was caused by the same chemical. Considering, that one of the molecules has importance in medical practice and the other is an environmental pollutant, the experiments forecast the probability of modification in the sexual behaviour of human adults.