Chlorpromazine Effects on Pregnancy and Offspring in Mice. ∗

Abstract

Summary

The aims of this investigation were to obtain quantitative data on the effects of chronic chlorpromazine treatments in mice during pregnancy on delays between mating and birth of litters, maternal debility evidenced by changes in weight and behavior after daily chlorpromazine treatment, and drug effects on litter size and weight of offspring at birth. Eighty inbred C57Bl/10 mice breeder pairs were selected from a colony, mated, and assigned to 4 groups. Twenty females received orally 4 mg/kg and 20 female mice received 16 mg/kg of chlorpromazine throughout pregnancy. The remaining 40 females were divided into 2 groups, received corresponding volumes of placebo orally, and served as controls for the 2 dose levels. There was a significant difference in number of days from mating to birth between drug and placebo mothers. Drug mothers had a significantly lower number of offspring per litter than the placebo groups. Mean litter weights of the drug mothers were also significantly lower than the mean litter weights of the placebo mothers. Incremental changes in weight in drug-treated mothers were not significantly less than those of placebo mothers during pregnancy. Although no significant differences in behavior were observed between placebo mothers and the 4 mg/kg drug mothers, at the higher dose level highly significant differences were observed during pregnancy between drug and placebo mothers in activity levels as determined in an open field test for exploratory behavior.