Effects of cyproterone acetate on uterine motility in rats

The effect of cyproterone acetate, an antiandrogen, on uterine contractility when the compound is administered to rats during midpregnancy was investigated. Pregnant Wistar rats were given cyproterone acetate subcutaneously on Days 8-11 of gestation. The results indicate that cyproterone acetate, either directly or indirectly, inhibits uterine contractility, an effect that may explain the prolongation of the gestational period observed in all treated animals.