2009 Volume 71 Issue 10 Pages 1309-1315
The aim of this study was to investigate the effect of exposure period and dose of diethylstilbestrol (DES), which has strong estrogenic activity, on pregnancy in rats. All rats with observed vaginal plugs or sperm in vaginal smear tests after mating were divided into 3 groups: those fed a normal diet, a diet mixed with DES throughout pregnancy and a diet mixed with DES from day 13 of pregnancy. DES was mixed into the diet at 0.1, 1, 10 and 100 ppm. All bred rats fed the normal diet and 0.1 ppm DES from day 13 of pregnancy delivered pups, while none of the rats treated with 1-100 ppm DES during pregnancy and 100 ppm DES from day 13 of pregnancy delivered any pups. The number of male and female pups born decreased in rats treated with 10 ppm DES from day 13 of pregnancy. These results suggest that DES could affect pregnancy and that the exposure period and dose may result in sterility, abortion, poor fetal growth and reduced number of pups born.