Pentobarbital intoxication in the pregnant rat.

Pregnant rats were treated intraperitoneally with low doses of pentobarbital (5, 15 or 25 mg/kg) on days 9 through 12 of gestation. There was no significant differences in fetal weight, length, or placental weight. Other than minor ossification delays, there were no external, skeletal or visceral abnormalities and no treatment-related variation in fetal mortality. Microscopic examination of various maternal and fetal tissues revealed no major deleterious effects of short-term pentobarbital intoxication.