The prenatal exposure to selective serotonin reuptake inhibitors (SSRIs) is very controversial. There is no conclusive evidence for increased risk of malformations after SSRI use in pregnancy. The aim of the study was to determine how fluoxetine is affecting gestation and fetal development in rats. Twenty sexually mature female Wistar rats weighting between 250-260 g received 20 mg/kg body weight fluoxetine from the first day of gestation and during the entire gestation period.The drug was administered by oral route. Healthy, primipareus animals were selected along with 20 female Wistar rats, as control group. Mature males were caged with virgin females for an entire week. Rat’s behaviour during gestation, after birth and rats body weight was examined. The number of healthy pups was also noted. The females not giving birth after 21 days to any pup were anesthetized (halothane through gas scavenging apparatus untilled death) and the gravid uterus were dissected out and examined. Compared to the controlled group, in which weight gain was more significant, the animals from the experimental group had a slight increase in body weight. The weight gain normally induced by gestation, is less significant in fluoxetine treated rats due to the increase serotonin levels in the brain. The uteri examination of pregnant rats showed an increase in the number of dead and resorbed rat embryos.
Preclinical studies suggest that the inclusion of fluoxetine in pregnancy category C is justified and the appropriateness of its administration in pregnancy is still an unresolved issue.