Developmental and behavioral consequences of prenatal fluoxetine

Background: Fluoxetine, a selective serotonin reuptake inhibitor, is the most commonly prescribed antidepressant drug for pregnant women. Studies regarding the teratogenic effect of fluoxetine on human and animal models are mainly concerned with structural malformation (congenital anomalies). Aim: Hence, the present study was planned to evaluate the postnatal behavioral effects of fluoxetine on albino rats. Methods: Three groups of female rats received either distilled water or doses of fluoxetine 8 and 12 mg/kg orally from the 6th to the 20th day of pregnancy. Weaning of the pups was done on the 21st day followed by a battery of behavioral tests to assess for any behavioral effect. The tests included negative geotaxis, open field exploration, rota-rod test, elevated plus maze and passive avoidance test. Results: In the present study there was no change in the gestational length of pregnancy, no premature birth or miscarriage during pregnancy. A high dose of in utero fluoxetine resulted in a decrease in birth weight of the offspring and also reduced weight gain during the preweaning period. No major congenital abnormalities were observed in the offspring exposed to fluoxetine. Prenatal fluoxetine exposure at high dose caused an initial transient delay in motor development and this poor motor activity was transient and not permanent. However, prenatal exposure to fluoxetine at a higher dose showed a favorable effect on learning and memory in water maze and passive avoidance tests. Conclusions: From the present study, it may be concluded that prenatal fluoxetine causes a transient delay in motor development but does not adversely affect the postnatal behavioral consequences.