Effects of the Therapeutic Doses of Topiramate on the Placenta of Rats: A Histological and Morphometric Study (LB62)

Abstract

The antiepileptic drug topiramate is used in the treatment of epilepsy in many patients including pregnant women. Topiramate was reported to have teratogenic effects. This study is focusing on the effects of topiramate on the placental structure. Pregnant rats were treated with topiramate at doses of 50 and 100 mg/Kg body weight orally. On day 20 the pregnant rats were sacrificed, and the placentae were collected and processed for histological and morphometric evaluation. There were degenerative changes affecting the three layers of the placenta. In the decidual layer, the cells showed deposition of fibrous and hyaline materials. Vacuolization of cells and hemorrhages were also detected. In the basal layer, the trophoblast cell types were affected. This ranged from vacuolization, cytolysis and cyst formation. In the labyrinthine layer, there was increase in the fibrinoid material and fetal mesenchyme. There was also degeneration of cells and congestion of blood vessels. Morphometric data revealed a significant decrease in the thickness of the decidual layer and increase in that of the basal layer of the treated groups compared to control. The results obtained from this study showed harmful effects of topiramate on the placental structure. This may explain one of the possible mechanisms which leads to its teratogenicity.