Impact of Prenatal Delta-9-Tetrahydrocannabinol Exposure on Neurodevelopmental Indices, Cerebellar and Placenta Morphology in Wistar Rats

Abstract

Introduction: The rising use of cannabis among women of childbearing age raises concerns about its effects on prenatal development. Delta-9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis, crosses the placenta and may affect both maternal and fetal health.

Aim: This study examines how prenatal THC exposure influences neurodevelopmental outcomes, cerebellar morphology, and placental function.

Methods: Nine adult Wistar rats (12 females, 6 males; 180–220 g) were housed under standard conditions and mated (2:1 ratio). THC was extracted from Cannabis sativa (acquired from NDLEA) using ethanol and solvent-solvent fractionation, then confirmed via thin-layer chromatography. Pregnancy was verified by vaginal plug detection. Pregnant rats were assigned to control or THC-treated groups (150 mg/kg) across defined gestational days. Dams were sacrificed on gestational day 19 for placental analysis; offspring were sacrificed on postnatal day 42 for cerebellar morphometric and histological evaluation (H&E staining). Reflex tests assessed cognitive and motor development. Data were analyzed using Student’s t-test (p < 0.05).

Results: THC exposure significantly reduced fetal (2.48 g vs. 3.27 g) and birth weights (3.65 g vs. 4.7 g). Placental weights and areas also declined. Reflex performance (righting, forelimb/hindlimb grasp, cliff avoidance, eye opening) was impaired. Histology showed significant reductions in junctional and labyrinth zone nuclei and areas.

Conclusion: Prenatal THC exposure impairs fetal growth, neurodevelopment, and placental integrity. These findings emphasize the risks of cannabis use during pregnancy and the urgent need for public awareness and further research into mitigating strategies.