Teratologic evaluation of synthetic Δ9‐tetrahydrocannabinol in rats

Abstract

Δ⁹‐Tetrahydrocannabinol (THC) was dissolved in propylene glycol and 25, 50, or 100 mg/kg administered daily sc to pregnant Charles River Sprague‐Dawley rats on days 6–15 of gestation (presence of sperm considered day 1). Maternal weight gain was depressed, but a significant decrease in fetal weight occurred only in the 50 mg/kg group. No malformations were noted, only some abnormalities consisting of several instances of rudimentary 14th rib and soft or spongy spinal cords.