Diabetes mellitus was simulated in rats on gestation day 1 by a single intraperitoneal injection of streptozotocin in doses of 40 and 50 mg/kg. Pregnant females showed increased glucose concentrations n the blood and urine, embryonic developmental disorders, such as tongue protrusion, edema, and skin hyperemia with concomitant vascular damage (hemorrhage, hematoma) as well as pre- and post-implantation embryo loss. Afobazole administered orally in doses of 10 and 50 mg/kg to pregnant rats with streptozotocin-induced diabetes significantly decreased prenatal developmental disorders and pre- and post-implantation embryo loss rate. Afobazole in a dose of 50 mg/kg produced maximum protective effect: in rats receiving 40 mg/kg streptozotocin, post-implantation embryo loss decreased by 14.7 times. Afobazole in doses of 10 and 50 mg/kg significantly reduced blood glucose concentration in pregnant rats and normalized glycemia in 90-day-old male offspring.