The effects of gestational cocaine exposure on pregnancy outcome, postnatal development, cognition and locomotion in rats

Pregnant female Sprague-Dawley rats were injected with either 40 mg/kg (-)cocaine hydrochloride or an equivalent volume of 0.9% saline, subcutaneously (s.c.), once daily from gestational day 12 (GD 12) to GD 21. Gestational cocaine exposure had no effect on maternal weight gain, length of gestation, birthweight, fetal mortality, postnatal weight gain or locomotive activity in offspring. There was an unusual reduction in the male/female offspring ratio in the treated group (1:0.65) verses controls (1:1.04) (p <0.01). Male offspring scored significantly lower on memory and learning tasks on post-natal day. 30 (PND30) as determined by the water maze test (p <0.01). Exposure to cocaine in utero had no effect on postnatal female sexual maturation or cognitive function. The present study indicates that gestational cocaine exposure can lead to cognitive impairment selectively in male offspring, without any apparent postnatal physical abnormalities or adverse effects on maternal health status.