COCAINE AS A CAUSE OF CONGENITAL-MALFORMATIONS OF VASCULAR ORIGIN - EXPERIMENTAL-EVIDENCE IN THE RAT

Cocaine hydrochloride was administered to pregnant Sprague‐Dawley rats as a single intraperitoneal dose or as two doses 1–4 hours apart. A single dose administered on day 16 of gestation was teratogenic in a dose‐dependent manner, with 40 mg/kg being a no‐effect dose and 50 mg/kg the lowest teratogenic dose; 80 mg/kg was lethal to the dam. Forty‐eight hours after exposure to a teratogenic dose on day 16 of pregnancy, the fetuses showed severe hemorrhage and edema in the their extremities, particularly the footplates, tail, genital tubercle, and upper lip/nose. When the fetuses were examined on day 21 of gestation, the main externally visible malformations were reduction deformities of the limbs and tail. When two doses of cocaine were administered 1–4 hours apart, the incidence of affected fetuses increased as the time interval between the two doses decreased. Two doses of cocaine administered 2 hours apart were not teratogenic on day 9, 10, 11, 12, 13, or 14 of gestation but did induce reduction deformities on days 15, 16, 17, 18, or 19. The same dose administered 1 hour apart was teratogenic on days 14–19. In general, cocaine administration on gestational days 14, 15, or 16 induced more severe and more widespread hemorrhage and edema than administration on days 17, 18, or 19. In the latter cases, damage was restricted to the distal parts of the hindlimb digits and the tail. The results show that in the rat cocaine is only teratogenic during the late organogenic or postorganogenic period. It exerts its teratogenic effect by inducing hemorrhage and edema in the fetuses, which lead to necrosis and disruption of existing and developing structures, particularly the limbs. It is proposed that cocaine causes severe constriction of the uterine vasculature, leading to an hypoxic response in the placental/fetal unit, which causes the observed hemorrhage and edema. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company