Marijuana: Prenatal and Postnatal Exposure in the Human

In a preliminary report from an ongoing prospective study in Canada, Fried (1980, 1982) found no difference in birth weight between marijuana users and nonusers, but infants of heavy users had shorter gestations and signs of neurobehavioral immaturity as compared with matched controls.

Abstract

Recent studies of prenatal exposure to marijuana have produced presumptive evidence that marijuana has an adverse effect on growth and development of the fetus. Two investigators (Linn et al. 1983; Gibson et al. 1983) reported a decrease in birth weight and an increase in malformations in marijuana— exposed infants, but differences between marijuana users and nonusers were not statistically significant when confounding factors were taken into account. Hingson et al. (1982) reported that woman who used marijuana during pregnancy delivered infants with a mean birth weight 105 grams lighter than infants of nonusers, and the infants were five times mere likely than infants of nonusers to have features compatible with Fetal Alcohol Syndrome. Although confounding factors were controlled statistically, the investigators cautioned that marijuana use might identify a group of women at higher pregnancy risk due to unexplored maternal factors, rather than identifying a specific agent causing abnormal fetal development. In a preliminary report from an ongoing prospective study in Canada, Fried (1980, 1982) found no difference in birth weight between marijuana users and nonusers, but infants of heavy users had shorter gestations and signs of neurobehavioral immaturity as compared with matched controls.