Maternal alcohol, tobacco and cannabis consumption and the outcome of pregnancy.

In a prospective study of 7,301 births, associations were sought between maternal alcohol, tobacco and cannabis use and several adverse outcomes of pregnancy. Apparent effects of alcohol use on prematurity, intrauterine growth retardation, congenital abnormalities and low Apgar score were consistent with previously reported work, but were not statistically significant. Infants born to smokers had lower birthweights and were more prone to intrauterine growth retardation, but they did not appear to have an increased risk of prematurity or perinatal death. Only 36 women reported using cannabis 2 or more times a week, not merely as smokers of marijuana but also as users of the more potent resin forms of cannabis. Subsequently 25% of these women gave birth to premature infants.