Effects of maternal drinking and marijuana use on fetal growth and development.

A study of 1,690 mother/child pairs at Boston City Hospital was conducted to assess the impact of maternal alcohol consumption on fetal development when confounding variables were controlled. Level of maternal drinking prior to pregnancy was associated with shorter duration of gestation. Lower maternal weight change, history of maternal illnesses, cigarette smoking, and marijuana use, however, were more consistently related to adverse fetal growth and development. New findings in this study include a negative association between maternal marijuana use during pregnancy and fetal growth. Also when confounding variables were controlled, women who used marijuana during pregnancy were five times more likely to deliver infants with features considered compatible with the fetal alcohol syndrome.