Growth from birth onwards of children prenatally exposed to drugs: a literature review.

Reductions in birth weight and length have been independently attributed to prenatal exposure to alcohol, cigarettes and cocaine. While pregnant women often use multiple substances, studies have not consistently controlled for exposure to other agents or other important differences in maternal lifestyle associated with the use of these substances. Despite these difficulties, the preponderance of evidence suggests that prenatal alcohol and cocaine independently reduce birth measurements. This review synthesizes the scientific literature focusing on prenatal exposures and the relationship to child growth. First examined are studies that investigated the link between prenatal exposures and birth weight and length, followed by the effects of these substances on childhood growth. Studies vary in the number of subjects, cohort characteristics, measurement of exposure and control for potential confounders. Differences in sample characteristics and size, as well as degree of statistical control for potential confounders and the examination of moderating characteristics, have led to differing conclusions regarding the long-term effect of prenatal substance exposure on growth. Large-scale, well-designed studies are needed to clearly examine the unique contribution of both varying prenatal exposures and the magnitude and timing of these exposures on childhood growth deficits.