RELATION OF MATERNAL COCAINE USE TO THE RISKS OF PREMATURITY AND LOW-BIRTH-WEIGHT

To determine whether maternal cocaine use at the time of delivery of t he infant is an independent risk factor for low birth weight or premat urity, we performed a prospective anonymous urine toxicology screening study among 425 women in a large urban university-based maternity hos pital. The data were subjected to univariate analysis with the Fisher Exact Test and odds ratio determination, and to multivariate analyses by logistic regression. Of 11 variables analyzed, cocaine use near del ivery, no prenatal care, marijuana and cigarette use, black race, a pr evious preterm infant, and staff service were significantly associated with premature birth by univariate analysis. No prenatal care (odds r atio, 9.89; 95% confidence intervals, 3.74 to 26.17) and cocaine use ( odds ratio, 7.31; 95% confidence intervals, 2.87 to 18.61) demonstrate d the greatest risk associated with premature birth by univariate pred iction. After analysis by multivariate logistic modeling, only cocaine use detected at birth remained a significant predictor of prematurity (odds ratio, 13.4; 95% confidence intervals, 1.23 to 145.0). Staff se rvice, black race, cocaine use near the time of delivery, marijuana an d cigarette use, a previous preterm infant, and no prenatal care were significant univariate predictors of low birth weight. Cocaine use (od ds ratio, 4.14; 95% confidence intervals, 1.18 to 14.56) and marijuana use (odds ratio, 4.52; 95% confidence intervals, 1.42 to 14.39) were the strongest univariate factors. After analysis by multivariate logis tic modeling, cocaine use near the time of delivery demonstrated the h ighest odds ratio (9.90) for predicting low birth weight, but the 95% confidence intervals included 1(0.53 to 184.0). We conclude that indep endent of potentially interrelated covariables, a positive result on a cocaine urine toxicology test at the time of delivery is the most dom inant factor that was tested to predict prematurity and possibly low b irth weight. The effect of cocaine on the duration of gestation or fet al growth may be due to its pharmacologic properties, or cocaine use d uring pregnancy may identify a subgroup of women whose risk is due to as-yet-unidentifiable socioeconomic or cultural characteristics.