Objective: To determine the risk of adverse pregnancy outcome among cr
ack cocaine users in a large homogeneous prenatal population with obje
ctive documentation of drug use. Methods: A retrospective cohort study
was performed on a population of inner-city women who were offered ro
utine voluntary urine drug screening and who delivered between January
and December 1992 at a large county hospital. The study population co
nsisted of 483 users (positive drug screens) and 3158 non-users (negat
ive drug screens). Univariate analysis and multiple logistic regressio
n were used to identify the relation between crack cocaine use and adv
erse perinatal outcome. Results: Users were significantly more likely
than non-users to deliver low birth weight (LBW) infants (31.3% versus
14.9%; crude odds ratio [OR] 2.6; 95% confidence interval [CI] 2.1, 3
.2), growth-restricted infants (29.0% versus 13.0%; crude OR 2.7; 95%
CI 2.2, 3.4), and preterm infants (28.2% versus 17.1%; crude OR 1.9; 9
5% CI 1.5, 2.4). In addition, users were more likely to have abruption
s (3.3% versus 1.1%; crude OR 3.0; 95% CI 1.6, 5.6) and infants with l
ow 5-minute Apgar scores (7.9% versus 4.5%; crude OR 1.8; 95% CI 1.2,
2.7). After adjusting for confounders (including alcohol use and smoki
ng), only the risks of LBW and fetal growth restriction (FGR) remained
significant, with adjusted OR 1.6 (95% CI 1.03, 2.4) and adjusted OR
1.7 (95% CI 1.2, 2.3), respectively. Although there was no significant
difference in the rate of low 5-minute Apgar scores between users and
non-users after controlling for confounders, users with a positive ur
ine drug screen within 1 week of delivery were significantly more like
ly than non-users to deliver infants with low 5-minute Apgar scores: c
rude OR 2.4; adjusted OR 2.0 (95% CI 1.1, 3.7). Conclusion: In this in
ner-city population, crack cocaine use is associated with adverse preg
nancy outcomes, as noted by increased risks of LBW and FGR. (C) 1997 b
y The American College of Obstetricians and Gynecologists.