Smoking and illicit drug use during pregnancy: impact on neonatal outcome

OBJECTIVE: To examine the effects of maternal substance use on neonatal outcomes in 212 pregnant cocaine/opiate dependent women who delivered while in active drug treatment. STUDY DESIGN: Using urine toxicology data at delivery, subjects were classified drug positive (+TOX) (n = 53) or negative (-TOX) (n = 159). RESULTS: Toxicology status was not associated with maternal or neonatal demographic or drug use variables. +TOX patients were enrolled in the treatment program for a shorter period of time than -TOX (68.3 vs. 91.3 days, p = 0.005). Infant birth weight ratio (IBR) was lower in +TOX women (0.84 vs. 0.90, p = 0.003). +TOX women were twice as likely to have small-for-gestational-age (IBR < 0.85) neonates than were -TOX. Length of stay (LOS) in the neonatal intensive care unit (NICU) was not associated with maternal toxicology but was associated with quantity of tobacco per day (p = 0.0001). NICU neonates with heavily smoking mothers (11+ cigarettes/day) averaged LOS = 9.5 days as compared to light (1-10 cigarettes per day) smokers (LOS = 7.9 days) and nonsmokers (LOS = 5.5 days). CONCLUSION: Maternal drug abstinence is associated with higher IBR. Maternal smoking is related to NICU LOS, even among polydrug-dependent women. These data are clinically and economically important and support the need for smoking cessation interventions in high-risk populations, such as drug-dependent pregnant women.