Association between prenatal tobacco exposure and outcome of neonates born to opioid-maintained mothers. Implications for treatment.

BACKGROUND: Prenatal nicotine exposure is associated with increased neonatal mortality, low birth weight, and smaller head circumference. Opioid-dependent pregnant women show a particularly high prevalence of tobacco smoking and are at greater risk for additional adverse events. However, little is known about the impact of tobacco smoking on opioid-maintained pregnant women and neonatal outcomes.

PATIENTS AND METHODS: This study examined the effect of cigarette smoking on 139 opioid-maintained pregnant women and their neonates. Forty-five percent of the participants were maintained on slow-release oral morphine (SROM), 39% received methadone maintenance, and 16% received buprenorphine. Participants were divided into two groups: (1) women who reported a low cigarette consumption of < or =10 cigarettes/day (56.8%) and (2) those reporting heavy consumption of > or =20 cigarettes/day (43.2%). Neonatal outcome measures were assessed, and a standardized Finnegan score was applied to determine the neonatal abstinence syndrome (NAS).

RESULTS: Fifty-two percent of the newborns did not require treatment for NAS (54% of neonates born to methadone-maintained mothers, 30% born to SROM-maintained mothers, and 95% born to buprenorphine-maintained mothers; p < 0.001). Heavy cigarette consumption was associated with significantly lower neonatal birth weight (p < 0.001), smaller birth length (p = 0.017) as well as with the severity of NAS (p = 0.03). With regard to concomitant consumption of opioids (p = 0.54), cocaine (p = 0.25), amphetamines (p = 0.90) or benzodiazepines (p = 0.09), no significant differences between heavy or low nicotine consumption were noted.

CONCLUSION: Heavy tobacco smoking in opioid-maintained pregnant women is associated with adverse medical and developmental consequences for the newborn. Future treatment programs for this target group should focus on an individualized approach to opioid maintenance therapy in addition to offering specially tailored counseling for smoking cessation.