Objective. This was a prospective study of the effects of maternal smoking during pregnancy on newborn neurobehavior, including dose-response relationships using self-report and a bioassay of nicotine exposure. Methods. The sample included 27 nicotine exposed and 29 unexposed full-term newborn infants with no medical problems from comparable social class backgrounds. Mothers were excluded for using illegal drugs during pregnancy, using antidepressant medication, or if they consumed >3 alcoholic drinks per month. Nicotine exposure was determined by maternal self-report and cotinine in maternal saliva. The NICU Network Neurobehavioral Scale (NNNS) was administered by masked examiners in hospital to measure neurobehavioral function. NNNS scores were compared between nicotine-exposed and -unexposed groups including adjustment for covariates. Dose-response relationships with NNNS scores were computed for maternal salivary cotinine and maternal report of number of cigarettes per day during pregnancy. Results. After adjustment for covariates, the tobacco-exposed infants were more excitable and hypertonic, required more handling and showed more stress/abstinence signs, specifically in the central nervous system (CNS), gastrointestinal, and visual areas. Dose-response relationships showed higher maternal salivary cotinine values related to more stress/abstinence signs (r = .530) including CNS (r = .532) and visual stress (r = .688) and higher excitability scores (r = .617). Cigarettes per day during pregnancy was related to more stress/abstinence signs (r = .582) including CNS (r = .561) and visual stress (r = .640). Conclusions. These findings suggest neurotoxic effects of prenatal tobacco exposure on newborn neurobehavior. Dose-response relationships could indicate neonatal withdrawal from nicotine. Research directed at understanding the effects of cigarette smoking during pregnancy on infants can lead to improved public health outcome.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health