Does in utero exposure to heavy maternal smoking induce nicotine withdrawal symptoms in neonates?

Maternal drug use during pregnancy is associated with fetal passive addiction and neonatal withdrawal syndrome. Cigarette smoking-highly prevalent during pregnancy-is associated with addiction and withdrawal syndrome in adults. We conducted a prospective, two-group parallel study on 17 consecutive newborns of heavy-smoking mothers and 16 newborns of nonsmoking, unexposed mothers (controls). Neurologic examinations were repeated at days 1, 2, and 5. Finnegan withdrawal score was assessed every 3 h during their first 4 d. Newborns of smoking mothers had significant levels of cotinine in the cord blood (85.8 +/- 3.4 ng/mL), whereas none of the controls had detectable levels. Similar findings were observed with urinary cotinine concentrations in the newborns (483.1 +/- 2.5 microg/g creatinine versus 43.6 +/- 1.5 microg/g creatinine; p = 0.0001). Neurologic scores were significantly lower in newborns of smokers than in control infants at days 1 (22.3 +/- 2.3 versus 26.5 +/- 1.1; p = 0.0001), 2 (22.4 +/- 3.3 versus 26.3 +/- 1.6; p = 0.0002), and 5 (24.3 +/- 2.1 versus 26.5 +/- 1.5; p = 0.002). Neurologic scores improved significantly from day 1 to 5 in newborns of smokers (p = 0.05), reaching values closer to control infants. Withdrawal scores were higher in newborns of smokers than in control infants at days 1 (4.5 +/- 1.1 versus 3.2 +/- 1.4; p = 0.05), 2 (4.7 +/- 1.7 versus 3.1 +/- 1.1; p = 0.002), and 4 (4.7 +/- 2.1 versus 2.9 +/- 1.4; p = 0.007). Significant correlations were observed between markers of nicotine exposure and neurologic-and withdrawal scores. We conclude that withdrawal symptoms occur in newborns exposed to heavy maternal smoking during pregnancy.