NEW YORK (Reuters Health) – Use of nicotine gum does not help pregnant women stop smoking, but it is linked to increased birth weight and gestational age, both of which correlate with neonatal well-being, US researchers report.

Their study involved 194 pregnant smokers who were randomized to use nicotine (2 mg) or placebo gum for 6 weeks, followed by a 6-week taper period. All of the women also received individual smoking cessation counseling. Women who were unable to quit smoking were told that they should still try to reduce the number of cigarettes smoked per day, substituting the gum as needed.

Women who used the gum had a 6-week smoking cessation rate of 13.0%, higher but not significantly different from the 9.6% rate seen in the placebo group, lead researcher Dr. Cheryl Oncken and colleagues report in the October issue of Obstetrics & Gynecology. The corresponding rates at 32-34 weeks of gestation were also not markedly different: 18.0% vs. 14.9%.

Nonetheless, the findings suggest that although the nicotine gum did not help women stop smoking all together, it may have helped them cut back on use, note Dr. Oncken, from the University of Connecticut School of Medicine in Farmington, and associates.

With use of the gum, the number of cigarettes smoked fell by 5.7 per day, on average, whereas with placebo, the reduction was just 3.5 cigarettes per day (p = 0.035). In parallel, cotinine levels fell to a greater extent in the nicotine gum group: -249 vs. -112 ng/mL (p = 0.04).

Infants of women who used the nicotine gum had a mean birthweight of 3287 g, significantly higher than the 2950 g logged in the control group (p < 0.001). The average gestational age was also slightly, but significantly higher in the active treatment group: 38.9 vs. 38.0 weeks (p = 0.014). In the study, the researchers note, cotinine levels from gum were measured to ensure that nicotine exposure did not exceed what the subjects experienced with smoking. Nonetheless, Dr. Oncken and colleagues recommend against using the gum on a routine basis in pregnant smokers as there is evidence from animal studies that nicotine exposure causes cellular abnormalities that may increase the risk of sudden infant death syndrome. Reference:
Obstet Gynecol 2008;112:859-867.