Association between nicotine replacement therapy use in pregnancy and smoking cessation.
There is an urgent need to find better ways of helping pregnant smokers to stop. Randomized controlled trials (RCTs) have not detected an effect of nicotine replacement therapy (NRT) for smoking cessation in pregnancy. This may be because of inadequate dosing because of faster nicotine metabolism in this group. In England, many pregnant smokers use single form and combination NRT (patch plus a faster acting form). This correlational study examined whether the latter is associated with higher quit rates. Routinely collected data from 3880 pregnant smokers attempting to stop in one of 44 Stop Smoking Services in England. The outcome measure was 4-week quit rates, verified by expired-air carbon monoxide level<10 ppm. Outcome was compared between those not using medication versus using single form NRT (patch or one of the faster acting forms), or combination NRT. Potential confounders were intervention setting (specialist clinic, home visit, primary care, other), intervention type (one-to-one, group, drop-in, other), months pregnant, age, ethnicity and occupational group in multi-level logistic regressions. After adjustment, combination NRT was associated with higher odds of quitting compared with no medication (OR=1.93, 95% CI=1.13-3.29, p=0.016), whereas single NRT showed no benefit (OR=1.06, 95% CI=0.60-1.86, p=0.84). Use of a combination of nicotine patch and a faster acting form may confer a benefit in terms of promoting smoking cessation during pregnancy. While this conclusion is based on correlational data, it lends support to continuing this treatment option pending confirmation by an RCT.