Effects of Smoking Reduction and Cessation on Birth Outcomes in a Scheduled Gradual Reduction Cessation Trial

Introduction Smoking during pregnancy can affect infant birthweight. We tested whether an intervention that promoted scheduled gradual reduction improved birth outcomes among pregnant women who smoked. We also examined race differences in birth outcomes. Methods We conducted a 2-arm randomized controlled trial where pregnant women who smoked received either SMS text-delivered scheduled gradual smoking reduction (SGR) program plus support texts or support messages only throughout their pregnancy. The outcomes for this paper were birth outcomes including birth weight and gestational age obtained from chart review. Analyses were conducted using chi-square and t-tests in SAS. Results We approached 2201 pregnant women with smoking history. Of the 314 women recruited into the study, 290 completed a medical release form (92%). We did not find any significant differences in birth outcomes by arm or race. The majority of participants reduced smoking by the 80%. Women who reduced more than 50% of their baseline cigarettes per day had a birth weight increase of 335 g compared to those that did not (p = 0.05). The presence of alcohol/drug use in prenatal visit notes was associated with low infant birth weight (p = 0.05). Discussion The scheduled gradual reduction intervention did not improve birth outcomes. Additional research is needed to help improve birth outcomes for pregnant women who engage in tobacco and illicit substance use. Clinical Trial # NCT01995097