A METAANALYSIS OF RANDOMIZED TRIALS OF PRENATAL SMOKING CESSATION INTERVENTIONS

OBJECTIVE: Our purpose was to assess the effect of prenatal smoking interventions on rates of smoking cessation and low birth weight. STUDY DESIGN: We used a meta-analysis model to compare and summarize smoking cessation and low birth weight outcomes with the risk ratio used as a common metric. We located 11 randomized, controlled trials with objective validation of smoking status; four of these studies also measured rates of low birth weight. RESULTS: Risk ratios for smoking cessation ranged from 0.9 to 7.1. The combined risk ratio for the homogeneous group of 10 studies was 1.50 (95% confidence interval 1.22 to 1.86) after the outlier study with a risk ratio of 7.1 was excluded. This was a 50% increase in smoking cessation. Low birth weight risk ratios of 0.6 for two studies that achieved a 50% increase in cessation suggested that the incidence of low birth weight was decreased. CONCLUSION: Prenatal smoking cessation interventions increase rates of smoking cessation during pregnancy, and there ib evidence that they reduce the incidence of low birth weight.