A meta-analysis of randomized trials of prenatal smoking cessation interventions.

Abstract

Our purpose was to assess the effect of prenatal smoking interventions on rates of smoking cessation and low birth weight. 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. 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. Prenatal smoking cessation interventions increase rates of smoking cessation during pregnancy, and there is evidence that they reduce the incidence of low birth weight.