Effects of national smoke-free legislation on the rates of preterm births and low birthweights in Taiwan.

This study evaluated the effects of partial and complete island-wide smoking bans on perinatal outcomes in Taiwan. Trends were determined in the yearly prevalence rates for preterm births and low birth weight (LBW) for a 1978 to 1997 pre-ban period, a 1998 to 2008 Phase 1 partial ban period, and a 2009 to 2016 Phase 2 complete ban period. Poisson regression with a yearly time-series model was employed to determine alterations in trends in prevalence rates for preterm births and LBW. Compared with pre-ban period, the rate ratio (RR) for Phase 1 preterm births was 0.969 (95% confidence interval [CI] = 0.968-0.971) and Phase 2 0.995 (95% CI = 0.992-0.998). The Phase 1 RR LBW fell 0.4% (95% CI = 0.2%-0.5%), but Phase 2 RR rose 1.7% (95% CI = 1.4%-2.1%). Data indicated that the risk of preterm births and LBW in Taiwan was reduced significantly after implementation of the smoking ban. These findings are in agreement with growing evidence suggesting that smoke-free legislation exerted a beneficial health effect on pregnant women and their newborn infants.