ObjectiveTo systematically evaluate the association between passive smoking during pregnancy and adverse birth outcomes in Chinese, as well as to provide evidence for the prevention of adverse birth outcomes.
MethodsWe electronically searched the CNKI, VIP, WanFang Data, PubMed and EMbase databases to collected cohort studies about the association between passive smoking during pregnancy and adverse birth outcomes in Chinese. The search date was from January 1st 1980 to 30th August, 2014. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the risk bias of included studies. Then meta-analysis was performed using RevMan 5.1 software.
ResultsA total of 24 studies were included in the meta-analysis. The results of meta-analysis showed that, the passive smoking during pregnancy was associated with increased risks of preterm (RR=1.97, 95%CI 1.38 to 2.80), low birth weight (RR=1.94, 95%CI 1.37 to 2.76), birth defects (RR=2.01, 95%CI 1.58 to 2.56), neonatal asphyxia (RR=3.34, 95%CI 1.76 to 6.33), small-for-gestational age (RR=2.62, 95%CI 1.49 to 4.63), stillbirth (RR=3.10, 95%CI 2.00 to 4.80) and spontaneous abortion (RR=1.37, 95%CI 1.19 to 1.59).
ConclusionPassive smoking during pregnancy is associated with increased risks of adverse birth outcomes.
