Objective: To study the association between maternal passive smoking during pregnancy and the small-for-gestational-age (SGA) infants and to analyze independent factors on duration, in different areas.
Methods: Totally, 8 retrospective studies published in PubMed (no year limited), OVID-MEDLINE (no year limited), CNKI (from 1911 to 2008), VIP (from 1989 to 2008), and CBM (no year limited), on maternal passive smoking during pregnancy and SGA were analyzed synthetically by Meta-analysis.
Results: The unadjusted pooled OR value on the association between maternal passive smoking during pregnancy and SGA was 1.45 (95% CI: 1.05-2.01). Data showed that the adjusted pooled OR value was 1.76 (95% CI: 1.15-2.69). Maternal passive smoking in early pregnancy was a risk factor for SGA (OR = 1.85, 95% CI: 1.25-2.72), and so was the exposure in mid or late pregnancy(OR = 2.12, 95% CI: 1.43-3.13). No statistically significant relationship between SGA and passive smoking at home or at workplace was found.
Conclusion: Avoiding passive smoking in pregnancy for mothers could reduce the possibility of delivering SGA infants. Other than at home or at workplace, problem of passive smoking in other places should also be brought up.