Effects of passive smoking on outcome in pregnancy

Background: Adverse health effects of exposure to environmental tobacco smoke (ETS) among non-smokers have been studied occasionally in developing countries.
Aims: To study the effects of exposure to ETS on outcome in pregnancy
Settings and Design: A cross-sectional study at a secondary level teaching hospital Material and Methods: Consecutive 576 non-smoking women delivering a singleton live baby were studied. A pre-designed structured questionnaire was used to record the details of exposure to ETS at home. The maternal and foetal variables were compared among those who were exposed to ETS vis-à-vis not exposed. Unpaired Student t-test was used for the comparison of continuous variables and Fisher's Exact test was used for categorical variables. Multiple logistic regression analysis was performed after including all variables found to have significant differences on univariate analysis.
Results: Of the 576 women studied 141 (24%) were exposed to ETS. In the mothers exposed to ETS, there was a significantly higher incidence of pre-term birth (24.1% vs. 16.1%; P = 0.027) and small-for-gestation babies (31.9% vs.17.2%; p<0.001) as compared to unexposed mothers. The mean birth weight of the babies born to the mothers exposed to ETS was 138 g less than that of babies in the unexposed group (2632 ±577 g vs. 2770 ±562 g respectively, P = 0.014). The multiple logistic regression analyses showed that ETS exposure during pregnancy was significantly associated with a higher risk of small-for-gestation babies (OR 2.10; 95% CI: 1.27- 3.48).
Conclusion: Exposure to ETS during pregnancy is associated with higher risk of having a small-for-gestation baby.

Keywords
Passive smoking, environmental tobacco smoke, pregnancy, outcome, small-for-gestation