Adverse effect of tobacco use on pregnancy outcome: a multi-center hospital based case control study in urban settings of Karachi, Pakistan

Background: A recent review on the effects of smoking on women’s health reported a higher rate of gynecological complications among smokers. Maternal tobacco used is also linked with low birth weight and still birth. Our... [ view full abstract ]

Background:
A recent review on the effects of smoking on women’s health reported a higher rate of gynecological complications among smokers. Maternal tobacco used is also linked with low birth weight and still birth. Our study aimed to assess the adverse effect of maternal tobacco consumption during pregnancy on birth outcomes as well as obstetric complications.
Methodology:
A multi-center hospital-based case control study was conducted in Karachi. A random sample of 1275 women admitted in the gynecology & obstetric departments of selected hospitals for delivery was interviewed within 48 hours of delivery. Cases were women with adverse birth outcomes and obstetric complications. Controls were women who had normal vaginal delivery or cesarean section without any of the above mentioned complications.
Results:
The multiple logistic regression analysis indicates that the odds of exposure to tobacco smoke (active/passive) among cases were significantly higher compared to controls (OR: 2.24; 95% CI: 1.56-3.23) after adjusting for covariates. Furthermore, increasing age (adjusted OR= 1.03; 95% CI: 1.0-1.1), no slits in the kitchen (adjusted OR: 1.90; 95% CI: 1.05-3.43), gravidity (adjusted OR= 0.83; 95% CI: 0.73-0.93), non-booked hospital cases (adjusted OR= 1.87; 95% CI: 1.38-2.74), history of still birth (adjusted OR= 4.06; 95% CI: 2.36-6.97), miscarriages (adjusted OR= 1.91; 95% CI: 1.27-2.85) and history of preterm delivery( adjusted OR= 6.04; 95% CI: 2.52- 14.48) were significantly positively associated with being a case as compared to control.
Conclusion:
Our study suggests that women who had adverse pregnancy outcomes were more likely to have been exposed to tobacco, had previous history of still births, miscarriages and preterm delivery. Furthermore, an important finding was the association of adverse pregnancy outcomes with no slits in the kitchen (proxy indicator for indoor air pollution). This indicates that pre-natal care and health education during the antenatal period might help in preventing such adverse events.