New research has found that second-hand smoke leads to more placental abruption than does smoking.
Placental abruption refers to a condition in which the placenta separates from the uterine wall before childbirth. This can reduce oxygen and nutrient supply to the unborn child and also cause heavy bleeding in the mother-to-be.
Research at the Tohuku University Hospital, Japan, which used data from 82,000 pregnant women, found that smoking during pregnancy accounts for 2.8 per cent of placental abruption cases.
Additionally, even among non-smoking pregnant women, second-hand smoke exposure contributed to 3.0 per cent of placental abruption cases.
The study, published in the BMJ Open (March 5, 2025), emphasises that any exposure to smoke is harmful for pregnant women.
It demonstrates the importance of second-hand smoke prevention alongside smoking cessation during pregnancy to safeguard maternal and fetal health. It highlights the need to strengthen public policies and educational campaigns to reduce all smoke exposure in public spaces and homes.
An April 2024 India-specific study [published](https://www.thelancet.com/journals/lansea/article/PIIS2772-3682(23)00134-8/fulltext) in The Lancet Regional Health drew similar conclusions.
It said that even smokeless tobacco consumption during pregnancy adversely affects the gestational age at birth and can lead to low birth weight babies and act as a neuro-teratogen (a substance that can damage the brain).
Women who did not use tobacco during pregnancy but lived with smokers had a two-time higher risk of stillbirth, indicating a strong causal association with second-hand smoke. Furthermore, tobacco use in mothers is known to present a greater risk for children than its use by fathers.
The study, which analyses data from the fifth National Family Health Survey, pegs the prevalence of tobacco use among currently married pregnant and lactating women at 2.5 per cent and 3.2 per cent, respectively, with over 85% of tobacco-using currently married pregnant (85.6 per cent) and lactating (85.6 per cent) women using smokeless tobacco only. Age group 30–34 years, working women and the richest wealth quintile were found to be the greatest smoked tobacco users among currently married pregnant women.
In contrast, among the currently married lactating women, the middle wealth quintile and South Indian region were found to be independent predictors of smoked tobacco use.