Mothers-to-be who breathe in second-hand smoke have a higher risk of delivering stillborn babies by almost one quarter (23%), and are 13% more at risk of delivering babies with birth defects, according to a recent global-wide study. Researchers at the University of Nottingham conducted the study and say the findings highlight how important it is for expectant fathers to not smoke around their pregnant partners.
Published in this month’s issue of the journal Pediatrics, researchers analyzed the effects of passive smoke on expectant mothers by pooling together 19 studies done in North America, South America, Asia, and Europe. These studies looked at pregnant women who did not smoke themselves but were exposed to second-hand smoke either in the home or at the workplace. The research looked at whether passive smoking affected incidence of miscarriage, newborn death, and congenital birth defects. An overall increase in the risk of stillborns and birth defects was seen after researchers pooled the results from all the studies.
What is unclear is whether these complications are due to the pregnant mother breathing in the smoke that comes off the end of a burning cigarette (side stream smoke), the direct effects on developing sperm when the father breathes in smoke after taking a puff from a cigarette (mainstream smoke), or both. It is also unclear when the effects of second-hand smoke harm the unborn child. However, because smoking does impact sperm development, fathers should quit smoking before trying to have a baby, say researchers.
“These results highlight the importance of smoking prevention and cessation to focus on the father in addition to the mother during the preconception period and during pregnancy,” write the authors.