The dangers of secondhand smoke exposure have long been recognized by the medical community, with continuing studies finding mounting evidence of the adverse effects of cigarette smoke. A recent study from Roswell Park Cancer Institute and the University of Buffalo has now made the harrowing link between passive smoking and miscarriage, with inadvertent exposure to cigarette smoke leading to a pronounced increase in fetal loss.
Secondhand smoke exposure was also found to influence rates of stillbirths and tubal ectopic pregnancy. The study looked specifically at women who had continued exposure to secondhand smoke over the course of their lifetimes, as opposed to exposure during pregnancy only. The control group, conversely, was comprised of women who had never been exposed to secondhand smoke.
"This study demonstrated that pregnancy outcomes can be correlated with secondhand smoking. Significantly, women who have never smoked but were exposed to secondhand smoke were at greater risk for fetal loss," said study leader Andrew Hyland, PhD, Chair of RPCI's Department of Health Behavior.
The study also examined adverse pregnancy outcomes of women who identified as active smokers in the past. Unsurprisingly, women who were active smokers at some point also had a higher risk of spontaneous abortion, stillbirths, and ectopic pregnancies. Overall, data was collated from 80,762 women who had been surveyed as part of the Women's Health Initiative Observational Study.
Lifetime exposure to secondhand smoke was measured as greater than ten years of exposure during childhood, greater than 20 years in the adult home environment, and greater than ten years in the adult work environment.
Co-author Jean Wactawski-Wende, PhD, Professor in the Departments of Social and Preventive Medicine and Obstetrics and Gynecology, referred to the large pool of test subjects in obtaining accurate data from which the findings drawn. "As a result of the Women's Health Initiative Observational Study, participants came from a broad range of geographic areas and had multiple ethnic, educational and socio-economic backgrounds. This allowed for a comprehensive assessment of detailed information on exposures, outcomes and potential confounders," she said. Generally, younger women who were better educated around the dangers of smoking carried pregnancies to full term at a higher rate than women who lacked similar educational status.
"This study offers new information for women regarding the lifetime impact secondhand smoke can have on reproductive outcomes and their ability to successfully bring a pregnancy to full term," said Dr. Hyland. "The strength of the study also provides public-health professionals and others with information upon which to base health guidelines about the significant consequences of secondhand smoke."
The study, titled Associations of lifetime active and passive smoking with spontaneous abortion, stillbirth and tubal ectopic pregnancy: a cross-sectional analysis of historical data from the Women's Health Initiative, was published in Tobacco Control on February 26 2014.