Exposure to secondhand smoke is strongly linked to a woman’s increased risk of miscarriage, stillbirth and ectopic pregnancy, according to one of the largest and most comprehensive studies yet to examine the links between passive smoking and pregnancy.
Researchers from Roswell Park Cancer Institute looked at data from more than 80,000 women who went through the Woman’s’ Health Initiative.
Some of the women were current smokers (5,000), some were ex-smokers who had smoked at least 100 cigarettes (35,000) and some were non-smokers (41,000). All had been pregnant at least once.
“We observed significant associations between women who were active smokers during their reproductive years and three outcomes of fetal mortality—spontaneous abortion, stillbirth and tubal ectopic pregnancy,” the authors noted.
The data showed that women who never smoked were less likely to miscarry, have a stillborn or an ectopic pregnancy than either current or former smokers.
But when compared to women who never smoked or were exposed to secondhand smoke, women who experienced the highest levels of lifetime exposure to secondhand smoke were:
- 17 percent more likely to miscarry
- 55 percent more likely to give birth to a stillborn child
- 61 percent more likely to have an ectopic pregnancy
Smokers, when compared to women who never smoked who were not exposed to secondhand smoke, were:
- 16 percent more likely to miscarry
- 44 percent more likely to give birth to a stillborn child
- 43 percent more likely to have an ectopic pregnancy
Participants came from broad geographic backgrounds, across the U.S., having multiple ethnic, educational and socioeconomic backgrounds.
The study also found that women who were younger or better educated were less likely to miscarry or have complications. Women of minority ethnic backgrounds and those who were overweight were more likely to do so.
NBC 4’s chief medical editor Dr. Bruce Hensel said the reasons for these findings may have to do with decreased blood supply to the womb and developing baby, and is “one more reason to avoid all smoke whenever pregnant.”
If a woman who is pregnant or who wants to get pregnant works or lives with a smoker, they may cut down on exposure with designated smoking rooms, properly ventilated rooms, and by using air filters.