Many of the negative health effects of secondhand-smoke exposure have been known for a while. There’s the increased risk of lung cancer, coronary heart disease, and stroke, and even low birth weight after maternal exposure, to name a few. But now, a new study from China has added another terrifying layer to the dangers of secondhand smoke: Nonsmoking women who were exposed to smoke in childhood may be more likely to suffer a miscarriage.
As Reuters reports, Chinese scientists found that nonsmoking women who lived with two or more smokers growing up were 20 percent more likely to have a miscarriage than women who weren’t exposed to secondhand smoke in childhood. Furthermore, women who were exposed to secondhand smoke at least five times a week as a child have a 14 percent higher risk of losing a pregnancy. Yet, nonsmoking women who only grew up with one smoker, or were exposed to smoke less than five times a week, weren’t found to have any increased miscarriage risk.
For the study, published in the journal Tobacco Control, scientists from the Chinese PLA General Hospital analyzed data from nearly 20,000 women over 50 years old, 57 percent of whom were exposed to secondhand smoke as a kid. “Our findings support the enactment of stringent national smoke-free laws and strict enforcement in China, and promotion of smoke-free homes to protect children, as well as the need for campaigns to change social norms of smoking and passive smoking,” the scientists wrote.
Of course, as with most studies, there were a few limitations. Namely, the study participants had to rely on childhood memories to provide some of the data. Additionally, the scientists weren’t able to figure out if the women were exposed to smoke during their pregnancies, or how old some of the women were when they had miscarriages.