Passive smoking and early miscarriage

Pregnant women exposed to large amounts of second hand smoke are more likely to miscarry during the early days of their pregnancy. Women who are trying to conceive should be aware that passive smoking increases the risk of miscarriage. Consequently, women trying to conceive should also try to avoid places where people are smoking. Researchers from the Harvard School of Public Health, USA, followed 526 non-smoking women in China who were trying to conceive. The team performed highly sensitive urine tests every day, which alerted them to a pregnancy only days after it happened. The researchers asked the participants' husbands how much they smoked, and found that women whose husbands smoked at least 20 cigarettes each day were 80 percent more likely to miscarry within 6 weeks of their last periods than women whose husbands did not smoke.Women whose husbands smoked less than 20 cigarettes per day showed a slightly higher risk of early miscarriage, as well. Also, the wives of heavy smokers also appeared to take slightly longer to achieve a pregnancy that lasted at least 6 weeks than the wives of light or non-smokers.

According to the researchers smoking may influence miscarriage risk by exerting a toxic effect on the pregnancy itself, or by disrupting the levels of crucial hormones. Though people are generally aware of the dangers of smoking, it is important for the public to know that passive smoking too is harmful.