The use of an electric blanket during early pregnancy may slightly increase the risk of miscarriage, a new study suggests. Electrically heated beds can increase exposure to electromagnetic fields, or EMFs. The level can range from three times higher than typical home background levels, to that found near high-voltage transmission lines, according to a study from researchers at Yale.

In the new study, women who used an electric blanket during early pregnancy were 1.74 times more likely to have a miscarriage than women who did not. The blanket users also had more education, were more likely to consume alcohol and were more likely to work, though there was still a small increase in risk even after the researchers took those factors into account. The study indicates that electric blanket use at the time of conception and in early pregnancy may be associated with increase in risk of pregnancy loss.

Epidemiology (1998;9:36-42)