By Steven Reinberg
What's more, only 57 percent of the women believed that e-cigarettes contain nicotine. And fewer than two-thirds of the women thought that e-cigarettes could be addictive.
"This study is concerning," said Dr. Edward McCabe, medical director of the March of Dimes.
E-cigarettes are nicotine delivery devices and nicotine can be addictive, McCabe said. In addition, exposing a fetus to nicotine -- which can pass from the mother through the placenta -- can result in low birth weight and preterm birth.
"There is also strong evidence in animal experiments that nicotine alters brain development," McCabe said. He added that the U.S. Surgeon General warns pregnant women not to use nicotine in any form.
Some e-cigarettes contain chemicals and heavy metals such as tin, chromium and nickel, which might harm a fetus, McCabe said.
Women need to be educated about e-cigarettes, he said. "It's not in the best interests of the companies making these products to provide this education. We would hope that there would be other sources of education," he said.
McCabe said he hopes the U.S. Food and Drug Administration will start regulating e-cigarettes sooner rather than later.
The results of the study were scheduled to be presented at the American Congress of Obstetricians and Gynecologists annual meeting in San Francisco. Findings presented at meetings are generally viewed as preliminary until they've been published in a peer-reviewed journal.
The research team -- led by Dr. Katrina Schafer Mark at the University of Maryland -- surveyed 316 pregnant women visiting a university-based outpatient obstetrics and gynecology clinic in Baltimore.
The researchers also found that among the women in the study, 13 percent had ever tried e-cigarettes. Nearly three-quarters of the women who had tried e-cigarettes believed they were less harmful than tobacco. In addition, most of these women also said that e-cigarettes could help them stop smoking.
"Misconceptions about electronic cigarettes are common among pregnant women, posing risks for both maternal and neonatal health," Mark's group said. The researchers added that screening and education regarding electronic cigarettes should be included in prenatal care.
Even the industry group the American Vaping Association says pregnant women shouldn't use e-cigarettes.
"All nicotine use during pregnancy should be avoided, whether the source be cigarettes, e-cigarettes, or nicotine replacement therapy products like nicotine gum and patches. Indeed, studies have shown that nicotine replacement therapy use by pregnant women is tied to low birth weight and preterm birth," said Gregory Conley, president of the American Vaping Association.