The study is published in the March 1 issue of the New England Journal of Medicine.
The U.S. Centers for Disease Control and Prevention does not recommend nicotine replacement in pregnant women, and ob-gyns typically use it as a last resort -- only when women are unable to quit on their own or with counseling, said Dan Jacobsen, a nurse practitioner at the Center for Tobacco Control at the North Shore-LIJ Health System in Great Neck, N.Y.
Safety concerns are one reason nicotine replacement isn't used all that often, Jacobsen said.
Smoking during pregnancy is associated with low birth weight babies, which can impact their growth and development throughout life. Smoking has also been associated with miscarriage, stillbirth and sudden infant death syndrome.
But the nicotine itself may affect the fetus. A study in the March issue of Pediatrics by researchers in the Netherlands found that exposure to nicotine -- either from cigarettes or nicotine replacement therapy -- was associated with a significantly increased risk of colic.
Colic, which usually starts when a baby is a few weeks old, is when an infant cries excessively and inconsolably for at least three hours a day, more than three days a week, for more than three weeks.
Experts believe nicotine may alter serotonin receptors in the gut.
Other research suggests that pregnant women clear nicotine from their bodies more rapidly, Jacobsen said. That may make the normal dosing in a nicotine patch (15 milligrams daily) insufficient to quell cravings, he suggested.
Higher levels of nicotine than the standard dose might be the answer for pregnant women, but such a study would raise safety concerns, Jacobsen noted.
For her part, Oncken said, it would be useful to know whether women in the study started smoking again, and then quit using the patch; or if they quit using the patch and then started smoking aga
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