Nicotine patches fail most pregnant smokers

Nicotine replacement therapy is widely used to help smokers kick the habit, but new research raises major doubts about its effectiveness during pregnancy.

The largest clinical trial ever to examine the use of nicotine patches in this setting found little evidence that the treatment helps pregnant women stop smoking.

Adherence with therapy was very low, with fewer than 1 in 10 women still wearing the patches after one month.

Nicotine Replacement During Pregnancy

Smoking during pregnancy increases the risk of miscarriage, preterm delivery, birth defects, and even sudden infant death.

Most women who smoke are highly motivated to stop when they become pregnant, but many are not successful.

Researcher Tim Coleman, MD, of the University of Nottingham in the United Kingdom, says it is clear that standard-dose nicotine replacement therapy is not a useful strategy for helping them achieve their goal. And at this point, it's not clear if nicotine replacement is totally safe for pregnant women, adding to Coleman's argument.

The study appears in the March 1 issue of The New England Journal of Medicine.

"There is no evidence that standard-dose nicotine replacement therapy works, so I can't see much point in recommending it to women who are pregnant," he says.

According to the CDC, about 45% of women who smoke prior to becoming pregnant give up the habit during pregnancy, but more than 1 in 10 women (13%) in the U.S. report smoking during their last three months of pregnancy.

Safety of Nicotine Treatment Not Known

Why were so many highly motivated women unable to quit smoking to protect their babies from harm?

"These women had high-quality behavioral support, yet most of them only stayed on the treatment for two to four weeks," Coleman says. "This suggests that either they did not trust that the treatment was safe for their babies or that it wasn't working for them."

He cites findings from a previous study suggesting that pregnancy alters the metabolism of nicotine so that more may be needed to get the same effect.

If this is true, Coleman says higher doses of nicotine than are delivered in most patches may be needed during pregnancy, but the safety of this approach is not known.

University of Connecticut School of Medicine professor of medicine and Ob-Gyn Cheryl Oncken, MD, says more research is needed to determine if nicotine replacement at any dose is safe during pregnancy.

Even though the new study was four times larger than any previous trial, she says low adherence kept it from addressing the safety question.

"We need a study where women use the patch as directed for enough time to determine its safety," she says.

Behavioral Therapy Proven to Work

Oncken and Coleman agree that in the absence of such research, nicotine replacement therapy cannot be recommended as an effective approach to help pregnant women quit smoking.

Behavioral therapy has been shown to be an effective smoking cessation strategy, and both advise pregnant smokers to seek out quality behavioral treatments to help them kick the habit.

Other tips include:

• Chose a "quit day" and throw out all cigarettes, lighters, and ashtrays on that date.
• Stay busy and get plenty of exercise to keep your mind off cravings.
• Avoid places and activities associated with smoking.
• Ask a friend or partner for help, and talk to them when you feel like smoking.