Counseling alone does not seem to help pregnant women quit smoking, according to a review of previous studies that concludes more research on the use of nicotine replacement and other therapies during pregnancy may be needed.

Published in the British Journal of Obstetrics and Gynaecology, the analysis included eight clinical trials of nearly 3,300 pregnant women. Researchers looked at whether counseling helped pregnant women quit smoking after six months.

Four of eight trials showed no difference between groups of pregnant women who got smoking-cessation counseling and those who didn’t, while the remaining four studies showed just a slightly lower quit rate in women who didn’t receive the counseling.

In the study with the highest success rate, for instance, just 24 percent of women who got counseling were able to quit, compared to twenty-one percent who didn’t get counseling.

In other words, three out of four moms-to-be in that study continued to smoke whether they had counseling or not, lead author Dr. Kristian Filion noted in an email.

“We were a little surprised by the small number of women that remained abstinent and by the small effect of counseling,” he told Reuters Health.

Filion doesn’t recommend abandoning counseling as an intervention, but he does see a need to study more effective approaches.

“Evidence regarding the safety and effectiveness of nicotine replacement therapies in pregnant women is limited,” he said. “More research in this area is needed so that we can better understand the risk-benefit ratio of nicotine replacement therapies in pregnant women.”

Dr. Nancy A. Rigotti, who directs the Tobacco Research and Treatment Center at Massachusetts General Hospital in Boston and who was not involved in the study, also agrees that medication should be considered to help pregnant smokers quit.

“There’s a concern using any medication in pregnant women,” Rigotti told Reuters Health. “But if a woman continues to smoke, exposing the fetus to nicotine and carbon dioxide, I would argue that it would be safer for her to take the small risk of taking a medication.”

U.S. Public Health Service guidelines recommend nicotine replacement therapies and drugs such as Wellbutrin and Chantix to help people stop smoking, notes Rigotti. But she wouldn’t suggest that pregnant women try Chantix, she added.

In 2009, the FDA required the drug’s maker Pfizer to add a so-called black box warning on the label listing side effects such as depression, suicidal thoughts and, just recently, the drug’s link to an increased risk of heart problems.

“It’s a relatively new medication,” Rigotti said. “There really is a lack of animal data to address any questions, and until we know more, we should be careful to use it in pregnant women. It probably wouldn’t be my first choice.”

Despite public awareness of the dangers of smoking, more than 13 percent of pregnant American women smoked in 2005, according to the Centers for Disease Control and Prevention.

Using counseling, nicotine replacement and other therapies that might help in a quit attempt before getting pregnant is a woman’s best bet, said Filion.

“When women think about getting pregnant, it’s probably the best time to intervene,” he explained. “It’s when they can use these drugs and increase the likelihood of quitting.”

SOURCE: British Journal of Obstetrics and Gynaecology, online August 22, 2011.