Researchers recruited pregnant women who were smokers to participate in this trial.
Half of the women were given real nicotine patches and the other half received fake patches. All of the women were given access to behavioral support during follow-up visits.
These researchers found that the nicotine patch did not improve rates of quitting smoking or birth weights.
"Ask your doctor for help quitting smoking, especially if you're pregnant."
Dr. Ivan Berlin, a senior lecturer and hospital practitioner at Université Pierre et Marie Curie-Faculté de Médecine, led this study.
Smoking during pregnancy can be dangerous and have negative effects on the baby, according to Dr. Berlin and colleagues.
Nicotine replacement therapies like nicotine patches are sometimes recommended for people who wish to quit smoking.
This study investigated whether nicotine patches would help pregnant women quit smoking.
The researchers recruited 402 pregnant smokers who were between nine and 20 weeks along in their pregnancy.
Each participant smoked at least five cigarettes each day.
A total of 203 participants were given 16-hour nicotine patches and 199 participants received placebo (fake) patches.
The researchers requested that the participants attend seven follow-up visits.
During each follow-up visit, the researchers reminded the participants about the risk of smoking while pregnant and the importance of quitting smoking.
The women also received behavioral support from medical professionals who were trained in smoking cessation.
During the follow-up visits, the researches noted whether the women had smoked cigarettes since their quit date. They also noted how long it took for participants to smoke a cigarette after their quit date, if they did relapse. Additionally, the birth weights of the women's babies were recorded.
The researchers found that 5.5 percent of the women who had nicotine patches and 5.1 percent of the women in the placebo group quit cigarettes completely without relapsing.
On average, the time from the quit date to the first cigarette relapse was 15 days for both groups of women.
A total of 42 percent of the women with nicotine patches and 37 percent of the women with placebo patches cut their cigarette consumption in half between their first and last visits.
Both groups experienced a progressive decline in tobacco cravings.
The researchers found that the newborns of the 21 pregnant women who quit smoking completely had a higher average birth weight than those of the women who did not completely quit.
These researchers also found that the nicotine patch may increase blood pressure toward the end of pregnancy, which may result in adverse pregnancy outcomes.
The authors of this study concluded that nicotine substitution therapy did not play a role in whether pregnant women quit smoking completely.
In a separate editorial, Leonie Brose, a lecturer with the UK Centre for Tobacco and Alcohol Studies, wrote that health care practitioners should still help pregnant women quit smoking.
Brose suggested that behavioral therapy may be effective for women who do not respond to nicotine patches.
The study was published by BMJ on March 11.
The research was funded by the Ministry of Health in France. One of the researchers declared financial ties to pharmaceutical companies.