Bad news for women attempting to quit smoking during pregnancy. A new study has found that nicotine patches do not appear to help.

It is already acknowledged that smoking during pregnancy is bad for the health of mothers and their babies. French researchers set out to assess the effectiveness of nicotine replacement therapies (NRT) in pregnant women who smoked.

They looked at just over 400 pregnant women who were between 12 and 20 weeks pregnant at the start of the study. All of the women smoked at least five cigarettes per day.

The participants were randomly selected to receive either 16-hour nicotine patches or placebo patches up to the time of delivery. All were assessed every month and all received smoking cessation support.

The researchers wanted to see who managed to completely abstain from smoking. They also looked at the birth weight of the babies - smoking increases the risk of having a low-weight baby.

The study found that nicotine patches did not increase smoking cessation among the women when compared to the placebo patches.

Just over 5% of the women in the nicotine patch group managed to completely abstain from smoking during pregnancy. This figure was roughly the same in the placebo group.

After a quit date was set, the average time to the first cigarette smoked was 15 days, irrespective of which group the women were in.

The birth weights of the babies were also similar, irrespective of which group the women belonged to.

"These are disappointing results and should encourage efforts to evaluate new approaches that are both drug and non-drug related. In the absence of evidence-based drug interventions, behavioural support remains the core intervention to help pregnant smokers to quit," the researchers said.

Details of these findings are published in the British Medical Journal.

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