Pregnancy and child

Pregnant pause in smoking

“Exercise is as effective as nicotine patches in helping women quit smoking”, reports The Daily Telegraph . A study in 32 pregnant women who smoked regularly found that exercising helped a quarter of smokers to quit. The women took part in supervised exercise at least once a week for six weeks and were “encouraged to do additional exercise on their own and were given advice and counselling on how to stop smoking and become more active”, the newspaper says. It adds that 20% of British women smoke, and 17% of pregnant women smoke, despite warnings over the damage to their own health and to that of their unborn children.

This preliminary research did not compare exercise with nicotine patches or any other stop-smoking strategy. Randomised controlled trials will be needed to assess how effective exercise is at promoting and maintaining smoking cessation. However, maintaining appropriate levels of physical activity during pregnancy will have health benefits for women, regardless of whether they smoke or not. Smoking carries health risks for mother and baby and if pregnant smokers wish to try using gentle exercise to reduce their cigarette cravings, this should be encouraged.

Where did the story come from?

Dr Michael Ussher and colleagues from the University of London, other universities and hospitals in the UK, the US and Spain carried out this research. There were two studies reported in this article; one received no external funding and the other was funded by the NHS. It was published in the peer-reviewed medical journal: BMC Public Health .

What kind of scientific study was this?

The two studies reported in this publication were both case series, looking at the feasibility of a physical activity intervention for pregnant women who smoke, aimed at increasing smoking cessation. In these pilot studies, the researchers wanted to find out how easy it would be to recruit women to take part, whether the women would stick with the intervention and what women thought of it.

For the first study, the researchers telephoned pregnant women who had made their first antenatal visit to one London hospital and identified as smokers on their records. They were then asked whether they would like to take part in the study, which was described to them. To be eligible, women had to be 12–20 weeks pregnant, to smoke at least one cigarette a day and to have done so for the past year, to want to quit and to have no medical reason why they could not take part in moderate intensity exercise. Women were not allowed to use nicotine replacement therapy (such as nicotine patches) during the study.

The women received weekly sessions consisting of 15 minutes of pregnancy-specific smoking cessation support (behavioural support and self-help guides), 15 minutes of physical activity counselling and 20–30 minutes of supervised exercise. Trained counsellors prepared the women for stopping, and the women stopped smoking on an agreed quit day during the second week of the study. The women had one session a week for six weeks, which consisted of moderate intensity exercise, such as walking in the local area or using an antenatal exercise DVD for 30 minutes. They were encouraged to use exercise outside of the supervised sessions to help reduce cigarette cravings and withdrawal. They were advised to be active for at least 110 minutes a week, starting with 10 minute sessions (as a minimum), and aiming for 30 minutes of moderate intensity activity at least five days a week. They were given a YMCA pregnancy exercise DVD and booklet to use at home and were encouraged to go for walks.

At the start of the study, the researchers assessed the women’s smoking habits, their confidence in being able to quit and other personal characteristics. After quit day, they asked the women at each exercise session how much they had smoked, and confirmed their reports by carrying out a carbon monoxide breath test. Physical activity levels in the previous week and attitudes to exercise were also recorded at each session. Assessments of smoking and physical activity continued up to eight months into the pregnancy.

The second study was similar in design, with adaptations based on what was learnt during the first study. The main differences were that women were sent a letter telling them about the study at the same time as the letter inviting them for their first antenatal appointment. The study was also advertised on posters and in talks at scanning clinics. The researchers increased the number of treatment sessions from six to 15, provided over an eight-week period (two sessions a week for six weeks, and one session a week for the next three weeks). One of the weekly exercise sessions consisted of using a 20–30 minutes of treadmill or stationary bicycle at the hospital, while the second session consisted of 20–30 minutes walking or using an exercise DVD at home, or exercise equipment at the hospital. Women were also given a pedometer and encouraged to walk 10,000 steps a day. One of the weekly sessions included 15 minutes of smoking cessation support and the other 15 minutes of physical activity counselling. The last three sessions included physical activity counselling and supervised exercise only.

What were the results of the study?

Across both studies, the researchers found that they were able to recruit about 12% of the 277 women whose medical records indicated they were smokers. At the start of the study, these 32 women reported that they smoked nine cigarettes a day on average, although carbon monoxide readings suggested they might have been smoking more. Less than a quarter of the women reported doing 30 minutes of moderate activity on five or more days a week.

After the intervention, eight of the 32 women (25%) managed to abstain from smoking up to their eight month of pregnancy. These women had attended 85% of the treatment sessions, and six of them had achieved the target of 110 minutes a week of physical activity by the end of treatment. Women in the first study (six treatment sessions) did not maintain this level of exercise by the eighth month of their pregnancy, but those in the second study (15 treatment sessions) did. When asked about the intervention, the women said that it increased their confidence in their ability to quit, reduced their cravings for cigarettes and helped them to control their weight.

What interpretations did the researchers draw from these results?

The researchers concluded that it would be possible to recruit pregnant smokers to take part in a trial of physical activity for smoking cessation. They suggest that a randomised controlled trial is now needed to assess how effective this intervention would be.

What does the NHS Knowledge Service make of this study?

These small pilot studies have shown that it is feasible to enrol pregnant smokers for a physical activity trial, and have provided important information to guide the content and delivery of the intervention for use in future trials. However, the fact that the women volunteered for an exercise programme combined with smoking cessation support suggests that they were keen to improve their health, and they may not be representative of all pregnant smokers (representing only 12% of all potential candidates for these studies).

Willingness to quit is the largest determinant of whether a person will be successful at giving up smoking, whatever the method used. As the authors acknowledge, it will not be possible to say whether the exercise intervention increases abstinence from smoking until they perform a randomised controlled trial comparing it with other strategies, such as the use of nicotine patches.

Smoking during pregnancy is harmful for both mother and baby; therefore women should take advantage of any support offered for quitting. Maintaining an appropriate level of physical activity during pregnancy will have health benefits and women should try to achieve this regardless of whether they smoke. If it is shown to help smokers to quit this will be a bonus.

Sir Muir Gray adds...

Many people have reported to me that they get the ‘nicotine twitches’ after stopping and that they have to do something to control the urge; this research supports their observation. The advice should be not only ‘stop smoking’ but also ‘when you feel like a fag go for a walk or a bike ride’.

NHS Attribution