Smoking during pregnancy often leads to lower birth weight, higher infant mortality, and is linked to learning difficulties, problem behavior and asthma in childhood.
Michael Ussher and colleagues from St George's, University of London conducted two pilot studies into whether physical exercise could feasibly help pregnant women quit smoking.
For both studies, pregnant women over 18, who smoked at least a cigarette a day, were recruited 12 to 20 weeks into pregnancy. In one study, women did supervised exercise once a week for six weeks; in the other, women did two sessions of exercise a week for six weeks, then one session a week for three weeks.
The participants were also encouraged to do additional exercise on their own and all received advice and counseling towards stopping smoking and becoming more active.
A quarter of the 32 women recruited for the studies gave up smoking before giving birth.
According to Dr. Ussher, "These results are very encouraging and we are now conducting a randomized controlled trial with 850 women. Regular exercise is ideal for any pregnant women who smoke as it's obviously safe and the benefits are enormous".