Open Access Open Badges Study protocol

Physical activity as an aid to smoking cessation during pregnancy (LEAP) trial: study protocol for a randomized controlled trial

Michael Ussher1*, Paul Aveyard2, Isaac Manyonda1, Sarah Lewis3, Robert West4, Beth Lewis5, Bess Marcus6, Adrian H Taylor7, Pelham Barton8 and Tim Coleman9

Author Affiliations

1 Division of Population Health Sciences and Education, St George’s University of London, Cranmer Terrace, London, SW17 ORE, UK

2 Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, England

3 Division of Epidemiology and Public Health and UK Centre for Tobacco Control Studies, University of Nottingham, Nottingham, NG5 1 PB, UK

4 Health Behaviour Research Centre, Department of Epidemiology and Public Health, UCL, Gower Street, London, WC1E 6BT, UK

5 School of Kinesiology, University of Minnesota, Minneapolis, MN 55455, USA

6 Department of Family and Preventive Medicine, University of California, San Diego, CA, 92093-0628, USA

7 School of Sport and Health Sciences, Sport and Health Sciences, University of Exeter, Exeter, EX1 2 LU, UK

8 Health Economics, School of Health and Population Sciences, University of Birmingham, Birmingham, B15 2TT, UK

9 Division of Primary Care and UK Centre for Tobacco Control Studies, University of Nottingham, Nottingham, NG5 1 PB, UK

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Trials 2012, 13:186  doi:10.1186/1745-6215-13-186

Published: 4 October 2012



Many women try to stop smoking in pregnancy but fail. One difficulty is that there is insufficient evidence that medications for smoking cessation are effective and safe in pregnancy and thus many women prefer to avoid these. Physical activity (PA) interventions may assist cessation; however, trials examining these interventions have been too small to detect or exclude plausible beneficial effects. The London Exercise And Pregnant smokers (LEAP) trial is investigating whether a PA intervention is effective and cost-effective when used for smoking cessation by pregnant women, and will be the largest study of its kind to date.


The LEAP study is a pragmatic, multi-center, two-arm, randomized, controlled trial that will target pregnant women who smoke at least one cigarette a day (and at least five cigarettes a day before pregnancy), and are between 10 and 24 weeks pregnant. Eligible patients are individually randomized to either usual care (that is, behavioral support for smoking cessation) or usual care plus a intervention (entailing supervised exercise on a treadmill plus PA consultations). The primary outcome of the trial is self-reported and biochemically validated continuous abstinence from smoking between a specified quit date and the end of pregnancy. The secondary outcomes, measured at 1 and 4 weeks after the quit date, and at the end of pregnancy and 6 months after childbirth, are PA levels, depression, self-confidence, and cigarette withdrawal symptoms. Smoking status will also be self-reported at 6 months after childbirth. In addition, perinatal measures will be collected, including antenatal complications, duration of labor, mode of delivery, and birth and placental weight. Outcomes will be analyzed on an intention-to-treat basis, and logistic regression models used to compare treatment effects on the primary outcome.


This trial will assess whether a PA intervention is effective when used for smoking cessation during pregnancy.

Trial registration


Smoking cessation; Pregnancy; Physical activity; Intervention; Randomized controlled trial