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

Michael Ussher, Paul Aveyard, Isaac Manyonda, Sarah Lewis, Robert West, Beth Lewis, Bess Marcus, Adrian H. Taylor, Pelham Barton, Tim Coleman

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


Background: 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.Methods/design: 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.Discussion: This trial will assess whether a PA intervention is effective when used for smoking cessation during pregnancy.Trial registration: ISRCTN48600346.

Original languageEnglish (US)
Article number186
StatePublished - Oct 4 2012

Bibliographical note

Funding Information:
This research has been conducted independently by St George’s University of London. It is funded by the Department of Health (DH) as part of the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) program (project number 07/01/14). The views and opinions expressed in this paper are those of the authors and do not necessarily reflect those of the HTA program, NIHR, NHS or the DH. We thank all the patients and staff participating in the trial and also to the members of our trial steering committee (TSC) for their valuable support. We thank all the researchers who have worked on the trial: Ory Bolooki, Janet Brown, Sarah Cleary, Caroline Dixon, Julie Fuller, Gail Harding, Maggie Hart, Tracey Kilbane, Rachel Lex, Zoe Magrath, Ilia Papachristou, Maureen Quin, Beth Steff, Bettina Wanninkhof. We also thank the trial administrator Mary Apps, including for her assistance with preparing this manuscript.


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


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