RESUMEN
INTRODUCTION: Tai Chi is a traditional Chinese martial art developed over 300 years ago. Although studies report that Tai Chi benefits practitioners' cardiovascular health, respiratory system and psychological outcomes, only limited studies have evaluated the effects of Tai Chi on pregnant women. More evidence is needed to examine the effects of a Tai Chi exercise programme among pregnant women. METHODS AND ANALYSIS: This is a randomised controlled trial to investigate the effects of a 12-week theory-based Tai Chi programme on improving physical activity levels, exercise self-efficacy and health outcomes among pregnant women. A total of 136 low-risk pregnant women (68 per group) were recruited and randomly assigned to receive usual care or usual care with the Tai Chi programme consisting of two group-based educational sessions and three Tai Chi sessions over 3 months. A Tai Chi video was provided to the participants to facilitate self-practice at home. Outcomes including physical activity levels, exercise self-efficacy, weight gain, prenatal depressive symptoms and prenatal anxiety symptoms were evaluated at baseline (T0), 6th week after intervention commencement (T1) and 1 week after intervention completion (ie, post-intervention) (T2). Intention-to-treat analysis and generalised estimating equations model will be used to analyse repeated outcome measures. ETHICS AND DISSEMINATION: The study has been approved by the Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Research Ethics Committee (Ref. 2022.043-T). Written consent was obtained from each participant. The findings will be disseminated in peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: ChiCTR2200059920.