Theory-based interventions aimed at promoting physical activity in pregnant women: A systematic review and meta-analysis of randomized controlled trials

The objectives were to assess (i) the quality of theory implementation, (ii) the application of behavior change techniques, and (iii) the effectiveness of theory-based interventions in promoting physical activity in pregnant women and improving maternal and neonatal outcomes. A systematic search was conducted across 8 databases (Cumulative Index to Nursing and Allied Health Literature, the Cochrane Library, EMBASE, MEDLINE, APA PsycINFO, PubMed, SPORTDiscus, and Web of Science) to identify randomized controlled trials published from database inception to 8 July 2023. The Cochrane risk-of-bias 2.0 tool was used to evaluate the quality of the included studies. The theory coding scheme was used to measure the quality of theory implementation, and behavior change techniques were coded according to behavior change taxonomy (version 1). The meta-analysis was performed using RevMan 5.3. The Grading of Recommendations, Assessment, Development, and Evaluation Approach was used to assess the certainty of evidence. Eleven studies met the study criteria. Nine studies were based on one theory, while two studies were based on a combination of two theories. The quality of theory implementation was generally moderate. A total of 24 unique behavior change techniques were extracted. The most commonly used types of behavior change techniques were 'instruction on how to perform the behaviour' (n = 9), 'goal setting' (behavior) (n = 8), 'action planning' (n = 7), and 'information about health consequences' (n = 7). Theory-based interventions significantly improved moderate-to-vigorous physical activity (standardized mean difference (SMD) = 0.17, 95 % confidence interval (CI) [0.04, 0.30], P = 0.01; moderate certainty of evidence), reduced the average gestational weight gain per week (mean difference (MD) = − 0.06, 95 % CI [− 0.11, − 0.01], P = 0.02; moderate certainty of evidence), and decreased the incidence of gestational diabetes mellitus (risk ratio (RR) = 0.64, 95 % CI [0.46, 0.89), P = 0.008; high certainty of evidence). However, the effects of theory-based interventions on total physical activity, total gestational weight gain and the incidence of gestational hypertension and preterm delivery were unclear (P > 0.05). (i) Most of the studies exhibited a moderate level of theory implementation quality. (ii) The use of theories varies, but common behavior change techniques were found across studies. (iii) Theory-based interventions can improve physical activity and maternal and neonatal outcomes and appear to be safe. Appropriate health behavior theories and behavior change techniques should be fully utilized in future interventions. PROSPERO: CRD42023440886. Theory-based interventions can improve physical activity and maternal and neonatal outcomes and appear to be safe. Appropriate health behavior theories and behavior change techniques should be fully utilized in the development of future interventions.