Evaluation of the mediating role of physical activity self-efficacy in the relationship between knowledge, social support, and physical activity in pregnant women with a high risk for gestational diabetes

Objective: This study aimed to examine the associations between knowledge, social support, and physical activity and explore the mediating role of physical activity self-efficacy in pregnant women with a high risk for gestational diabetes mellitus (GDM). Methods: A cross-sectional study was conducted in Guangzhou, China, from July 2022 to May 2023. Five hundred thirty-seven pregnant women with a high risk for GDM completed the Pregnancy Physical Activity Questionnaire, Pregnancy Physical Activity Self-Efficacy Scale, Pregnancy Physical Activity Knowledge Scale, Physical Activity Social Support Scale, and a socio-demographic data sheet. The mediation effect was tested using structural equation modeling (SEM) and the bootstrap method. Results: 42.5% of pregnant women did not meet the current physical activity guidelines. Physical activity self-efficacy (β, 0.16; P<0.001), knowledge (β, 0.15; P = 0.001), social support (β, 0.10; P = 0.019), education, and type of conception were predictors of physical activity. The SEM results found that physical activity self-efficacy mediated the association between physical activity and knowledge (β, 0.24; 95% CI, 0.17 to 0.32) and social support (β, 0.30; 95% CI, 0.20 to 0.39). The data fit of the model (RMSEA = 0.067, CFI = 0.851, TLI = 0.828, χ²/df = 3.440) was acceptable. Conclusion: This study found that the prevalence of being physically inactive was high in pregnant women with a high risk for GDM. The present study’s findings suggested that healthcare providers should try to enhance physical activity self-efficacy, knowledge, and social support of pregnant women with a high risk for GDM to improve their physical activity with a focus on physical activity self-efficacy.