Barriers to physical activity among pregnant women in China: a mixed methods study based on the COM-B model and the theoretical domains framework

Although physical activity has numerous benefits during pregnancy, most pregnant women remain physically inactive. This study aimed to explore barriers to physical activity among Chinese pregnant women through an integrated application of the Capability, Opportunity, Motivation, and Behavior model and the Theoretical Domains Framework. A sequential explanatory mixed methods study was conducted. First, a cross-sectional survey of 400 pregnant women with convenient sampling (December 2023–January 2024) was conducted using the Chinese version of the Barriers to Physical Activity during Pregnancy Scale. Data entered using EpiData version 3.1 were analyzed with SPSS version 27.0, employing descriptive statistics, univariable analysis, and multivariable regression to identify factors associated with barriers to physical activity among pregnant women. Subsequently, semi-structured interviews were conducted with 13 participants purposively sampled from the survey respondents. The interview data were organized using NVivo version 12.0 and analyzed through thematic analysis. Quantitative and qualitative findings were integrated via side-by-side comparison. The mean barrier score was (79.58 ± 10.97). Univariable analysis revealed that there were statistically significant differences in the scores of trimesters, desired delivery mode, parity, history of abortion, specific physical activity guidance during pregnancy, and pre-pregnancy habitual physical activity (all P < 0.05). Multivariable regression identified desired delivery mode, parity, specific physical activity guidance during pregnancy, and pre-pregnancy habitual physical activity as significant predictors (F = 6.081, P < 0.05), explaining 23.40% of the total variance. Thematic analysis mapped barriers to the Capability, Opportunity, and Motivation components and nine domains of the Theoretical Domains Framework, including skills, knowledge, memory, attention and decision processes, environmental context and resources, social influences, emotion, goals, belief about capability, and beliefs about consequences. Findings from both quantitative and qualitative studies were mapped to the two theoretical frameworks. This mixed methods study used the Capability, Opportunity, Motivation, and Behavior model and the Theoretical Domains Framework to identify barriers to physical activity among Chinese pregnant women. Future interventions should combine individualized counseling to enhance skills and motivation with family-level initiatives to provide supportive environments and accessible resources, integrating structured physical activity guidance into routine prenatal care.