Physical activity levels and their multilevel determinants in pregnant women screened for contraindications: a cross-sectional study in Shanghai, China

BACKGROUND: Physical activity is recommended for a healthy pregnancy, yet activity levels among pregnant women remain insufficient worldwide. Although guidelines advise women with contraindications to seek professional guidance, the extent to which such contraindications influence actual activity levels, particularly in China, is unclear. OBJECTIVE: This study aimed to identify multilevel factors associated with physical activity levels among Chinese pregnant women, following a systematic screening for contraindications to physical activity. DESIGN: A cross-sectional study. SETTING: A university-affiliated tertiary hospital in Shanghai, China. PARTICIPANTS: A total of 821 pregnant women receiving routine prenatal care were recruited from March to September 2024. METHODS: Data were collected via a self-administered web-based questionnaire using a standardized two-stage screening procedure for contraindications to prenatal physical activity, along with validated scales for psychosocial factors. Physical activity levels were categorized using the International Physical Activity Questionnaire criteria. Multivariable logistic regression analysis was performed to identify factors associated with achieving moderate physical activity levels. RESULTS: The two-stage screening identified 127 women (15.47%) with contraindications: 29 (3.53%) with absolute contraindications (including severe respiratory, cardiovascular, or systemic diseases, fetal growth restriction, unexplained persistent vaginal bleeding, cervical insufficiency, and severe preeclampsia) and 98 (11.94%) with relative contraindications. The presence of contraindications was not associated with activity levels. Factors independently associated with higher odds of achieving moderate activity included: second trimester (aOR = 6.020, 95% CI: 3.314-10.935), third trimester (aOR = 2.678, 95% CI: 1.408-5.092), sufficient knowledge about prenatal physical activity (aOR = 3.365, 95% CI: 1.661-6.817), and higher scores in health belief, self-efficacy, and social support (each one-point increase associated with 10.5%, 17.4%, and 11.3% higher odds, respectively; all P < 0.05). Monthly household income showed a non-linear association: both lower- and higher-income women were less active than middle-income women (aOR = 0.378, 95% CI: 0.235-0.607; and aOR = 0.374, 95% CI: 0.219-0.641, respectively). CONCLUSIONS: Having a contraindication was not a significant independent predictor of physical activity levels in this sample. The key modifiable barriers were psychosocial and knowledge-based. Integrating systematic screening with personalized counseling that target these factors is recommended to effectively promote physical activity in prenatal care.