Abstract: Objective: To adapt the Social Support Scale for Exercise into the Pregnancy Physical Activity Social Support Scale (P-PASSS), and to test its reliability and validity. Methods: The P-PASSS was adapted from the Social Support Scale for Exercise based on literature review and interviews with pregnant women, adjusted and revised the items through pilot study. Using the convenience sampling method, 495 pregnant women were selected to test the reliability and validity of the P-PASSS. Results: The P-PASSS included 4 dimensions and had 24 items in total. The content validity index of the scale was S-CVI/UA=0.92, S-CVI/AVE=0.98. The Cronbach's α coefficient was 0.95. The test-retest reliability coefficient after 2 weeks was 0.88. Four common factors were extracted by exploratory factor analysis and the cumulative variance contribution rate was 78.88%. The results of confirmatory factor analysis showed that the model fits well, indicating that the factor structure of the questionnaire was stable. Conclusion: The P-PASSS has good reliability and validity, which can be used to evaluate social support regarding pregnant women's physical activity.

Key words: pregnant women; physical activity; social support; reliability; validity