Abstract: Objective: To develop a questionnaire about the pregnancy weight management and protective motivation, and test its psychometric properties. Methods: Based on the protective motivation theory, an initial questionnaire was formed through literature analysis, semi-structured interviews and Delphi expert correspondence. Purposive sampling method was used to investigate 381 pregnant women, and the questionnaire was evaluated by item analysis method, content validity, structure validity, internal consistency reliability, combination reliability, and test-retest reliability. Results: The final pregnancy weight management and protective motivation contained six dimensions and thirty-two items; explorative factor analysis extracted seven common factors and retained six common factors, explaining 63.236% of variance contribution. Confirmatory factor analysis showed that χ2/df=1.331, RMSEA=0.047, CFI=0.942, IFI=0.927, TLI=0.917. The content of the questionnaire validity index was S-CVI/UA=1.00, S-CVI/AVE=0.92, and the I-CVI of each item was 0.83 to 1.00, and the overall Cronbach's alpha coefficient was 0.894. The Cronbach's alpha coefficient of each dimension was 0.652 to 0.920 respectively. The overall test-retest reliability of the questionnaire was 0.947, and the test-retest reliability of each dimension was 0.846 to 0.956. The combined reliability coefficient of each dimension was 0.563 to 0.915, respectively, and the squared variance extraction was 0.305 to 0.624. Conclusion: The pregnancy weight management and protective motivation questionnaire has good reliability and validity, so it can be used to evaluate the level of protective motivation for weight management in pregnant women in China, and it can predict the likelihood of pregnant women adopting weight management health behaviors to a certain extent. It provides basis and reference for the formulation and evaluation of weight management plan.

Key words: pregnant women; weight management; protection motivation; reliability; validity