Assessing attitudes towards surrogacy: psychometric validation and invariance testing of the ATSS-PT

OBJECTIVE: This study adapted and evaluated the psychometric properties of the Attitudes Towards Surrogacy Scale (ATSS) for use in Portugal. METHODS: A total of 443 adults residing in Portugal completed the Portuguese version of the scale, hereafter referred to as the ATSS-PT, along with measures of psychological distress, attitudes towards assisted reproductive technologies, populist attitudes, and sociodemographic variables. The adaptation process included translation, back-translation, expert review, and pilot testing. Exploratory and confirmatory factor analyses were conducted to examine the scale's factorial structure, reliability, validity evidence, measurement invariance, group differences, and predictors. RESULTS: Exploratory and confirmatory factor analyses supported a three-factor structure comprising Surrogacy Ethical Context, Acceptance of Surrogacy, and Financing and Legalising Surrogacy, although bifactor results indicated the predominance of a general attitudes factor. The model showed acceptable fit, and the total scale and subscales demonstrated adequate to high internal consistency. Convergent validity was supported by the association with attitudes towards assisted reproductive technologies, whereas discriminant validity among the subscales was only partially supported, particularly due to the strong correlation between Acceptance and Financing/Legalising. LGBTQIA+ participants reported more favourable attitudes than heterosexual participants. Political ideology emerged as the only significant predictor, although the regression model explained a modest proportion of variance. CONCLUSION: The ATSS-PT appears to be a promising research instrument for assessing attitudes towards surrogacy in Portugal. However, the total score should be prioritised, and subscale-level interpretations should be made cautiously. Further validation in more representative samples is recommended.