Maad Rayan Publishing Company Biomedical Research Bulletin 2980-9924 3 4 2025 12 29 Psychometric Validation of the Persian Version of the Fertility and Infertility Treatment Knowledge Score 153 157 10.34172/biomedrb.9106 EN Hamidreza Maghsoudlloo Tahereh Fathi Najafi Ali Nakhaei https://orcid.org/0009-0003-9411-2846 Bita Saifi https://orcid.org/0000-0002-3077-9532 Journal Article 10.34172/biomedrb.9106 2025 08 16 2025 09 15 Introduction: Fertility awareness among reproductive-age women is inadequate worldwide, and valid measurement tools are a prerequisite for targeted education. The 29-item Fertility and Infertility Treatment Knowledge Score (FIT-KS) is a validated knowledge measure developed in the United States. However, no Persian version was available. Therefore, this study assessed the psychometric properties of the Persian FIT-KS in Iranian women. Methods: This methodological study was conducted from 2024 to 2025 in Mashhad, Iran, following the COSMIN standards and established guidelines for cross-cultural adaptation of health measurement instruments. Forward and backward translation and expert committee review preceded face and content validity by 10 specialists (Lawshe’s content validity ratio, content validity index, and modified Cohen’s kappa). Furthermore, construct validity was examined through confirmatory factor analysis (CFA) among 250 women of reproductive age using AMOS 24 with maximum-likelihood estimation. Additionally, criterion validity was tested against the Persian Cardiff Fertility Knowledge Scale (CFKS-P) in a subsample (n=40). Finally, internal consistency (Cronbach’s alpha) and two-week test-retest reliability (intraclass correlation coefficient [ICC], n=50) underwent assessment. Results: One item on the average cost of IVF in the United States was removed after content validity (CVR=0), yielding a 28-item Persian FIT-KS. The mean age of participants was 30.14±6.05 years, and the mean total knowledge score was 15.8±4.2 out of 28 (56.4%). The two-factor CFA model showed acceptable fit (χ²/df≈1.52, GFI=0.86, RMSEA=0.05, SRMR=0.07). Moreover, criterion validity was supported by a strong correlation with the CFKS-P (Spearman r=0.75, P<0.001). Internal consistency (α=0.77) and test–retest reliability (ICC=0.75) were also acceptable. Conclusion: The Persian FIT-KS is a valid and reliable instrument for assessing fertility and infertility treatment knowledge among Iranian women of reproductive age.