Prevalence of Polyendocrine Metabolic Ovarian Syndrome (PMOS) in treatment-naïve trans people assigned female at birth: A systematic review and meta-analysis

Introduction The prevalence of PMOS among treatment-naïve trans people assigned female at birth (AFAB) remains uncertain, yet its identification has important implications for cardiometabolic risk assessment and individualized clinical care.Aims To estimate the pooled prevalence of PMOS in treatment-naïve trans people AFAB and to assess the methodological quality of available evidence.Methods A systematic review and meta-analysis was conducted in accordance with PRISMA 2020. Studies reporting PMOS/PCOS prevalence in treatment-naïve trans people AFAB were included. Prevalence estimates were pooled using random-effects models with logit transformation and Hartung-Knapp adjustment. Heterogeneity was assessed using Cochran’s Q and I2. Prediction intervals, sensitivity analyses, leave-one-out analyses, and exploratory meta-regression were performed. Small-study effects were evaluated using the Doi plot and Luis Furuya-Kanamori (LFK) index. Risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.Results Ten studies comprising 1,010 treatment-naïve trans people AFAB were included, with 286 PMOS cases. Eight studies explicitly enrolled female-to-male participants, trans men, or transmasculine participants identifying as male; one used the broader category of transgender adults AFAB; and one included both trans men and nonbinary people AFAB. The pooled prevalence was 28.7% (95% CI 22.1–36.3%), with moderate-to-substantial heterogeneity (I2 = 66.1%). The 95% prediction interval ranged from 14.0 to 49.9%. Pooled estimates remained stable across all predefined sensitivity analyses (range: 27.9–29.3%). No evidence of small-study effects was detected.Conclusions PMOS is a common finding among treatment-naïve trans people AFAB, with approximately one in three individuals meeting diagnostic criteria in the absence of testosterone therapy. These findings highlight the importance of comprehensive endocrine and cardiometabolic assessment at baseline within an individualized and affirming model of care.