Endometriosis in Transgender Men – a Systematic Review with Metanalysis

Study Objective To assess the prevalence of endometriosis in transgender men during surgery and clinical treatment for the reported symptoms. Design Systematic review. Setting N/A. Patients or Participants Transgender men that were being treated at their institutions with or without presenting pelvic pain at the time of their investigation. Interventions A literature search was performed using the PubMed, Embase, Web of Science (WOS) and AAGL JMIG Abstracts since inception to April 4th, 2021, with no language restrictions. Two authors screened for study eligibility and extracted data. Metanalysis of the prevalence and heterogeneity was calculated with the MetaXL package whether two studies could be pooled. Quality of the studies were measured by the Newcastle-Ottawa Scale (NOS) for cross-sectional studies. Measurements and Main Results Our search strategy retrieved 102 results (PubMed =6, Embase=19, WOS = 6, AAGL/JMIG Abstracts =71). Of these, only 2 retrospective studies were included, comprising 102 patients. One study focused on patients under 26 years that were followed in an outpatient clinic (n=35); the other described intraoperative findings for patients undergoing hysterectomy as gender affirmation surgery (n=67). The pooled prevalence of endometriosis in this population was 25.14% (17.24-33.94%) and the frequency of patients using testosterone without other medications and presenting dysmenorrhea was 70.58% (63.87-80.91%); mean pooled duration of using testosterone was 25 months. Five patients were using combined testosterone and progestins. Stage 1 (40%) and 2 (32%) endometriosis were the most reported findings. In one study, endometriosis was found in 21.9% of the patients without pelvic pain. Both studies scored 4 out of 10 in the NOS assessment. A high heterogeneity was found across the studies. Conclusion The prevalence of endometriosis in transgender men is higher than the female cisgender population. Surgeons must perform a careful intraoperative assessment of endometriotic foci within this group of patients. However, these data need confirmation with future, prospective studies.