Functional ovarian reserve in transgender men receiving testosterone therapy: evidence for preserved anti-Müllerian hormone and antral follicle count under prolonged treatment

Abstract STUDY QUESTION Is the functional ovarian reserve in transgender men affected by testosterone therapy? SUMMARY ANSWER Serum anti-Müllerian Hormone (AMH) levels slightly decrease during testosterone treatment but remain within the normal range, suggesting preserved follicular ovarian reserve. WHAT IS KNOWN ALREADY Few small studies have investigated the impact of gender-affirming treatment on reproduction in transgender men. Conflicting results were reached concerning ovarian morphology and AMH levels in this context. STUDY DESIGN, SIZE, DURATION The study consisted of two arms. The first arm was a prospective pilot study, which enrolled 56 transgender men (median age 22.5 [interquartile range (IQR)—19–27.7] years), 27 of whom had polycystic ovary syndrome (PCOS), prior to the initiation of gender-affirming testosterone therapy. A structured assessment was conducted prior to, and at 3 and 12 months after treatment initiation. The second arm was a cross-sectional study that comprised 47 transgender men (median age 24 [IQR—20–31] years) who received testosterone for a median duration of 35 [IQR 13–62] months. The main outcome measures were serum AMH and antral follicle count (AFC) as indices of ovarian follicular reserve. PARTICIPANTS/MATERIALS, SETTING, METHODS The study was conducted at a tertiary center for transgender health. Gender-affirming therapy was administered according to standard practice. AFC was determined by pelvic (abdominal or transvaginal) ultrasound and blood collection for measurements of AMH, testosterone, estradiol, LH and FSH was performed at the designated time-points. MAIN RESULTS AND THE ROLE OF CHANCE Prospective arm for the entire group we observed a decrease of 0.71 ng/ml in AMH levels between baseline and 12 months (P = 0.01). When expressed in age-specific percentiles, AMH went from the 47.37th to the 40.25th percentile at 12 months (P