The progestin anchor: salvaging mature oocyte yield after an unplanned six-day gonadotropin pause in oncofertility—a case report

Objective To describe the retrieval of mature oocytes after an unplanned six-day gonadotropin-free interval during oncofertility ovarian stimulation. Design Case report. Subject(s) A 22-year-old active-duty soldier with a serous borderline ovarian tumor undergoing fertility preservation after ovarian surgery. Exposure(s) Progestin-primed ovarian stimulation using follitropin alfa and medroxyprogesterone acetate as the sole luteinizing hormone suppressor. Gonadotropin administration was unexpectedly interrupted for six days because of a non-deferrable military summons, while oral medroxyprogesterone acetate was maintained. Main Outcome Measure(s) MII oocyte yield and maturation rate. Results The patient had undergone ovarian surgery approximately nine months before the reference cycle and twelve months before the index cycle. Baseline anti-Müllerian hormone before fertility preservation was 1.77 ng/mL. In the reference cycle, 13 follicles ≥14 mm were present on the trigger day, and 13 oocytes were retrieved, including 6 MII oocytes that were vitrified. At the ultrasound assessment immediately preceding the gonadotropin-free interval in the index cycle, ultrasound showed 9 visible follicles, including 3 follicles measuring 10-14 mm and 6 follicles ≥14 mm. After the six-day interval, the trigger-day ultrasound showed 7 follicles ≥14 mm in diameter, ranging from 17 to 19 mm. Estradiol remained nearly stable across the interval, from 1,612 to 1,580 pg/mL, and endogenous progesterone on the trigger day was 1.1 ng/mL. Seven oocytes were retrieved, including 5 MII oocytes that were vitrified. Conclusion In this selected oncofertility patient undergoing progestin-primed ovarian stimulation, an unplanned six-day gonadotropin-free interval did not preclude retrieval of a clinically meaningful number of mature oocytes. Continuous medroxyprogesterone acetate may represent a biologically plausible protective factor against premature luteinization, although causality cannot be inferred from a single case.