Continuous ovarian stimulation: a proof-of-concept study exploring the uninterrupted use of corifollitropin alpha in duostim cycles for enhanced efficiency and patient convenience (Alicante protocol)

Objective To explore the use of weekly continuous dosing of corifollitropin alfa in DuoStim cycles. Design Pilot matched case-control study Setting Fertility center in Alicante, Spain. Patient(s) Cases were defined as DuoStim cycles performed from November 2022 to May 2023 receiving weekly continuous dosing of corifollitropin alfa (n=15). Controls were chosen from a database comprising DuoStim cycles conducted at our institution during the years 2021/2022. Matching was done on a 1-to-1 basis, based on AMH values (+/- 0.4 pmol/l) and age (n=15). Intervention(s) Injections of corifollitropin alfa once every eight days, along with uninterrupted oral administration of micronized progesterone 200 mg/day (for LH surge prevention) throughout the follicular and luteal phases for ovarian stimulation. Oocyte retrieval. Main outcome measure(s) Total number of cumulus-oocyte complexes and metaphase II oocytes obtained in follicular + luteal phase stimulation. Secondary outcomes evaluated fertilization rates, number of blastocysts, days of stimulation, number of injectables required and gonadotrophin cost. Result(s) The study group achieved similar total oocyte and MII yield versus daily-FSH protocol (13.3±6.9 vs 11.8±6.1, p0.2 and 10.4±6.3 vs 9.2±4.6, p0.2, respectively). All secondary outcomes showed no significant differences. The study group experienced a significant reduction of injections to complete a DuoStim cycle [4.5±1.4 vs 35.2±12.2, p0.0007; MD -30.7, (95%CI, -37-5 to -23.9)]. Conclusion(s) Corifollitropin alfa on a weekly basis throughout a DuoStim cycle yields an equivalent number of oocytes as standard daily-FSH administration while drastically reducing the number of required injections.