P-694 Desogestrel did not affect Follicular Output Rate (FORT) during controlled ovarian stimulation for oocyte vitrification: prospective cohort study

Abstract

Abstract Study question Does desogestrel an option for LH suppression during controlled ovarian stimulation for oocyte vitrification? Summary answer This new option for LH suppression did not affect FORT and, consequently, the number of collected oocytes for vitrification. What is known already Traditionally, LH suppression is achieved by using a gonadotropin-releasing hormone (GnRH) analogue. However, improved cryopreservation techniques and freeze-all strategies are introducing new concepts, including the possibility of using progesterone instead of GnRH analogues. Progesterone compounds are currently wide-used during ovarian stimulation for oocyte freezing for LH suppression. The use of oral medroxyprogesterone was previously shown to effectively prevent the LH surge, without impacting embryo development or pregnancy rates after frozen embryo transfer. The use of dydrogesterone with the same purpose was also effective. Desogestrel is a progesterone broadly known and accepted, and has good tolerability and low cost. Study design, size, duration A prospective cohort study was performed during the period of 2019-2021 including 75 patients submitted to oocyte freezing and 173 women matched by age as the controls (patients submitted to IVF for the first time). Participants/materials, setting, methods Patients from the control group used a flexible GnRH antagonist for LH suppression, and patients in the desogestrel group utilized desogestrel 75 mcg oral twice a day (starting from the beginning of gonadotropin to hCG/agonist day). All patients received the same gonadotropin regimen (recombinant FSH). The final oocyte maturation was equal for both groups (recombinant hCG and GnRH analogue agonist). The primary endpoint was the antral follicle responsiveness to follicle-stimulating hormone, measured by FORT. Main results and the role of chance Age [control group= 36 years (median 28-45); desogestrel group= 36 years (median 23-43); p = 0.793; Mann Whitney U test], baseline antral follicle count [control group= 8 (2-23); desogestrel group= 9 (2-21); p = 0.741; Mann Whitney U test] and anti-Mullerian hormone [control group= 1.5 (0.05-7.95); desogestrel group= 1.00 (0.01-16.00); p = 0.540; Mann Whitney U test] were similar between both groups. However, the controlled ovarian stimulation length was shorter in the control group [10.4±1.6 vs. 11.0±1.6; p = 0.044; t-student test,] and those patients utilized less gonadotropin than the desogestrel group [2736 UI ± 745 vs. 2933 UI ± 785; p = 0.047; t-student test,]. Finally, Follicular Output Rate (FORT) [control group= 45%; desogestrel group= 52%; p = 0.217; t-student test], number of collected oocytes [control group= 6 (1-33); desogestrel group= 8 (1-20); p = 0.293; Mann Whitney U test] and MII [control group= 5 (1-27); desogestrel group= 6 (1-19); p = 0.156, Mann Whitney U test] were the same between both groups. Limitations, reasons for caution The small sample size and the absence of randomization are the main limitations of our study. Since the first results were encouraging, a randomized study should be performed. Wider implications of the findings Desogestrel is a cheap and easy option to be used during controlled ovarian stimulation for oocyte vitrification, since the final results are the same. This is the first scientific report showing the use of desogestrel did not affect FORT and, consequently, the number of collected oocytes for vitrification. Trial registration number Not applicable