P-632 Micronized progesterone is better than GnRH antagonist to prevent LH surge in oocyte donation cycles

Abstract Study question Micronized progesterone or GnRH antagonist: which is better to control the LH surge in egg donation process? Summary answer better. Is just as effective antagonist and offers three additional advantages: cheaper, more convenient, saves intermediate controls. What known already antagonists have been widely considered prevent surge. When fresh embryo transfer not advised, micronized has shown be an alternative with some other very interesting advantages. If efficacy would prove similar, there will obvious advantages for preferential use of over protocol: oral vaginal administration preferred subcutaneous injection, cost much lower, can used from day one avoid inconvenient This particularly preservation, preimplantation genetic screening, oocyte programs. design, size, duration We retrospectively analyzed our program 2018 2021. All 358 cycles under short cycle protocol were studied. 67 donors Antagonist cycle; age 24,7 years (18 – 32) normal Body Max Index (22,2 Kg/m2 range 17-29) 291 24,5 (18-31) (22,3 18-29) Participants/materials, setting, methods cycle: suppression was accomplished by injections Ganirelix 0.25 mg starting when follicles >14mm E2 levels >400 pg/ml continued until triggering. No patients cancelled. endogenous (200 mg) once a at bedtime, stimulation 1 continuing Four Main results role chance cycle. 1115 oocytes retrieved (16,6 2-39). but two had vitrification: 65 patients, 916 (14,1 1-30) so 82% could preserved. (916 / 1115). From cycles, vitrified obtained (average 13,7). cancelled (no response two, follicular asynchrony personal reasons one. surges observed). 287 collections, 4683 (16,3 2-49). 285 3784 (13,3 2-37) 81% (3784 4683). 13,2) Both groups similar: total recovered per patient vs 16,6) maturation (81 82%) global (13,2 13,7) obviously cheaper than antagonist. Also, route commonly injections. And allows offer flexible donor making unnecessary set CONCLUSION: similar convenient controls avoided. Limitations, caution Although they are most likely fertilization pregnancy rates after both protocols should deeply analyzed. Wider implications findings also useful preservation screening Trial registration number applicable