P-640 No impact of Progestin Primed Ovarian Stimulation (PPOS) on euploid blastocyst rate per cohort of metaphase-II oocytes during PGT-A cycles: a case-control study

Abstract Study question Can progestins be used to prevent spontaneous LH surge during ovarian stimulation (OS) without affecting the euploid blastocyst rate (EBR) per metaphase-II (MII) oocytes? Summary answer Progestin Primed Ovarian Stimulation (PPOS) (conducted with norethisterone acetate) and conventional-OS GnRH-antagonist show similar EBR MII-oocytes What is known already PPOS a novel OS protocol based exogenous progesterone inhibit ovulation as an alternative GnRH analogues. The rationale of its use that multiple follicular waves arise cycle no occurs luteal phase. effectiveness safety have been supported lately in literature. A recent study reported number blastocysts after medroxyprogesterone versus GnRH-antagonist. design, size, duration Case-control involving advanced-maternal-age women undergoing ICSI PGT-A at two private IVF centers (May-2017 February-2020). 80 were matched 160 control on maternal-age reserve markers. Patients poor-ovarian-reserve (AFC<3), premature-ovarian-failure, III-IV stage endometriosis, cyst, severe-male-factor, PGT-SR or PGT-M excluded. was primary outcome. All other embryological clinical outcomes reported. Participants/materials, setting, methods Both groups underwent recombinant-FSH GnRH-agonist trigger; only difference acetate 10mg/day administered orally patients starting from second day menstrual until trigger. group, instead, conventional antagonist protocol. laboratory procedures both groups: ICSI, culture, trophectoderm biopsy, comprehensive-chromosome-testing report non-mosaic aneuploidies vitrified-warmed single-embryo-transfers (SETs). Main results role chance mean fertilization blastulation 2PN-zygotes among (75.5%±21.8% 71.7±20.7%, p = 0.1; 56.5%±27.7% 53.2%±27.5%, 0.4, respectively). No for (15.4%±19.8% 14.8%±18.2%, 0.9). biopsied terms morphological quality development. total 47 86 SETs conducted groups. There live-birth-rates (LBR) SET (N 19/47, 40.4%, 95%CI 26.7-55.7 N 35/86, 40.7%, 30.4-51.8, 0.9), nor miscarriage pregnancy 1/20, 5%, 0.3-26.9 3/36, 8.3%, 2.2-25.6, At last, cumulative-LBR concluded cycles (i.e., LB achieved transferable/all transferred blastocysts) also 19/68, 27.9%, 18.1-40.3 31/132, 22.0%, 15.4-30.2, 0.4). Limitations, reasons caution main limitation retrospective non-randomized design. More data are required, especially follicle recruitment, oocyte yield, gestational perinatal outcomes. Wider implications findings Norethisterone acetate-based has impact competence when compared OS. These promising support further investigation PPOS, view reduced cost, putative increase patient compliance decrease discomfort. Trial registration none