O-182 The clinical value of rescued MI-oocytes. Retrospective analysis of 625 MI-oocytes versus 2124 sibling MII-oocytes obtained in 285 fresh donor ICSI cycles

Abstract Study question What are the developmental competence and clinical value in ICSI cycles of retrieved metaphase-I oocytes matured vitro (rescued-MI) to metaphase-II (MII) stage? Summary answer Rescued MI-oocytes showed lower but similar post-implantation than their sibling MII-oocytes, thereby contributing a + 9.5% relative-increase cumulative-live-birth rate per completed-cycle. is known already typically excluded from ICSI. Nevertheless, some authors reported use cancer or poor responder patients. On average, 15-20% IVF immature, 45% them may mature within few hours culture. These rescued-oocytes developmental, chromosomal reproductive competence. Regardless, they might be valuable for To date, most studies were conducted including patients using own oocytes, thus implicitly involving bias infertility prognosis. Here we aimed at outlining rescued-MI context egg donation cycles. design, size, duration Observational study private center 284 fresh oocyte (Jan-2020 Dec-2021). Two after oocyte-retrieval, all identified denudation cultured 1-2 additional hour(s). If reaching MII-stage, inseminated via with ejaculated sperm, as MII-oocytes. Single culture continuous media was conducted. MI- MII-derived embryonic cohorts monitored compared. One-hundred-fifty-three same period had no MI-oocyte available. Participants/materials, setting, methods Two-hundred-eighty-four 272 recipients (42.1±4.0 years) 215 donors (25.5±5.0 years). All sperm samples (42.3% fresh; 15% oligoasthenoteratozoospermic). The number MII-oocytes 2.2±1.3 (range:1-7) 7.5±1.6 cycle, respectively. 1.7±1.2 (0-6) (rescue-rate: 78.1±33.4%) inseminated. Embryological data compared between cohorts. Clinical relative contributions also reported. Main results role chance mean fertilization cohort 54.3±43.0% 74.4±18.1%, respectively (paired t-test<0.01). blastulation zygotes 53.1±44.4% 59.1±25.9%, t-test=0.1). Overall, 0.5±0.7 (0-4) MI-derived blastocysts obtained adding up 3.2±1.7 ones, resulting 20.8±40.1% (0 300%) increase cycle. 268 (94%), 247 (89.7%), 188 (66.2%) ≥1, ≥2 ≥3 blastocyst(s), rates 1.1% (N = +3), +4.9% +12) +7.4% +24) due use. 19 out 63 transferred resulted live-birth (30.2%, 95%CI 19.6-43.2) versus 124 399 ones (31.1%, 26.6-35.9; p 0.99). We 4 miscarriages 27 pregnancies (14.8%, 4.8-34.6) 38 162 (23.5%, 17.3-30.9, 0.45), 70% 199/284) concluded, cumulative-live-birth-rate 61.3% 122/199). This +18) Among 85 non-completed cycles, (22.4%) have still Limitations, reasons caution Retrospective study. A cost-effectiveness analysis warranted, especially because involves workload costs. 31% 44/140) ≥1 supernumerary cryopreserved blastocysts. Many not concluded. Gestational/perinatal outcomes More eggs and/or testing needed. Wider implications findings Rescuing available possibly cumulative-live-birth-rate. this practice higher production more Mostly prognosis couples benefit use; therefore couple-specific decision-making process desirable. Trial registration n/a