O-183 Forecast of Total and Mature Oocyte Number for Three Different Trigger Days using Machine Learning Prediction Models

Abstract

Participants/materials, setting, methods: If embryos were assessed at fertilisation check and found to be 1PN they were not discarded, but rather they were maintained in culture. If any such embryos successfully produced a blastocyst the patients received counselling from their fertility consultant and an embryologist, giving them the options to either go ahead with transfer (only IVF derived), have the embryos genetic status clarified using PGT-A, freeze without testing, or to discard the embryo. Main results and the role of chance: Of the 288 1PN embryos cultured (IVF and ICSI derived) 85 displayed signs of blastulation (29.5%). 134 of these were derived from ICSI with 20 forming blastocysts (14.9%). 154 were derived from IVF with 65 forming blastocysts (42.2%). Three IVF derived 1PN embryos have been transferred. Currently one is an ongoing singleton pregnancy , one is an ongoing twin pregnancy and the third has resulted in a live birth. 35 embryos were biopsied and underwent genetic testing to confirm their ploidy status. Six of these were ICSI derived, four of which were found to be haploid and two diploid. The other 29 tested embryos were derived from IVF. Of these, 27 were found to be diploid (93.1%) and two were shown to be triploid (6.9%). None were confirmed as haploid. Traditionally, PGT-A methods using NGS examine relative chromosome copy number, but in cases of haploidy/triploidy all of the chromosomes are decreased/in-creased in number, meaning there is no change in the relative number of individual chromosomes. We established embryo ploidy status using an advanced PGT method, genotyping thousands of polymorphisms scattered across the genome, which are essential for accurate diagnosis of haploidy/ triploidy. Limitations, reasons for caution: The sample size for genetically tested ICSI derived 1PN's is currently too small to clearly determine whether culture and testing of these embryos is beneficial to the patient. Patients who decided to transfer an embryo categorised as 1PN were made fully aware of the potential risks in doing so. Wider implications of the findings: These findings show that the culture of 1PN embryos is clinically beneficial to a large number of patients, especially those with poor prognosis who would otherwise have had a failed cycle. Genetic testing demonstrates that IVF derived 1PN embryos that reach the blastocyst stage are likely to have fertilised normally. Trial registration number: * Abstract citation ID: dead093.223 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 Study question: What are the developmental competence and clinical value in ICSI cycles of retrieved metaphase-I oocytes matured in vitro (rescued-MI) to the metaphase-II (MII) stage? Summary answer: Rescued MI-oocytes showed lower developmental but similar post-implantation competence than their sibling MII-oocytes, thereby contributing to a þ 9.5% relative-increase in the cumulative-live-birth rate per completed-cycle. What is known already: MI-oocytes are typically excluded from ICSI. Nevertheless, some authors reported their use in cancer or poor responder patients. On average, 15-20% of the oocytes retrieved in IVF are immature, but 45% of them may mature within a few hours of culture. These rescued-oocytes showed lower developmental, chromosomal and reproductive competence. Regardless, they might be valuable for some patients. To date, most of the studies were conducted including patients using own oocytes, thus implicitly involving the bias of infertility and poor prognosis. Here we aimed at outlining the clinical value of rescued-MI oocytes in the context of egg donation cycles. Study design, size, duration: Observational study conducted at a private IVF center including 284 fresh oocyte donation cycles (Jan-2020 to Dec-2021). Two hours after oocyte-retrieval, all MI-oocytes identified after denu-dation were cultured for 1-2 additional hour(s). If reaching the MII-stage, they were inseminated via ICSI with ejaculated sperm, as for sibling MII-oocytes. Single culture in continuous media was conducted. MI-and MII-derived em-bryonic cohorts were monitored and compared. One-hundred-fifty-three cycles in the same period had no MI-oocyte available. Participants/materials, setting, methods: Two-hundred-eighty-four cycles were conducted from 272 recipients (42.1 § 4.0 years) with fresh oocytes retrieved from 215 donors (25.5 § 5.0 years). All sperm samples were ejaculated (42.3% fresh; 15% oligoasthenoteratozoospermic). The number of MI-and MII-oocytes after denudation was 2.2 § 1.3 (range:1-7) and 7.5 § 1.6 per cycle, respectively. 1.7 § 1.2 (0-6) MI-oocytes matured in vitro (rescue-rate: 78.1 § 33.4%) and were inseminated. Embryological data were compared between sibling MI-and MII-derived cohorts. Clinical data and relative contributions of MI-oocytes were also reported. Main results and the role of chance: The mean fertilization rate per co-hort of inseminated MI-and MII-oocytes were 54.3 § 43.0% and 74.4 § 18.1%, respectively (paired t-test<0.01). The mean blastulation rate per cohort of MI-and MII-derived zygotes were 53.1 § 44.4% and 59.1 § 25.9%, respectively (paired t-test¼0.1). Overall, 0.5 § 0.7 (0-4) MI-derived blastocysts were obtained adding up to the 3.2 § 1.7 MII-derived ones, thereby resulting in a þ 20.8 § 40.1% (0 to þ 300%) relative increase per cycle. Overall, 268 (94%), 247 (89.7%), and 188 (66.2%) cycles had 1, 2 and 3 MII-derived blastocyst(s), respectively. These rates showed a þ 1.1% (N ¼ þ3), þ4.9% (N ¼ þ12) and þ7.4% (N ¼ þ24) relative increase due to MI-derived blastocysts use. To date, 19 out of 63 MI-derived blastocysts transferred resulted in a live-birth (30.2%, 95%CI 19.6-43.2) versus 124 out of 399 MII-derived ones (31.1%, 95%CI 26.6-35.9; p ¼ 0.99). We reported 4 miscarriages out of 27 clinical pregnancies (14.8%, 95%CI 4.8-34.6) versus 38 out 162 (23.5%, 95%CI 17.3-30.9, p ¼ 0.45), respectively. To date, 70% (N ¼ 199/284) of the cycles was concluded, with a cumulative-live-birth-rate of 61.3% (N ¼ 122/199). This rate showed a þ 9.5% (N ¼ þ18) relative increase due to MI-derived blastocysts use. Among 85 non-completed cycles, 19 (22.4%) have MI-derived blastocysts still available. Limitations, reasons for caution: Retrospective study. A cost-effectiveness analysis is warranted, especially because MI-oocytes clinical use involves additional workload and costs. 31% (N ¼ 44/140) of patients with 1 live-birth have supernumerary cryopreserved MI-derived blastocysts. Many cycles are not concluded. Gestational/perinatal outcomes were not reported. More data with own eggs and/or including chromosomal testing are needed. Wider implications of the findings: Rescuing MI-oocytes might increase the number of blastocysts available per cycle, and possibly the cumulative-live-birth-rate. Nevertheless, this practice involves a higher workload and the production of more supernumerary blastocysts. Mostly poor prognosis couples might benefit from their use; therefore a couple-specific decision-making process is desirable. Trial registration number: n/a Abstract citation ID: dead093.224