Minimum number of mature oocytes needed to obtain at least one euploid blastocyst according to female age in in vitro fertilization treatment cycles

Objective To find a useful tool for estimating the minimum number of metaphase II oocytes (MII) needed to obtain at least one euploid blastocyst according to female age. Design Retrospective analysis of In Vitro Fertilization (IVF) cycles with pre-implantational genetic testing for aneuploidies (PGT-A) performed over 5 years in IVIRMA Valencia (Spain), January 2017 - March 2022. Approval from the Institutional Review Board of IVI Valencia (2204-VLC-040-CR). Subjects Eligible patients were undergoing their first IVF-PGT-A cycle, in which at least one MII was obtained, regardless of oocyte and semen origin. Oocyte donation cycles were included in the Donors Group (≤34y.o.). Cycles from women with their own oocytes were selected only if oocyte age ≥35y.o. (Patients Group). Only trophoectoderm biopsies performed on day 5 or 6 of development and analyzed using Next Generation Sequencing (NGS) were included. PGT-A cycles due to a known abnormal karyotype were excluded. Main Outcome Measures Number of MII needed to obtain one euploid blastocyst according to female age. Results A total of 2660 IVF-PGT-A cycles were performed in the study period in the eligible population (Patients Group=2462; Donors Group=198). Mean number of MII needed to obtain one euploid blastocyst increased with age, as the number of cycles that didn't get at least one euploid blastocyst. An adjusted multivariate binary regression model was designed using 80% of the Patients Group sample (n=2462; training set). A calculator for the probability of obtaining at least one euploid blastocyst was created using this model. The validation of this model in the remaining 20% of the Patiens Group sample (n=493; validation set) showed that it could estimate the event of having at least one euploid blastocyst with an accuracy of 72.0%. Conclusion Our results show a preliminary model capable of predicting the number of MII needed to obtain at least one euploid blastocyst according to female age, calculated with the largest database of IVF-PGT-A cycles ever used for this purpose, including only cycles using NGS on trophoectoderm biopsies. Once this model has been properly validated, it could help with decision making, for both clinician and patient coming to an infertility clinic. To find a useful tool for estimating the minimum number of metaphase II oocytes (MII) needed to obtain at least one euploid blastocyst according to female age. Retrospective analysis of In Vitro Fertilization (IVF) cycles with pre-implantational genetic testing for aneuploidies (PGT-A) performed over 5 years in IVIRMA Valencia (Spain), January 2017 - March 2022. Approval from the Institutional Review Board of IVI Valencia (2204-VLC-040-CR). Eligible patients were undergoing their first IVF-PGT-A cycle, in which at least one MII was obtained, regardless of oocyte and semen origin. Oocyte donation cycles were included in the Donors Group (≤34y.o.). Cycles from women with their own oocytes were selected only if oocyte age ≥35y.o. (Patients Group). Only trophoectoderm biopsies performed on day 5 or 6 of development and analyzed using Next Generation Sequencing (NGS) were included. PGT-A cycles due to a known abnormal karyotype were excluded. Number of MII needed to obtain one euploid blastocyst according to female age. A total of 2660 IVF-PGT-A cycles were performed in the study period in the eligible population (Patients Group=2462; Donors Group=198). Mean number of MII needed to obtain one euploid blastocyst increased with age, as the number of cycles that didn't get at least one euploid blastocyst. An adjusted multivariate binary regression model was designed using 80% of the Patients Group sample (n=2462; training set). A calculator for the probability of obtaining at least one euploid blastocyst was created using this model. The validation of this model in the remaining 20% of the Patiens Group sample (n=493; validation set) showed that it could estimate the event of having at least one euploid blastocyst with an accuracy of 72.0%. Our results show a preliminary model capable of predicting the number of MII needed to obtain at least one euploid blastocyst according to female age, calculated with the largest database of IVF-PGT-A cycles ever used for this purpose, including only cycles using NGS on trophoectoderm biopsies. Once this model has been properly validated, it could help with decision making, for both clinician and patient coming to an infertility clinic.