JBRA Assist. Reprod. 2025;29(Suppl 1):4-4
ORAL PRESENTATION
doi: 10.5935/1518-0557.20250062
1Centro de Fertilidad y Reproducción Asistida, CEFRA S.A.C., Lima, Peru
Objective: Given that, in our center, the blastocysts recovery time prior to embryo transfer was not standardized, we aimed to investigate the impact of the recovery time on clinical outcomes.
Methods: This retrospective cohort study includes embryos of 566 ICSI cycles of infertile patients aged 25 to 45 years old. Additionally, as controls, 132 ICSI cycles, from our oocyte donation program, were analyzed separately. Enrolments took place between January 2019 and December 2024.Considering that transfers of more than 1 embryo would make it complicated to the assess the clinical outcomes, it was decided to assess frozen embryo transfer cycles that transferred only 1 euploid embryo. Moreover, prior to run the study, the data on the recovery time was split in 4 groups (<30min, 30 - 59min, 1h - 1h29 & ≥1h30) and biochemical pregnancy was evaluated. It was observed that the rate of biochemical pregnancy increased and reached a plateau after 1h. Therefore, for the detailed analysis, the recovery time was split in two groups: <1h & ≥1h.
Results: Our analysis showed that the rate of biochemical pregnancy following the transfer of 1 euploid blastocyst was significantly higher when blastocysts were given a recovery time of ≥1h prior to transfer in comparison to <1h (68.7% vs 58%, respectively; p=0.0237). Furthermore, the rate of clinical pregnancy following the transfer of 1 euploid blastocyst was also significantly higher when blastocysts were given a recovery time of ≥1h prior to transfer (57.1% vs 46.6%, respectively, p=0.0367). Additionally, euploid blastocysts from our oocyte donation program displayed the same trend for the <1h vs ≥1h groups (N. S.). The rate of biochemical pregnancy was 67.1% vs 69.6%, respectively. The rate of clinical pregnancy was 45.6% vs 47.8%, respectively. These latter results are consistent with the excellent oocyte/embryo quality in young donors.
Conclusion: Integrating 3D ultrasound, hysteroembryoscopy, and molecular diagnostics enhances the identification of both structural andIn our setting, this data suggests that a recovery time of at least 1h (prior to transfer) will maximize the clinical outcomes of euploid blastocysts in Frozen Embryo Transfer cycles.