JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):213
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263870

P-201. Rescue Oocytes in IVF: Biological Performance and Clinical Impact – A Literature Review

Vitória Luiza Batalhoti Brogiato¹, Priscila Luiza dos Santos², Maria Eduarda Gomes de Freitas³

¹ Universidade Santo Amaro - São Paulo – SP -Brasil
² Faculdade Santa Marcelina - São Paulo – SP -Brasil
³ EmbrioLógica - São Paulo – SP -Brasil

Objective: To review the current evidence on the biological performance and clinical impact of rescue oocytes submitted to in vitro maturation (IVM) during in vitro fertilization (IVF) cycles, focusing on maturation rates, embryo development, and clinical outcomes.
Methods: A literature review was conducted using articles published between 2010 and 2025. Searches were performed in PubMed using the terms "rescue oocytes", "in vitro maturation", and "IVF". After screening titles, abstracts, and full texts, five articles were included for consideration. Data from the selected studies was analyzed and summarized narratively.
Results: In stimulated IVF cycles, 15–25% of retrieved oocytes are immature. Culturing these oocytes through rescue in vitro maturation (rIVM) has been explored as an option, particularly for patients with poor ovarian response or a poor prognosis. The available studies are limited in number and highly variable in patient selection, stimulation protocols, and culture methods. Overall, oocytes matured through rIVM tend to have lower developmental competence than those matured in vivo, often showing meiotic abnormalities and reduced quality. This is reflected in lower fertilization, cleavage, blastulation, and clinical pregnancy rates. However, evidence from meta-analyses and prospective studies indicates that when euploid blastocysts derived from rIVM are transferred, live birth rates can be comparable to those from in vivo matured oocytes. Thus, although less efficient, the technique may still yield viable embryos in specific clinical contexts.
Conclusion: Rescue in vitro maturation can increase the total number of available gametes, especially in cycles with poor ovarian response, potentially reducing cancellation rates and improving treatment efficiency. Nevertheless, its clinical use remains debated due to inconsistent protocols and lower efficiency compared to in vivo maturation. Current recommendations highlight the need for clear patient counseling, as rIVM is considered an add-on procedure. More standardized protocols and long-term follow-up studies are needed to confirm its safety, effectiveness, and role in assisted reproduction.