Research Mentor Name
Dr. Keri Bergin
Research Mentor Email Address
kbergin@rmaofny.com
Institution / Department
Reproductive Medicine Associates of NY
Document Type
Research Abstract
Research Type
clinicalresearch
Graduate Level Research
no
Abstract
Title: Assessing the reproductive potential of late mature cryopreserved oocytes
Authors: Keri Bergin, Ashna Mehra, Rick Slifkin, Morgan Baird, Dmitry Gounko, Carlos Hernandez-Nieto, Joseph Lee, Chelsea Canon, Alan B Copperman, Lucky Sekhon
Background:
Oocytes retrieved at the germinal vesicle (GV) or metaphase I (MI) stage may mature in vitro to MIIs for cryopreservation. Limited data exist on the reproductive potential of late mature MIIs after thaw. This study assesses the thaw, fertilization, and embryo development outcomes of late mature versus immediately mature cryopreserved oocytes.
Methods:
This retrospective cohort study analyzed autologous oocyte cryopreservation cycles with thaws from January 2016 – September 2024. Group 1: immediately mature oocytes (“MII”). Group 2: late mature oocytes (“late mature MII”), including late Day 0 and Day 1. Comparative statistics and univariate analysis were performed using Wilcoxon Ranks Sum and chi-square. Logistic regression fitted with GEE adjusting for oocyte age, AMH, BMI, and years of cryopreservation/thaw was performed for thaw survival, fertilization, blastulation, and ploidy.
Results:
Among 565 patients (699 cryopreservation and 629 thaw cycles), Group 1 included 6,899 MIIs and Group 2 included 956 late mature MIIs. Thaw survival rate was comparable (79.4% vs. 78.0%, p=0.33). Fertilization rate was significantly higher in Group 1 (75.3%) than Group 2 (59.8%) (aOR 0.52, CI 0.42-0.63, p < 0.001). Group 1 had significantly higher blastulation (37.7% vs 26.1%, p≤0.001) and euploidy rates (54.5% vs. 39.3%, p=0.0023), confirmed on adjusted analysis. A sub-analysis showed no difference between Day 0 and Day 1 late MIIs.
Conclusion:
Cryopreserved late mature oocytes show lower reproductive potential than those immediately mature. This could be attributed to dyssynchronous cytoplasmic and nuclear maturation. Despite suboptimal development, late mature MIIs can create high-quality blastocysts, offering additional opportunities for future family building.
Disciplines
Medicine and Health Sciences | Obstetrics and Gynecology
Recommended Citation
Bergin, Keri and Mehra, Ashna, "Assessing the Reproductive Potential of Late Mature Cryopreserved Oocytes" (2026). Medical Student Research Symposium. 493.
https://digitalcommons.wayne.edu/som_srs/493