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Updated: Aug 14, 2026

Collection of Human Follicular Fluid, Follicle Somatic Cells, and Immature Oocytes from Individuals Undergoing In Vitro Fertilization
Published on: October 24, 2025
[Morphological observation of metaphase I arrested oocytes in IVF-ET cycles]
Ning-Yuan Zhang1, Ya-Li Hu, Hai-Xiang Sun
1Reproduction Medicine Center, Department of Obstetrics & Gynecology, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Jiangsu Nanjing 210008.
Objective:
To observe morphological characteristics and in-vitro maturation ratio of all metaphase I arrested oocytes in IVF-ET cycles.
Methods:
In two IVF-ET cycles, maturation culture in vitro was performed and we evaluated morphological characteristics of all oocytes arrested in metaphase I.
Results:
Metaphase I arrested oocytes presented with uniform cytoplasm, compact zone and no space between oocyte and zone. Incompact association was observed between granule cell and zone without radiated structures. There was no markedly alterations in morphological characteristics after 24, 48, 72 hours of maturation culture, respectively. All oocytes were arrested in Metaphase I and no polar growed.
Conclusion:
All metaphase I arrested oocytes possess of unique morphological characteristics and fail to mature following current culture assay in IVF-ET cycles.
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