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Updated: Jul 7, 2026

Human Egg Maturity Assessment and Its Clinical Application
Published on: August 19, 2019
Significance of metaphase II human oocyte morphology on ICSI outcome
Laura Rienzi1, Filippo Mari Ubaldi, Marcello Iacobelli
1Reproductive Medicine, European Hospital, Rome, Italy. laurarienzi@fastwebnet.it
Objective:
To evaluate the influence of specific oocyte morphologic features (morphotypes) on intracytoplasmic sperm injection (ICSI) outcome. The identification of oocyte quality markers is particularly important when a low number of oocytes can be used for IVF.
Design:
Retrospective analysis.
Setting:
Medical center.
Patient(S):
Five hundred sixteen consecutive ICSI cycles. Only couples affected by severe male factor infertility were excluded.
Intervention(S):
A total of 1,191 metaphase II (MII) oocytes (1-3 per patient) were randomly selected from the cohort of oocytes obtained from each patient and evaluated for morphologic appearance.
Main Outcome Measure(S):
Fertilization, pronuclear morphology, embryo quality, pregnancy rate.
Result(S):
There was a presence of vacuoles, abnormal I polar body, and large perivitelline space related to a lower fertilization rate. Pronuclear morphology was effected by the presence of a large perivitelline space, diffused cytoplasmic granularity, and/or centrally located granular area. The latter characteristic also negatively related to day 2 embryo quality. According to the odds ratios obtained for each oocyte morphotype to reach at least one outcome, an MII oocyte morphologic score (MOMS) was calculated. A significant relationship was found between MOMS and female age, female basal FSH, and clinical outcome.
Conclusion(S):
Morphologic evaluation before ICSI helps to identify MII oocytes with higher developmental potential.
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