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Updated: Jul 10, 2026

Whole Ovary Immunofluorescence, Clearing, and Multiphoton Microscopy for Quantitative 3D Analysis of the Developing Ovarian Reserve in Mouse
Published on: September 3, 2021
Developmental fate of ovoid oocytes
1Landes- Frauen- und Kinderklinik, IVF-Unit, Krankenhausstr. 26-30, A-4020 Linz, Austria. thomas.ebner@gespag.at
Background:
Irregularities in composition, thickness and/or color of the zona pellucida may impair optimal function and result in reduced outcome. Anomalies of oocyte shape have not been investigated in detail in this respect.
Methods:
Therefore, all patients attending our clinic within a period of 1 year were screened for the presence of ovoid gametes and the corresponding developmental potential was evaluated. For all elongated gametes, a roundness index (RI; length divided by width) was calculated in order to quantify shape.
Results:
RI did not affect fertilizability (P > 0.05). The degree of dysmorphism was found to be related to cleavage pattern. The more ovoid a gamete was, the higher was the risk of the corresponding zygote not cleaving like a tetrahedron (P < 0.01). Abnormal cleavage (a rather flat array of blastomeres) was associated with delayed compaction (P < 0.01) and blastocyst formation (P < 0.001). The quality of blastocysts was not affected at any stage in ovoid concepti (P > 0.05).
Conclusions:
Ovoid oocytes with abnormal cleavage pattern show delayed preimplantation development, probably due to a reduced number of cell-to-cell contacts.
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