Human oocyte zona pellucida abnormalities: evaluation of clinical impact for different zona pellucida abnormalities and role of using assisted hatching.

Background Zona pellucida (ZP) plays an important role in oocyte development and fertilisation, as well as in early embryo development. However, there is currently no exploration of systematic categorising and clinical treatment measures for patients with abnormal ZP, especially the fast and easy method that can be used clinically.

In this study, 185 patients with abnormal ZP (ZPA) and 222 patients with normal ZP (ZPN) were enrolled and analysed.

Patients with ZPA exhibited altered hormone levels and lower laboratory outcomes in in vitro fertilisation (IVF), such as reduced MII rate, cleavage rate, high-quality embryo rate, and blastocyst formation rate compared to ZPN group. ZPA patients were sub-categorised into ZPA-A/B/C/D group according to the status of oocyte polar body and the width of perivitelline space (PVS). There are also differences in the degree of sperm binding to ZP derived from different ZPA patients and the elasticity of the oocyte membrane. ZPA subgroup analysis revealed further disparities in various IVF parameters and pregnancy outcomes. In addition, by performing different treatments on oocytes derived from ZPA patients, we found that ZP assisted hatching before the first oocyte cleavage on D1 of embryonic development in the ZPA-A/B groups and before blastocyst expansion on D4 of embryonic development in the ZPA-C/D groups were beneficial to improve embryonic development.

The degree of the impact on clinical outcomes is correlated with the types of ZPA, and laser-assisted hatching of the ZP helps to improve embryonic development in patients with ZPA. Similar content being viewed by others Data availability All relevant data are within the paper and its Supplementary Information files.

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The authors thank all the patients involved in this study and the staff in our center. Funding This work was supported by the National Natural Science Foundation of China (U1904138), Open Research Fund of National Health Commission Key Laboratory of Birth Defects Prevention (NHCKLBDP202407), and Provincial and Ministerial co-construction project of Henan Medical Science and Technology Program (SGJ202102104). Author information Authors and Affiliations Corresponding author Ethics declarations Competing interests The authors declare no competing interests. Additional information Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Supplementary Information Below is the link to the electronic supplementary material. Supplementary file1 (MP4 15907 KB) Supplementary file2 (MP4 17984 KB) Supplementary file3 (MP4 16893 KB) Supplementary file4 (MP4 16579 KB) Supplementary file5 (MP4 18024 KB) Supplementary file6 (MP4 15172 KB) Supplementary file7 (MP4 45448 KB) Supplementary file8 (MP4 36277 KB) Supplementary file9 (MP4 18577 KB) Supplementary file10 (MP4 34239 KB) Supplementary file11 (MP4 35895 KB) Supplementary file12 (MP4 36816 KB) Supplementary file13 (MP4 28064 KB) Rights and permissions Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law. About this article Cite this article Wang, H., Yang, G., Jiang, R. et al. Human oocyte zona pellucida abnormalities: evaluation of clinical impact for different zona pellucida abnormalities and role of using assisted hatching. J Assist Reprod Genet 42, 303–317 (2025). https://doi.org/10.1007/s10815-024-03306-3 Received: Accepted: Published: Version of record: Issue date: DOI: https://doi.org/10.1007/s10815-024-03306-3