Empty Zona Pellucida Only Case: A Critical Review of the Literature.

Charalampos Siristatidis,Mara Simopoulou,Nikolaos Vlahos,Panagiotis Bakas,Sofoklis Stavros,Christina Vaitsopoulou,Michail Papapanou,Despoina Tzanakaki,Petroula Tsioulou,Peter Drakakis

doi:10.3390/ijerph18179409

Abstract

The presence of empty zona pellucida (EZP) in oocytes following oocyte retrieval (OR) during an in vitro fertilization (IVF) cycle presents a major clinical and laboratory challenge in assisted reproduction. It has been attributed to several factors such as the ovarian stimulation protocol employed, the damaging of the follicles during oocyte retrieval (OR) mainly through the high aspiration pressure, during the denudation technique, and the degeneration of oolemma within the zona pellucida (ZP) through apoptosis. The role of ZP is pivotal from the early stages of follicular development up to the preimplantation embryo development and embryo hatching. Polymorphisms or alterations on the genes that encode ZP proteins may contribute to EZP. We present a critical review of the published literature hitherto on EZP and available options when encountered with the phenomenon of EZP. Concerning the former, we found that there is rare data on this phenomenon that merits documentation. The latter includes technical, genetic, and pathophysiological perspectives, along with specific treatment options. In conclusion, we identify the lack of a definitive management proposal for couples presenting with this phenomenon, we underline the need for an algorithm, and indicate the questions raised that point towards our goal for a strategy when addressing a previous finding of EZP.

Highlights

Oocyte quality constitutes a parameter of paramount importance with respect to in vitro fertilization (IVF) outcomes [1]
A conundrum that IVF clinicians are called to confront is the presence of empty zona pellucida (EZP) oocytes, referring to a finding described as the lack of ooplasm in the presence of an empty zona pellucida (ZP) [2]
This study aims to present a thorough review of the respective literature, while attempting a critical evaluation of the options that should be presented to an infertile couple undergoing controlled ovarian stimulation (COH) for IVF when the entire cohort of the retrieved oocytes are classified as EZP

Summary

Introduction

Oocyte quality constitutes a parameter of paramount importance with respect to in vitro fertilization (IVF) outcomes [1]. A conundrum that IVF clinicians are called to confront is the presence of empty zona pellucida (EZP) oocytes, referring to a finding described as the lack of ooplasm in the presence of an empty zona pellucida (ZP) [2]. EZP may entail followThe plausible initial explanations for may entail thethe following: ing: the small diameter of employed the employed needle during [10,31,36], high aspirathe small diameter of the needle during the the OROR [10,31,36], the the high aspiration tion pressure used, and the size of the denudation pipettes “stripper tips”. As soon as higher-aspiration vacua were used, decreaseof inoocytes the number

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