The Immediate Partial Removal of Cumulus-Oocyte Complexes: A Refined Approach for Rapid Observation of In Vitro Fertilization

Summary

Here, we present an optimized method for promptly removing a portion of cumulus-oocyte complexes following egg retrieval to expedite the IVF observation process, reducing the time required for granulosa cell removal, minimizing oocyte exposure to external elements, and does not hinder embryo development, ultimately improving the efficiency of IVF laboratory procedures.

Abstract

Despite the rapid advancements in clinical and laboratory technologies for in vitro fertilization (IVF), a significant proportion (10%-15%) of patients continue to experience fertilization disorders, leading to low fertilization rates and the production of nonviable embryos. Short-term fertilization involves the early removal of granulosa cells to observe the extrusion of the second polar body, enabling the assessment of fertilization and early remedial measures to address low fertilization rates and complete fertilization failure. However, the observation of short-term fertilization in IVF is impeded by challenges such as excessively large unprocessed clusters of cumulus-oocyte complexes and adhesion between eggs, necessitating complex external procedures for granulosa cell removal, and prolonged observation duration. To tackle this issue, this study proposes a method of immediate partial removal of granulosa cells post egg retrieval. This approach streamlines subsequent stages of short-term fertilization and traditional fertilization monitoring, reduces the time needed for oocyte extrusion, minimizes the likelihood of external environmental impacts on the oocytes, and decreases the risk of missing the critical fertilization observation window. Consequently, the study yields novel clinical evidence aimed at enhancing the operational efficiency of embryonic laboratories in IVF.

Introduction

In the field of in vitro fertilization-embryo transfer (IVF-ET), the typical fertilization rate falls within the range of 60% to 80%¹. However, approximately 4% to 16% of cases encounter either complete fertilization failure or low fertilization rates, presenting challenges in prediction^2,3. To improve clinical pregnancy outcomes and decrease the occurrences of complete non-fertilization and low fertilization, the utilization of short-term fertilization in IVF procedures is on the rise⁴. This approach entails the prompt removal of granulosa cells to monitor the e....

Protocol

All procedures were conducted in accordance with the standard operating procedures of the Department of Reproductive Medicine at Meizhou People's Hospital and were subject to review by the Ethics Committee of the same department. Written informed consent was obtained from each participating couple.The study included participants undergoing their first IVF cycle with cleavage or blastocyst stage embryo transfer, as well as females between 20 and 45 years of age. Exclusion criteria included the use of donor eggs/sperm .......

Discussion

The immediate partial removal of granulosa cells can accelerate the early disintegration process of short-term fertilization, reduce the observation time for the second polar body in both short-term fertilization and conventional IVF and do not compromise subsequent embryo development. Currently, laboratories globally employ various strategies to mitigate fertilization disorders and low success rates. The preferred method involves removing granulosa cells for observing the second polar body 4-6 h post short-term fertiliz.......

Materials

Name	Company	Catalog Number	Comments
G-IVFT PLUS	Vitrolife	10136
OVOIL	Vitrolife	10029
G-MOPS PLUS	Vitrolife	10130
Falcon 3003 dish	Corning	353003
Falcon 3001 dish	Corning	353001
Falcon 2001 tube	Corning	352001
Falcon 4013 cup	Corning	354013
Falcon 3037 dish	Corning	351058
Pasteur pipette	Darwin	D1150-5P