P-170 A sibling oocyte study using a real-time image analysis system to identify optimal puncture positions in Piezo-ICSI
Authors: Maekawa T , Morimoto T , Mizuta S , Matsubayashi H , Takeuchi T , Hata Y , Ishikawa T 
Published: June 2023

Abstract

Study question
Is the newly developed image analysis system capable of visualizing the shape features of the oolemma in real-time, useful for reducing oocyte degeneration during Piezo-ICSI?

Summary answer
Unintentional membrane rupture (UMR) can be reduced by this real-time image analysis, which lowers the risk of oocyte degeneration following Piezo-ICSI.

What is known already
UMR in the puncturing process of ICSI often predisposes oocyte degeneration. Identifying the appropriate puncturing positions may decrease the likelihood of UMR and thus degeneration, but this cannot be visualized via a microscope. We have reported that visualization of the shape features of the oolemma using moving image analysis during Piezo-ICSI can locate areas on the oolemma where UMR is likely to occur. It is feasible to assess the incidence of UMR and oocyte degeneration by performing ICSI while selecting appropriate puncturing positions with the aid of the newly developed imaging system.

Study design, size, duration
Our team have developed an image analysis system called ICSI POSITION DETECTOR (IPD), which can identify areas where rupture is likely to occur and visualize it in real-time using a video monitor. We prospectively evaluated the usefulness of IPD in a sibling oocyte study. From January 2020 to August 2021, a total of 1268 oocytes obtained in 225 oocyte retrieval cycles (average maternal age: 38.3 ± 4.7 years old) was included.

Participants/materials, setting, methods
The oocytes were randomly assigned to two groups: IPD-using vs. non-IPD-using. In the IPD-using group, Piezo-ICSI was performed at the “appropriate” position with a low chance of UMR indicated by IPD. In the non-IPD-using group, Piezo-ICSI was performed blindly. The rates of UMR, oocyte degeneration, fertilization and embryonic development were compared between the two groups. In addition, in the non-IPD-using group, moving images were recorded during Piezo-ICSI and analyzed retrospectively using IPD.

Main results and the role of chance
The rates of UMR and degeneration were significantly lower in the IPD-using group compared to the non-IPD-using group (6.0% vs. 11.9%, P &lt; 0.001 and 1.6% vs. 4.6%, P &lt; 0.01, respectively). The rates of fertilization (83.7% vs. 79.7%), blastocyst formation (51.9% vs. 51.0%), and good-quality blastocyst (24.7% vs. 24.3%) were not significantly different. Retrospective analysis of moving images using IPD on the non-IPD-using group showed that in 45.3% of oocytes (286 out of 632) ICSI was performed at a position with a high chance of UMR (inappropriate position). When ICSI was performed at the appropriate positions using IPD, the rates of UMR (6.0% vs. 18.2%, P &lt; 0.001) and degeneration (1.6% vs. 7.3%, P &lt; 0.001) were significantly lower, while the rates of fertilization (83.7% vs. 74.5%, P &lt; 0.01) and blastocyst formation (51.9% vs. 43.0%, P &lt; 0.05) were significantly higher than those when ICSI was performed at an inappropriate position. The rate of good-quality blastocyst (24.7% vs. 19.7%) was also higher, but not statistically significant. These results indicate that IPD can reduce the risk of UMR, thereby lower the degeneration rate. Furthermore, the embryonic development was better when using IPD to identify the appropriate position to perform ICSI, suggesting that UMR seems to be associated with poor ICSI outcome.

Limitations, reasons for caution
In this study, Piezo-ICSI was performed by only two designated embryologists in a single center. It did not assess clinical outcomes. Further research involving more embryologists is needed. Moreover, it would be feasible to investigate whether the usage of IPD is similarly effective on conventional-ICSI outcome.

Wider implications of the findings
The application of IPD to perform ICSI at the appropriate position can significantly avoid UMR, and thereby reduce oocyte degeneration and provide better embryonic development. We therefore, consider IPD to be a highly clinically useful tool, which contributes to the production of more embryos that can be used for treatment.

Trial registration number
not applicable