The clinical results of piezo-ICSI compared to conventional-ICSI: a sibling-oocyte study

Abstract

Clinically, conventional ICSI (CI) is a common, widely-used method, while there are few reports with respect to Piezo ICSI (PI). PI is effective in degeneration rate and fertilization rate (Kimura, Y & Yanagimachi, R, 1995). It is known that the survival rates of mice oocytes are low after CI; however, degeneration rate improved markedly using PI. PI is an effective technique for cases with fragile oocytes. It has been reported that the survival rate is similarly improved in human oocytes (Hiraoka, K & Kitamura, S, 2015). However, most of the studies reporting on PI are retrospective studies. Here, we prospectively compared the degeneration rates, fertilization rates and embryo development of PI and CI in a sibling study. This is a prospective randomized controlled single-center study, using sibling oocytes, conducted from August 2018 to March 2019. Written informed consent was obtained from all patients involved in this study. This sibling oocyte study comprised 26 cycles in 26 cases. CI was performed in 149 mature oocytes. CI consists of mechanical penetration of the zona pellucida, breaking the oocyte membrane by aspiration of cytoplasm. PI was performed in 162 mature oocytes. PI consists of breaking the oocyte membrane and zona pellucida by Piezo pulse. P-value of 0.05 or less was considered to be statistically significant.　Limitation: The clinical results using vitrified oocytes, artificial oocyte activation, cryptozoospermia, azoospermia cases, and females aged over 40 years old were not included in this study. The pregnancy outcome has not been confirmed in our study. There were no statistically significant differences in the fertilization rates, degeneration rates, cleavage rates, blastocyst formation rates or good quality blastocyst rates (according to the Gardner criteria) between CI and PI (75.8% vs. 78.4% (P=0.592), 7.4% vs. 3.7% (P=0.146), 100% vs. 96.8% (P=0.160), 61.9% vs. 64.0% (P=0.743) and 41.6% vs. 36.8% (P=0.450), respectively). In conclusion, the present study has demonstrated there was no significant difference in the clinical results of piezo-ICSI and conventional-ICSI. However, this may be attributable to the limited number of cases with fragile oocytes, etc. In our experience, PI is safer and easier to learn and perform in clinical work in a shorter period, especially for beginners. Further studies are necessary.Tabled 1GroupConventional ICSIPiezo ICSIPPatients (N)26-No. of ICSI cycles26-Female age, years (mean ± SD)34.8 ± 4.2-Male age, years (mean ± SD)36.9 ± 5.4-No. of oocytes149162-N(%) of zygotes (2PN)113 (75.8)127 (78.4)0.592N(%) of degenerated oocytes11 (7.4)6 (3.7)0.146N(%) of cleaved oocytes113 (100)122 (96.8)0.167N(%) of blastocysts70 (61.9)80 (64.0)0.477N(%) of good quality blastocysts47 (41.6)46 (36.8)0.498 Open table in a new tab