Replacement of the intracytoplasmic sperm injection (ICSI) holding pipette with a microfabricated device (microICSI) reduces changes to oocyte shape during sham injection of human oocytes

Objective: Previous studies indicate that intracytoplasmic sperm injection (ICSI) holding pipettes can be replaced by a three-dimensional printed device (microICSI) that supports oocytes during injection. Use of microICSI reduced the size of the injection funnel in porcine oocytes, suggesting less trauma and resulting in increased blastocyst rates. This study measured changes in oocyte shape using donated human oocytes matured overnight. Methods: Donated human oocytes not suitable for clinical use and matured in vitro overnight were subjected to sham ICSI using conventional methods (cICSI, n=39) or microICSI (n=38). Procedures were video recorded, and oocyte shape during injection was measured. Results: Immediately before injection, the area, perimeter, and x-axis diameter of cICSI oocytes were larger than those of microICSI oocytes, and cICSI oocytes were less circular and round, indicating that the holding pipette distorted oocyte shape. Mid-injection, cICSI oocytes showed greater changes in x-axis and y-axis diameter than microICSI oocytes relative to pre-injection shape, and they were less round. There was no difference in injection funnel depth. Post-injection, microICSI oocytes showed a greater decrease in x-axis diameter and area compared to pre-injection shape than cICSI oocytes. There was no difference in the rate of lysis or degeneration after injection. Needle set-up time was faster with microICSI, but the time required to move oocytes in and out of the device was slower. Total procedure time was unchanged. Conclusion: The microICSI device reduced distortion in oocyte shape caused by the holding pipette before and during injection, although it did not reduce injection funnel size or overall procedure time.