A new research study conducted at IVF-Life, led by clinical embryologist Alessandra Parrella, compared two microinjection techniques of sperm into oocytes during ICSI, the most common procedure to treat male infertility. This study will be presented at this year's ASEBIR conference, to be held in November in Barcelona.

ICSI can be performed mainly by two methods: the aspiration technique, which involves slightly suctioning part of the oocyte’s cytoplasm to facilitate sperm introduction, and the pressure technique, which injects the sperm directly by applying pressure without extracting cytoplasm. Although aspiration is more common, there is little scientific evidence analyzing whether these technical differences affect outcomes.
The prospective study included 35 patients between March 2024 and March 2025. In each cycle, mature oocytes were divided into two groups for microinjection by aspiration or by pressure, allowing a direct comparison controlling variables.
The results showed similar fertilization and embryonic development rates between both techniques. However, the pressure technique was associated with a lower rate of degenerated oocytes (0%) compared to aspiration (5.7%), indicating greater safety for oocyte integrity.
“Although both methods are effective, using pressure for injection seems to reduce oocyte damage, which can help optimize the technique and improve success chances,” comments Parrella. “This study provides valuable contribution to improving assisted reproduction outcomes, offering evidence that will help embryologists choose the most appropriate technique for each patient.”