Laser-assisted intracytoplasmic sperm injection (LA-ICSI) is safe and less traumatic than conventional ICSI

Abstract

In metaphase II (MII) oocytes with difficult oolemma breakage, mechanical trauma due to sperm injection may cause oocyte degeneration or fertilization failure. Laser-assisted intracytoplasmic sperm injection (LA-ICSI) has been reported to alleviate damage to the oocyte membrane during the injection procedure. The aim of this study was to evaluate the efficacy of LA-ICSI as a routine procedure for sperm injections in comparison with conventional ICSI. Prospective and randomized controlled study. A total of 434 first-attempt ICSI cycles were randomized to receive either LA-ICSI or conventional ICSI. LA-ICSI was performed by creating a 5-7 micron aperture in the zona pellucida with a 1.48 micron diode laser before microinjection. A total of 1,819 and 1,575 MII oocytes were injected in the groups of LA-ICSI and conventional ICSI, respectively. Comparisons were performed with Student's t, Fisher's exact and chi-square tests. Fertilization rate was significantly higher in the LA-ICSI group compared with the control group (62.5% and 54.5%, respectively, p<0.001), and the degeneration rate was significantly lower in the LA-ICSI group (5.6% and 8.5%, respectively, p<0.01). There were no significant differences in cleavage (98.6% and 99.3%), top-quality embryos on culture day-3 (44.4% and 40.4%), miscarriage (15.0% and 21.7%) and live birth (30.7% and 35.7%) rates. Demographic data including female and male age, proportion of cases with azoospermia, stimulation protocol for ovarian stimulation, number of oocytes retrieved and number of embryos transferred, were not different between groups. LA-ICSI is less traumatic than conventional ICSI. LA-ICSI is also safe and can be applied routinely during sperm injection. Its main benefits are to decrease oocyte degeneration and increase 2PN fertilization. However, embryo development and pregnancy rates are not impacted by the application of LA-ICSI or conventional ICSI.