Sperm DNA fragmentation (SDF) and sperm morphological defects can negatively affect ART outcomes. Consequently, there is a need for additional semen processing technique that accounts for sperm DNA status and morphology prior to ICSI. The objective was to evaluate the efficacy of an additional zona pellucida adhesion-based sperm selection for obtaining sperm populations with a high percentage of normal morphology and DNA integrity as compared to native semen and routine swim-up preparation. Semen samples from 78 normozoospermic men were subjected to swim up and placed in petri dishes coated with 48 acid-solubilized zonae pellucidae. Sperm DNA fragmentation and morphology were assessed in the native semen, the swim-up samples, and the zona-adhered spermatozoa from each patient. The mean sperm DNA fragmentation of the zona-selected spermatozoa (3.5 ± 0.7%) was significantly lower than the swim-up samples (15.3 ± 5.2%) (P  < 0.001) and native semen (24.9 ± 7.1%) (P  < 0.001). All of the samples had lower levels of DNA damage after additional selection by zona pellucida adhesion. Significantly higher percentage of sperm with normal morphology was observed after zona-adhesion selection (11.4 ± 3.9%) when compared to the swim-up samples (8.9 ± 4.3%) (P  < 0.001) or the native semen (5.3 ± 3.2%) (P  < 0.001). In 94% of the samples, the percentage of spermatozoa with normal morphology increased after the additional zona selection. This study demonstrates that sperm selection by additional zona-adhesion technique yields a significantly higher percentage of spermatozoa with normal morphology as well as a significantly decreased level of DNA fragmentation when compared to the native semen and the swim-up-only prepared samples.

The objective of this study was to compare the motility, morphology, and levels of DNA fragmentation of spermatozoa subjected to conventional swim-up or cumulus matrix (CM) sperm selection. Semen samples were collected from 60 normozoospermic men at a private hospital between December 2021 and March 2022. After liquefaction, semen samples were separated into two portions – one part was subjected to conventional swim-up preparation, and the remaining spermatozoa were subjected to CM selection. The CM was obtained by mechanical isolation from healthy donor oocytes. Semen analysis and evaluation of sperm were performed according to the WHO 6th Edition Laboratory Manual and Kruger’s strict criteria, respectively. Sperm DNA fragmentation (SDF, %) of the two preparations was evaluated using the Halosperm G2 detection Kit (Halotech, Madrid, Spain). Wilcoxon rank-sum test was used to compare the characteristics of spermatozoa obtained by the two preparations. Spermatozoa selected by CM showed significantly better rapidly progressive motility (43.5% vs 30.6%, respectively, P < 0.001), a higher percentage of morphologically normal forms (14.0% vs 9.0%, respectively, P < 0.05), and lower levels of SDF (26.0% vs 45.0%, P < 0.05) compared to those prepared by conventional swim-up. Moreover, the incidence of multiple sperm defects was considerably lower in the samples that underwent CM selection compared to those that did not (30.0% vs 49.0%, respectively, P < 0.05).The selection by CM significantly increases sperm motility and reduces morphologically abnormal spermatozoa and DNA fragmentation rates compared to the conventional swim-up preparation. The application of this selection technique may increase the chances of successful IVF outcomes.