Dados do Trabalho

Title

Efficiency of different seminal processing methods in reducing sperm DNA fragmentation.

Objective

To demonstrate whether distinct sperm sorting methods improves the capacity of selecting spermatozoa with lower DNA fragmentation.

Methods

This observational prospective study comprised 22 seminal samples from patients undergoing in vitro fertilization treatment. The seminal samples were evaluated according to the sixth edition of the World Health Organization (WHO) Manual, and only those with a sperm concentration above 5 million sperm/mL and a volume greater than 2.5 mL were included. DNA integrity assessment was performed using the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay under fluorescence microscopy. The samples were evaluated before and after using three different sorting methods: swim-up, density gradient centrifugation, and the ZyMōtTM Multi microfluidic device. Statistical analysis was carried out using the repeated-measure ANOVA with Bonferroni correction for paired data with normal distribution, and the Friedman test for paired data with non-normal distribution.

Results

The mean age was 37.9 years (ranging from 24 to 52 years). Infertility factors such as varicocele, obesity, smoking, and others were not considered in the patient selection process. The ZyMōtTM device (10.20 ± 5.13 vs 4.84 ± 4.23; p < 0.05) and the Swim-Up technique (10.20 ± 5.13 vs 4.90 ± 2.40, p < 0.05) significantly reduced sperm DNA fragmentation levels when compared to the pre-processing fragmentation rates. Conversely, the density gradient centrifugation technique did not lead to a decrease in DNA fragmentation levels, maintaining values very similar to the pre-processing DNA fragmentation index (10.37 ± 5.60 vs 10.20 ± 5.13, p > 0.05). No significant differences were found between the ZyMōtTM device and the Swim-Up technique. Sperm morphology showed no significant differences between the three techniques.

Conclusion

Currently, the microfluidic device for sperm sorting is gaining increasing attention as it pledges to recover sperm with higher quality and lower DNA fragmentation compared to other conventional techniques. In this study, both the Swim-Up and the ZyMot Multi device improved sperm selection regarding to the rates of DNA fragmentation. However, no differences were found in the rate of improvement between the two methods. Nevertheless, caution should be used when interpreting this data once this is a preliminary proof-of-concept study with a small sample size. Further research is needed to evaluate larger sample sizes and the effect of different seminal processing techniques in both the IVF laboratory and reproductive outcomes.

Keywords

MICROFLUIDICS; SPERM SORTING; IVF; DNA FRAGMENTATION; SWIM UP; DENSITY GRADIENT CENTRIFUGATION