Póster Congreso ESHRE20: Microfluidics is highly effective in selecting a sperm subpopulation with low DNA fragmentation index.

  • Fecha: July 2020. Congreso ESHRE 2020
  • Revista: ESHRE 2020
  • Autores: K. Wouters, L. Vandenberghe, A. Racca, D. Jankovic, G. Verheyen, I. Mateizel.


Study question: Is microfluidic sorting of unprocessed semen better in selecting non-DNA fragmented sperm compared with other semen preparation techniques?

Summary answer: The use of microfluidic sperm sorting chip allows the selection of highly motile sperm with very low levels of DNA fragmentation.

What is known already: DNA fragmentation represents the last event of cell apoptosis. The use of sperm cells with DNA fragmentation for oocyte insemination is correlated with a negative paternal effect on embryo development and an increased miscarriage rates. Both microfluidic sorting (MS) of unprocessed semen and Magnetic activated cell sorting (MACS) performed after density gradient centrifugation were reported to improve the sperm quality by selecting non apoptotic cells. However, it is uncertain which procedure leads to the lowest DNA fragmentation index (DFI).

Study design, size, duration: The study investigates whether microfluidic sorting of unprocessed semen improves sperm selection as compared to standard preparation procedures (sperm washing and density gradient centrifugation) or MACS in split samples after routine diagnostic semen analysis. The primary outcome was sperm DNA fragmentation index and the secondary outcome was sperm motility.

Participants/materials, setting, methods: Sperm samples from 6 different patients were used. Each sample was split and subjected to 4 different sperm selection techniques: 1) sperm washing (SW), 2) density gradient centrifugation (DGC), 3) DGC followed by MACS (Miltenyi Biotec, Germany) and 4) MS (Fertile plus, Koek Biotechnology). DNA fragmentation was analyzed using the Sperm-Chromatin-Dispersion Assay (GoldCyto sperm kit, Goldcyto Biotech corp.). The DFI was calculated on at least 500 cells by the Sperm Class Analyzer CASA-system (Microptic, Spain).

Main results and the role of chance: The median DFI for the 4 processing techniques were: 18.3% (range 13.9-87.6) for SW; 14.6% (range 6.1-71.7) for DGC; 11.8% (range 3.9-46.9) for MACS, and MS: 0.7% (range 0-34.2) for MS. The samples processed by microfluidics showed a significantly lower DNA fragmentation rate compared to the other techniques (Friedman test, P<0.05). The median progressive motility for the 4 processing techniques were: 47.5% (range 29-54) for SW; 58% (range 27-61) for DGC; 46% (range 3-78) for MACS and 92.5% (range 82-96) for MS. The samples processed by microfluidics showed a significantly higher progressive motility (Friedman test, P<0.05).

Limitations, reasons for caution: The major limitation of the study is the low sample size although the advantage of MS is obvious. Consequently, there is a lack of variation between the samples regarding sperm quality. As this observational study was conducted on semen samples for diagnostic analysis, data on clinical outcome are not available.

Wider implications of the findings: Microfluidic sorting of sperm selects a population with significantly lower DNA fragmentation index and higher proportion of progressive motility compared to standard selection methods or MACS. Moreover, MS offers the advantage of using unprocessed semen, as such reducing the negative impact of centrifugation as compared to standard sperm selection methods..