P-063 Microfluidic technology is highly effective in selecting a sperm population with high progressive motility and low DNA fragmentation index
Authors: Mateizel I , Racca A , Aligianni E , Distasi E , Segers I , Jankovic D , Schoemans C , Wouters K , Tournaye H , De Munck N 
Published: June 2023

Study question

Which sperm preparation procedure is able to select the best population of sperm?

Summary answer

Microfluidic sperm sorting using Fertile Plus device isolates sperm with the highest motility and lowest levels of DNA fragmentation.

What is known already

The sperm selection in Medically Assisted Reproduction should lead to fully functional spermatozoa able to reach the fertilization site and allow optimal fertilization and embryo development. These abilities are dependent on specific sperm parameters such as, but not limited to, motility, morphology, Acrosome Index (AI), and DNA fragmentation Index (DFI). At present, the routine sperm selection is suboptimal, does not replicates the physiological processes observed in nature and consequently may induce sperm damage. The new Microfluidic Sperm Sorting technology allows a physiological selection of sperm. However, no comparison with other selection procedures regarding all the above-mentioned parameters was reported.

Study design, size, duration

Prospective-observational study performed at an University Hospital-IVF Centre between April-November 2022 comparing the effect of four different sperm selection procedures on various semen parameters. Fifty-two samples with minimum 20x106 sperm/ml and progressive motility ≥30% were included.

Descriptive statistics reported the mean±SD [minimum-maximum] values for each variable. Interclass correlation coefficient (ICC) was calculated for the absolute agreement in between the four different procedures, where DGC was considered the standard-of-care. An ICC-value &lt;0.4 indicates a low agreement.

Participants/materials, setting, methods

Unused raw semen after routine diagnostic analysis were individually split in 4 fractions and processed immediately by different sperm preparation methods: 1) sperm wash (SW), 2) Density Gradient Centrifugation (DGC), 3) Magnetic Activated Cell Sorting (MACS, (Miltenyi Biotec)), and 4) Microfluidic Sperm Sorting (MSS) using Fertile Plus Device (Koek Biotechnology).

Each fraction was analyzed for progressive motility, morphology, Acrosome Index (AI) and DNA fragmentation Index (DFI; TUNEL assay protocol).

Main results and the role of chance

The mean age of the patients was 35.9 years (SD ± 6.8). The mean value of days of abstinence was 4.1 (SD ± 6.8).

Mean progressive motility rates were: 54.3±10.6% [23-86%], 74.3±11.8% [38-90%], 77.2±12.5% [37-92%] and 88.6±4.2% [73-96%] for SW, DGC, MACS, and MSS, respectively.

Mean percentages of normal morphology were: 3.3±2.9% [0-13%], 4.1±3.1% [0-13%], 4.2±3.7% [0-18%], and 5.1±3.9% [0-16%] for SW, DGC, MACS, and MSS, respectively.

Mean AI were: 8.5±4.9% [1-20%], 9.7±6.0% [1-30%], 8.7±4.9% [0-19%], and 10.8±6.8% [1-30%] for SW, DGC, MACS, and MSS, respectively.

Mean DFI were: 6.2±4.6% [0.8-26.1%], 2.7±3.2% [ 0.2-14%], 2.1±4.3% [0.9-20.8%], and 0.2±0.4% [0.0-2.3%] for SW, DGC, MACS, and MSS, respectively.

Values referring to ICC absolute agreement between the DGC and the other methods indicate MSS as the only procedure in strong disagreement regarding progressive motility [0.29, 95%CI (-0.2-0.58)] and DFI [0.17; 95%CI (-0.19-0.45)]. No disagreement regarding morphology and AI was observed between all techniques.

A further paired comparison confirmed the strong disagreement between MSS and MACS [0.2; 95%CI (-0.17-0.49) and 0.21; 95%CI (-0.25-0.52)] and between MSS and SW [0.06; 95%CI (-0.04-0.25) and 0.06; 95%CI (-0.15-0.28)] regarding progressive motility and DFI, respectively.

Limitations, reasons for caution

Differences in DNA-damage may have been smaller between techniques if abstinence period was shorter. Due to the design of the experiment, data on clinical outcomes are not available.

Wider implications of the findings

The selection of a population of highly motile spermatozoa with undamaged DNA from unprocessed semen is ideally performed with MSS using Fertile Plus. Question remains how these results compare with a shorter abstinence period and whether this improves the embryological outcomes in the IVF laboratory.

Trial registration number

NCT05383599