Póster Congreso ESHRE20: Sperm selection using microfluidics sorting chips in patients with high DNA fragmentation improves clinical outcomes in egg-donor cycles.

  • Fecha: July 2020 . Congreso ESHRE 2020
  • Revista: ESHRE 2020
  • Autores: A. Farreras Ayestaran, A. Munuera , B. Freijomil , S. Novo , À. Garcia-Faura , B. Marquès , F. Garcia , C. Castelló , M. Lopez-Teijón. Institut Marquès


Study question: Can sperm selection using microfluidic sorting chips improve reproductive outcomes in patients with high sperm DNA fragmentation (SDF)?

Summary answer: Microfluidics sperm selection significantly increases the number of blastocysts and improves clinical pregnancy rate in egg-donation (ED) cycles and high SDF.

What is known already: Previous studies have described a DNA fragmentation negative effect on early embryo development. Concretely, high levels of DNA fragmentation have been associated with embryo development arrest, as well as low implantation and pregnancy rates. Conventional methods used to select sperm for ICSI, as swim-up or density gradients, require centrifugation. It is well known that centrifugation forces increase Reactive Oxygen Species (ROS), one of the main promoter of SDF. Microfluidic systems don’t need centrifugation, consequently avoid ROS formation and could allow us to select sperm with better motility, morphology and lower SDF than conventional sperm selection methods.

Study design, size, duration: Preliminary retrospective cohort study including until now 63 cycles of ICSI-ED and sperm with high SDF (>30%) between January 2017 and October 2019. In all the cycles single fresh blastocyst transfer were performed. SDF was evaluated by SCD (Sperm Chromatin Dispersion) test.

Participants/materials, setting, methods: Two groups of cycles were established according to the sperm selection method used for ICSI: microfluidic chip (G1; n=30) and density gradients (G2; n=33). The groups were homogeneous in terms of the donor age, mean number of mature oocytes collected and embryos transferred. No differences were found between groups in the SCD test using T-student statistics (G1: 45.6±14.5%; G2: 39.0±11.7%; p=0.05). The results were analyzed using Fisher test.

Main results and the role of chance: The two considered groups of this study were diagnosed with pathological percentage of sperm DNA fragmentation. Fertilization rate was equivalent (p=0.07) between G1 (172/216; 79.6%) and G2 (169/234; 72.2%). However, good quality blastocyst rate (GQB; ≥3BB Gardner score) of G1 (84/172; 48.8%) was significantly higher (p<0.05) than in G2 (64/169; 37.9%), as well as pregnancy rate (G1: 90.0%; G2: 54.55%). Additionally, clinical pregnancy rates were higher in G1 (63.3%) than in G2 (48.5%), not being statistically significant. Perhaps, with a higher sample could help to asses if the tendency of this increase keeps on the clinical pregnancy rate. Our results show that processing sperm samples with a microfluidic sperm sorting device could be a more efficient alternative to density gradients in cycles where patients were diagnosed with increased SDF. This method allows the selection of sperm with a low DNA fragmentation promoting the formation of a higher number of GQB to transfer and/or vitrify.

Limitations, reasons for caution: This is a preliminary retrospective study, so the main limitation is the small sample size achieved until now. These results should also be confirmed by further randomized prospective studies.

Wider implications of the findings: Our findings suggest that the application of microfluidic systems could be improving the sperm selection with conserved DNA integrity. In this sense, microfluidic systems increase significantly the number of GQB and therefore could potentially improve the cumulative pregnancy rates and the efficiency of the cycle.