RESUMO
OBJECTIVE: To test a novel method to select spermatozoa with high chromatin integrity. DESIGN: Specimens with high sperm chromatin fragmentation (SCF) were selected by density gradient selection (DGS) and microfluidic sperm sorting (MSS). SETTING: Academic medical center. PATIENT(S): Ejaculates from consenting men were processed by DGS/MSS. Couples underwent ICSI cycles with spermatozoa processed by DGS/MSS. Clinical outcomes were evaluated after embryo transfer. INTERVENTION(S): SCF was measured by TUNEL. ICSI with spermatozoa selected by DGS and MSS was performed. MAIN OUTCOME MEASURE(S): Fertilization, embryo implantation, and pregnancy outcomes were compared between DGS and MSS. RESULT(S): A total of 23 men had an average SCF of 20.7 ± 10%. After DGS and MSS, the SCF was 12.5 ± 5% and 1.8 ± 1%, respectively. In couples who underwent ICSI, the average SCF was 28.8 ± 9%, which fell to 21.0 ± 9% after DGS and 1.3 ± 0.7% after MSS. Four couples underwent 11 ICSI cycles with DGS and achieved one (25%) pregnancy that resulted in pregnancy loss. In four subsequent ICSI cycles with MSS, an ongoing clinical pregnancy rate of 50% was achieved. Five additional couples underwent 12 cycles of ICSI with DGS. After preimplantation genetic testing for aneuploidy, 30.3% of the embryos were euploid. One pregnancy was achieved, resulting in pregnancy loss. With MSS, 31.5% of the embryos were euploid and 4 couples obtained a pregnancy. Finally, sixteen couples underwent 20 ICSI cycles solely with MSS at our center. Of these couples, 8 had failed 13 ICSI cycles with DGS elsewhere. These couples achieved an overall implantation of 34.5% (10/29) and a pregnancy rate of 58.8% (10/17). CONCLUSION(S): Microfluidic selection yielded spermatozoa with optimal genomic integrity and improved chances of obtaining a euploid conceptus.