UTILIZING SPERMATOZOA WITH THE HIGHEST GENOMIC INTEGRITY ENHANCES ICSI OUTCOME

Abstract

To demonstrate that selecting spermatozoa with the highest genomic integrity enhances ICSI outcomes. Over the last 4 years, consenting men undergoing ART provided ejaculates for sperm chromatin fragmentation (SCF) screening before and after density gradient centrifugation (DGC). In a subsequent cycle, this assay was carried out before and after microfluidics sperm selection (MFSS). SCF was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL); at least 500 spermatozoa were assessed per sample with a normal threshold of ≤15%. Ejaculated specimens were analyzed in the standard fashion and used for ICSI after selection by DGC or MFSS. Fertilization and clinical outcome were recorded and compared between sperm-processing methods. A total of 21 men (43.3±8 years) had an average SCF in their raw semen of 22.1±10%, which decreased to 19.1±7% after DGC. These men underwent 39 ICSI cycles with their female partners (38.0±4 years), achieving a fertilization rate of 57.0% (167/293), an implantation rate of only 5.1% (4/78), and a clinical pregnancy rate (CPR) of 11.8% (4/34), with half resulting in pregnancy loss (2/4). Subsequently, these couples underwent 26 ICSI cycles with MFSS. The SCF after selection was 1.2±1%, remarkably lower than in the raw specimen (P<0.05). In these cycles, there was an improved fertilization rate of 69.3% (167/241; P<0.05). The implantation rate rose to 30.8% (16/52; P<0.0001) and the CPR increased to 53.8% (14/26; P<0.001); all are ongoing or have delivered (P<0.0001). Based on these results, 55 men (42.3±8 years) with elevated SCF in their ejaculate solely selected by MFSS were treated in 69 ICSI cycles with their female partners (38.3±5 years). The SCF in their raw samples was 22.3±10%, which fell to 3.0±4% following MFSS (P<0.0001). These cycles led to a 75.9% (456/605) fertilization rate, with an implantation rate of 24.8% (36/145), and a CPR of 47.8% (32/67), with 41.8% (28/67) ongoing or delivered pregnancies. Compared to the more conventional DGC, MFSS is capable of selecting the most progressively motile spermatozoa with the highest genomic integrity. Treatment by ICSI with MFSS for men with high sperm DNA fragmentation enhances fertilization, embryo development, and clinical pregnancies.