Is sperm hyaluronic acid binding ability predictive for clinical success of intracytoplasmic sperm injection: PICSI vs. ICSI?

Although intracytoplasmic sperm injection (ICSI) is now a widely-used technique, it is still of interest to improve our knowledge as to which is the best spermatozoon to be selected for ICSI. Infertile men have increased risks of producing aneuploid spermatozoa. Using hyaluronic acid (HA)-binding sperm selection may reduce the genetic risks such as chromosomal aberrations of offspring. In the present study we examined the clinical success of ICSI with HA-selected sperm ('physiologic' ICSI, PICSI) compared to conventional ICSI, as well as the necessity to differentiate patients according to the initial HA-binding assay result (HBA score) and whether the sperm concentration or HBA score can provide additional information. We observed a significantly higher fertilization rate (FR) of the PICSI group with >60% HBA, implantation rate (IR) of the PICSI group with <= 60% HBA, and clinical pregnanacy rate (CPR) in every PICSI group compared to the ICSI groups (p<0.01). We also observed a significantly higher life birth rate (LBR) in the PICSI group with <= 60% HBA compared to ICSI patients with <= 60% HBA (p<0.001). The pregnancy loss rate (PLR) was significanly lower in PICSI patients compared to the ICSI group (p<0.0001). The FR, IR, CPR, and LBR of the PICSI group with <50% HBA were significantly higher and the PLR was lower than in the ICSI group with <50% HBA (p<0.01). A statistically significant correlation was found between the sperm concentration and the HA-binding capacity (r = 0.62, p<0.001). We found a closer relationship between HBA score and FR (r = 0.53, NS) than between sperm concentration and FR (r = 0.14, NS). HBA could be considered for sperm selection prior to ICSI because of its success and apparant ability to reduce genetic complications. However, this must be extended to a larger study.