Increased clinical pregnancy rates (CPR) and statistically significant decrease in loss rates using hyaluronan in sperm selection: prospective, multi-center, double-blind, randomized clinical trial

Clinical assessment of the male fertility

The evaluation of infertility in males consists of physical examination and semen analyses. Standardized semen analyses depend on the descriptive analysis of sperm motility, morphology, and concentration, with a threshold level that must be surpassed to be considered a fertile spermatozoon. Nonetheless, these conventional parameters are not satisfactory for clinicians since 25% of infertility cases worldwide remain unexplained. Therefore, newer tests methods have been established to investigate sperm physiology and functions by monitoring characteristics such as motility, capacitation, the acrosome reaction, reactive oxygen species, sperm DNA damage, chromatin structure, zona pellucida binding, and sperm-oocyte fusion. After the introduction of intracytoplasmic sperm injection technique, sperm maturity, morphology, and aneuploidy conditions have gotten more attention for investigating unexplained male infertility. In the present article, recent advancements in research regarding the utilization of male fertility prediction tests and their role and accuracy are reviewed.

A prospective randomized study to evaluate the effect of hyaluronic acid sperm selection on the intracytoplasmic sperm injection outcome of patients with unexplained infertility having normal semen parameters

PURPOSE

Sperm quality plays an important role in determining embryo development and intracytoplasmic sperm injection (ICSI) outcome. Selection of competent sperm based on its ability to bind to hyaluronic acid (HA) has been suggested as one of the methods to assess sperm quality. The aim of the present study was to examine whether injection of HA bound sperm helps in improving outcome in patients undergoing ICSI with unexplained infertility having normal semen parameters.

METHODS

Patients with unexplained infertility having normal semen parameters in accordance with WHO 2010 criterion, undergoing their first IVF-ICSI cycle were enrolled during the course of the study.156 patients were prospectively randomized after oocyte retrieval and were assigned to either the ICSI group, where sperm selection for injection was based on visual assessment, or the PICSI group, where sperm were selected based on their ability to bind to HA. Only fresh embryo transfers were included in the analysis.

RESULTS

There was no difference in the fertilization rates, number of top quality embryos and clinical pregnancy rates between the ICSI and PICSI groups (65.7 % vs 64.7 %; 45.8 % vs 43.6 % and 35 % vs 35.2 % respectively). However, a higher pregnancy loss rate was observed in the ICSI group (25 % vs 12 %; P = 0.227) as compared to the PICSI group, but the difference was not statistically significant. Implantation rates were 22.03 % and 18.84 % in the PICSI and ICSI groups respectively. There were 22 (31 %) live births in the PICSI group and 21(26.3 %) live births in the ICSI group.

CONCLUSIONS

Patients with unexplained infertility having normal semen parameters may constitute a patient group which does not benefit from this sperm selection method. A larger study may be necessary to establish a relationship between PICSI and pregnancy loss rate in patients undergoing IVF with unexplained infertility.

Application of sperm selection using hyaluronic acid binding in intracytoplasmic sperm injection cycles: a sibling oocyte study

The purpose of this study was to investigate whether sperm selection by hyaluronic acid (HA) binding could improve fertilization rate and embryo quality in intracytoplasmic sperm injection (ICSI) cycles. Two hundred nineteen oocytes obtained from eighteen women were injected with either HA-bound (n = 107) or conventionally selected spermatozoa (n = 112) in a randomized way. All of the participants were infertile couples who had normal sperm parameters but low fertilization rate in previous in vitro fertilization (IVF) cycle (n = 5) or experienced multiple IVF failures (n = 13). Lower fertilization (75.7% vs 83.0%) and cleavage rate on day 2 (72.9% vs 83.0%) was observed in oocytes injected with HA-bound spermatozoa than the conventional group, but the difference was not significant. Significantly lower cleavage rate was observed on day 3 in HA group (56.0% vs 69.6%, P = 0.038). Blastocyst formation rate and the number of transferred embryos were similar in both groups. In multiple IVF failure patients, significantly reduced fertilization rate (71.8% vs 85.3%, P = 0.046) and cleavage rate on day 2 (70.4% vs 85.3%, P = 0.029) and day 3 (53.5% vs 77.3%, P = 0.002) were noticed in HA group. Five women achieved pregnancy continuing more than 12 weeks after transfer (27.8%). Success of ICSI was not related with the number of embryos fertilized by HA-bound spermatozoa. Application of ICSI by sperm selection using HA binding is not helpful in couples with repeated poor fertilization or implantation despite normal sperm parameters.