Evaluation of a new sperm density gradient and sperm wash for assisted reproductive technology

Abstract

Sperm preparation is an important factor that affects the results of conventional IVF and ICSI. Typically, separation methods that yield a higher number of motile spermatozoa combine density-gradient centrifugation with a subsequent swim-up procedure. However, fertilization in vivo is not only based on absolute sperm numbers, but also on their functional capability. A sperm preparation solution that mimics the physiology of the sperm environment in vivo was developed as the ORIGIO® GradientTM (OG) system. The effect of this new sperm preparation system in ART is still unknown. The aim of this study was to evaluate and compare sperm quality and IVF/ICSI outcomes following density gradient sperm preparation with two different media: Percoll and the OG. A prospective quasi-randomized controlled study was performed in a single IVF center between January 2016 and October 2016. We examined 87 conventional IVF cycles and 167 ICSI cycles. Patients were allocated to two groups randomly: for the control group, sperm preparation was performed using 80% Percoll solution (Sigma) with Sperm Washing Medium (Irvine Scientific); for the test group, sperm preparation was performed using 80% OG with ORIGIO® Sperm Wash (Origio). Only cycles using fresh autologous gametes were included. We excluded testicular sperm extraction-ICSI cycles and cycles combining IVF/ICSI. Sperm preparation was performed using density gradient centrifugation in the control or test solutions (25 min at 500 g) with a subsequent swim-up (30 min). We analyzed 668 inseminated (IVF) and 966 microinjected (ICSI) oocytes. All embryos were cultured using the same protocol. Sperm quality and IVF/ICSI outcomes were compared between the two groups. In both the IVF and ICSI cycles, there were no significant differences in patient characteristics, semen parameters before preparation (ejaculate volume, total and motile sperm concentrations, and percentage motility) or sperm quality after preparation (motile sperm concentration, and percentage motility), when comparing the two groups. Among the 87 conventional IVF cycles, 44 were in the control group and 43 were in the test group. The fertilization rate in the test group was significantly higher (P < 0.05) than in the control group (77.6% vs. 68.2%, respectively). The high-quality embryo formation rate on day 2 in the test group was significantly higher (P < 0.05) than in the control group (48.5% vs. 37.3%, respectively). The cleavage and blastocyst formation rates were similar between the test and control group (97.4% vs. 99.5%, and 58.3% vs. 57.6%, respectively). Among the 167 ICSI cycles, 87 were in the control group and 80 were in the test group. The fertilization, cleavage, high quality embryo rate on day 2 and blastocyst formation rates were similar between the test and control groups (83.8% vs. 82.3%, 98.1% vs. 99.3%, 47.6% vs. 50.9%, and 56.1% vs. 54.6%, respectively). This new sperm preparation system improved the fertilization and early embryonic development rates in conventional IVF cycles.