140 COMPARISON OF 3 DIFFERENT METHODS TO SELECT HIGH SPERM QUALITY FOR IVF

Abstract

Sperm selection is a fundamental step for IVF, influencing treatment and the health of offspring. Over the years, several techniques have been tested to recover highly motile sperm, including centrifugation with discontinuous gradients and numerous filtration procedures. In our previous paper, we showed that it is possible, in ~20 min, to select a high quality sperm population using an electric charge in a microchannel device. This method produced the same blastocyst rates as a discontinuous gradient (DG), but in less time [25 min less; Rubessa et al. 2016 Andrology (Los Angeles) 5]. This technique takes advantage of one of the physiological characteristics of high quality sperm; that is, the head has a negative electric charge. The aim of the present experiment was to analyse the characteristics of the sperm selected with our device. We compared 2 standard sperm procedures and our device, with semen assessed using a computer-assisted sperm analyzer to evaluate the principal sperm parameters. Standard procedures were used to select sperm by DG and swim-up (SU). Thawed semen was pipetted into the microchannel of our device and then exposed to the electric charge (10 V) for 10 min [Rubessa et al. 2016 Andrology (Los Angeles) 5]. For each replicate, 3 straws of frozen bovine semen were thawed at 37°C for 40 s and pooled. The pooled sample was divided into 3 aliquots: one for each technique, 5 replicates of the experiment were performed. Data were analysed by ANOVA using the general linear model (GLM) procedure (SPSS Inc., Chicago, IL, USA). Bonferroni’s post hoc test was used to perform statistical multiple comparison. The α-level was set at 0.05. The results show an effect of the method all motility parameters are not significantly different, although some of the motility parameters were statistically different (P < 0.05). (P < 0.05). The beat cross frequency results were 23 ± 2.4 v. 37.7 ± 2.1 v. 19.5 ± 0.7 (µm/s) for DG, SU, and EC. The same statistical differences were found for the STR (straightness): 75 ± 3.5 v. 84.5 ± 2.0 v. 62.3 ± 2.4 (µm/s), and LIN (linearity): 39.8 ± 4.4 v. 53 ± 1.2 and 31.8 ± 1.4. These results confirmed the potential of this new device, and that it is possible to use this new method to select high motility sperm without harming sperm characteristics. These results showed that our device produced the same quality of sperm obtained with DG and SU but in as little as 20 min.