Intrauterine insemination in male subfertility: a comparative study of sperm preparation using a commercial Percoll kit and conventional sperm wash.

In order to evaluate the possible benefit of sperm preparation using a commercially available, ready-to-use Percoll gradient kit (PerWash, FertiPro, Belgium) for intrauterine insemination (IUI), a two-centre study was performed comparing this method with conventional sperm preparation by means of centrifugation-resuspension. In the Percoll group, 25 couples out of 52 (48%) achieved pregnancy requiring 136 cycles of insemination, with a per cycle success rate of 18.4%. This result was significantly better (P < 0.01) than the per cycle pregnancy rate of 8.9%, which is 23 pregnancies out of 65 cases treated during 259 cycles of insemination with conventionally prepared semen. Also, the 10th percentile of sperm characteristics among successful cases was lower for sperm concentration, proportion and concentration of grade (a) motile spermatozoa in the Percoll group as compared to couples inseminated with conventionally prepared semen. In contrast, cases with elevated proportion of grade (a) motility (> 22%) were significantly less likely (P < 0.001) to obtain pregnancy with IUI, using either sperm preparation method. It is concluded that sperm preparation for intrauterine insemination using the Percoll gradient kit gives a better success rate and can be applied in cases with more severe sperm deficiency.