The impact of semen processing on sperm parameters and pregnancy rates after intrauterine insemination

The objective of this retrospective study was to evaluate the effect of semen processing on computer analyzed semen parameters and pregnancy rates after intrauterine insemination (IUI).

Over a two-year period, a total of 981 couples undergoing 2231 IUI cycles were evaluated and the freshly collected non-donor semen was analyzed before and after density gradient centrifugation (DGC).

DGC led to significant increases in sperm concentration by 66±74 ×106/mL (P=0.0001), percentage of motile sperm by 24±22% (P=0.0001), concentration motile by 27±58 ×106/mL (P=0.0001), and forward sperm progression by 18±14 µ/s (P=0.0001). In 95% of cases, there was a decrease in the total motile sperm count (TMSC), with an average decrease of 50±124% compared to pre-processed samples (P=0.0001). Importantly, the decrease in TMSC did not negatively affect pregnancy rates (P=0.45).

This study proves that DGC leads to significant increases in most sperm parameters, with the exception of TMSC. Remarkably, the decrease in TMSC did not affect the pregnancy rate. This should reassure clinicians when the TMSC is negatively affected by processing.