Pattern of changes in motility, vitality and morphology of human sperm in different in vitro segments of the ejaculate

Analyzing sperm parameters in raw semen or in in vitro processing is controversial. The present study compares the progressive changes of sperm parameters in raw semen to those in in vitro processed sperm. A single fertile donor was used in the experiment to avoid individual variability. Each ejaculate was divided into raw semen, Percol rejected, Percol recovered and cultured sperm subsets. The motility, vitality and morphology of spermatozoa were evaluated at 24 hr intervals up to 120 hours in each. The number of motile sperm were substantially lower in percol rejected group compared with the other groups. The motility decreased 45, 7, 15 and 13% in raw semen, Percol rejected, Percol recovered and cultured sperm, respectively at 24 hrs. All sperm were non-motile in raw semen at 48 hrs, while significant sperm motility was noticed in Percol rejected (11%), Percol recovered (15%) and cultured (37%) sperm even in the 120 hrs observation. The most and the least change in motility grade composition occurred in the raw semen and Percol rejected sperm, respectively. From 24 hrs onward, the HOS scores (vitality index) were almost twice the motility scores in raw semen and percol rejected sperm, while the HOS and motility scores were closely identical in Percol recovered and cultured sperm. The pre-existing morphologies were indiscriminantly well preserved in all four groups. Our findings suggest that 1) analysis of sperm motility and vitality in raw and processed semen combined may provide more information than performing any of the single analysis and 2) sperm morphology evaluation in raw semen will be more effective since it contains the spermatozoa of normal and abnormal morphologies and apparently does not change the balance of their occurrence over the time.