This post is a brief summary of what you need to know about semen analysis. Due to efforts of the World Health Organization, andrology labs now measure the same things when analyzing semen. These factors are semen volume, sperm concentration, total sperm number, sperm morphology, sperm motility, and sperm vitality. There may be wide variations in these variables in the same person, thus it is recommended to have more than one sample to analyze, collected over a period of weeks. It seems like there is no exact criteria for that so I would just consult with a lab technician to figure that out. Below, I will define the parameters and provide reference values as listed in “World Health Organization reference values for human semen characteristics” and “WHO laboratory manual for the examination and processing of human semen” Let’s define each of the parameters and keep things brief.
The amount of semen released during ejaculation. The money shot. According to the WHO, the low limit for this value is 1.5 ml (fifth percentile). See table II in the report linked to above.
This is the most important. Sperm concentration is measured as millions of sperm per milliliter of ejaculate.
Total sperm number
The total number of sperm in ejaculated semen. This value is estimated based on sperm concentration and volume of semen.
The threshold for percentage of normally shaped sperm is only 4%. I guess that’s all you need to be considered “fertile” but I am unclear if this is healthy. Most of the “normal” values for these parameters are likely low from a health standpoint, rather than from the standpoint of fertility alone.
Spermatozoa contain a head and a tail. The head portion consists of the head and tail, and the tail consists of a midpiece, principal piece, and endpiece. Descriptions of a normal shape can be found on pages 68-70 of the laboratory report. In general, there should be no breaks, proportions matter, and the head should be oval in shape. Shape is pretty important for health in general, whether it’s the human body or a sperm cell apparently.
Sperm movements are categorized in three different ways (see page 21 of laboratory manual linked to above for a picture). Sperm cells, or spermatozoa, are either categorized as progressively motile (PR: able to move linearly or in a circle), non-progressively motile (NP: tails may be undulating but no linear movement occurs), or immotile (IM: not progressing and not moving at all). Total motility is calculated as percentage of PR and NP sperm.
Vitality in this case means alive. The sperm vitality is thus the percentage of live cells, assessed by the cell membrane’s integrity.
There you have it. Those are the basics!