Sperm vitality is the number of live sperm in the semen sample. And this parameter is even more vital should the sperm motility be lower than normal. At least 60% of the sperm in a semen sample must be alive on average for successful chances of conception. A semen sample must contain both sperms that are alive and mobile to achieve conception. Alive but immotile sperm may be suitable for Assisted Reproductive Technology (ART) called ICSI. However, it would not be helpful either to perform conventional in vitro fertilization (IVF) or artificial insemination (AI) since a sperm that does not move properly may not reach the egg.

Sperm motility test

The eosin test ascertains sperm motility. Dead sperm cells with holes in the membranes absorb the eosin and appear pinking while, normal live sperm with intact sperm will remain without the stain. Secondly, a hypo-osmotic swelling test is also used but to a lesser degree. The semen, in this case, is diluted in a hypoosmotic solution so that it enters the sperm cell. A sperm that is alive shows a tail as the solution enters the cell, while a dead sperm will not.

Results of the eosin stain test

The eosin test should not result in a score of less than 58% alive sperm cells. However, a percentage under 58% may still qualify an individual for an ICSI procedure.