How is this indicator being established?
To establish the fertility index in the spermogram performed, the total number of active, inactive and, at the same time, inactive sex cells is counted. The calculation is made in the total volume of ejaculate isolated during ejaculation, as well as in 1 ml of sperm.
It is worth noting that the value of this indicator directly depends on the age of the man.
What methods are used to establish fertility?
In order to determine whether the fertility rate is normal or not, after evaluation of the ejaculate in men, the evaluation can be performed using the Farris or Kruger index.
When counting according to the first method, doctors determine the total number of sex cells, as well as the percentage of mobile, immobile and slow-moving, but living spermatozoa. It is used mainly in the CIS countries. The results are estimated as follows: the index is 20.0-25.0 - the norm, less than 20.0 - violation. About a high fertility index for Farris say, when it exceeds 25.0.
However, recently the Kruger index has become more widespread. A distinctive feature of it is the fact that during the research the head size, the condition of the neck and tail of the sperm are estimated. The finished result is calculated in percent. The low fertility index for men is fixed if the indicator falls below 30%. If values above 30% are obtained, they speak of a good fertility and a high probability of conception.
It is worth noting that most men have an average fertility rate. Increased fertility is rarely recorded. This is said about when sperm have special properties and a high degree of viability. Usually in the percentage of them not more than 1-3% in all ejaculate. However, if the test showed that they are about 50%, then we can say with confidence that such a man can easily have children.