The amount of spermatozoa found in semen is important, because it organically travels to the egg, and many die in the journey. To travel along the vagina, the uterine neck and the arrival in the egg through the fallopian tubes constitues a real biological gymkhana in which many don’t reach destination. That is why it is important to start the race with a good concentration.
Sperm concentration in semen is evaluated through a seminogram. The seminogram shows a picture of the condition of the semen, but a male fertility test must not only rely on a seminogram. The objective should be to diagnose the origin of infertility, although the seminogram helps assessing at a glance whether there is an evident problem in the quantity and motility of the spermatozoa, and, in case there is one, to choose the most adequate assisted reproduction technique for every particular case.
Procedure to evaluate sperm concentration
Semen sample is deposited on a sterile container. The sample rests for 20 minutes, to help the liquefaction of the fluid. Later, a drop of semen is studied under the microscope.
An instrument known as counting chamber is used to facilitate the counting. A slide with a sharply outlined grid can be seen under the microscope, making possible the spermatozoa count.
The drop of semen is a sample of the total spermatozoa volume. To make the sample more representative, two drops are used to make the counting. If there are lots of spermatozoa, some rows of the grid are counted and a mean is calculated. To count motile spermatozoa is no easy task, as they swim underneath the grid and sometimes is hard to distinguish one from the other.
Once spermatozoa is completely counted, the amount of millions per milliliter in the ejaculate is calculated. According to the World Health Organisation (WHO), normal values are those equal or higher than 15 millions per ml of ejaculated semen. That means that in couples that have children by natural ways, the male counterpart has 15 million spermatozoa/ml on average.
Altered values of sperm concentration
Values below 15 millions do not necessarily indicate a fertility problem. A reliable spermiogram comprises at least two seminograms.
When a semen analysis shows abnormal, non-permanent findings, it may be due to some of the following factors or situations:
- Nutritional deficiencies
- An episode of fever three months prior to the test
- Being under stress
After these initial symptoms pass, sperm concentration levels usually return to normal. Hence the importance of undergoing a second seminogram once these factors or situations have finished.
Determination of sperm concentration
Depending on the sperm concentration results determined after the seminogram, a disease may be diagnosed. The patient will be then recommended that ART which greater chances for pregnancy offers according to his pathology.
In case normal parameters have not been reached, it is time to decide which procedure to use. A concentration of less than 15 millions/ml is called oligozoospermia or oligospermia. In mild cases, artificial insemination (AI) may be enough to achieve pregnancy.
Situations of less than 100.000 spermetazoa per ml, when oligozoospermia is quite noticeable, are known by the name of cryptozoospermia, requiring a more complex technique to achieve pregnancy: in vitro fertilisation or ICSI.
The azoospermia is the total lack of spermatozoa. There are two types: secreting azoospermia, with no production at all of spermatozoa, and obstructive spermatozoa, in which the production of spermatozoa cannot be released because of the obstruction of a duct.