The CatSper test assesses the function of ion channels in the sperm flagellum. These channels trigger the intense sperm movement required for the sperm to penetrate the egg. Their dysfunction may be a cause of unsuccessful attempts to achieve pregnancy both naturally and through intrauterine insemination (IUI).
CatSper is a unique type of ion channel (Ca²⁺) found exclusively in the flagellum of human sperm. It allows a massive influx of calcium ions into the sperm, triggering flagellar hyperactivation, which is essential for the sperm to penetrate the egg.
If CatSper channels do not function properly or are completely absent, the sperm may be unable to fertilise the egg even though its appearance and motility are normal.
The CatSper test can therefore detect a disorder that remains hidden in a routine semen analysis.
The examination monitors how sperm respond to a special test solution. In sperm with functional CatSper channels, the solution causes a change in ion concentration that leads to a loss of motility. If the CatSper channels do not function or are absent, the sperm remain motile.
A control sample is examined at the same time to confirm that the change in motility is genuinely related to CatSper channel function. The result is expressed as the CatSper Index, which indicates their function in the examined sample.
The test is performed on a fresh, unprocessed semen sample and can be carried out together with a basic semen analysis. Approximately two days of sexual abstinence are recommended before sample collection. The combined semen analysis and CatSper test take approximately 90 minutes.
For reliable evaluation, the sample must contain a sufficient number of progressively motile sperm. If their count or motility is significantly reduced, it may not be possible to evaluate the CatSper test reliably.
The examination is particularly suitable for couples who have not achieved pregnancy naturally or through intrauterine insemination (IUI), even though the results of the basic semen analysis are normal.
If the test confirms impaired CatSper channel function, assisted fertilisation using ICSI is recommended. During this procedure, the embryologist injects a selected sperm directly into the egg, thereby overcoming the obstacle that prevents the sperm from fertilising the egg naturally.
Hlinky 144, 603 00 Brno, CZ
Hlinky 144, 603 00 Brno, CZ
