The Hypoοsmotic Swelling Test (HOS test) is used to assess male infertility and the functionality of the sperm cell membrane.
More Information
Water permeability is an essential physiological property of all cell membranes, including sperm membranes. Membranes allow the selective transport of fluids and molecules across them, and the sperm membrane plays a vital role during fertilization.
The test of hypoosmotic swelling of spermatozoa is based on the ability of living spermatozoa to withstand moderate hypoosmotic stress. At moderate hypoosmotic stress, the membranes swell and reach a steady state, and then any amount of fluid that enters the cells is pumped out by an equal amount through the intact functional membrane. Sperm swell to varying degrees at this stage but do not rupture. Dead spermatozoa whose membranes are not intact and functional do not swell in hypotonic media.
Low values in the HOS test correlate with an increased damage rate to sperm DNA, as measured by the DNA fragmentation index (DFI). Testing for hypoosmotic swelling of spermatozoa can be used as an additional indicator of sperm vitality and to diagnose abnormalities such as immobile cilia syndrome.
Testing for hypoosmotic swelling of spermatozoa is the most reliable indicator for sperm selection during in vitro fertilization with ICSI. The percentage of spermatozoa that swell during the HOS test significantly correlates with the rate of successfully fertilized oocytes.
Many recent studies have found that high HOS test values positively correlated with all key sperm quality factors (sperm concentration, morphology, and motility).
Important Note
Laboratory test results are the most critical parameter for diagnosing and monitoring all pathological conditions. Between 70 to 80% of diagnostic decisions are based on laboratory tests. Correctly interpreting laboratory results allows a doctor to distinguish "healthy" from "diseased."
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be analyzed based on each case and family history, clinical findings, and the results of other laboratory tests and information. Your physician should explain the importance of your test results.
At Diagnostiki Athinon, we answer any questions you may have about the test you perform in our laboratory and contact your doctor to ensure you receive the best possible medical care.
