Anti-sperm Antibody Testing
The semen sample which is collected for a semen analysis may also be used at the same time to test for the presence of antibodies to the man’s sperm. If present, these sperm antibodies can further reduce the chances for a couple to conceive. The importance of testing for sperm antibodies is to know that they are present. If their presence is known, the sperm antibodies can be overcome by the addition of solutions to the semen at the time of the semen collection.
Sperm Function Testing: Vital Staining of Sperm
It is normal for some of the sperm that are examined at the semen analysis to be non-motile. Among these non-motile sperm, some may be dead while others are alive but incapable of movement. When there is a very high percentage of non-motile sperm it is helpful to know if some of them are alive. This will dictate the type of treatment that is available for the physician to employ in order to help the couple achieve pregnancy. If the semen analysis has revealed that there are 95% or more non-motile sperm in the sample, a portion of the sample will be combined on a slide with a vital stain. This stain will reveal what percent of the sperm are non-motile but alive. These stained sperm will not be available for use by the patient, but will give an indication of how many sperm are alive in the semen sample. If there is a small portion of sperm that are alive, intracytoplasmic sperm injection may be used during an IVF cycle in order to fertilize eggs that have been retrieved during the IVF procedure.
Sperm Function Testing: Hypo-Osmotic Swelling Test
A second test that may be used to differentiate dead sperm from living, non-motile sperm is a hypo-osmotic swelling test (HOST). This particular test is used during the actual IVF process. If the male partner has very few or no motile sperm, the embryologist may use a combination of culture medium and water to make a solution in which non-motile living sperm will react. The reaction is one in which the tail of the living sperm will curl as a response to the unfavorable osmotic condition caused by the presence of water in the culture medium. The dead sperm will not react. The living sperm are picked out of the culture medium and water solution and are gathered in a drop of medium to await their use for injecting eggs. The percent of living sperm can be calculated, but this technique is primarily used to identify sperm for immediate use during the ICSI process.