Sperm Penetration Tests
All men undergoing investigation for infertility will have a semen analysis done as part of their fertility workup. While a semen analysis is a very helpful test, as it determines how well sperm is produced and matured in your body, the results fail to offer any information about how well your sperm is able to perform. For this reason, sperm penetration tests may be done.
Tests Under the Umbrella
Sperm penetration tests are not just one male infertility test but a series of infertility tests designed to evaluate sperm’s ability to swim through cervical mucus as well as penetrate an egg. Two tests are done to assess these factors: the sperm mucus penetration test and the sperm penetration assay. Results of the tests can directly affect what type of infertility treatment you and your partner should pursue and can indicate which treatments you are most likely to benefit from.
Sperm penetration tests may be done for a variety of reasons, including:
- Other fertility tests have failed to find a reason for your male infertility problems
- Confirmation of abnormal results from a post-coital test
- To assess how well sperm deemed mildly to moderately abnormal in a semen analysis can function
- To evaluate sperm’s ability before performing IVF
Sperm Mucus Penetration Test
This part of the sperm penetration tests involves both the female and male partner. To do this test, the female partner will have her menstrual cycle monitored in order to detect ovulation (indicated by a rise in LH levels). Once ovulation has been detected, a sample of the woman’s cervical mucus will be taken.
On the day of the test, the male partner will provide a fresh semen sample through masturbation, using a sterile cup to collect his ejaculate. Sperm from the semen sample will then be introduced to the cervical mucus and left for 90 minutes. After this time, the sperm’s motility will be evaluated by measuring how far the sperm was able to travel through the cervical mucus.
If abnormal results are found, meaning that the sperm has not traveled very far, the test will be repeated, first with the female’s cervical mucus and donor sperm known to be fertile, then with the male’s sperm and cow mucus (which is similar to human cervical mucus and more readily available) or fertile human donor cervical mucus. Based on these results, fertility doctors will be able to discern whether the fertility problem lies in the male’s sperm or the female’s cervical mucus.
If sperm is found to clump together on contact with the cervical mucus, then it is likely that either the male’s sperm or the female’s mucus contain antisperm antibodies.