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.

Sperm Penetration Assay
For this test, hamster eggs are used in place of female eggs because they are more readily available and are very similar to human eggs in structure. However, due to the difference in species, although sperm are able to penetrate the egg, further development cannot occur. For this test, also known as the hamster zona-free ovum test, the hamster eggs have been specially treated to remove the outer layer of the egg (known as the zona) and to allow sperm to fuse to the egg.

As with the sperm mucus penetration test, the male partner will provide a semen sample. Collected sperm will then be processed and refrigerated for three days. After this time, once sperm have undergone capacitation (a process necessary for the sperm to be able to penetrate an egg), sperm are combined with numerous hamster eggs.

Once the sperm and hamster eggs have incubated for three hours, the eggs are then evaluated to determine how many eggs have been penetrated and by how many sperm. Men whose sperm is able to penetrate all hamster eggs with between six and 20 sperm per egg are thought to be fertile. The fewer sperm that are able to penetrate the eggs, the less fertile a man is deemed to be.

This particular test is especially helpful for couples considering IVF. If test results reveal sperm that cannot penetrate an egg, a couple may decide to use ICSI in order to ensure fertilization.

Interpreting the Results
If the results of your sperm penetration tests show abnormal sperm, IVF may be suggested to help you conceive. However, so long as there are no fertility problems indicated for the female, some couples may also want to consider using donor sperm with IUI.

It is important to note, though, that test results can be compromised if a semen sample has not been collected properly or if a sperm mucus penetration test is performed when a woman is not ovulating. Therefore it is important that you have these tests performed by fertility doctors who are experienced in sperm penetration tests.

We are unable to provide answers to medically related questions or other medical advice via e-mail. Our physicians look forward to addressing your medical needs in person. To schedule an appointment or for more information about this practice as well as the programs and treatments they offer, please complete the form below. Be sure to include a valid telephone number and e-mail address so that one of our patient services coordinators may contact you directly.

Full Name:  State:  --- Select --- Outside US AE AK AL AR AZ CA CO CT DC DE FL GA HI IA ID IL IN KS KY LA MA MD ME MI MN MO MS MT NC ND NE NH NJ NM NV NY OH OK OR OU PA RI SC SD TN TX UT VA VT WA WI WV WY Your city:  Closest major city:  --- Select --- Atlanta Boston Chicago Dallas Denver Houston London Los Angeles Miami Minneapolis New York Philadelphia Phoenix San Diego San Francisco Seattle St Louis Sydney Washington DC Email:  Phone:  Program:  --- Select --- General information IUI - Artificial Insemination IVF - In Vitro Fertilization Fertility Drugs Tubal Reversal Vasectomy Reversal Mind/Body Programs Egg/Sperm Donation Alternative Treatments Other Comments: