Infertility in Men - Assisted Reproductive Technologies

Sperm Retrieval and Preparation for ART

Before fertilization using intrauterine insemination (IUI) or advanced assisted reproductive technologies (ART) can take place, the sperm must be collected and prepared for optimal chances for success.

Retrieval Procedures

When a man has no available sperm in the ejaculate (usually from blockage, vasectomy, or lack of vas deferens), the sperm must be retrieved from the testes or the epididymis. Various microsurgical techniques are now available for retrieval. The procedure may be done under local or general anesthesia, using a spring-loaded biopsy device, a thin needle, incisions, or microsurgical techniques.

Surgical Biopsy. In men without obstruction, sperm can be retrieved using a surgical testicular biopsy.

Testicular Fine Needle Aspiration (TFNA). TFNA employs a fine needle to remove sperm. This can be performed with local anesthetic and by surgeons who do not have to be experienced in microsurgeries.

Microsurgical Epididymal Sperm Aspiration (MESA). MESA uses microsurgical techniques to collect sperm that are close to blocked portions of the epididymis. It involves an open incision and may be done under general or spinal anesthesia in a hospital setting, although the patient can often go home the same day. The doctor accesses the epididymis and retrieves sperm with an extremely fine needle-like device. It has the advantage that it can retrieve the largest number of sperm compared to other procedures. However, as with any invasive procedure, it carries some risks of complications, such as bleeding or infection.

Percutaneous Epididymal Sperm Aspiration (PESA). PESA uses a needle to obtain mature sperm from areas in the upper parts of the epididymis (the coiled tube where sperm are stored before ejaculation). It is done under local anesthesia, sometimes in the doctor's office, is less expensive than other techniques, and recovery is fairly painless. However, it has less of a chance of achieving sufficient sperm than MESA, and there is also a chance of hitting a blood vessel, causing bleeding.

Testicular Sperm Extraction (TESE). TESE is a microsurgery that removes a small amount of tissue from one or more areas of the testes using incisions and microsurgery techniques. The tissue is placed in a culture and chopped into tiny pieces. Sperm are liberated from the tiny tubes and extracted. It is a complex process, however. This is the second best method for men with vasectomies, according to some experts. It is more painful than PESA, however. In addition, if the procedure is repeated too often, it can cause permanent alterations in testicular function that may even reduce male hormone levels.

Testicular Sperm Aspiration (TESA). TESA uses a needle-like biopsy device to draw a small sample of testicular tissue. Multiple attempts are sometimes required to retrieve sperm, and it is not as effective or as safe as TESE, although imaging techniques using ultrasound may improve results.

Sperm Washing

A sperm's energy output is 20 times greater once it is removed from the seminal fluid. Methods for washing sperm can have a dramatic effect on the ability of sperm to move towards the egg. The simplest method involves:

• The sperm is mixed with a nutrient-rich fluid (or culture media) in a test tube.
• They are then centrifuged (spun very rapidly) for about 5 minutes.
• The sperm, which are heavy, settle on the bottom, forming a dense button of millions of pure sperm. The fluid left on top is siphoned off.
• This procedure may be repeated.

This simple method of sperm washing, however, does not eliminate heavy debris, such as dead sperm, white blood cells, or bacteria, which may impair fertility. Scientists are developing new techniques, such as adding a substance called platelet-activating factor during the sperm washing process, which may enhance pregnancy rates.

Swim-Up Technique

The swim-up technique is not only a useful diagnostic procedure for testing the ability of sperm to escape from the semen into the cervical mucus, but it also achieves the goal of removing sperm from semen.

• A specially prepared semen sample is placed in a tube.
• A culture media (a nutrient-rich substance in which cells thrive) is placed on top of the sample.
• The medium is a hospitable environment for sperm, and those that are healthy will swim up to it.
• After an hour or more, the culture is examined, and the number of sperm that have reached the medium is compared to the number still remaining in the semen.

The result gives a fair estimation of the number of sperm potentially capable of fertilization. It is superior to sperm washing because the live sperm will swim up to the culture media, leaving behind most of the debris, although some may float up into the medium. There is also some evidence that such sperm may have fewer genetic abnormalities than those retrieved through sperm washing. The strongest sperm, which are those at the top of the medium, can be collected for in vitro fertilization or artificial insemination. A good swim test yields about half a million very active sperm.

Freezing Sperm

Sperm can be fresh or frozen in advance. Studies are reporting that frozen sperm provide excellent results and can be used confidently for fertilization procedures. Fresh sperm, however, are preferred by some centers for cases when low sperm count is not caused by obstruction.