TESTIS BIOPSY AND SPERM HARVESTING FOR IVF

The testes perform two functions. The first is to produce the male hormone testosterone which is secreted into the blood stream and has wide ranging effects upon the body. The other role of the testis is to produce sperm. Either one or both functions may go astray during a man’s lifetime. Since the testis has an absolute requirement for testosterone in order to make sperm, it is possible to have abnormalities in spermatogenesis with normal testosterone but not vice versa. It is extremely rare for men of reproductive age to have abnormal testosterone levels and much more common for them to have abnormalities in sperm production associated with normal testosterone levels.

The most common finding amongst infertile men is abnormal sperm production in terms of numbers and quality. However, a small percentage of men have a zero sperm count known as azoospermia. There are three causes for azoospermia. The first is insufficient hormones and this is easily established by blood tests. The second is a problem in the testis producing sperm and the third is a blockage preventing sperm from getting out similar to a vasectomy. The last two can sometimes be differentiated by findings in the history, physical examination or on blood tests, however, there are a significant number of times when it is still uncertain. In that case, a diagnostic testicular biopsy is performed to differentiate between obstruction and a problem inside the testis. A diagnostic testicular biopsy consists of taking a small pea sized amount of tissue out of both testes and sending them to the pathology laboratory for examination. The tissue must be handled properly in a special way for the biopsy to be worthwhile. Thus, even though the procedure is quite simple, it is best performed at a center that has a great deal of experience with male infertility.

The management options for couples in whom the husband has a zero sperm count depend upon the exact cause. Adoption and donor insemination are always an alternative option to fixing the husband’s problem or using sperm harvested from him in combination with in vitro fertilization (IVF), test tube baby technology. Hormonal therapy is highly effective in men who have insufficient hormones. For those men who have a problem in the testis, therapies aimed at improving testicular function may be employed such as varicocele repair. The alternative is to harvest sperm from the testes. About 50% of men with a zero sperm count have sufficient sperm production within the testes to allow fertilization of the wife’s eggs using intracytoplasmic sperm injection (ICSI) a form of IVF. The options for couples where the man has a zero sperm cont due to a blockage are to repair the blockage or harvest sperm to be used in IVF.

Sperm harvesting is entirely different from a diagnostic testicular biopsy since in this setting the goal is not to identify what is happening in the testis but instead it is to find sperm. This may involve a simple aspiration for men who have a blockage or require much more extensive sampling of the testis for men who have a sperm production problem. This involves a significant difference in the amount of time ti takes, the need for anesthesia and the equipment utilized. Very few tests allow for an accurate prediction of whether or not sperm will be found in the testes of men with testicular problems. Genetic testing may give insight into the chance of finding sperm but are not absolute. The pattern of the problem of the testis found at the time of a diagnostic testicular problem may be slightly predictive but again there is no finding that absolutely predicts the presence or absence of sperm. Other blood tests including hormonal studies are not predictive. Finally, even having sperm found on previous harvesting session does not guarantee that sperm will be found on future harvesting attempts. Thus, diagnostic testicular biopsy is not routinely performed in patients who are to undergo testicular harvesting of sperm when the cause of their zero sperm cont is already established through other means.

The timing of sperm harvesting in conjunction with the IVF cycle is a difficult matter to resolve. There are advantages for and against doing the sperm harvesting prior to the IVF cycle or in conjunction with the harvesting of the wife’s eggs. The ultimate decision is made by the preference of the IVF program. Performing the harvesting in advance and freezing the sperm until the eggs are harvested allows the couple to make an informed decision whether to go forward with IVF since in most circumstances the chance of finding sperm may be only 50% or less. Moreover, it is difficult for many couples to undergo operative procedures the same day since it requires their enlisting other resources to help them get to and from the hospital and assistance at home. IVF laboratories frequently prefer to work with fresh rather than frozen sperm and thus their desire to have fresh sperm trumps any other consideration.

There are numerous ways to harvest sperm from a man with normal sperm production and a blockage. The simplest and most cost-effective is an aspiration of sperm. This is routinely performed under local anesthesia and takes approximately ten minutes. Harvesting sperm from a man with a testicular problem is much more difficult and often takes several hours. The ideal procedure is performed with the aid of a surgical microscope whereby the chances of finding sperm are increased and the amount of tissue taken out of the testis can be minimized. It is important to understand that the microscope utilized in the operating room does not have sufficient magnification to see sperm but instead just helps sort out which tubules within the testis are more likely to contain sperm. Small amounts of tissue are sent to the IVF laboratory during the course of the procedure so that they can assess whether sufficient numbers of sperm have been harvested. A more powerful microscope is used by the IVF laboratory to evaluate this tissue. Repeated biopsies from one or both testes are obtained until sufficient sperm has been harvested for that IVF cycle. Extra sperm may be harvested to preserve for future cycles of IVF in case the current cycle is unsuccessful or the couple desires more children in the future. This procedure can take as long as four hours depending upon how quickly sperm are found.