Azoospermia is the term that’s used when there is virtually no sperm count in the ejaculate. If this is the case, does this mean that there’s no chance for a couple to conceive a child? If there’s no sperm, can there be conception? Well, the reality is that a semen analysis that shows the absence of sperm in the ejaculate does not rule out either the possibility that sperm are being produced and not delivered to the semen or that interventions may help the man produce sperm. Even in those cases where, after intervention, there is still no sperm in the ejaculate, there may be a possibility of harvesting small amounts of sperm, which have been produced in the testes as a result of the interventions. These sperm may be used in in-vitro fertilization (IVF) or intracytoplasmic sperm insertion (ICSI).
What we’re looking at here is whether the problem lies in the sperm production or in the delivery. Is it the testes that are not producing sperm or are they unable to deliver it in the ejaculate? The initial evaluation is to distinguish between these two conditions. If the testes are making sperm but none are in the ejaculate, the sperm must be retrieved by some other mechanism, either by restoring the normal flow of sperm or by circumventing it. If the testes are not producing sperm, we need to explore whether the problem can be reversed. Even if the problem cannot be reversed, there are a number of cases in which the level of spermatogenesis is advanced enough to allow sperm “harvesting” in conjunction with in-vitro insemination and other advanced reproductive techniques (ART) and micromanipulation. The following briefly describes causes for both production and delivery problems:
The three major causes for lack of sperm production are hormonal problems, testicular failure, and varicocele.
The testicles need pituitary hormones to be stimulated to make sperm. If these are absent or severely decreased, the testes will not maximally produce sperm. Importantly, men who take androgens (steroids) for body building, either by mouth or injection, shut down the production of hormones for sperm production.
In general, this means that the sperm-producing part of the testicle (the seminiferous epithelium) isn’t making adequate numbers of mature sperm. This failure may occur at any stage in sperm production for a number of reasons. Either the testicle may completely lack the cells that divide to become sperm (this is termed “sertoli cell-only syndrome”) or there may be an inability of the sperm to complete their development (this is termed a “maturation arrest.”) This situation may be caused by genetic abnormalities. A physician must screen for these.
As we’ve discussed in other sections, a varicocele is a dilated vein in the scrotum (much like varicose veins in the legs). These veins are dilated because the blood does not drain properly from them. These dilated veins allow extra blood to pool in the scrotum, which has a negative effect on sperm production. This condition may be corrected by minor out-patient surgery.
Ductal Absence or Blockage
Generally, a sperm delivery complication is caused by a problem in the ducts that carry the sperm, or problems with ejaculation. The sperm-carrying ducts may be missing or blocked. Both sides of the patient’s vas deferens may be absent from birth. Or he may have obstructions either at the level of the delicate tubular structure draining the testes (the epididymis) or higher up in the more muscular vas deferens. He may have become mechanically blocked during hernia or hydrocele repairs.
Sperm are stored in sacs called the seminal vesicles, and then are deposited in the urethra, which is the tube through which men urinate and ejaculate. The sperm must pass through the ejaculatory ducts to get from the seminal vesicles to the urethra. If these are blocked on both sides, no sperm will come through.
Finally, there may be problems with ejaculation. Before a man ejaculates, the sperm must first be deposited in the urethra. This process is called emission. There may be neurological damage from surgery, diabetes, or spinal cord injury that prevents this from happening. Also, for the sperm to be pushed out the tip of the penis, the entry to the bladder must be closed down.If it does not close down, the sperm will be pushed into the bladder and washed out when the patient urinates.
If you’re wondering what causes azoospermia, the answer is often complex. But we can discuss some of the tests that help determine a cause.
The simplest test is the physical exam. Since most of the testes is comprised of sperm producing elements (the seminiferous epithelium), if the size of the testicle is severely diminished, the seminiferous epithelium may be affected. Follow-up hormonal profiles can determine whether this is a primary problem or caused by inadequate hormonal stimulation.
The scrotum is examined for the presence of dilated veins (varicoceles). Their presence can be confirmed by an ultrasound probe placed on the skin at the scrotum.
During a physical exam, the ductal systems can be felt. If they are absent, the patient has what is called congenital bilateral absence of the vas deferens (CBAVD). In most cases, this is due to the patient’s genetic make-up and requires chromosomal analysis as part of the evaluation and treatment.
Finally, during examination of the ductal structures, the epididymis may feel as though it is dilated. Generally, it is flat and the middle cannot be felt. What this means is that if there is a dilated epididymis there may be a blockage.
Follicle stimulating hormone (FSH) is the hormone made by the pituitary, which is responsible for stimulating the testes to make sperm. When the sperm-producing capacity of the testes is diminished, the pituitary makes more FSH in an attempt to make the testes do their job. Therefore, if a man’s FSH is significantly elevated, there is a strong indication that his testicles are not optimally producing sperm. Testosterone, prolactin, leutenizing hormone (LH), and thyroid stimulating hormone (TSH) are also measured to assess a man’s hormonal status. These may reveal problems that can significantly impact sperm production.
This is an area of active research. At this point, it is recommended that all men receive basic genetic testing, measuring the number of chromosomes and looking at the blocks of genetic material. Screening for the genes that can cause cystic fibrosis is sometimes suggested. There are tests for specific genetic abnormalities on the male chromosomes that can cause azoospermia. If a son were to inherit this, he might have the same problem.
In order to rule out a blockage of the ejaculatory duct, an ultrasound of the ejaculatory duct and seminal vesicles is often performed. In this test, the ultrasound probe is placed in the rectum since the ducts lie near its wall. Also, the ejaculatory duct traverses the prostate, a gland that can be felt through a man’s rectal wall. If the seminal vesicles are dilated, this indicates that they may be full of semen because they cannot empty properly. Cysts blocking the ejaculatory ducts by exerting pressure on their walls, or calcifications in the ejaculatory ducts themselves, may also be noted. A cyst, in some cases, may be unroofed by operating through the urethra to open it, thus decompressing the ejaculatory duct. If the blockage occurs within the ejaculatory duct, the blocked part may be removed in a similar operation.
It is possible that ejaculation is occurring “backwards”; the sperm is being pushed into the bladder and then washed out when the man urinates after ejaculation. To test for this, we have the patient empty his bladder and then ejaculate into a cup. He is then asked to urinate again into a different specimen container. If there are sperm in his urine, he has ejaculated backwards. Sometimes, this can be corrected by oral medication. If not, the urine can be prepared so that it does not damage the sperm as much, and the sperm is then harvested from the post-ejaculatory urine.
Testes mapping refers to a procedure where multiple fine needle biopsies (fine needle aspirations or FNA) are done on the testes in order to see if there are any areas where sperm are produced. The reason why this is useful is that the testes are “heterogeneous;” different areas of the testes have different patterns of sperm production. Thus, even if the majority of the areas of the testes produce no sperm, there may be some harder-to-find areas that do. Testes mapping, therefore, tells us if there are some areas of sperm production in the testes, and where they are so they are easier to find.
If no sperm are found on the testes mapping, it can be presumed that there are no sperm produced anywhere in the testes and no further evaluation or treatment is possible. This saves the couple from having the man go through an open testicular biopsy and prevents a couple from undergoing a fruitless in vitro fertilization cycle. Read more about Testes mapping and its advantages.
Most men facing a semen analysis fear the diagnosis of azoospermia. However, that diagnosis does not necessarily mean that the man will never have a biological child. Accurate diagnosis of azoospermia is complicated. Correctible causes must be found and treated. Even then, if there are no sperm in the ejaculate, sperm can often be harvested and used to achieve fertilization.