Testicular Failure

In the male reproductive system, there is a series of events that needs to take place in order to produce mature sperm. This series of events spans from 70-72 days for a complete production cycle. Testicular failure means that an issue that is originating in the testes is causing this cycle to be disrupted in some manner.

The Cycle

The hypothalamus is an ancient part of the brain. It produces a hormone that is known as gonadotropin releasing hormone (GnRH). This hormone will monitor the production of testosterone and sperm in the male reproductive system and tell the pituitary gland what gonadotropins to release. The gonadotropins are follicle stimulating hormone (FSH), which orders the testicles to produce sperm, and luteinizing hormone (LH) which orders the Leydig cells within the testes to produce testosterone.

If the hypothalamus is doing its job properly, then there is a constant level of gonadotropins that encourage germ cells (starter cells for sperm production) to be nurtured by Sertoli cells in the seminiferous tubules (the production line for sperm cells). As the spermatazoa achieve maturity, they are guided into the epididymus, where they learn to swim on their way to the vas deferens. The vas deferens is where sperm will line up to wait for semen to join them for eruption from the urethra, and into the vagina.

There are three major failures of the testes that can occur. Each has its own set of identifiers, but all result in infertility. Though for many there are no treatment options to reverse testicular failure, often aspiration of sperm is still a possibility.

Sertoli Cell-Only

One form of testicular failure is known as Sertoli cell-only. In Sertoli cell-only there are no, or very few, germ cells present to produce mature sperm. This is a congenital condition, which means that you are born with it. Your fertility specialist may test your blood for elevated levels of FSH if he suspects that you have Sertoli cell-only, as the GnRH would be pressing your pituitary to produce the maximum amount of FSH to respond to the lack of sperm being produced.

There is no way to reverse or correct Sertoli cell-only. Those that suffer from this condition may still have the ability to fertilize an egg with their own gametes. Some mature sperm can be retrieved during testicular biopsy, which can be used in intracytoplasmic sperm injection (ICSI). This is a technique in which sperm are injected directly into the egg to create an embryo during in vitro fertilization (IVF). These embryos will be deposited into the female partner's uterus via catheter for conception.

Hypospermatogenesis

Hypospermatogenesis refers to a condition where too few sperm are being produced. This can occur for many reasons, including intrinsic testicular defect. This means that the testicles have genetically reduced spermatogenesis (sperm production). Intrinsic testicular defect is hereditary and does not have a cure. Like Sertoli cell-only, aspirated mature sperm cells can be used in ICSI for IVF.

If the Leydig cells are not producing enough testosterone, it can have a devastating effect on sperm production. The most common treatment for decreased testosterone production is to start therapy of injected LH. LH is the only treatment that can encourage sperm production, as using testosterone therapies only makes the GnRH signal believe that there is more testosterone being produced than ordered. In response to the perceived over-production, the pituitary gland reduces the LH that is released. The result is decreased testicular testosterone production as the body begins to rely on introduced sources of testosterone. This is the reason that anabolic steroid use causes testicular shrinkage and failure.

Chemical or physical trauma can decrease sperm production. Severe blunt trauma to the groin can cause testicular failure. Motorcycle riding can cause slow, steady trauma to the testicles as well. Medication, recreational drug use, or steroids may be chemically or hormonally traumatic and cause disruptions in the hormonal balance that lead to testicular failure. Each of these conditions is best treated by discontinuing the traumatic behavior.

Spermatogenic Arrest

The production line in the male reproductive tract does not slow down or stop for any reason, whether the individual be sick, injured, or medicated. There is no way to force sperm production to slow down to allow cells that are not maturing to catch up. If a sperm cell was a stuffed animal on a production line, and the position of stitching on the ears was not filled, then the stuffed animal would be delivered without ears rather than slowing down production to allow another worker to attach them.

Spermatogenic arrest is the term that is used to describe sperm production that is disrupted at some phase, resulting in underdeveloped sperm (as with the stuffed animal without ears). When sperm do not achieve maturity, they are incapable of fertilizing an egg. Spermatogenic arrest is often only detectable through semen analysis. It is possible that testicular biopsy can yield some mature sperm for aspiration. These sperm can be used for ICSI and IVF procedures.

Treatment

Sadly, for genetic and congenital conditions that hinder or restrict sperm production, there is little that can be offered except for sperm aspiration via testicular biopsy. Those that partake in activities or chemicals that are potentially traumatic to testicular function are best advised to halt such activities and discuss the extent of the damage and treatment options with their physician. Hormonal supplementation may be helpful to those that suffer hormonal deficiencies.

ICSI has been able to offer success for many families seeking conception. Those that suspect they suffer from genetic testicular failure, or are concerned that trauma may have affected their ability to produce sperm should refer to a fertility specialist. Your doctor can order tests to diagnose your male factor infertility, which will reveal the treatment options that are available to you.