Cornell University

Cornell University
Weill Medical College

Cornell Institute for Reproductive Medicine

Center for Male Reproductive Medicine and Microsurgery

"State-of-the-Art Compassionate Care for the Infertile Couple"

Understanding Male Infertility

Infertility effects one in every six couples who are trying to conceive. In at least half of all cases of infertility a male factor is a major or contributing cause. This means that about 10% of all men in the United States who are attempting to conceive suffer from infertility.

Historically, infertility has been considered a women's disease. It is only within the last fifty years that the importance of the male factor contribution to infertility has been recognized. The mistaken notion that infertility is associated with impotence or decreased masculinity may contribute to this fear. The good news is that the rapid research advances in the area of male reproduction have brought about dramatic changes in the ability to both diagnose and treat male infertility. The majority of couples suffering from infertility can now be helped to conceive a child on their own.

The most common identifiable cause of infertility in men is varicocele. This is a condition of enlarged veins in the scrotum that causes abnormalities in the temperature regulation of the testis. Enzymes that are responsible for both sperm and hormone (testosterone) production have an optimal temperature at which they operate most effectively. If this temperature is elevated by even one degree, sperm and testosterone production are adversely effected.

The evidence for the negative effect of varicocele on testicular function in male fertility is now overwhelming. What is less certain, however, is the effect of repairing the varicocele on restoring testicular function. Dozens of reports have been published demonstrating the benefit of varicocele surgery. However in most of these reports, controlled studies were lacking. Microscopes were not used in older surgical procedures, which made it extremely difficult to locate the tiny artery that provides the major source of nourishment for the testis. Subsequently this artery was often tied off which clearly was unlikely to improve testicular function. Tiny lymph ducts were also inadvertently tied off, often causing a condition called "hydrocele," which is a bag of fluid that develops around the testicle.

These results led me and a colleague, Joel Marmar, to independently and simultaneously develop a microsurgical technique of varicocelectomy employing an operating microscope providing magnification between 6 and 30 power. This enabled positive identification and preservation of the main artery and the lymph ducts eliminating potential damage to the testicle as well as eliminating the complication of hydrocele. Using these techniques in several thousands of patients, the average healthy sperm count after repair of the large varicoceles has been shown to increase 128%. In addition, the first prospective randomized study comparing varicocelectomy to no surgery was sponsored by the World Health Organization (WHO) and reported in Fertility and Sterility. The results showed the pregnancy rate in couples where men with varicoceles underwent surgery was three times higher than when men did not undergo surgery.

The second major cause of infertility in men is blockages or obstructions of the male reproductive tract. This is particularly true for men with zero sperm count, a condition called "azoospermia." Men with zero sperm count can be divided into two broad groups:
  1. men who have an obstruction problem or blockage, meaning they are making sperm, but the sperm can't get out, or
  2. men who have a production problem, meaning they are not making sperm, a condition called "non-obstructive " azoospermia."
We can easily determine which group an infertile male is in by doing a testicular biopsy, also using a microscope to minimize discomfort and complications.

Blockage can also be caused by a urinary tract infection or by the sexually transmitted diseases chlamydia and gonorrhea. Bacteria can infect the tiny duct called the "epididymis," which is essentially a swimming school for sperm before they are able to swim to fertilize an egg. Infection of the epididymis can cause scarring and blockage, inhibiting the sperm from leaving the duct to fertilize an egg. With the use of microscopes employing 30-power magnification, blockage repair success rates are extremely high.

One of the most common causes of blockage is vasectomy. Approximately 500,000 to a million men undergo vasectomy each year in this country for permanent birth control. With an increase in divorce rates coast-to-coast, the demand for reversal of vasectomy is also growing. Currently, using a new technique we developed here at New York Presbyterian Hospital-Weill Medical College of Cornell University called the microdot technique, we have achieved return of sperm in 99% of men undergoing vasectomy reversal in whom we find sperm in at least one of their vas ducts.

Approximately 1% of all infertile men are born with the congenital absence of the vas deferens, the "equivalent" of a vasectomy. Unfortunately, there are no artificial tubes strong enough to replace the vas deferens. However, we are now able to help such men conceive using an operating microscope to retrieve sperm from the tiny ducts of the epididymis, freeze them and use them later for in- vitro fertilization (IVF) with the injection of the single sperm directly into an egg.

The most exciting new development in the field of male infertility is the ability to treat men with severe sperm production problems called non-obstructive azoospermia. Even though these men may have no sperm in their semen, we can now find sperm between the cells of the testicles in almost half of these cases. Using an operating microscope, the medical team at New York Presbyterian Hospital-Weill Medical College of Cornell University, including Drs. Schlegel, Girardi, Rosenwaks, Davis, Palermo and other colleagues, has been able to achieve pregnancies in half of those men in whom sperm can be found within the testicle. Genetic testing of these men with non-obstructive azoospermia has revealed that 10% to 15% are missing a tiny piece of their Y chromosome. This condition is called micro Y deletion. Human beings have 46 chromosomes, males have one X chromosome and one Y chromosome and females have two X chromosomes. The Y chromosome carries the genes that are responsible for producing sperm. Men who have low to no sperm count might be missing a small piece of that Y chromosome. Unfortunately helping men with micro Y deletion have children almost guarantees their male children will have the same infertility problem. However, these children will be healthy in every other way.

Artificial techniques of reproduction have advanced to the point where a single sperm can be physically injected into an egg. This procedure, called intracytoplasmic sperm injection (ICSI), was developed in Belgium by Gianpiero Palermo, a physician/scientist who now works with us at The New York-Cornell Hospital. ICSI has dramatically changed the treatment available for even the most severe male factor infertility. Because of this technique, 90% of all infertile men, including half of all men with non-obstructive azoospermia, have the potential to conceive their own genetic child.

Our ability to combat male infertility has never been stronger. It is entirely possibly that, within 10 to 20 years, scientists will be able to take cells from any tissue in a man's body and induce these cells to fertilize an egg using some future version of ICSI. The steps in such a process are very complex and not understood at present. Once the process is mastered, however, male infertility will become a thing of the past.

(Source: This Article was published on the American Infertility Association (aia), November 1999,

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