Male Infertility / General Information
Understanding Male Infertility
By Marc Goldstein, M.D., FACS
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.
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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.
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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:
- men who have an obstruction problem or blockage, meaning they are
making sperm, but the sperm can't get out, or
- 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.
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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 The 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 The 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.
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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, http://www.americaninfertility.org)
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