Male Infertility

By: Russell A. Foulk, M.D.
Assistant Clinical Professor
University of Nevada, School of Medicine

Medical Director
The Nevada Center For Reproductive Medicine
The Idaho Center For Reproductive Medicine

There are over three million infertile couples in the United States. Factors affecting men account for about 40% of the causes. Until the past few years, many of these couples were only able to become parents through the use of donor sperm or adoption. Fortunately, an increased focus on male infertility has led to a series of recent advances in the medical world. Now, virtually all forms of male infertility are treatable.

Historically, male factor infertility has largely been neglected. This accounts for the many treatment options available for the management of female-related infertility, but few for men. Interestingly, in 1677 the sperm was the first microscopic organism ever seen. Yet, except for the use of sperm banks, which surprisingly have existed for many decades, many men could not become fathers because of the lack of other available treatments. During the 1950 and 1960s, techniques were developed to cleanse sperm from semen and capacitate them. This enabled couples to undergo intrauterine inseminations. In 1978, the first in-vitro fertilized (IVF) baby was born. IVF was designed primarily to help women with tubal factor infertility to become pregnant. It was finally in the early 1990's, that techniques were created that helped men with very low sperm counts. The beneficial impact these techniques have on the treatment of male-related infertility is comparable to the helpful impact antibiotics had on treating infectious disease when they were introduced 65 years ago.

Male factor infertility centers on the sperm. Sperm are very simple creatures. They are the smallest cells in the human body composed basically of encapsulated DNA (i.e. genetic blueprint) with a "propeller". They resemble tiny tadpoles. Difficulty conceiving results from any disorder that limits the sperm from reaching and fertilizing the egg. Some of these disorders include poor sperm production by the testicles, blockage of the passageway that carry sperm out, destruction of sperm by forces in the female tract, and inability of the sperm to recognize and fertilize an egg. A very common cause of male infertility is a defect with the "propeller" (i.e. poor motility). This naturally does not allow the DNA package to be delivered to the awaiting egg. Fortunately, defects with the propeller do not correlate with defects in the DNA. Thus, if we can help deliver the DNA package by another means we can restore that sperm's capacity of fertilizing an egg.

The average ejaculate contains over 100 million sperm. A common question is why are so many required for conception to occur. The reason lies in the tremendous journey sperm must make from the top of the vagina (after penile emission) to the end of the fallopian tube where the egg awaits. If the sperm were enlarged relative to a grown man's size, the man must swim across the Pacific Ocean to match the distance a sperm swims. If there were 100 million of him, perhaps some would make it. However, the likelihood is much smaller if there are fewer numbers or half are crippled,. The World Health Organization recommends there be a minimum of 20 million moving sperm available for effective conception to occur with intercourse. Male factor infertility occurs when the numbers are less than this.

The treatment for male factor infertility then is simply to help the sperm reach and fertilize the egg. If a lower number of available sperm is the problem, we can help this by decreasing the distance they must swim. Intrauterine insemination (IUI) places a sperm sample half way up the female reproductive tract, essentially starting them from Hawaii in their quest across the Pacific Ocean. The advanced reproductive techniques like Gamete intra-fallopian transfer (GIFT) and IVF places them as far as the opposite shore. By cutting the distance, the minimum numbers needed are less such that only about 10 million are desired for IUI and 1 - 2 million for GIFT or IVF. These treatments have greatly reduced the threshold of sperm needed to achieve conception. These techniques have helped tens of thousand of couples worldwide to become parents.

What about those individuals whose sperms are a fewer than a million and for the many men who have no sperm at all due to obstruction or non-development of the passageway? In 1992, a revolutionary technique called intracytoplasmic sperm injection (ICSI) was first used to help four couples have babies. The technique uses micromanipulation so that a single sperm can be handled to fertilize a single egg. Thus, if a man produces any sperm, he is capable of becoming a genetic father. Over the past seven years, thousands of healthy babies have been born as a result of ICSI. And for the many men who have no sperm released, newer techniques of sperm retrieval have been developed to obtain them before any obstruction. We can even take sperm directly from the testicle and apply ICSI to achieve conception. These newer techniques have an alphabet soup of acronyms: Percutaneous and Microsurgical Epididymal Sperm Aspiration (PESA and MESA), Testicular Sperm Extraction (TESE). These techniques are commonly used for men who are born without a vas deferens or who have had vasectomies but later desire children. PESA and MESA allow men to avoid surgical reconstruction of the blocked vas and still maintain contraception after their baby is born. Finally, we have learned to identify viable sperm even if they do not move at all. No movement was the previous definition of a dead sperm, but with the hypoosmotic-swelling test (HOS) we can pick individual living sperm and apply ICSI to help these couples conceive.

There are treatments currently available to overcome virtually all forms of male factor infertility. From andrology to technology, improvements have been made that enable infertile men with any viable sperm to become genetic fathers. For the few men who never made or no longer make any viable sperm, the remaining options are to use donor sperm or adoption to become parents. Given the rate of progress over the past two decades, there may eventually be treatments available for these men also. It is exciting to review how far we have come and where we might be in the future. Infertility, whatever the cause, is a disease that can severely cripple the lives of many people. Fortunately, there are effective means now available for the male factor which may foster hope and alleviate the distress it adds to one's life.