For normal conception, a man must have sperm cells that are functionally able to fertilize eggs. The most common problems that lead to infertility in men are issues relating to sperm counts and the function of the testicles (testes). Other difficulties include hormone imbalances, blockages in the male reproductive ducts, or swollen veins in the scrotum, called varicoceles.
Male factor problems are the sole cause of the couple’s infertility in approximately 25% of all IVF cases. In 30% of cases, a combination of factors involves both partners.
Approximately 1 in 16 men are sub-fertile or infertile based on sperm parameters. In most cases, the etiology remains largely unexplained. Lifestyle choices and environmental factors may contribute to this problem. In my practice, 40–45% of the men with abnormal sperm counts have absolutely no other abnormality. In some cases, specific tests of sperm function and DNA integrity can provide further insight into the causes of sperm dysfunction.
Semen analysis remains the gold standard for the basic evaluation of male fertility. We look for the count, movement (motility), and shape (morphology) of the sperm cells. For most men, 2–4 days of abstinence is ideal. A sperm cell is called a spermatozoon.
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WHO Reference Range |
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Total Sperm Count in Ejaculate |
39–928 million |
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Ejaculate Volume |
1.5–7.6 mL |
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Sperm Concentration |
15–259 million per mL |
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Total Motility |
40–81% |
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Progressive Motility |
32–75% |
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Morphology (Kruger) |
4% |
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Total Motile Count |
Over 20 million |
Remarkably, 8–10% of all men have at least one abnormal parameter on a semen analysis. A markedly abnormal semen analysis will almost certainly be indicative of male factor infertility. Sometimes, even minor abnormalities are associated with a poor prognosis. Indeed, male factor infertility can be present even in the setting of a normal sperm count. Although aging is not a significant factor in male infertility, the absolute best semen parameters are seen in men between the ages of 22–29.
Sperm concentration is the first parameter I evaluate. I believe it is significantly more valuable and predictive to look at the sperm concentration rather than the total number of sperm. Sperm concentration is the number of sperm per milliliter (ml) of semen. Sperm concentration is considered normal if at least 15 million sperm per ml of semen are present, and it can reach up to 250 million per ml. The count is determined by examining the semen sample under a microscope to see how many sperm cells appear within squares on a grid pattern.
Sperm concentration is the first component in assessing possible male factor infertility. It is useful for both diagnostic and treatment purposes. In the case of a man with reduced sperm concentration, a possible underlying problem should be identified. Measurements of sperm concentration are valuable in assessing basic fertility treatments, including medications, supplements, and lifestyle changes. Furthermore, it is often a crucial factor when determining if IVF should be offered early during treatment.
One ml (or cc) represents 1/5 of a teaspoon. In other words, a healthy man could have 100 million sperm cells in just 1/5 of a teaspoon. If the total volume of his semen sample is 5 ml, then his total sperm count would be 500,000,000 cells. As seen herein, the total sperm count is less important because it varies according to the volume of the semen sample.
Sperm motility is expressed as the percentage of sperm that are moving. We also determine the degree to which sperm cells are moving in a forward progression. Progressive sperm motility correlates with the sperm’s ability to reach and penetrate an egg. It is desirable to see a motility of at least 40%. Reduced sperm motility is called asthenospermia.
Sperm cells with progressive motility move forward in a straight direction. Non-progressive motility is seen when sperm cells are moving in place or in a random direction. Immotile sperm have no movement. If you want to know the ‘total motile sperm count,’ simply multiply the total sperm count by the percent motile.
Sperm morphology refers to the shape, size, and structure of sperm cells. We use a standardized method to evaluate sperm, called Kruger’s strict criteria. This allows us to assess the head, midpiece, and tail of the sperm cell. Defects include large or misshaped heads or irregular contorted tails. The presence of 4% or more of normal-shaped sperm is considered satisfactory. Less than 4% is associated with severely impaired fertility. Men with sperm morphology in the range of 4–14% may have some reduced fertility potential. Remarkably, many men have abnormalities in morphology based on this kind of evaluation.
Reduced sperm morphology is referred to as teratozoospermia. Men with this condition may still be able to impregnate their partner if the count and motility are normal. However, in many cases, IVF with sperm injection, called ICSI, will be required.
It is important to note that a normal semen analysis does not guarantee fertility, and an abnormal analysis does not necessarily mean infertility. If only one sperm cell is needed to fertilize each egg, then why would a low sperm count, which is still in the millions, be a hindrance to fertility? The answer is very important.
An abnormal semen analysis is an indicator that the sperm function is abnormal. It correlates with the likelihood that fertilization will not occur naturally. It is not a numerical issue. It is a parameter that suggests an impairment in male reproductive function.
In the case of an abnormal semen analysis, I recommend that my patients repeat the test at least four weeks later. Sometimes, a third test is required. This will provide a more reliable assessment and eliminate false positive results. In a sensitive way, I try to mention to my female patients that even the most robust man can feel undue pressure when it comes to the collection of a sperm sample. Anxiety and stress can reduce the ease of masturbation ‘on demand.’ Because of this, it is always my preference to discuss the semen analysis directly with the male partner, regardless of whether the wife is present.
Semen samples can be collected in several different ways. You can provide a sample by masturbating and ejaculating in a sterile container provided to you by the office. If the sample is produced at home, it should be brought in within one hour and kept close to body temperature.
Some religious and cultural groups require men to use alternative methods of semen collection. This is because the interpretation of Genesis 38: 9–10 indicates that the destruction of the ‘seed’ in vain, unrelated to intercourse, is a violation. In these cases, the husband can use a condom, one without spermicide, to collect semen during intercourse. Some religions denote that masturbation is a mortal sin, based on Romans 8:5–6. Sperm counts and semen volume usually continue to rise during the five days of abstinence. However, after 5–7 days, sperm quality, motility, and morphology begin to suffer. Furthermore, beyond 5 days, there is a small but significant increase in DNA fragmentation within the sperm.
Our medical director Steven A. Brody MD PhD is available to explain all aspects of reproductive medicine to help you overcome infertility. He has written a definitive text on IVF in association with Robert G. Edwards Ph.D., who received the Nobel Prize in medicine for inventing IVF. Doctor Brody's book is titled "Principles and Practice of Assisted Human Reproduction."
Call Pat at 858-344-5020 to learn more information about our fertility services, and to arrange a consultation with Doctor Brody. He will spend sufficient time with you to make you aware of all the possible tests and treatments that will help you.
