Infertility is caused by a male factor in approximately 30%-40% of cases. An additional 20% of infertile couples are found to have both male and female factors.
What Causes Male Infertility?
Most cases of male infertility (90%) can be attributed to sperm production
CAUSES OF MALE INFERTILITY
- Sperm production abnormalities
- Sperm transport disorders
- Erectile dysfunction
- Ejaculation disorders
Abnormalities resulting in low sperm count and/or poor motility (i.e. the number of sperm which are viable and moving). Abnormal morphology (i.e. malformed sperm) appears to play a lesser role in male infertility. While there are many theories about what causes these conditions, it is not always possible for the fertility specialist to identify the cause. Sometimes an infection may be discerned by finding inflammatory or white cells in the semen. A semen culture can identify the organism involved and antibiotics can be prescribed to resolve the problem. Sometimes the cause of sperm abnormality can be traced to genetic abnormalities, past testicular infection, environmental causes (such as smoking, hot tubs and marijuana use), hormonal deficiency (Hypogonadism), or genetic defects (cystic fibrosis). It is becoming more common to see men with low sperm count as a result of steroids or testosterone shots given to them at the local gym to help them bulk up. The presence of a varicocele or distended testicular veins may result in temperature elevation in the testes resulting in abnormal sperm production.
- The remaining cases of male infertility (10%) may be attributed to obstructions in sperm transport caused by infection or congenital absence of the vas or epididymis. Sometimes, stress, depression, alcohol, certain medications and low testosterone level may cause temporary erectile problems which may affect the couple’s ability to have sexual intercourse. At other times, the problem may be attributed to retrograde ejaculation or ejaculation into the bladder. This can happen after bladder or abdominal surgery, with certain medications or stricture (narrowing) of the urethra.
- Aging causes a decline in the count, motility and genetic quality of the sperm.
- Unlike female infertility, which requires a battery of tests to diagnose, male infertility is a relatively simple evaluation consisting of medical history, physical examination and a semen analysis. If it is normal, usually, no other testing of the male partner is required.
- Of course, the couple should ensure that the laboratory performing the semen analysis is highly experienced in this procedure and that the lab performs a complete evaluation.
- If the semen analysis shows that there is a problem, an evaluation by an urologist- ideally one who specializes in infertility is necessary. Your partner can expect to undergo a careful examination, blood tests and an ultrasound to try to pinpoint the cause
Male Infertility – Medical History
The Male Partner – Medical History
- Duration of infertility/sexual frequency
- Testicular surgery or injury
- Childhood illnesses
- Heat exposure; pesticide exposure
- Smoking, alcohol and drug abuse
- Sexually transmitted diseases
Male Infertility – Physical Examination
The urologic examination may reveal abnormalities of the penis or testicles, or the presence of a varicocele (abnormal enlargement of the veins in the scrotum).
Male Infertility Testing – The Semen Analysis
In this test, freshly ejaculated semen is examined under the microscope to evaluate the number and quality of sperm and several other characteristics of the semen.
Why the Test is done?
- Infertility: The semen analysis is one of the first tests done to help determine if a man has an infertility problem. About 15% of couples experience problems conceiving, and 40% of the time, the problem can be traced to a male factor.
- After vasectomy (male sterilization): The semen analysis is performed about 6 weeks after surgery to make sure that there is no sperm present in the ejaculate, confirming that the man is sterile.
- After vasectomy reversal: The semen analysis is done to determine if there is sperm present in the ejaculate, indicating that the reversal was successful and fertility has been restored.
Normal Semen Analysis Results
- Count (the number of sperm) – sperm concentration is the number of sperm per milliliter. Average concentration is about 60 million per milliliter. A sperm concentration of over 20 million per milliliter is considered normal.
- Motility (the percentage of moving sperm) – Motility is considered normal when at least 50% of observed sperm, show good forward movement. These are the strongest sperm, swimming fast in a straight line (Grade 4). Some of the sperm may be moving slower in a circle or in crooked lines (Grade 3). Other sperm move their tail but have no forward motion (Grade 2) or fail to move at all (Grade 1).
- Morphology (the size and shape of the sperm) – Morphology is considered normal if 14% or more of the observed sperm have normal shape.
- Volume – greater than 2.0 milliliters is considered normal. A low volume may reflect complete or partial blockage of gland secretions contributing to the seminal fluid. If the volume is less than 1 milliliter, the semen may not be in close enough proximity to the cervix to allow sufficient sperm to swim up to the uterus and fallopian tube.
- White Blood Cells - Finding bacteria or white blood cells in the semen indicate that an infection may be present. A semen culture may identify the organism involved and antibiotics can be prescribed to resolve the problem. A repeat semen analysis usually follows.
- PH level - normal pH range is 7.2 – 8.0. Too little or too much acid in the semen is detrimental to the sperm.
- Liquefaction – It normally takes less than 20 minutes for semen to change from a thick gel into a liquid. An unusually long liquefaction time may indicate an infection.
- Fructose level - Semen is analyzed for fructose when there is no sperm in the ejaculate (azoospermia) or if the semen volume is very low (less than 1 ml). Absence of fructose in the semen may indicate blockage of the seminal vesicles which secrete a significant amount of the fluid of the ejaculate.
What Abnormal Results Mean
- Semen samples may vary from day to day, so if the test is abnormal, you may be asked to repeat it in a month to reevaluate the abnormality. An evaluation by a urologist is necessary to pinpoint the cause for the problem.
- Sometimes the cause of sperm abnormalities can be traced to genetic defects (cystic fibrosis), hormonal deficiency, environmental factors (such as smoking, hot tubs and marijuana use), or blockage of the ejaculatory ducts.
- Low sperm count can occur in men who are treated with testosterone or anabolic steroids.
- If a varicocele (distended testicular veins) is present, it may disrupt sperm production.
- In some men, low sperm count or complete absence of sperm (azoospermia) may be attributed to deletions of very small regions in their Y chromosome (detectable by genetic studies).
Absence of sperm in the semen may be caused by:
- Ejaculation of the sperm into the bladder (retrograde ejaculation);
- Congenital absence of the vas deferens (sperm transport ejaculatory duct);
- Scarring of the ejaculatory duct;
- Testicular failure;
- Surgery, chemotherapy or radiation treatment for cancer;
Testicular failure can be distinguished from sperm transport abnormalities by measuring the husband’s hormone levels; these may include Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Inhibin, Testosterone, Prolactin and Thyroid stimulating Hormone (TSH). Testicular biopsy is sometimes recommended to see if the testes are producing sperm.
Tests for Sperm DNA Damage
Infertile men, with abnormal sperm count are more likely to have increased sperm DNA damage. The cause for this is not clear but it may occur as a result of heat exposure, radiation or chemotherapy, infection, cigarette smoking and varicocele. There are several tests for sperm DNA damage (SDD, SCSA). Their usefulness is questionable and The Practice Committee of the American Society for Reproductive Medicine issued the following statements:
- Existing data on the relationship between abnormal DNA integrity and reproductive outcomes are limited.
- Sperm DNA damage is more common in infertile men and may affect reproductive outcomes in selected couples, including those with recurrent spontaneous miscarriage or unexplained infertility
- At present, the results of sperm DNA integrity testing alone do not predict pregnancy rates achieved with intercourse, IUI, or IVF and ICSI.
- Currently, there is no proven role for routine DNA integrity testing in the evaluation of infertility.
- Treatments for abnormal DNA integrity have not been shown to have clinical value.
Treatment of Male Infertility
Once the cause for the infertility is identified, your doctor will recommend the appropriate therapy.