What is it?
Approximately 15 percent of couples are infertile. This means they aren't able to conceive a child even though they've had frequent, unprotected sexual intercourse for a year or longer. In about half of these cases, male infertility plays a role.
Male infertility is due to low sperm production, misshapen or immobile sperm, or blockages that prevent the delivery of sperm. Illnesses, injuries, chronic health problems, lifestyle choices and other factors can play a role in causing male infertility.
Not being able to conceive a child can be stressful and frustrating, but a number of male infertility treatments are available. Approaches can include treatment for the male partner, the female partner, or both.
The main sign of male infertility is the inability to conceive a child. Often, there are no other obvious signs or symptoms. In some cases, however, an underlying problem such as an inherited hormonal imbalance or a condition that blocks the passage of sperm may cause signs and symptoms. Male infertility symptoms may include:
- The inability to conceive a child
- Problems with sexual function — for example, difficulty reaching orgasm (delayed ejaculation) or difficulty maintaining an erection (erectile dysfunction)
- Pain, swelling or a lump in the testicle area.
- Decreased facial or body hair or other signs of a chromosomal or hormonal abnormality
Male fertility is a complex process. To get your partner pregnant, you must be able to produce healthy sperm that can reach, penetrate and fertilize your partner's egg. For this to occur:
- You must produce healthy sperm. Initially, this involves the growth and formation of the male reproductive organs during puberty. At least one of your testicles must be functioning correctly, and your body must produce testosterone and other hormones to trigger and maintain sperm production.
- Sperm have to be carried into the semen. Once sperm are produced in the testicles, delicate tubes transport them until they mix with semen and are ejaculated out of the penis.
- There needs to be enough sperm in the semen. If the number of sperm in your semen (sperm count) is low, it decreases the odds that one of your sperm will fertilize your partner's egg. A low sperm count is fewer than 20 million sperm per milliliter of semen.
- Sperm must be shaped correctly and able to move. If the movement (motility) or shape (morphology) of your sperm is abnormal, the sperm may not be able to reach or penetrate your partner's egg.
Problems with male fertility can be caused by a number of health issues and medical treatments. Some of these include:
- Varicocele. A varicocele is a swelling of the veins that drain the testicle. This may prevent normal cooling of the testicle, leading to reduced sperm count and fewer moving sperm.
- Infection. Some infections can interfere with sperm production or sperm health, or can cause scarring that blocks the passage of sperm. These include some sexually transmitted diseases (STDs), including chlamydia and gonorrhea; inflammation of the prostate (prostatitis); inflamed testicles due to mumps (mumps orchitis); and other infections of the urinary tract or reproductive organs.
- Retrograde ejaculation. This occurs when semen enters the bladder during orgasm instead of emerging out the tip of the penis. Various health conditions can cause retrograde ejaculation, including diabetes, multiple sclerosis, spinal injuries, and surgery of the bladder, prostate or urethra. Retrograde ejaculation can also be caused by certain medications — particularly medications for enlarged prostate, such as terazosin (Hytrin), tamsulosin (Flomax) and olealfuzosin (Uroxatral).
- Lack of ejaculation. Some men with spinal cord injuries or certain diseases can't ejaculate semen, even though they still produce sperm.
- Antibodies that attack sperm. Anti-sperm antibodies are immune system cells that mistakenly identify sperm as harmful invaders and attempt to eliminate them. This is especially common in men who've had a vasectomy.
- Tumours. Cancers and nonmalignant tumours can affect the male reproductive organs directly, or can affect the glands that release hormones related to reproduction (such as the pituitary gland). In some cases, surgery to treat tumours can affect male fertility.
- Undescended testicles. In some males, during fetal development one or both testicles fail to descend from the abdomen into the sac that usually contains the testicles (scrotum).
- Hormone imbalances. Infertility can result from disorders of the testicles themselves or an abnormality affecting the glands in the brain that produce testosterone and other hormones that control the testicles (the hypothalamus or pituitary glands). Low testosterone (male hypogonadism) and other hormonal problems have a number of possible underlying causes.
- Sperm duct defects. The tubes that carry sperm (sperm ducts) can be damaged by illness or injury. Some men are born with a blockage in the part of the testicle that stores sperm (epididymis) or a blockage of one or both of the tubes that carry sperm out of the testicles. Men with cystic fibrosis and some other inherited conditions may be born without sperm ducts altogether.
- Chromosome defects. Inherited disorders such as Klinefelter's syndrome — in which a male is born with two X chromosomes and one Y chromosome instead of one X and one Y — cause abnormal development of the male reproductive organs.
- Problems with sexual intercourse. These can include trouble keeping or maintaining an erection sufficient for sex (erectile dysfunction), premature ejaculation, painful intercourse, or psychological or relationship problems that interfere with sex.
- Celiac disease. A digestive disorder caused by sensitivity to gluten, celiac disease can cause male infertility. Fertility may improve after adopting a gluten-free diet.
- Certain medications. Testosterone replacement therapy, long-term anabolic steroid use, cancer medications (chemotherapy), certain antibiotics, some ulcer medications and certain other medications can impair sperm production and decrease male fertility.
Overexposure to certain environmental elements such as heat, toxins and chemicals can reduce sperm production or sperm function. Specific causes include:
- Pesticides. Some men exposed to pesticides such as ethylene dibromide and organophosphates have lowered sperm counts. Pesticide exposure has also been linked to testicular cancer. Most studies have been done on men who work in agriculture or live in agricultural areas.
- Heavy metal exposure. Exposure to lead or other heavy metals also may cause infertility.
- Exposure to radiation or X-rays. Exposure to radiation can reduce sperm production. It can take several years for sperm production to return to normal. With high doses of radiation, sperm production can be permanently reduced.
- Overheating the testicles. Frequent use of saunas or hot tubs may temporarily lower your sperm count. Sitting for long periods or wearing tight clothing also may increase the temperature in your scrotum and reduce sperm production.
- Prolonged bicycling. Prolonged bicycling is another possible cause of reduced fertility due to overheating the testicles. In some cases, bicycle seat pressure on the area behind the testicles (perineum) can cause numbness in the penis and erectile dysfunction.
Health, lifestyle and other causes
Some other causes of male infertility include:
- Illegal drug use. Anabolic steroids taken to stimulate muscle strength and growth can cause the testicles to shrink and sperm production to decrease. Use of cocaine or marijuana may temporarily reduce the number and quality of your sperm as well.
- Alcohol abuse. Heavy drinking can lower testosterone levels, cause erectile dysfunction and decrease sperm production. Liver disease caused by excessive drinking also may cause fertility problems.
- Tobacco smoking. Men who smoke may have a lower sperm count than do those who don't smoke. Secondhand smoke also may affect male fertility.
- Emotional stress. Stress may interfere with certain hormones needed to produce sperm. Your sperm count may be affected if you experience severe or prolonged emotional stress. A problem with fertility itself can sometimes become long term and discouraging, producing stress.
- Vitamin deficiency. Deficiencies in nutrients such as vitamin C, selenium, zinc and folate may contribute to male infertility.
- Weight. Obesity can cause hormone changes that reduce male fertility. Men who are underweight also may have reduced fertility.
- Age. Men older than 35 begin to have a gradual decline in fertility.
A number of risk factors are linked to male infertility. They include:
- Being age 35 or older
- Smoking tobacco
- Abusing alcohol
- Using certain illegal drugs
- Being overweight
- Being underweight
- Having certain past or present infections
- Being exposed to toxins
- Overheating the testicles
- Having a prior vasectomy or vasectomy reversal
- Being born with a fertility disorder or having a blood relative with a fertility disorder
- Having certain medical conditions, including tumours and chronic illnesses
- Undergoing medical treatments, such as certain medications, surgery or radiation for cancer
- Bicycling for prolonged periods, especially on a hard seat or poorly adjusted bicycle
Infertility can be stressful for both you and your partner. Complications can include:
- Surgery or other treatments for an underlying cause of low sperm count or other reproductive problems
- Expensive and involved reproductive techniques such as in vitro fertilization
- Stress related to the inability to have a child
Many infertile couples have more than one cause of infertility, so it's likely you will both need to see a doctor. It may take a number of tests to determine the cause of infertility. In some cases, a cause is never identified. Infertility tests can be expensive and may not be covered by insurance — find out what your medical plan covers ahead of time.
Diagnosing male infertility problems usually involves:
- General physical examination and medical history. This includes examination of your genitals and questions about any inherited conditions, chronic health problems, illnesses, injuries or surgeries that could affect fertility. Your doctor may also ask about your sexual habits and questions about your sexual development during puberty.
- Semen analysis. Semen is generally obtained by masturbating and ejaculating into a special container at the doctor's office. Your semen is then sent to a laboratory to measure the number of sperm present and look for any abnormalities in the shape (morphology) and movement (motility) of the sperm. The lab will also check your semen for signs of problems such as infections. Often sperm counts fluctuate from one specimen to the next. In most cases, several semen analysis tests are done over a period of time to ensure accurate results. If your sperm analysis is normal, your doctor will likely recommend thorough testing of your female partner before conducting any more male infertility tests.
Depending on initial findings, your doctor may recommend additional, more specialized tests that can help identify the cause of your infertility. These can include:
- Scrotal ultrasound. This test uses high-frequency sound waves to produce images inside your body. A scrotal ultrasound can help your doctor look for evidence of a varicocele or obstruction of the part of the testicle that stores sperm (epididymis). A small wand is moved over the surface of your scrotum to produce images on a video screen.
- Transrectal ultrasound. This test is similar to a scrotal ultrasound. To do this type of ultrasound, a small, lubricated wand is inserted into your rectum. It allows your doctor to check your prostate, and check for blockages of the tubes that carry semen (ejaculatory ducts and seminal vesicles).
- Hormone testing. Hormones produced by the pituitary and hypothalamus glands and the testicles play a key role in sexual development and sperm production. Your doctor may recommend a blood test to measure your testosterone and other male hormones that can affect sperm count.
- Post-ejaculation urinalysis. This test involves collecting a urine sample after orgasm. The urine is checked for the presence of sperm. Sperm in your urine can indicate your sperm are traveling backward into the bladder instead of out your penis during ejaculation (retrograde ejaculation).
- Genetic tests. These tests are used if your doctor suspects your reduced sperm count or other fertility problems could be caused by an inherited sex chromosome abnormality. When sperm concentration is extremely low, genetic causes could be involved. A blood test can reveal whether there are subtle changes in the Y chromosome — signs of a genetic abnormality. Genetic testing may also be ordered to diagnose Klinefelter's syndrome or cystic fibrosis.
- Testicular biopsy. This test involves removing samples from the testicle with a needle. It may be used if your semen analysis shows no sperm at all. The results of the testicular biopsy will tell if sperm production is normal. If it is, your problem is likely caused by a blockage or another problem with sperm transport.
- Anti-sperm antibody tests. These tests are used to check for immune cells (antibodies) that attack sperm. You are especially likely to have anti-sperm antibodies if you've had a vasectomy reversal.
- Vasography. In some cases, contrast dye is injected into each of the tubes that carry sperm (vas deferens) to check for blockage.
- Specialized sperm function tests. A number of different tests can be used to check how well your sperm survive after ejaculation, how well they can penetrate an egg, and whether there's any problem attaching to the egg. If you do have a low sperm count, having healthy sperm can be an important factor in male fertility.