Learn about Male Infertility

Infertility affects 15% of couples and male infertility accounts for around 40% of all cases. Some cases of male infertility can be treated by medical or surgical intervention, whilst for others, assisted reproduction techniques may be the best pathway to having a baby.

Male infertility is most commonly caused by problems that affect either sperm production, sperm transportation, or sperm DNA quality. The most common cause is a problem with making sperm in the testes. Either low numbers of sperm are made or the sperm that are made do not work properly. After sperm are made in the testes they are transported along a maze of tubes before they reach the penis. Blockages (often referred to as obstructions) in these tubes can prevent any sperm being ejaculated even though sperm production in the body is normal. Sperm DNA can be damaged during sperm production and transport. This damage is known as DNA fragmentation. High levels of sperm DNA fragmentation is associated with delayed natural conception and recurrent miscarriage. Sperm DNA fragmentation also reduces the success of fertility treatments like IVF.

Learn about Male Infertility

Causes of male infertility

Medical causes


A varicocele is a swelling of the veins in the scrotum, the sac around the testes. It is a common and yet reversible cause of male infertility. It is thought that it causes the testes to become too hot which leads to poor quality sperm production.


Infections can interfere with sperm production and sperm health. Some infections can cause scarring that blocks the passage of sperm. These include inflammation of the epididymis (epididymitis) or testicles (orchitis) and some sexually transmitted infections, including gonorrhea or HIV.

Defects in tubes that transport sperm

The tubule system that carries the sperm through the male reproductive system is complex. The tubes can be blocked due to various causes, including inadvertent injury from surgery, childhood illnesses like mumps, prior infections, trauma or abnormal development such as with cystic fibrosis or similar inherited conditions.

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. Other genetic syndromes associated with infertility include cystic fibrosis, Kallmann’s syndrome and Kartagener’s syndrome.


Testosterone replacement therapy, long-term anabolic steroid use, cancer medications (chemotherapy), certain antifungal medications, hair loss products, some ulcer drugs and certain other medications can impair sperm production and decrease male fertility.

Prior surgeries

Certain surgeries may prevent you from having sperm in your ejaculate, including vasectomy, inguinal hernia repairs, scrotal or testicular surgeries, prostate surgeries, and large abdominal surgeries performed for testicular and rectal cancers, among others. In most cases, surgery can be performed to either reverse the blockage or to retrieve sperm directly from the epididymis and testicles.

Environmental causes

Industrial chemicals

Extended exposure to benzenes, toluene, xylene, pesticides, herbicides, organic solvents, painting materials and lead may contribute to low sperm counts.

Heavy metal exposure

Exposure to lead or other heavy metals may cause infertility.

Radiation or x-rays

Exposure to radiation can reduce sperm production, though it will often eventually return to normal. With high doses of radiation, sperm production can be permanently reduced.

Overheating the testicles

Elevated temperatures impair sperm production and function.

Health and lifestyle causes

Illicit 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 reduce the number and quality of your sperm as well.

Alcohol use

Drinking alcohol can lower testosterone levels, cause erectile dysfunction and decrease sperm production. Liver disease caused by excessive drinking also may lead to fertility problems.

Tobacco smoking

Men who smoke may have a lower sperm count than do those who don’t smoke. Second hand smoke also may affect male fertility.

Emotional stress

Stress can interfere with certain hormones needed to produce sperm. Severe or prolonged emotional stress, including problems with fertility, can affect your sperm count.


Obesity can directly impact sperm themselves and cause hormone changes that reduce male fertility.


Diabetes is associated with poorer semen and poorer fertility treatment success.

Treating male infertility

One in eight infertile men has a treatable condition. After treatment couples can often become pregnant naturally. The treatment of male infertility can include medical and surgical intervention. For example, repairing a varicocele can improve sperm numbers and function, and may potentially improve outcomes when using assisted reproductive techniques such as IVF.

For the remaining men, assisted reproduction treatments like IVF may be the best pathway to having a baby. IVF success is impacted by both low sperm count and high sperm DNA fragmentation. In these cases, ICSI may be the more successful treatment. That is why it is so important to test the man carefully so that the best treatment may be chosen first time around. Fertility treatment can also be more successful if sperm DNA quality is improved beforehand.


SpermComet® is Examen’s market leading sperm DNA fragmentation test. SpermComet® measures the actual DNA damage in individual sperm making it the most sensitive fertility test available. SpermComet® is highly predictive of male infertility, male involvement in miscarriage and IVF success. It is the only test that can be used to check sperm quality for men with low sperm count.

Learn about the test

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