Male Infertility

Male infertility at a glance

  • The male partner is either the sole or a contributing cause of infertility in approximately 40 percent of infertile couples.
  • Male infertility issues are caused by a variety of problems within the testes, often due to structural abnormalities, genetic issues, impotence or lifestyle factors.
  • Conditions affecting fertility are discovered through physical exam, semen analysis, blood testing and sometimes by ultrasound.

What is male infertility?

Male infertility, also known as male factor infertility, occurs when the male partner is either the sole or a contributing cause of infertility. While infertility was once considered a problem that primarily affected women, research shows that infertility in men is almost as common.

Male factors account for approximately half of infertile couples according to the American Society for Reproductive Medicine. Males are the sole cause in 20-30 percent of infertile couples and are a contributing factor, along with the female, in another 20-30 percent of cases. For this reason, it is important for couples struggling to conceive to understand that fertility is a team effort, and the male role is just as important as the female’s part.

There are a number of causes of infertility in men. These include:

  • Structural abnormalities or blockages
  • Chromosomal and other genetic conditions
  • Sperm production disorders
  • Impotence
  • Lifestyle factors that negatively impact the quality of sperm.

The importance of male infertility testing

Since infertility occurs equally in males and females, evaluating the male partner can be essential to diagnosing and treating infertility. Infertility can occur after a successful pregnancy in both partners. Even a man who has had little trouble with fertility in the past should have his fertility tested if he and his partner are having difficulty conceiving. Ensuring that both partners undergo fertility testing can help diagnose and treat male infertility conditions, potentially preventing other unnecessary fertility treatments.

Learn more about male infertility evaluation options available at Servy Massey Fertility Institute.

Male infertility conditions related to structural abnormalities

Blockage of sperm ducts

About 10 percent of men who have infertility problems make sperm normally but have an obstruction in their genital tract that prevents sperm in the testicles from getting into the semen (ejaculate). When there is no sperm present in semen, it is known as azoospermia.

In some cases, men may have been born with the absence of the vas deferens, the duct that conducts sperm from the testicle to the penis. This is usually associated with cystic fibrosis. Additionally, infections may have blocked the sperm ducts. Surgical correction may allow sperm to be ejaculated normally.


Varicocele, a condition that can diminish sperm quality, shows up as dilated or varicose veins in the scrotum and may be corrected surgically. It is estimated that 40 percent of men with infertility problems have varicoceles. The varicocele may increase the temperature of the scrotum and damage sperm health. Since a varicocele doesn’t usually present any symptoms, it is often only discovered when men are being tested for infertility.

Varicocele can be corrected via open or laparoscopic surgery. For both procedures the doctor will administer a general or local anesthetic and then work to redirect blood flow from the dilated vein to normal veins. Most patients can return to nonstrenuous activities within two days, and to strenuous activity two weeks after these procedures.

Repair is controversial because of variable and unpredictable results. Often in these cases, IVF is a quicker route to pregnancy than surgery.


Boys may be born without their testicles fully descended into their scrotum, which is called undescended testicle or cryptorchidism. This needs to be corrected medically or surgically in early life. If this is not performed, sperm production after puberty is usually deficient. This cannot be corrected later.

Testicular trauma

The exposed position of the testicles makes them susceptible to injury. Sometimes injuries interfere with the blood supply to the testicle and reduce the growth and maturation of sperm.

Male infertility conditions that affect sperm and sperm production

For various hormonal or sometimes unknown reasons, some men do not produce adequate quantity of sperm or adequate quality of sperm. Regarding sperm quantity, men usually ejaculate 2 to 5 milliliters of semen. An adequate amount of sperm in a milliliter is over 20 million sperm. Men who produce less than this are considered subfertile.

Sperm quality refers to the health of the sperm, its shape (morphology) and its ability to move (motility). Sperm quality can also prevent it from being able to break through the egg’s outer surface (zona pellucida) to reach the area of fertilization. Good sperm morphology is an oval head and a long tail. Today we use the strict criterion of Dr. Kruger. The shape must be almost perfect. Only 4 percent of sperm need to meet this standard.

Good motility means the sperm moves consistently at a good pace. We evaluate the total number of motile sperm in the ejaculate. The sperm of men with motility problems does not move fast enough or does not move at all. Motility can affect the sperm’s ability to penetrate cervical mucus.

The potential causes may be detected by physical exam, sperm and semen analysis and hormonal testing.

Hormonal abnormalities

Men who have hormonal abnormalities may have inhibited sperm production. For sperm to be produced, the man’s hypothalamus, pituitary and testicles must have normal hormonal secretion.

Furthermore, the normal hormones must work on the testicular tissue that actually produces sperm. These can be investigated and sometimes treated, with improvement of a man’s sperm production. About 10 percent of men with male infertility have problems with their hormones that lead to very low sperm counts.

A doctor might prescribe male infertility medications. These include Clomid, gonadotropins like human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG), or follicle stimulating hormones (FSH) to help treat hormonal abnormalities and increase sperm production.   Also, nutritional supplements or antioxidants may be suggested to optimize sperm health. 

Systemic disease

Major medical conditions such as kidney failure, liver disease, cancer and cardiovascular illnesses may impact sperm production. Cancer treatments such as chemotherapy and radiation can affect male fertility, as they can interrupt hormone production, impact sperm health and disrupt the ejaculation process.

The risk of infertility after cancer treatment varies by patient age, treatment type, and the medication and dosage used. Chemotherapy is the process of introducing medicine into the body that attacks rapidly dividing cancer cells. This can be damaging to sperm and the body’s ability to create mature sperm. Some medications put patients at a higher risk of infertility than others, especially when administered in higher doses.

Radiation therapy is the process of aiming high-energy rays of radiation directly at cancerous areas of the body to kill cells. Radiation treatments directed at the pelvic area or parts of the lower abdomen can kill the stem cells that produce sperm. Radiation can also affect the parts of the brain that produce the hormones that signal sperm production, causing infertility.

Depending on the treatment received and when it was received, fertility can recover. It is important for patients to talk with their oncologist about  their risk, and consult a fertility specialist about fertility preservation options.

Other factors that affect male fertility

Behavior and lifestyle

The number and quality of a man’s sperm can be affected by his lifestyle choices and overall health. These include such factors as:

  • Excess alcohol consumption
  • Tobacco, marijuana use or the use of other drugs
  • Certain prescription medications
  • Activity levels, diet and weight
  • Environmental toxins, pesticides and harsh chemicals
  • Regular exposure of the groin area to high heat from hot tubs, laptops or activities that increase scrotal temperature
  • Regular, long distance cycling that may reduce blood flow, increase scrotal temperature or cause trauma
  • Use of testosterone (patients should report to their physician if they are taking or have taken testosterone).


Five percent of severe male factor is due to chromosome disorders. Other genetic mutations can also result in male infertility. Genetic problems are passed on to the embryo in the male’s DNA during fertilization, which can result in failure of the embryo to implant or a miscarriage. Chromosome testing of males with sperm counts under 5 million is a method to detect these errors.


Sometimes men are unable to complete intercourse through ejaculation. This can include not being able to have or maintain an erection, which is called erectile dysfunction. Due to anatomical problems, some men experience pain during intercourse, which can curtail sex and result in infertility.

Male infertility may be due to premature ejaculation, which is climaxing before penetration or very soon after it. Psychological issues can also prevent men from engaging in efficient intercourse to achieve pregnancy. The above causes of impotence can add to psychological distress and result in a cycle of infertility.


A vasectomy is an elective form of contraception for men intended to be permanent. Sometimes men who have had a vasectomy will change their mind and want to father a child again. They can opt to have it reversed.