Male infertility means not being able to father children. The word infertility is used when the female partner in a sexually active couple has not become pregnant after 1 year without the use of contraception. If the cause of the fertility problem is found in the man, this is male infertility. Male infertility is found in approximately half of all childless couples.
Male infertility has several causes:
- Hormonal problems
- Genetic disorder or chromosome defects
- Problems with the testicles and sperm production
- Difficulties with erection or ejaculation
- Some medications
The tests and treatments vary depending on the cause of infertility.
Your doctor will do an examination and tests to evaluate the possible cause of male infertility.
The medical history is a conversation with your doctor. The doctor will try to determine whether any lifestyle factors could affect your fertility. The interview will focus on different known causes:
- Thyroid disease
- Erectile dysfunction
- Occupational or behavioural hazards such as working with pesticides
- Exposure to extreme heat
- Current smoking or exposure to smoke during pregnancy
- The use of cannabis and alcohol, steroids, opioids, or androgens
- Prior surgery in the genital region
- Trauma in the genital area
- Descent of the testicles at birth/ in childhood
Some medications can also affect male fertility:
- Heart conditions: non selective beta blockers, thiazides, calcium channel blockers, digitalis, antiarrhytmics
- Antidepressants: tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRI)
- Hormonal therapy: antiandrogens
- Painkillers and antipyretics: Nonsteroidal anti-inflammatory drugs (NSAIDs
- Antiepilectics and neuroleptics
Read more about how male infertility is diagnosed
The doctor will examine the male genitalia. This is done by looking at the genitals and then using a hand to feel them. Any abnormalities will be noted, such as lumps in the scrotum. In addition, your height and weight will be measured. Body mass index can affect:
- Erectile function
- Sexual hormone regulation
- Scrotal temperature
- Semen quality
Hormone blood tests
Hormones circulate in the blood stream. They can be taken from a vein with a simple blood sample and can give information about the function of the testicles. Other blood tests can show your doctor other diseases that can affect your fertility.
Some typical blood tests may be run:
- Both gonadotropins: follicle-stimulating hormone (FSH) and luteinising hormone (LH)
- Inhibin B
- Sexual hormone binding globulin
- Thyroid hormones
- Cholesterol levels
- Blood glucose
- Tests for renal function and liver disease
Your semen is collected by ejaculating into a sterile container. The semen is then analysed at a laboratory. Not having an ejaculation for 2–5 days before semen collection can provide a better sample for more precise semen analysis. A short time between collection and analysis also helps the accuracy of the test. Semen quality can change dramatically within days. Having at least two (or more) tests will give a clearer result.
The lab will assess the amount of semen and its colour, odour, and thickness. A microscope study will show the number of sperm cells and their health in the semen. Signs of infection can also be seen.
An ultrasound uses sound waves to create an image of the tissue inside the body. It can be used to evaluate the tissue of the testicles and tubes that carry semen (vas).
Urine sample and urethral swab
A urine test and/or a urethral swab can be done to rule out any infections in the urogenital tract.
Your doctor might want to rule out abnormal cell growth (malignant cells) or the early stages of cancer in the testicle. In this case, tissue from the testicle has to be analyzed. Your doctor will numb the testicles (local anaesthesia) and make a small cut in each. A very small amount of tissue is taken from each testicle (biopsy) and sent for analysis.
Causes and treatment
In most cases of male infertility, either the semen is unable to reach the egg (obstructive) or the semen quality is poor (non-obstructive). The most common causes of male infertility and their treatments are discussed.
Obstructive causes of male infertility
The path of the sperm cells can be obstructed in several places:
- In the testicles, where sperm cells are produced
- In the epididymis, the tube that carries sperm from the testicle to the vas deferens
- In the vas deferens, the tube that transports sperm to the prostate and posterior urethra
The most common causes of obstruction are infections (for example, gonorrhea, chlamydia, prostatitis, tuberculosis), birth defects (congenital disorders), or trauma to the genitalia.
Treatment depends on the amount of obstruction. Semen can be collected by biopsy from the testicle or the epididymis. Surgery on the vas deferens can reestablish the pathway.
Read more about obstructive causes of male infertility
Cystic fibrosis (CF) is the most common genetic disorder in white persons, and a small number of white men have CF mutations. These men might lack the vas deferens on both sides. This means that sperm cells cannot mix with the ejaculate, so the ejaculate will not include any sperm (azoospermia). To achieve pregnancy, sperm must be collected directly from the testicles by a biopsy. In the case of CF as the cause of male infertility, the female partner should also be genetically tested for CF. Two carrier parents have a 50% chance of having a child with CF.
Vasectomy is a surgical procedure that disconnects the epididymis from the vas deferens to make the man infertile. This procedure is permanent and is considered to be irreversible. In some cases it can be reversed, but the chance of success depends on when the vasectomy has taken place.
Read more about Vasectomy
Problems with ejaculation
In some cases, the ejaculate cannot reach the urethra. The man might not be able to ejaculate, it might be delayed, or the semen might go into the bladder(retrograde ejaculation). Causes can be psychological, physical (for example, nervous system dysfunction after surgery or trauma), or related to medication use. Treatment options include medication and physical stimulation.
Nonobstructive causes of male infertility
Abnormal sexual chromosomes can cause low levels of testosterone. Klinefelter syndrome is the most common sexual chromosome abnormality. In some patients, this condition can cause characteristic features like long limbs, small firm testicles, and female-type hair distribution.
The treatment for this kind of infertility is to collect sperm cells directly from the testicle if possible (TESE). Sperm cells will be functional in less than half of men with Klinefelter syndrome.
Low levels of sexual hormones affect male fertility. For example, Kallmann syndrome causes low levels of sexual hormones. Men with this syndrome often have low muscle mass, fatigue, infertility, erectile dysfunction, hot flashes, and enlarged breasts.
The treatment is to supplement male hormones using injections that can restore spermatogenesis completely (hormone therapy).
In addition, an increase in general health—for example, losing weight, stopping smoking, adjusting diet, and exercising regularly—may improve fertility.
Read more about non-obstructive causes of male infertility
When a testicle does not descend into the scrotum, the condition is called cryptorchidism. It is a birth defect and is associated with infertility. However, if a man has only one undescended testicle, his ability to father children is almost equal to that of men without cryptorchidism.
When cryptorchidism is diagnosed in early childhood, surgery to move the testicle from the abdomen into the scrotum should be performed within the first year. This can prevent later infertility and reduce the risk of testicular cancer. If an adult has an undescended testicle, surgery can optimise testosterone production.
Abnormal cell growth in the testicular tissue affects sperm production. So does cancer treatment. Testicular cancer is mostly seen in younger men and is associated with poor semen quality, cryptorchidism and in families with a history of testicular cancer.
Treatment is surgical removal of the testicle. Sometimes additional chemotherapy will be used, which can also lower semen quality. If a man wants to father children in the future, a semen sample should be collected and preserved before surgery.
Varicocele is enlargement of the veins that drain blood from the testicles. The condition affects about 2 in 10 men and is seen in a quarter of men with abnormal semen analysis. The enlargement of these veins can be uncomfortable and can lower sperm quality. It is not fully understood how varicocele affects fertility.
Varicocele can be diagnosed easily by physical examination or by ultrasound. The treatment is surgery to close the dilated vessels and minimize blood reflux into the scrotum. Surgery can improve semen quality if no other explanation of infertility is found.
Infections in the male reproductive organs
Infections in the urethra, prostate, epididymis, and testicles are all potential causes for infertility. The infection creates antibodies that can lower semen quality. This can have a negative effect on fertility. When the location of the infection and the bacteria are identified, the treatment is mostly antibiotics.
Nevertheless, in almost half of cases, it is not possible to find a cause of infertility.