Reproduction is a simple and natural experience for most couples. However, for some couples, it is very difficult to conceive.
A man’s fertility generally relies on the quantity and quality of his sperm. If the number of sperm a man ejaculates is low or if the sperm is of a poor quality, it will be difficult, and sometimes impossible, for him to cause a pregnancy.
Male infertility is diagnosed when, after testing both partners, reproductive problems have been found in the male.
How common is male infertility?
Infertility is a widespread problem. For about one in five infertile couples, the problem lies solely in the male partner.
It is estimated that one in 20 men has some kind of fertility problem with low numbers of sperm in his ejaculate. However, only about one in every 100 men has no sperm in his ejaculate.
Symptoms of male infertility
Infertility symptoms in men can be vague. They may go unnoticed until a man tries to have a baby.
Symptoms depend on what is causing infertility. They can include:
- Changes in hair growth
- Changes in sexual desire
- Pain, lump, or swelling in the testicles
- Problems with erections and ejaculation
- Small, firm testicles
Causes male infertility
Male infertility is usually caused by problems that affect either sperm production or sperm transport. Through medical testing, the doctor may be able to find the cause of the problem.
About two-thirds of infertile men have a problem with making sperm in the testes. Either low numbers of sperm are made and/or the sperm that is made do not work properly.
Sperm transport problems are found in about one in every five infertile men, including men who have had a vasectomy but now wish to have more children. Blockages (often referred to as obstructions) in the tubes leading sperm away from the testes to the penis can cause a complete lack of sperm in the ejaculated semen.
Other less common causes of infertility include: sexual problems that affect whether semen is able to enter the woman’s vagina for fertilization to take place (one in 100 infertile couples); low levels of hormones made by the pituitary gland that act on the testes (one in 100 infertile men); and sperm antibodies (found in one in 16 infertile men). In most men, sperm antibodies will not affect the chance of a pregnancy but in some men sperm antibodies reduce fertility.
Known causes of male infertility
- Sperm production problems
- Chromosomal or genetic causes
- Undescended testes (failure of the testes to descend at birth)
- Torsion (twisting of the testis in scrotum)
- Varicocele (varicose veins of the testes)
- Medicines and chemicals
- Radiation damage
- Unknown cause
- Blockage of sperm transport
- Prostate-related problems
- Absence of Vas deferens
- Sexual problems (erection and ejaculation problems)
- Retrograde and premature ejaculation
- Failure of ejaculation
- Erectile dysfunction
- Infrequent intercourse
- Spinal cord injury
- Prostate surgery
- Damage to nerves
- Some medicines
- Hormonal problems
- Pituitary tumors
- Congenital lack of LH/FSH (pituitary problem from birth)
- Anabolic (androgenic) steroid abuse
- Sperm antibodies
- Injury or infection in the epididymis
Risk factors linked to male infertility include:
- Smoking tobacco
- Using alcohol
- Using certain illicit drugs
- Being overweight
- Having certain past or present infections
- Being exposed to toxins
- Overheating the testicles
- Having experienced trauma to the testicles
- Having a prior vasectomy or major abdominal or pelvic surgery
- Having a history of undescended testicles
- Being born with a fertility disorder or having a blood relative with a fertility disorder
- Having certain medical conditions, including tumors and chronic illnesses, such as sickle cell disease
- Taking certain medications or undergoing medical treatments, such as surgery or radiation used for treating cancer