Causes of Male Infertility

May 06, 2009
For a healthy couple the chances of getting pregnant during most fertile days is around 20 to 30 percent every month. It takes only one egg from a woman to conceive and a man needs healthy sperm to reach the fallopian tube and fertilize the egg. However, in case that you have already tried for more than a year and failed to conceive, you might suspect that you have fertility problem.

In almost half of all cases, couples have difficulties to conceive because of male infertility. What are the most common causes of male infertility?

Poor quality of sperm

Problems like low sperm count, abnormal shape or decreased motility of the sperm contribute to worse quality of the sperm. Normal sperm count is around 20 million sperm per millilitre in ejaculate. In cases when this number is less than 10 million per milliliter, it is considered low sperm count. Rarely, the sperm is absent. As a result a man doesn't have enough sperm to fertilize the egg. In spite of the fact that it takes only a single sperm to conceive, the chances of getting pregnant become quite low if a man has inadequate amount or low quality sperm. In case a man has abnormally shaped sperm or sperm has low motility, it cannot reach the egg and penetrate the egg.


Hormonal problems

Various hormonal disorders are sometimes the main cause of infertility. A number of glands produce male sex hormones which in their turn regulate the production of sperm. In case when hormonal disorders are present due to decreased levels of such hormones as gonadotrophin, sperm production is impaired. Low sperm count is often caused by testosterone deficiency.

Sexually transmitted diseases (STDs)

Sexually transmitted diseases (STDs) often affect man's ability to produce healthy sperm. Infections like gonorrhea and chlamidia often result in decreased motility of the sperm and affect male reproductive organs, causing blockages in the tubes or inflammation of the prostate and urethra. This may affect the motility of sperm and become the main cause of infertility.


Varicocele is the condition of swollen veins in the scrotum caused by abnormal temperature in the testicles. The increased temperature in the testes leads to problems with sperm production or sperm quality.


Cryptorchidism is the condition when a man has an undescended testicle. Normally, the testicles move down into the scrotum. Undescended testicles cannot produce sperm since it remains inside the body where the temperature is higher than in the scrotum.

Functional disorders

Infertility may also be caused by functional problems. An inability to deliver sperm into the vagina often leads to failure to conceive.


Erectile disorders

Erectile dysfunction caused by a number of physical and psychological factors also may lead to male infertility as a result of inability to maintain adequate erection and ejaculation.


Sperm is produced in the testes. During ejaculation, sperm moves through a number of small tubes called the epididymis, and later through larger tube called vas deferens. The blockages of these tubes after vasectomy or injury often lead to male infertility.

Dry orgasm

In certain cases a man orgasms without ejaculation. The condition is called retrograde ejaculation when semen enters the bladder. This is often caused by some medications, surgery or such conditions as diabetes and multiple sclerosis.


Sometimes, male infertility is a result of antibodies produced by immune system to disable the activity of sperm. This often occurs after such procedures as vasectomy.


Having the prostate gland removed holds a number of risks including erectile dysfunction, infertility and urinary incontinence.

Other problems that can cause male infertility include different environmental factors such as:

Toxins and chemicals

There is a number of toxic chemicals associated with male infertility. These include exposure to lead and pesticides, as well as anesthetic gasses, benzene and others that not only impair sperm production but also can lead to serious health problems.

Hot baths

Overheating of the testicles is often damaging to sperm and leads to male infertility. Taking hot baths or wearing tight clothes increases the temperature in the scrotum, which decreases the sperm count.

Alcohol and Smoking

Numerous studies showed that such habits as smoking or drugs and tobacco use may negatively affect male fertility. The use of marijuana, tobacco and heroin leads to low sperm count and increases the risk of having abnormal sperm.