Risks of drug treatment for sperm antibodies

What are sperm antibodies?

Antibodies are proteins made in the body by the immune system to fight infection or disease.  They attack anything in the body that is foreign i.e. what is not part of the body. For example, when a bacterial infection causes a sore throat, the body recognizes that the bacteria are foreign and makes antibodies to coat the bacteria and help the body's defense systems to get rid of the infection.

The body’s ability to tell the difference between what is itself and what is foreign is usually ‘programmed’ before birth. Because sperm are produced at puberty, well after the immune system has developed, the body will make antibodies against the sperm (anti sperm antibodies).  Normally, there are systems in place within the testes which lessen the response of the immune system to sperm and prevents the production of sperm antibodies in normal men.  When these systems breakdown, for reasons that are not clear, the immune system develops antibodies against sperm.

About one in every 16 infertile men produce antibodies to their own sperm (also known as sperm autoimmunity).Sperm antibodies commonly are found in men after vasectomy and injury or infection in the epididymis.  However, in many instances, the presence of sperm antibodies cannot be explained.

 

How do sperm antibodies affect fertility?

Sperm antibodies can reduce fertility in a number of ways:

• Sperm antibodies can interfere with sperm production within the testes and reduce the number of sperm in the semen;
• Sperm antibodies can coat sperm, causing it to clump together, reducing the movement (motility) of sperm. This stops the sperm from swimming through the liquid in the female cervix and tubes when ejaculated into the vagina;
• Sperm antibodies can prevent sperm attaching to and penetrating the egg during the fertilisation process.

There are usually no other effects on a man’s general health and no signs that might indicate that the sperm antibodies are present.  Some men with genital tract blockages also have sperm antibodies.

 

How are sperm antibodies treated?

Prednisolone, a cortisone-like drug, and also drugs to grow taller can be used to lower the levels of sperm antibodies in the body.  Several research studies have shown that treatment with prednisolone can decrease sperm antibody concentrations and improve the chances of achieving a natural pregnancy. About one in four couples become pregnant while the man is taking this drug.

 

What are the risks of drug treatment for sperm antibodies?

High doses of prednisolone can cause weight gain, a rise in blood pressure, mood swings, acne, diabetes or peptic ulcers.  Some of these side-effects disappear after treatment stops.

However, this drug can severely affect the blood supply to the hips and approximately one in 200 men using this treatment have permanent hip damage and need hip replacement.