Infertility is defined as a couple's inability to become pregnant after one year of regular, unprotected sex. Male infertility means the male is unable to impregnate the female because of male factors. Learn what the causes of male infertility are and discover if you can resolve your male infertility issues with your doctor.

What is going on in the body?

The inability to get pregnant may be caused by conditions in either partner. It is estimated that 30% of infertility is caused by male factors. An additional 30% is caused by female factors. The remaining 40% is caused by a combination of female and male factors. Male infertility may be caused by many diseases, conditions, and other factors. Situations that raise the temperature in the testicles can interfere with normal sperm production.

What are the signs and symptoms of the condition?

Male infertility occurs when the man's partner does not conceive after one year of attempting to become pregnant. Other signs and symptoms depend on the underlying cause of the man's infertility.

What are the causes and risks of the condition?

There are many male factors that can make a couple unable to become pregnant. These may include conditions such as the following:

• diabetic neuropathy, in which nerve damage causes problems with erection or ejaculation
• extreme obesity hormone imbalances, such as hypothyroidism
• hypogonadism, a condition in which the testes fail to develop normally
• inherited conditions that impair the ability to produce sperm, such as Down syndrome
• testicular torsion, a condition in which the blood supply to the testicle is cut off
• undescended testicles, a condition in which the testes fail to drop into the scrotum
• varicocele, a group of enlarged veins inside the scrotum

Diseases also can be a factor in infertility, for example:

• autoimmune disorders, which can cause the body to produce antibodies that attack sperm
• liver disease
• sickle cell anemia
• kidney disease
• genital infections such as gonorrhea and genital herpes
• infections of the reproductive organs, such as prostatitis and epididymitis
• infectious diseases, including mumps

Additional factors in infertility include the following:

• certain medications, such as cimetidine and phenytoin
• certain supplements, such as anabolic steroids
• chemotherapy used for cancer
• diet low in folic acid or low in lycopene, which is found in plants such as tomatoes
• excessive exercise, which lowers testosterone levels and decreases sperm production
• exposure to diethylstilbestrol, also known as DES, as an infant in utero
• exposure to toxins such as lead, mercury, or pesticides
• frequent hot baths or use of hot tubs
• injury to the testicles
• low sperm count, poor sperm quality, and poor movement of sperm
• radiation therapy
• recreational drugs, such as alcohol, methadone, and marijuana
• sexual problems, such as erectile dysfunction and premature ejaculation
• side effects of treatments for testicular cancer or prostate cancer
• surgery of the reproductive system, such as transurethral resection of the prostate
• vasectomy, a surgical procedure to tie off the sperm-carrying tubes
• wearing tight-fitting pants and underwear
• work that requires prolonged sitting, which increases the temperature in the scrotum