Male infertility most commonly cause by sperm

Dear Doctor:

My second husband and I have tried to get pregnant for over a year now, but we have had no luck. Should we be worried about infertility? I’m the mother of a 2-year-old girl and a 4-year-old boy, so the problem probably isn’t with me. What causes that in a man?

Dear Reader: When a woman and man have not achieved pregnancy after a year of regular unprotected sex, they meet the clinical definition of infertility.

You and your husband may feel as though you’re alone in this, but studies suggest that up to 15% of couples are unable to conceive in the first year of trying. About one-third of the time, infertility is due to issues with the man; one-third of the time, it’s issues with the woman; and in the remaining cases, the problem lies in an often-complex mix of issues with both partners. In some cases, the cause of infertility cannot be identified.

For men, the most common causes of infertility are tied to problems with sperm production and sperm motility. These can arise as a result of health problems like diabetes; previous infections such as the mumps or HIV; hormonal problems, including low testosterone; various genetic issues; sexually transmitted diseases; autoimmune disorders; and even lifestyle factors such as smoking, drinking, illicit drug use or steroid use. Some men have blockages in their reproductive systems that can range from partial to total, and that can affect the sperm count. These can be present from birth, or they can develop as the result of physical trauma.

Swollen veins in the scrotum, known as varicoceles, can have a negative effect on sperm growth. These are present in up to 40% of men with infertility problems. A condition known as retrograde ejaculation, which prevents sperm from exiting via the penis and sends it to the bladder instead, can result in infertility in men with normal sperm counts.

Certain medications can change sperm production, function and delivery, including those used to treat depression, infection, high blood pressure and arthritis. Chemotherapy and radiation treatments can also affect male fertility. The causes of male infertility are numerous and varied -- our list is nowhere near complete

-- and addressing the issue requires medical assistance.

Diagnosis begins with a physical exam, which will include a detailed medical history. Your husband will be asked about chronic health conditions, past health problems or injuries, prior surgeries and environmental or lifestyle factors. In addition to those already mentioned, they can include obesity, stress, age and diet.

Knowing one’s family history helps to identify inherited conditions. Your husband will also be asked for a semen sample to assess sperm count, structure, motility and concentration. If the semen analysis finds no problems with the sperm, then further testing is needed. This can include hormone tests, scans of the testicles and scrotum to visualize possible blockages, and post-ejaculation urinalysis to look for sperm in the urine. Treatment depends on the results of the tests. Hormone therapy helps to address low testosterone. Surgery can often successfully remove blockages.

Unfortunately, diagnosing male infertility is challenging and a definitive answer is not always found.

Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.