When it comes to planning a family, you might take the sperm end of the equation for granted. This makes good sense, of course, because the majority of men have enough strong swimmers to fertilize female eggs. But for some couples, azoospermia, or a lack of sperm in the ejaculate, may stand in the way of conception.
"Most men with azoospermia have normal semen volumes but don't realize that there's no sperm in their fluid," says Marc Goldstein, M.D., chief surgeon in the department of male reproductive medicine at New York Presbyterian Hospital, Weill Cornell Medical Center in New York City.
Infertility affects about 15 percent of the male population in the United States. Of this group, 10 to 15 percent suffer from azoospermia, which is approximately 1 to 2 percent, or over 1 million, post-pubertal men. "The rest of this group have either oligospermia [low sperm count or concentration], asthenospermia [slow swimmers], both conditions together [oligoasthenospermia] or crytoozoospermia [rare or very few sperm]," Dr. Goldstein explains.
Fortunately, if you're trying to conceive, azoospermia isn't the end of the world. "There are many treatment options available for men with this condition to become biologic fathers, so it certainly doesn't mean there's no hope," notes Michael Eisenberg, M.D., director of male reproductive medicine and surgery and an assistant professor in the department of urology at Stanford University School of Medicine.
Here's what you need to know about the causes, diagnosis, and treatment of azoospermia:
The two main types of azoospermia are defined as obstructive and nonobstructive. "If a man has the obstructive variety, it means that sperm is being produced inside the testicle but it's somehow blocked and can't get out," Dr. Goldstein says. The problem for those with the nonobstructive type lies in the production department: sperm just isn't being made.
Most cases are idiopathic or have unknown causes, explains Michael Feinman, M.D., a reproductive endocrinologist and the medical director at HRC Fertility, which has centers in Southern California. For both kinds of azoospermia, there may be rare genetic causes that impair sperm production or transit, Dr. Eisenberg says. "Some men are born without the duct leading from the testis to the penis, which is called the vas deferens," Dr. Feinman adds. Without this channel, sperm can't travel out the end of the penis. This condition, which is the most common type of obstruction, is known as congenital absence of the vas, or CAVD, and most men with it also carry the gene for cystic fibrosis.
Nonobstructive causes of azoospermia include a chromosomal abnormality such as Klinefelter syndrome, pituitary dysfunction resulting in low hormone production, and certain operations like prostate removal or a bilateral hernia repair. "Medical conditions like diabetes can cause reversal of the flow of semen or retrograde ejaculation," Dr. Feinman says. Cancer patients who need to undergo radiation and chemotherapy may develop azoospermia as these two treatments destroy the sperm-producing cells. "Any type of scrotal injury sustained in sports can harm the testes or epididymis [where sperm matures], leading to production or transport issues," Dr. Eisenberg adds. Lastly, excessive use of testosterone can result in a temporary, or even permanent, case of azoospermia.
In general, there aren't any obvious symptoms, such as pain, that might indicate a man has azoospermia. "The exception to this are those men who have low hormone levels," Dr. Feinman notes. "Males with Klinefelter syndrome will have other physical features typical of the syndrome," he says. These may include enlarged breast tissue, low energy levels, small genitals and above average height. "In rare cases of azoospermia, men may have small testes or swollen structures within the testes, or symptoms of low testosterone," Dr. Eisenberg adds.
"Azoospermia is most commonly diagnosed when a couple discovers they are unable to conceive," Dr. Eisenberg says. An analysis of the semen is the only way to determine whether this condition is present. "If there's zero sperm, a reproductive urologist will establish whether it is obstructive or nonobstructive," Dr. Goldstein explains. A blood test for follicle stimulating hormone (FSH) and testosterone and genetic tests will confirm the diagnosis. If FSH is elevated and the testis is small and soft, then this is typically a case of nonobstructive azoospermia. If the FSH, testosterone, and testis are all normal and the ducts are missing or swollen with sperm that can't get out, obstructive azoospermia is diagnosed.
Care for this condition depends on the cause. "The obstructive variety that's caused by complications due to sexually transmitted infections, like epididymitis, or because a hernia repair has injured the vas can be repaired successfully with microsurgery," Dr. Goldstein says. Obstructive azoospermia due to congenital missing ducts is treated by microsurgically sucking sperm out (sperm aspiration) and using it to fertilize the partner's eggs retrieved by in vitro fertilization (IVF).
"In the rare few men with hormonal deficiencies, azoospermia may be treated with gonadotropins, like non-ovulating women. And for many with nonobstructive azoospermia—even Klinefelter—small patches of sperm can be found in the testes and may be used for IVF," Dr. Feinman says. If the diagnosis is reversal of semen flow, sperm may be retrieved from the urine.
Avoiding sexually transmitted diseases, or at the very least getting early treatment of genital infections, may lower the risk of azoospermia. "For men receiving cancer treatments, freezing sperm prior to treatment can preserve fertility even if future sperm production is compromised," Dr. Eisenberg says. There are also prophylactic measures that can be taken to lessen testicular exposures in certain cases of radiation treatments for cancer.
For some hernias, microsurgically assisted inguinal repairs may prevent injury and, as a result, cases of azoospermia. It's also recommended that men avoid excess alcohol and drugs, as abuse of either can cause infertility and possibly azoospermia. Testosterone and anabolic steroids should also be avoided. "Testosterone is a contraceptive for men, so those who take it, or any anabolic steroid, often develop azoospermia," Dr. Goldstein warns. If these drugs are used long enough, the condition may be irreversible.