Vasectomy Risks and Benefits

What every man should know

Medically Reviewed by Amal Chakraburtty, MD on June 01, 2007
6 min read

Once you’ve made up your mind that you never want to have any more children, there’s no more reliable form of contraception than vasectomy. But one precaution: To lower the risk of your vasectomy failing, make sure the surgeon who does yours is qualified and has a lot of experience.

When done correctly by an experienced physician, as few as 1 in 1,000 vasectomies fail to do their job — preventing you from ejaculating sperm when you have an orgasm, thus preventing pregnancy. But when performed by doctors who do vasectomies fewer than 50 times a year, the failure rate is as high as 10% to 17% or more.

To understand how a vasectomy works, you need to understand a bit of your own anatomy. Sperm are made in your testes and stored in an adjacent sac called the epididymis. From there, they travel, whipping their tails, through a 15-inch, shoestring-sized tube called the vas deferens. Inside your abdomen, the vas connects with the semen-producing prostate gland and seminal vesicles adjacent to the bladder.

This is the launching pad for the male contribution to reproduction. If the sperm don’t get to the pad, there’s still blastoff, but it’s the unmanned version — no sperm astronauts to couple with the ova in their space.

To perform a vasectomy, the surgeon first kneads the scrotum until they can feel the vas — a process that looks something like guys trying to find the tie-string after it has retracted into the waistband of their sweatpants. After finding it, the doctor pokes a hole (the best surgeons use a needle rather than a scalpel) in the scrotum and uses tiny clamps to pull out a short length of vas.

Surgeons have used a variety of techniques to cut, inactivate, and close the two ends of the vas. The best technique, according to recent surveys, is called “intraluminal cauterization with fascial interposition.” With this technique, the surgeon slices the vas in two, scars the inside — or lumina — of one tube with a heated needle. Then the surgeon pulls up the fascia — tissue surrounding the tube — and clamps or sutures it over the tube end.

Sewing up the tube prevents “recanalization,” which can occur when microscopic channels grow between the severed ends of the vas. When that happens, sperm can find their way through these microchannels and into the semen.

One review of 14,000 men who’d had various types of vasectomy reported six conceptions among their partners, but as many as 10% of men in some surveys have significant amounts of sperm in their semen a few months after a vasectomy.

Michel Labrecque, MD, PhD, a professor of family medicine at Laval University in Quebec and one of the world’s authorities on the procedure, recalls that earlier in his career, when he clipped each end of the vas and did not cauterize it, up to 1 in 300 of his patients got their mates pregnant.

“With the technique I’m using now, it went down to 1 in 7,000,” Labrecque says. “I redo one vasectomy per year at the most. With interposition, you are putting tissues between the two cut ends, so it’s like a double zip lock.”

“Ultimately, the experience of the surgeon performing the vasectomy is the most important factor in achieving success with minimal complications,” adds Ninaad Awsare, a British urology researcher.

About 500,000 vasectomies are performed each year in the U.S. Although the procedure is cheaper, faster, safer, and more reliable than female sterilization (1 pregnancy in 100), only 9% of sexually active men in the United States get vasectomies, while 27% of women get tubal ligations. More affluent men, however, are more likely to be sterilized than their wives.

The discrepancy probably has to do with the economics of our healthcare system. “Poor women have access to reproductive services, but they aren’t usually available to men,” says David Sokal, MD, a researcher at the Family Health Institute in North Carolina.

Fancy American urologists charge up to $1,200 for the in-patient vasectomy procedure, which takes all of 10 minutes, including local anesthetic. Planned Parenthood charges about $100. Under Canada’s nationalized healthcare system, the procedure is free and the state pays the doctor $55. That may explain why one-third of Canadian men are sterilized. (The highest rate of vasectomy is in New Zealand, where half of men go under the knife).

It’s important to use birth control for at least three months after vasectomy because sperm are still swimming around “downstream” of the cut. At 12 weeks, it is a good idea for men to get a follow-up test for sperm in their semen. A negative result generally confirms that the operation was successful.

“Still,” says Labrecque, “if the doctor tells you, ‘There are no sperm,’ there’s a 1 in 2,000 chance that you will later become fertile again. So if your wife gets pregnant, don’t assume she’s cheating on you. The first assumption should be that your body healed itself.”

Most men fear pain more than any other aspect of a vasectomy, and with good reason. While the procedure, if done well, is almost painless, soreness for a few days afterward is common. Sexual intercourse and sports are best postponed for a week. “I had one guy who tried to have sex the day after the surgery,” recalls Labrecque. “He was in terrible pain and his scrotum was swollen.”

Estimates on the rates of chronic pain, however, range widely. In a variety of studies, anywhere between 1% and 50% of men complained of sore testicles, including epididymitis (“blue balls”) for up to a year. As many as 15% described the pain after vasectomy as seriously aggravating. Again, the surgeon’s technique and experience appeared to be key.

A handful of studies in the early 1990s reported an association between vasectomy and prostate cancer, but a conclusive survey in New Zealand refuted the link.

In 2006, a group of Northwestern University researchers published a study that seemed to link vasectomy and dementia. The study was prompted by a patient at an Alzheimer’s disease clinic who told doctors that his aphasia—problems with speech—had begun shortly after a vasectomy. A survey of 47 clinic patients with early aphasia found that 19 had had a vasectomy.

The study caused some concern because there is a plausible, if unlikely, mechanism for a vasectomy to cause brain damage. Sperm normally doesn’t come in contact with the bloodstream, but antibodies to sperm form in the blood of about two-thirds of men who get vasectomies. (The sperm leaks into the normal tissue of the body after the vas is cut.) The theory put forward by the Northwestern study is that antibodies to sperm, which happen to have some proteins in common with brain cells, might cause an autoimmune attack on the brain.

But the study was small and hasn’t been replicated, so it’s too early to make much of it. For the time being, according to both Sokal and Labrecque, dementia is a hypothetical risk of vasectomy, though one that requires further research.

More importantly, both Sokal and Labrecque stress that it’s vital not to expect that a vasectomy can be undone. Labrecque says that he can successfully perform a vasectomy reversalabout half the time, but there are no guarantees.

“Before I give you a vasectomy,” says Labrecque, “you must be sure you don’t want kids anymore for the rest of your life, no matter what your personal situation is.”