A vasectomy is an operation that makes a man permanently unable to get a woman pregnant. It involves cutting the 2 tubes called vas deferens so that sperm can no longer get into the semen.

A vasectomy is usually done in your doctor's office or in an outpatient surgery center. The operation takes about half an hour. You'll be awake during the procedure. Your doctor will give you a local anesthetic to numb your scrotum.

After you're numb, your doctor will cut a small opening (an incision) on one side of your scrotum and pull out part of the vas deferens on that side. You may feel some tugging and pulling. A small section of the vas deferens is removed. The ends of the vas deferens will be sealed by stitching them shut, by searing them shut with heat, or by using another method. Your doctor will then do the same thing on the other side.

Your doctor will close the 2 openings in your scrotum with stitches. After 3 to 10 days, the stitches will disappear by themselves.

The no-scalpel vasectomy involves making a very small puncture (a hole) in the scrotum instead of an incision. The puncture is so small that it heals without stitches.

Vasectomy may be the safest, most effective kind of birth control. Only about 15 out of 10,000 couples get pregnant the first year after a vasectomy.

Don't have a vasectomy unless you're sure you don't want to have children in the future. You may need to wait to have a vasectomy, or may not be able to have one, if you have an infection on or around your genitals, or you have a bleeding disorder.

Some vasectomies can be undone, or "reversed," but the surgery is expensive, not usually covered by insurance and must be performed in a hospital. Even though most men can ejaculate sperm after the reversal surgery, the sperm are often not able to fertilize an egg.

On the day of the operation, bring a jockstrap (an athletic supporter) with you and make sure your genital area is clean. Your doctor will probably give you instructions on how to clean the area before you come in. Your doctor may suggest you bring someone to drive you home after surgery.

Right after the operation, your doctor will have you lie down for a couple of hours with an ice pack placed on your scrotum. You may have some bruising in the area of the surgery. The bruises should slowly lighten and be gone in about 2 weeks. You should feel back to normal within a couple of weeks.

Don't take aspirin, ibuprofen (brand names: Advil, Motrin, Nuprin), ketoprofen (brand name: Orudis) or naproxen (brand name: Aleve) for 2 weeks before or after the operation. All of these can thin your blood and cause bleeding. Try acetaminophen (brand name: Tylenol) to relieve pain.

If you have a desk job, expect to return to work after a couple of days. If you do physical labor, or walk or drive a lot, talk with your doctor about when you can go back to work.

No. You'll need to ejaculate as many as 15 to 20 times before the sperm will be cleared from both the vas deferens. For that reason, keep using birth control. Your doctor will ask you to bring in samples of your ejaculation after the operation. Only after you have 2 sperm-free samples will you be considered unable to get a woman pregnant. This may take 3 months or longer.

Problems that might occur after your vasectomy include bleeding, infection and a usually mild inflammatory reaction to sperm that may have gotten loose during the surgery (called sperm granuloma). Call your doctor if you notice any of the signs in the box below.

Another risk is that the ends of the vas deferens may find a way to create a new path to one another. This doesn't occur very often. But if it does, you could be able to cause a pregnancy.

Once sperm can't get through the vas deferens, your testicles will begin making fewer sperm. Your body will absorb the sperm that are made.

After you have healed from the vasectomy, your sex life shouldn't change at all. You'll still ejaculate almost the same amount of semen as you did before, and you won't notice a change in your sex drive.