Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Birth Control Health Center

Font Size

Vasectomies Don't Always Prevent Pregnancy

Nearly 1 in 100 Vasectomies May Fail

WebMD Health News

May 5, 2004 -- As many as one in 100 vasectomies may fail to prevent pregnancy within five years of the procedure, a new study shows.

Researchers say that the study shows that like other birth control methods, vasectomies are not always 100% effective.

The study showed that six pregnancies were reported among 540 women within six weeks to 1.5 years after their husbands had a vasectomy.

"Couples considering vasectomy should be counseled about the small, but real risk of pregnancy following the procedure and that men are not sterile immediately after vasectomy," write researcher Denise J. Jamieson, MD, MPH, of the CDC, and colleagues.

A vasectomy is considered a permanent form of birth control to make a man unable to father a child. It is a surgical procedure in which the tube that carries the sperm from the testes to the urethra is cut or sealed off to prevent sperm from being released during ejaculation.

Vasectomies Not Fail-Safe

In the study, researchers followed a group of women whose husbands underwent vasectomy in five different medical centers in the U.S. from 1985 to 1987. The women were participants in the U.S. Collaborative Review of Sterilization (CREST) study and were interviewed by phone one, two, three, and five years after the procedure.

Researchers found that of the 540 women at risk for pregnancy, six pregnancies were reported after vasectomy and were considered caused by failure of the procedure. Three of the pregnancies occurred within three months of the vasectomy.

The results appear in the May issue of Obstetrics & Gynecology.

Although the women were not specifically asked, two of them reported that their husband did not follow the urologist's instructions regarding abstinence or use of back-up contraception. A common recommendation is to have semen analysis performed three months after vasectomy or after 20 ejaculations and to avoid intercourse or use another birth control method until no sperm has been documented.

Researchers estimated that around one in 100 vasectomies would fail within one to five years of surgery. They say those failure rates are similar to those reported in two prior studies on vasectomy failure.

Vasectomy vs. Tubal Ligation

The rates are also comparable to failure rates following tubal ligation (a female sterilization procedure also known as having the tubes tied) found among women in CREST.

Researchers say this is the first major study to compare pregnancy rates for female vs. male sterilization procedures.

"Couples who are considering sterilization should be counseled that both male and female sterilization are highly effective methods of permanent contraception but that pregnancies can occur," conclude the researchers.

Today on WebMD

Here's what to expect.
man opening condom wrapper
Do you know the right way to use them?
birth control pills
Here's what to do next.
doctor and patient
His and her options.
Concerned teenage girl
hospital gown
Birth Control Pills Weight Gain
pregnancy test and calendar
contraceptive pills
Young couple looking at each other, serious
woman reading pregnancy test result