An explanation of condom failure rates

Originally Published: August 30, 2002 - Last Updated / Reviewed On: April 11, 2013
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Dear Alice,

When people say that contraceptives, like condoms, have a 12 percent failure rate, do they mean that they result in pregnancy in 12 out of every 100 women who use them? I hope that means that 12 percent of people who use them become pregnant in a year, or something like that. Otherwise, it sounds as risky as Russian roulette to rely on condoms.

Dear Reader,

Good news — your second interpretation of contraceptive effectiveness rates is more like it. During a year of typical condom use, between 10 and 15 out of 100 sexually active women will become pregnant. During a year of perfect condom use, that number drops to between 2 and 3 out of 100 sexually active women becoming pregnant. Just for the record, 21 percent (typical use) and 5 percent (perfect use) of women who use the female condom experience an unintended pregnancy within the first year of use.

Here's the difference between perfect use and typical use. Perfect use means using a condom during intercourse consistently and correctly every single time, and reflects the effectiveness of condoms themselves. Typical use gets at the reality that people may use condoms incorrectly or may not use them every single time they have sex. That is, the "typical use" condom effectiveness rates you see include the possibility of human error or omission. It follows that typical use condom effectiveness would be lower than perfect use — if someone uses a condom 90 percent of the times they have sexual intercourse there is a higher chance of pregnancy than if they use a condom 100 percent of the time.

As long as we're on the subject of effectiveness, it should be noted that condoms are also highly effective in preventing transmission of HIV and a number of other STIs (sexually transmitted infections). Studies done on heterosexual sero-discordant couples — where one partner is HIV-positive and the other HIV-negative — show that HIV was transmitted in zero to two percent of couples who correctly and consistently used male condoms for both vaginal and anal sex. With typical use, the HIV transmission rate increased to between 10 and 15 percent. While condoms can also reduce the risk of other STIs, but their exact effectiveness is harder to determine.

Here are some tips for using condoms consistently and correctly:

Before you put a condom on:

  1. Store condoms in a cool, dry place away from direct sunlight.
  2. Check the expiration date on the condom.
  3. Do a pillow test — does the air stay in the package?
  4. Tear the condom package carefully — without using your teeth — to open.
  5. If the condom looks damaged, discolored, or brittle, do not use.
  6. Add a drop of lube inside the condom for extra pleasure.

To put a condom on:

  1. With one hand, pinch the tip of the condom to leave room for the ejaculate.
  2. With the other hand, roll the condom to the base of the penis or object.
  3. Continue using this hand to guide any air bubbles out of the condom.
  4. Add lube to the outside of the condom to avoid excess friction that may cause breakage.

After the action:

  1. Hold the base of the condom as you pull out to avoid slippage.
  2. Remove the condom and throw away in the trash, not the toilet.

Practice is the best way to learn to use condoms correctly. You/your partner may want to try using condoms during (mutual or solo) masturbation — there'll be less pressure and anxiety than during intercourse, so it may be easier to get the hang of the steps. For more tips on condom use, check out the Related Q&As below. Also, check out the Safer Sex Map for locations of safer sex supplies on the Columbia campus.

Alice