Birth Control Methods: How Well Do They Work?
The most effective way to prevent pregnancy is not to have sex. (That’s called abstinence.) However, within the first year of committing to abstinence, almost a quarter of couples become pregnant because they have sex anyway but don’t use protection. So it’s a good idea even for people who don’t plan to have sex to be informed about birth control.
Couples that do have sex need to use birth control properly and every time to prevent pregnancy. For example, the chart below shows that the birth control pill can be effective in preventing pregnancy. But if a girl forgets to take her birth control pills, then this is not an effective method for her. Condoms can be an effective way to prevent pregnancy, too. But if a guy forgets to use a condom or doesn’t use it correctly, then it’s not an effective way for him to prevent pregnancy.
For every 100 couples using each type of birth control, the chart shows how many of these couples will get pregnant within a year. The information shown is for all couples, not just teenage couples. Some birth control methods may be less effective for teen users. For example, teenage girls who follow the rhythm method may have a greater chance of getting pregnant than grown women because their bodies have not yet settled into a regular menstrual cycle.
We have ranked the effectiveness of different birth control methods based on their typical use rates. Typical use refers to how the average person uses that method of birth control (compared to "perfect" use, which means no mistakes are made in using that method). For a birth control method to be ranked completely effective, no couples will become pregnant while using this method. Very effective means that between 0 and 1 out of 100 couples become pregnant while using this method. Effective means that 2 to 12 out of 100 couples become pregnant while using this method. Moderately effective means that 13 to 20 out of 100 couples become pregnant while using this method. Less effective means that 21 to 40 out of 100 couples become pregnant while using this method. And not effective means that no method of birth control is used.
|Method of Birth Control||How Many Couples Using This Method Will Get Pregnant in a Year?||How Well Does This Method Work in Preventing Pregnancy?||Does This Also Protect Against STDs?|
|Consistent Abstinence||None||Completely effective||Yes|
|Birth Control Patch ("The Patch")||8 out of 100||Effective||No|
|Birth Control Pill ("The Pill")||5 to 8 out of 100||Effective||No|
|Birth Control Ring ("The Ring")||8 out of 100||Effective||No|
|Cervical Cap (before childbirth)||16 out of 100||Moderately effective||No|
|Cervical Cap (after childbirth)||40 out of 100||Less effective||No|
|Female Condom||21 out of 100||Less effective||Yes|
|Male Condom||15 out of 100||Moderately effective||Yes|
|Birth Control Shot||3 out of 100||Effective||No|
|Diaphragm||16 out of 100||Moderately effective||No|
|Emergency Contraception||1 to 2 out of 100||Very effective||No|
|IUD||Fewer than 1 out of 100||Very effective||No|
|Rhythm Method||25 out of 100||Less effective||No|
|Spermicide||29 out of 100||Less effective||No|
|Withdrawal ("Pulling Out")||75 out of 100||Less effective||No|
|Not Using Any Birth Control||85 out of 100||Not effective||No|
Choosing a birth control method based on how well it works is important, but so are other things. Other important things to keep in mind include how easy a particular birth control method is to use or how much it costs. Sometimes, a person’s health condition or whether that person is taking other medication could affect what type of birth control method should be used or avoided.
In addition to preventing pregnancy, some birth control methods provide some protection against sexually transmitted diseases (STDs). Most kinds of birth control methods, though, do not provide much protection against STDs. Abstinence and condoms are the most effective in preventing STDs.
Updated and reviewed by: Barbara P. Homeier, MD
Date reviewed: March 2005
Originally reviewed by: Neil Izenberg, MD