Whenchoosing a contraceptive, it’s important to factor in failure rates. These statistics, which refer to how often specific methods ofbirth controlfail in preventing pregnancy, are one way to measure how effective a particular method is likely to be.
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The concept of birth control failure rates may sound complicated, but in fact, it’s based on simple and straightforward math. Once you understand how birth control failure rates are determined and what they mean, you’ll be able to use them to make an informed decision about the best contraceptive method for you.
How Birth Control Failure Rates Are Determined
For example, what does it mean that condoms have a 2% to 15% failure rate? Another way to understand this is that condoms are 85% to 98% effective. The effectiveness rate is the opposite of the failure rate. Subtract the failure rate from 100, and that number is the birth control effectiveness rate. Condoms are 85% to 98% effective (meaning they have a failure rate of 2% to 15%).
This means thatfor every 100 women whose partners use condoms, from two to 15 of them will become pregnant within the first year of use.So basically, the failure rate doesnotrefer tohow manytimes you have sex, it correlates thenumber of people(100) who use that method over the course of one year. Failure rates refer to the number of pregnancies that take place when 100 women use that birth control method for one year.
Comparing Birth Control Failure Rates
Birth control failure rates usually refer to the number of people (out of 100) who use a birth control method and who will become pregnantduring the first year of use.There are a number of factors that can affect failure rates, including experience with the method, the difficulty and effort associated with the method, and if the method is used correctly and consistently.
In practice, it appears failure rates tend to be higher during the first year a contraceptive is used. There are several reasons why failure rates may decrease after using a method for one year:
The reason you may see a range in the birth control failure rates has to do with"typical use"vs.“perfect use.” So, when the failure rates are presented in a range,the lower number represents perfect use and the higher number is for typical use.
Typical user failure rates tend to be higher than perfect use. Birth control methods that require more for a person to do (i.e., remember to use, be inserted or put on a certain way, be used within a certain timeframe, etc.), tend to have higher failure rates because there is more room forerror.
These methods include:
Sometimes, you will not see a range in failure rates. This means that typical use isequal toperfect use, as is the case withIUDs, surgeries (tubal ligationandvasectomy), and others.
Birth Control Methods, ComparedMethodPerfect UseTypical UseSurgical sterilization (vasectomy, tubal ligation)0.100.15Implant0.50.5IUD0.20.2Pill0.37Patch0.39Vaginal ring0.39Diaphragm612Internal condom521External condom213Withdrawal420Fertility Awareness04.-524Spermicides1828No method8585Emergency contraception00* this method is not measured on a one year basis as others areChoosing Birth Control Based on Failure RatesWhen comparing birth control methods, pay attention to whether the numbers refer to failure rates or effectiveness rates, as well as typical use or perfect use. Keep in mind that, regardless of the posted effectiveness or failure rate, other factors (in addition to user error or inconsistent use) can lower the effectiveness of birth control methods. These range frommotivationtoweighttomedicationsyou may be taking.Alsoconsiderhow often you have sex: If you know you’ll be having sex frequently, it may be a wiser choice to use a more effective method to have the best chances of not getting pregnant.Understanding how to interpret failure rates, knowing factors that could influence contraceptive effectiveness, evaluating your lifestyle and sexual behavior, and determining the level of effectiveness that is most acceptable to you can greatly help in the birth control decision you make. Consult with a healthcare provider for help in making a decision about what method will work for you and your lifestyle.Is Pregnancy Possible After Tubal Ligation?
Choosing Birth Control Based on Failure Rates
When comparing birth control methods, pay attention to whether the numbers refer to failure rates or effectiveness rates, as well as typical use or perfect use. Keep in mind that, regardless of the posted effectiveness or failure rate, other factors (in addition to user error or inconsistent use) can lower the effectiveness of birth control methods. These range frommotivationtoweighttomedicationsyou may be taking.
Alsoconsiderhow often you have sex: If you know you’ll be having sex frequently, it may be a wiser choice to use a more effective method to have the best chances of not getting pregnant.
Understanding how to interpret failure rates, knowing factors that could influence contraceptive effectiveness, evaluating your lifestyle and sexual behavior, and determining the level of effectiveness that is most acceptable to you can greatly help in the birth control decision you make. Consult with a healthcare provider for help in making a decision about what method will work for you and your lifestyle.
Is Pregnancy Possible After Tubal Ligation?
4 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397-404. doi:10.1016/j.contraception.2011.01.021Trussell J.Understanding contraceptive failure.Best Pract Res Clin Obstet Gynaecol. 2009;23(2):199–209. doi:10.1016/j.bpobgyn.2008.11.008Bradley SEK, Polis CB, Bankole A, Croft T.Global Contraceptive Failure Rates: Who Is Most at Risk?.Stud Fam Plann. 2019;50(1):3–24. doi:10.1111/sifp.12085Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397–404. doi:10.1016/j.contraception.2011.01.021Additional ReadingCenters for Disease Control and Prevention.Contraception.Updated March 17, 2020.Hatcher RA et al., eds.,Contraceptive Technology, 20th revised ed., New York: Ardent Media, 2011.
4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397-404. doi:10.1016/j.contraception.2011.01.021Trussell J.Understanding contraceptive failure.Best Pract Res Clin Obstet Gynaecol. 2009;23(2):199–209. doi:10.1016/j.bpobgyn.2008.11.008Bradley SEK, Polis CB, Bankole A, Croft T.Global Contraceptive Failure Rates: Who Is Most at Risk?.Stud Fam Plann. 2019;50(1):3–24. doi:10.1111/sifp.12085Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397–404. doi:10.1016/j.contraception.2011.01.021Additional ReadingCenters for Disease Control and Prevention.Contraception.Updated March 17, 2020.Hatcher RA et al., eds.,Contraceptive Technology, 20th revised ed., New York: Ardent Media, 2011.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397-404. doi:10.1016/j.contraception.2011.01.021Trussell J.Understanding contraceptive failure.Best Pract Res Clin Obstet Gynaecol. 2009;23(2):199–209. doi:10.1016/j.bpobgyn.2008.11.008Bradley SEK, Polis CB, Bankole A, Croft T.Global Contraceptive Failure Rates: Who Is Most at Risk?.Stud Fam Plann. 2019;50(1):3–24. doi:10.1111/sifp.12085Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397–404. doi:10.1016/j.contraception.2011.01.021
Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397-404. doi:10.1016/j.contraception.2011.01.021
Trussell J.Understanding contraceptive failure.Best Pract Res Clin Obstet Gynaecol. 2009;23(2):199–209. doi:10.1016/j.bpobgyn.2008.11.008
Bradley SEK, Polis CB, Bankole A, Croft T.Global Contraceptive Failure Rates: Who Is Most at Risk?.Stud Fam Plann. 2019;50(1):3–24. doi:10.1111/sifp.12085
Trussell J.Contraceptive failure in the United States.Contraception. 2011;83(5):397–404. doi:10.1016/j.contraception.2011.01.021
Centers for Disease Control and Prevention.Contraception.Updated March 17, 2020.Hatcher RA et al., eds.,Contraceptive Technology, 20th revised ed., New York: Ardent Media, 2011.
Centers for Disease Control and Prevention.Contraception.Updated March 17, 2020.
Hatcher RA et al., eds.,Contraceptive Technology, 20th revised ed., New York: Ardent Media, 2011.
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