Best Birth Control Options

The effectiveness of a birth control method is measured by how many women become pregnant within the first year of use. That is, if a particular birth control method has a 5% failure rate, you would expect 5 out of every 100 women using that method to become pregnant within the first year of use.

In general, the effectiveness of birth control methods increase as the amount of regular user action required decreases. In other words, birth control methods such as surgical sterilization, implants, and intrauterine devices that don't require regular action tend to be the most effective forms of birth control while forms depending on the user regularly taking some action, such as taking daily birth control pills or using a condom, tend to have lower rates of effectiveness.

User Error Is A Factor

While most forms of birth control are theoretically extremely effective, human error can increase pregnancy rates significantly. For example, Estrogen/Progestin birth control pills, if always used properly, have a theoretical pregnancy rate of 0.1%, meaning they prevent pregnancy in 999 of 1000 women in the first year of use. The phrase “if always used properly” is key, however. In the real world, birth control methods are rarely used properly all the time. A woman may occasionally forget and skip a day, for example. Thus, in reality, the pregnancy rate of Estrogen/Progestin birth control pills as they are used by real women is closer to 5%. That is, 5 out of 100 women using these birth control pills will become pregnant within the first year, mostly due to improper use. That's quite a difference.

The difference between theoretical and actual effectiveness rates using condoms is even more striking. If used properly every time, condoms result in a pregnancy rate of approximately 3%. As they are used in the real world? A surprising 14%. Fully 14 of every 100 women using condoms will end up pregnant within the first year of use.

The following table from the Food and Drug Administration (FDA) lists the typical use pregnancy rate and lowest expected pregnancy rate of several common forms of birth control where “lowest expected pregnancy rate” represents the theoretical failure rate of a given method and “typical use pregnancy rate” represents actual real-world failure rates due to human error and other factors.

Columns in order: Method, Typical Use, Lowest Expected

Hormonal Methods
Combined Pill (estrogen/progestin), 5%, 0.1%
Mini Pill (progestin only), 5%, 0.5%
Implant, 0.09%, 0.09%
Hormone Shot (Depo-Provera), 0.3%,0.3%

Barrier Methods
Male latex condom, 14%, 3%
Diaphragm, 20%, 6%

Natural Methods
Withdrawal, 19%, 4%

No Method, 85%, 85%