The IUD is over 99% effective at preventing pregnancy.
That’s about as effective as it gets.
In fact, the IUD is one of the most effective long-term and reversible methods of birth control available today.
The chart below shows just how well IUDs work compared to other kinds of birth control. The effectiveness rate is how well the method works in preventing pregnancy for the typical, or average, person who may not always or consistently use their birth control correctly.
Since IUDs are pretty hard to mess up once you have one, you will see the two types of IUDs—Mirena and ParaGard—listed right up there at the very top! Both are over 99% effective.
Fewer than 1 out of 100 women will accidentally get pregnant during one year of using an IUD.