June 27, 2025, 2:49 pm | Read time: 2 minutes
When it comes to contraception, women have a wide range of options, both hormonal and non-hormonal. But how effective is each method? This is where the Pearl Index comes into play.
IUDs, condoms, NFP, the pill, implants, injections, patches, diaphragms, temperature method, etc.–there are numerous contraceptive methods for women and a few for men. Some suit you, some don’t. However, not all are equally reliable. The key term is Pearl Index. It indicates how safe a contraceptive method is and can be a helpful tool when deciding on a new method.
Overview
What is the Pearl Index?
The Pearl Index is named after the American scientist Raymond Pearl. It defines the safety of a contraceptive method, indicating the likelihood of becoming pregnant despite using contraception. The rule is: the lower the Pearl Index, the safer the method.
Also interesting: 7 hormone-free contraceptive methods reviewed.
How the Pearl Index is calculated
Two examples: If 100 women use a particular contraceptive method for one year and four become pregnant, the Pearl Index is 4, because four out of 100. If the method you choose has a Pearl Index of 0.1, it is better in terms of safety. This lower Pearl Index means that only one out of 1,000 women using the same method became pregnant in a year.
Important to note: The stated value often assumes perfect use, meaning the daily pill or daily temperature measurement, for example, was never forgotten. Therefore, the Pearl Index can often only provide a guideline. The only way to ensure 100 percent certainty of not becoming pregnant is to abstain from sex.
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The reliability of different contraceptives
- Contraceptive implant: 0.1 – 0.9
- Pill: 0.1 – 0.9
- Hormonal IUD: 0.16
- Micro pill: 0.2 – 0.5
- Copper IUD: 0.3 – 0.8
- Depot injection/three-month injection: 0.3 – 0.88
- Vaginal ring: 0.4 – 0.65
- Contraceptive patch: 0.72 – 0.9
- Temperature method: 0.4 – 2.3
- Estrogen-free pill/mini pill: 0.14 – 4
- Diaphragm: 1 – 20 (when used with a contraceptive gel)
- Condom: 2 to 12
- Cervical mucus method: 3 – 5
- Withdrawal method: 4 – 18
- Female condom: 5 – 25
- Cervical cap: 6 (when used with a contraceptive gel)
- Calendar method: 9
- Female sterilization: 0.2 – 0.3
- Male sterilization: 0.1
Besides the Pearl Index, it’s also crucial to consider what makes a woman feel comfortable and secure. Do you prefer to be protected for weeks without having to think about contraception at the crucial moment? Or do you find this specific timing more convenient? Lastly, there’s another important decision to make: Do you want to take hormones or would you rather avoid them?