Health Topics

Birth Control Education

Efficacy Chart

A birth control method's effectiveness is estimated based on the percentage of women who experience an unintended pregnancy in one year using a particular method. This may also be stated as a method's failure rate: the percentage of women experiencing pregnancy during a one year period of method use.

Two rates are reported for each method of birth control: the theoretical rate (or perfect) and the actual user (or typical) rate. The theoretical rate estimates how well a method performs when used as intended and consistently by "perfect" users. The actual (typical) user rate estimates how well a method performs when all of the errors and problems that people typically encounter with a method are taken into account.

Failure Rates of Birth Control Methods

Method
% of Women Experiencing
an Unintended Pregnancy
within the First Year of Use
Typical
Use
Perfect
Use
No Method
85
85
Spermicides
28
18
Withdrawal
22
4
Fertility Awareness-Based (FAB) Methods
24
N/A
• FAB: Standard Days Method
N/A
5
• FAB: TwoDay Method
N/A
4
• FAB: Ovulation Method
N/A
3
Contraceptive Sponge
• never given birth before
12
9
• previously given birth
24
20
Diaphragm
12
6
Condom
• Female Condom (Reality)
21
5
• Male Condom
18
2
Combined Pill and Minipill
9
0.3
Evra Patch
9
0.3
NuvaRing
9
0.3
Depo-Provera
6
0.3
Intrauterine Device (IUD)
• IUD: ParaGard (copper T)
0.8
0.6
• IUD: Mirena (LNG-IUS)
0.2
0.2
Implanon
0.05
0.05
Female Sterilization
0.5
0.5
Male Sterilization
0.15

0.10

Emergency Contraceptive Pills: Treatment initiated within 120 hours after unprotected intercourse reduces the risk of pregnancy by 75%-89%.


Online Birth Control Education

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