Contraception

Effectiveness of Prescription Birth Control

Updated: March 14, 2008

About.com Health's Disease and Condition content is reviewed by Meredith Shur, MD

Birth Control Pills

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Prescription birth control include medically prescribed hormones, barriers, or devices. When comparing contraceptive effectiveness,

Typical use refers to failure rates for women who do not consistently or always correctly use their birth control. These rates usually apply to the average woman as it is sometimes difficult to always and reliably use birth control the correct way
Perfect use refers to failure rates for those whose use is consistent and always correct.

The Pill

Typical use: 92% effective
Perfect use: 99.7% effective
Of every 100 women who use The Pill, 8 will become pregnant (with typical use) within the first year and less than one will become pregnant with perfect use

For Different Types of Birth Control Pills:

NuvaRing

Typical use: 92% effective
Perfect use: 99.7% Effective
Of every 100 women who use the ring, 8 will become pregnant (with typical use) within the first year and less than 1 will become pregnant with perfect use

The Ortho Evra Patch

Typical use: 92% effective
Perfect use: 99.7% Effective
Of every 100 women who use the patch, 8 will become pregnant (with typical use) within the first year and less than 1 will become pregnant with perfect use

Depo-Provera Injections

Typical use: 97% effective
Perfect use: 99.7% effective
Of every 100 women who injections, 3 will become pregnant (with typical use) within the first year and less than 1 out of 100 will become pregnant with perfect use

Mirena IUD

Typical and Perfect use: 99.9% effective
Of every 100 women who use Mirena, less than 1 will become pregnant within the first year with typical use as well as with perfect use

ParaGard IUD

Typical use: 99.2% effective
Perfect use: 99.4% effective
Of every 100 women who use ParaGard, less than 1 will become pregnant within the first year with typical use as well as with perfect use

Implanon

Typical and Perfect use: 99.9% effective
Of every 100 women who use Implanon, less than 1 will become pregnant within the first year with typical use as well as with perfect use

Diaphragms

Typical use: 84% effective
Perfect use: 94% effective
Of every 100 women who use diaphragms, 16 will become pregnant (with typical use) within the first year and 6 will become pregnant with perfect use

Cervical Caps

For those who have not given birth:

Typical use: 84% effective
Perfect use: 91% effective
Of every 100 women who use cervical caps, for those who have not given birth, 16 will become pregnant (with typical use)within the first year and 9 will become pregnant with perfect use

For those who have given birth:

Typical use: 68% effective
Perfect use: 74% effective
Of every 100 women who use cervical caps, for those who have given birth, 32 will become pregnant(with typical use) within the first year and 26 will become pregnant with perfect use