APPENDIX A - Contraceptive Effectiveness
Rates of Unintended Pregnancies per 100 Women
|First-Year Pregnancy Rates (Trussella)||12-month Pregnancy Rates (Cleland & Alib)|
|Family planning method||Consistent and correct use||As commonly used||As commonly used|
|LAM (for 6 months)||0.9c||2c|
|Combined oral contraceptives||0.3||8||7|
|Progestin-only oral pills||0.3||8|
|Combined vaginal ring||0.3||8|
|Standard Days Method||5|
|Diaphragms with spermicide||6||16|
|Other fertility awareness methods||25||24|
|Cervical caps||26d, 9e||32d,16e|
a Rates largely from the United States. Source: Trussell J. Contraceptive efficacy. In: Hatcher R et al., editors. Contraceptive technology. 19th revised ed. 2007. Rates for monthly injectables and cervical cap are from Trussell J. Contraceptive failure in the United States. Contraception. 2004;70(2): 89—96.
b Rates from developing countries. Source: Cleland J and Ali MM. Reproductive consequences of contraceptive failure in 19 developing countries. Obstetrics and Gynecology. 2004;104(2): 314—320.
c Rate for consistent and correct use of LAM is a weighted average from 4 clinical studies cited in Trussell (2007). Rate for LAM as commonly used is from Kennedy KI et al. Consensus statement: Lactational amenorrhea method for family planning. International Journal of Gynecology and Obstetrics. 1996;54(1): 55—57.
d Pregnancy rate for women who have given birth
e Pregnancy rate for women who have never given birth