Method | Percent of women experiencing an unintended pregnancy within the first year of use (%) | Percent of women continuing use at one year (%)Δ | |
Typical use* | Perfect use¶ | ||
No method◊ | 85 | 85 | |
Spermicides§ | 21 | 16 | 42 |
Internal condom¥ | 21 | 5 | 41 |
Withdrawal | 20 | 4 | 46 |
Diaphragm‡ | 17 | 16 | 57 |
Sponge | 17 | 12 | 36 |
Parous women | 27 | 20 | |
Nulliparous women | 14 | 9 | |
Fertility awareness-based methods† | 15 | 47 | |
Ovulation method† | 23 | 3 | |
TwoDay method† | 14 | 4 | |
Standard Days method† | 12 | 5 | |
Natural Cycles† | 8 | 1 | |
Symptothermal method† | 2 | 0.4 | |
External condom¥ | 13 | 2 | 43 |
Combined and progestin-only pills | 7 | 0.3 | 67 |
Evra patch | 7 | 0.3 | 67 |
NuvaRing | 7 | 0.3 | 67 |
Depo-Provera | 4 | 0.2 | 56 |
Intrauterine contraceptives** | |||
ParaGard (copper T) | 0.8 | 0.6 | 78 |
Mirena (52 mg LNG) | 0.7 | 0.5 | 80 |
Skyla (13.5 mg LNG) | 0.4 | 0.3 | |
Kyleena (19.5 mg LNG) | 0.2 | 0.2 | |
Liletta (52 mg LNG) | 0.1 | 0.1 | |
Nexplanon | 0.1 | 0.1 | 89 |
Tubal occlusion | 0.5 | 0.5 | 100 |
Vasectomy | 0.15 | 0.1 | 100 |
Emergency contraceptives: Use of emergency contraceptive pills or placement of a copper intrauterine contraceptive after unprotected intercourse substantially reduces the risk of pregnancy. | |||
Lactational amenorrhea method: LAM is a highly effective, temporary method of contraception.¶¶ |
LNG: levonorgestrel; LAM: lactational amenorrhea method; FABM: fertility awareness-based methods; NSFG: National Survey of Family Growth; LH: luteinizing hormone.
* Among typical couples who initiate use of a method (not necessarily for the first time), the percentage who experience an accidental pregnancy during the first year if they do not stop use for any reason other than pregnancy. Data from United States populations.
¶ Among couples who initiate use of a method (not necessarily for the first time) and who use it perfectly (both consistently and correctly), the percentage who experience an accidental pregnancy during the first year if they do not stop use for any other reason.
Δ Among couples attempting to avoid pregnancy, the percentage who continue to use a method for 1 year.
◊ This estimate represents the percentage who would become pregnant within 1 year among women now relying on reversible methods of contraception if they abandoned contraception altogether.
§ 150 mg gel, 100 mg gel, 100 mg suppository, 100 mg film.
¥ Without spermicides.
‡ With spermicidal cream or jelly.
† Approximately 80% of segments of FABM use in the 2006 to 2010 NSFG were reported as calendar rhythm. Specific FABM methods are too uncommonly used in the United States to permit calculation of typical use failure rates for each using NSFG data; rates provided for individual methods are derived from clinical studies. The Ovulation and TwoDay methods are based on evaluation of cervical mucus. The Standard Days method avoids intercourse on cycle days 8 through 19. Natural Cycles is a fertility app that requires user input of basal body temperature (BBT) recordings and dates of menstruation and optional LH urinary test results. The Symptothermal method is a double-check method based on evaluation of cervical mucus to determine the first fertile day and evaluation of cervical mucus and temperature to determine the last fertile day.
** All of these estimates are low, below 1%, and we caution readers not to put any emphasis on the differences among these very small probabilities.
¶¶ However, to maintain effective protection against pregnancy, another method of contraception must be used as soon as menstruation resumes, the frequency or duration of breastfeeds is reduced, bottle feeds are introduced, or the baby reaches 6 months of age.Do you want to add Medilib to your home screen?