Failure rates of birth control
- “The Pill” – failure rate of 7%. A combined variety of contraceptive chemicals including estrogen and progestin – to be taken once a day at the same time each day. Requires a doctor’s prescription.
- Progestin onlypill – failure rate of 7%. Much like “The Pill,” but only contains progestin. Requires a doctor’s prescription.
- Implant – failure rate of 0.01%. Inserted into the upper arm and releases progestin for three years.
- “The Shot” – failure rate of 4%. Women are administered a shot into the butt or arm by a doctor every three months.
- Patch – failure rate of 7%. This is worn on the lower abdomen, butt, or upper body (but not the breasts). The woman applies the patch once a week for three weeks – and during the fourth week, it is left out to allow menstruation.
- Ring – failure rate of 7%. The ring is inserted into the vagina for three weeks per month, and subsequently taken out during the fourth week to allow menstruation. A new ring is then inserted. This ring releases progestin and estrogen.
- Copper T IUD – failure rate of 0.8%
- Levonorgestrel (LNG) IUD – failure rate of 0.1 – 0.4%
- [this device releases small doses of progesterone every day]
External or “Barrier”:
- Male condoms – failure rate of 13%.
- Female condoms – failure rate of 21%. Can be applied eight hours prior to intercourse
- Diaphragm or cervical cap – failure rate of 17%. Inserted into the vagina, come in different sizes
- Sponge- failure rate of 14% for women who have never given birth – 27% for women who have. This is put over the cervix and it contains spermicides. This must remain in the woman for six hours following intercourse.
- Spermicides – failure rate of 21%. Come in many forms: foam, gel, cream, film, suppository, or tablet.
Failure rates of fertility-based awareness methods (FBAM)
Depending on consistent tracking, and the use of condoms throughout the month, fertility-based awareness method failure rates can range between 2-23%. The CDC considers the use of condoms throughout the nine days each month of a woman’s prime fertility as still adhering to the definition of FBAM.
“If you have a regular menstrual cycle, you have about nine or more fertile days each month. If you do not want to get pregnant, you do not have sex on the days you are fertile, or you use a barrier method of birth control on those days.” –CDC
Birth Control Effectiveness
|Type of Contraceptive||Failure Rate|
|Hormonal vaginal contraceptive ring||7%|
|External Barrier (male condoms)||13%|
|External Barrier (female condoms)||21%|
Fertility-Based Awareness Methods:
Standard Days Method
Failure rate of 5% (in the context of perfect adherence) See above, days 8 through 19 are the most fertile days for a woman who has a normal menstrual cycle length
Cervical Mucous Method
Failure rate of 3% (in the context of perfect adherence). This involves observing the presence, amount, and consistency of cervical mucous throughout a woman’s ovulation. Just beforeovulation, the woman’s mucous becomes thin and slippery, and deposits in large amounts. To mark the end of the ovulation period, there is less mucous – and it is thicker and less conspicuous overall. To prevent pregnancy, it is advised that the woman does not have intercourse during the days when the mucous is thin and slippery.
The TwoDay Method — this is simply a variation of the cervical mucous method. When a woman checks her mucous – this time twice per day — she minds two factors: secretions the day-of and those the day before.
Basal Body Temperature Method (BBT)
A woman’s BBT is the temperature she is when at rest, increases 0.5 to 1 degrees when ovulating. A woman is most fertile during the two to three days prior to this temperature increase. This method involves the woman checking her body temperature each morning. Basal Body Temperature is often combined with other methods, decreasing its failure rate to .01%.
Failure rate of less than 1% (in the context of perfect adherence) and 2-8% regularly.
- This is, definitively, a combination of methods. The most common combination is with the cervical mucous and BBT This is managed through the use of an electronic hormonal fertility monitor.
- Another combination women use involves the Standard Day Method as an addition.
|Method Type||Failure Rate|
|Billings Ovulation/Cervical Mucus||3%|
In 2018, the FDA approved the fertility app Natural Cycles as a form of birth control because it consistently observed key components of fertility that caused only a 1.8% failure rate at preventing pregnancy. Since then, more apps have been developed that track multiple symptoms to increase accuracy and effectiveness:
- Natural Cycles
- Femm Health
- Ovia Fertility
Display Panel Sources:
- Thijssen, A., Meier, A., Panis, K., & Ombelet, W. (2014). ‘Fertility Awareness-Based Methods’ and subfertility: a systematic review. Facts, views & vision in ObGyn, 6(3), 113–123.