Birth Control Failure

Birth Control Different birth control methods can be highly effective at preventing pregnancy, but birth control failure is more common than most people realize.

Here is a chart displaying birth control failure rate percentages, as well as common risks and side effects.

Birth Control Failure Chart

Note that the failure rates are for the average use of the method. Consistent and correct use may further decrease your chances. For specific hormonal birth control methods, the risk of pregnancy for correct use should be listed in the instructions/details.

When speaking of hormonal birth control, it is important to consider both the high success rate and the ethical concerns of the third action of the birth control:  changing/thinning the lining of the uterus to prevent implantation.

Since this can stop an already begun pregnancy from continuing, it is said to have abortifacient qualities. This will be an action of any of the hormonal birth control methods listed.

Below are some short explanations of how each birth control method works along with risks and side effects associated with each:

Method How it is Used Failure Rate (average use) Risks & Side Effects
Abstinence No sexual intercourse and no type of contact between the male and female sexual organs where bodily fluids could be exchanged 0% No Side Effects
Cervical Cap A soft rubber barrier that covers the cervix in order to prevent sperm from entering the uterus 12% (higher after childbirth) No Side Effects (unless allergic)
Condom – Female A sheath, often made of latex rubber, inserted into the vaginal canal to block the passage of sperm 21% No Side Effects (unless allergic)
Condom – Male A sheath, often made of latex rubber, covering the erect penis to block the passage of sperm 18% No Side Effects (unless allergic)
Depo-Provera Injection Injection of Progestin that is given every 3 months to prevent ovulation, change cervical mucus to block sperm, and change the lining of the uterus to prevent implantation of a fertilized egg 6% Irregular, missed, or heavier than normal menstrual cycle, weight gain, breast tenderness, depression, bloating, abdominal pain, headaches, allergic reaction
Diaphragm A soft rubber dome that covers the cervix to block the passage of sperm. 12% No Side Effects (unless allergic)
Fertility Awareness Using the menstrual cycle and other tools to predict ovulation and abstaining from intercourse during these expected fertile times 25% No Side Effects
Implant – Hormonal A small, matchstick-sized implant inserted in the upper arm and lasts for 3 years, releasing a hormone supply. Works in a similar way to Depo-Provera. 0.05% No period, spotting, light or heavy and prolonged bleeding; painful menstruation, acne, weight gain, depressed mood; blood clots, movement of implant, ectopic pregnancy, ovarian cysts
Intrauterine Device (IUD) – Copper A device is inserted into a woman’s uterus (by a doctor) to block sperm and change the uterus lining to prevent implantation of a fertilized egg 0.8% Ectopic pregnancies, increased bleeding during menstrual cycle, severe menstruation cramps, perforation of the uterus, Pelvic Inflammatory Disease (PID)
Intrauterine Device (IUD) – Progestin 0.2%
Nothing/Chance No birth control method 85% No Side Effects; highest chance of unintended pregnancy
Oral Contraceptive (estrogen/progestin) Taken daily by women to suppress ovulation, change cervical mucus, and change the lining of the uterus to prevent implantation of a fertilized egg 9% Nausea, headaches, weight gain, depression, irregular bleeding, acne, blood clots *Women who smoke are advised not to take oral contraceptives
Oral Contraceptive (progestin only) Taken daily by women to change cervical mucus to block sperm and also changes the uterus lining to prevent implantation of a fertilized egg 9% Breast tenderness, weight gain, menstrual cycle changes *Women who smoke are advised not to take oral contraceptives
Ortho-Evra Patch A patch containing synthetic hormones placed on your skin; works the same as oral contraceptives 9% (greater if over 198 lbs) Similar to oral contraceptives
Spermicide (only) A jelly, foam, or cream containing chemicals that kill sperm 28% No Side Effects (unless allergic)
Sponge A soft saucer-shaped polyurethane sponge that blocks the cervix and absorbs semen 20% (40% after childbirth) No Side Effects (unless allergic)
Sterilization – Female Permanent surgical procedure to prevent pregnancy:  fallopian tube is damaged (cut, tied, burnt) to prevent passage of eggs and sperm 0.5% If a woman conceives after a sterilization procedure there is a risk of ectopic pregnancies. The earlier the age of the woman at the time of the procedure, the greater risk of pregnancy after 10 years (up to ~5%).
Sterilization – Male Permanent surgical procedure to prevent pregnancy:  vas deferens tube is damaged (cut, tied, burnt) to prevent passage of sperm into ejaculate fluid 0.15% No Side Effects
Vaginal Ring – Hormonal A flexible ring placed inside the vagina near the cervix. Active for 3 weeks. Has actions similar to oral contraceptives. 9% Blood clots, liver or gallbladder problems, TSS, depressed mood, acne, headache, weight gain, nausea/vomiting, movement of the ring
Withdrawal Withdrawal of the penis before ejaculation 22% No Side Effects

Last updated: February 28, 2018 at 18:00 pm


1. Centers for Disease Control:  Reproductive Health.

https://www.cdc.gov/reproductivehealth/contraception/index.htm

2. Centers for Disease Control:  Reproductive Health “Implants.”

https://www.cdc.gov/reproductivehealth/contraception/mmwr/spr/implants.html

3. Mayo Clinic: Depo-Provera (contraceptive injection).

https://www.mayoclinic.org/tests-procedures/depo-provera/about/pac-20392204

4. Nexplanon: Side Effects.

https://www.nexplanon.com/side-effects/

5. Nuva Ring: Risks and Side Effects.

https://www.nuvaring.com/risks-side-effects/

6. University of Pittsburgh Medical Center (UPMC): Tubal Ligation (Tubes Tied).

http://www.upmc.com/patients-visitors/education/contraception/Pages/tubal-ligation.aspx