Contraceptive Failure Rate: Causes, Chart and more

Birth Control Failure Rates

The various birth control methods may not offer 100% protection against pregnancy. There have been cases where contraceptive methods failed to prevent a pregnancy. The ability of any contraceptive method to avert a pregnancy usually depends on its effectiveness. The effectiveness rate of contraceptive methods chiefly rests on its consistency, and correct usage.

Only a few birth control methods like vasectomy, tubal ligation, Nexplanon (contraceptive implant), IUD (intrauterine contraceptive device) can guarantee consistency and accurate usage when correctly placed while the effectiveness of other contraceptive methods like the pill, contraceptive shots, the patch may get comprised mainly because of incorrect and inconsistent usage.

What are the Reasons Behind Birth Control Failure?

An upset woman with a pregnancy test stick

Some of the reasons behind birth control failure can be:

  • The main reason behind birth control failure can be the inability to follow the instructions correctly. It is important to read the product instructions carefully and then use the product as directed. For example, while using the male condom one must ensure that the condom fits correctly and also take particular care while removing it. Any lapse in this respect can adversely affect the effectiveness of the condom to stop a pregnancy.
  • Another reason behind birth control failure can be inconsistency in usage. For example, while using birth control pills if you skip or forget to take a pill as required you will simply increase your chances of an unexpected pregnancy. Therefore, it is vital that you devise a fail-proof method for taking your birth control pills consistently without fail.
  • Apart from human error, some medications like some antidepressants, diabetes drugs and antibiotics can reduce the effectiveness of the birth control methods.
  • In some cases, taking supplements or certain natural herbs can also interfere with the effectiveness of contraceptive methods.
  • Hormonal birth control means may not function efficiently in case a woman is obese or overweight.

Birth Control/ Contraceptive Failure Chart

The birth control failure chart includes the actual use of the methods. Right and consistent use of birth control methods is likely to reduce the contraceptive failure rate.

In case of hormone-based birth control, it is imperative to take note of its higher success rate along with the ethical concerns that may arise due to its effect on the uterus’s lining to prevent implantation. Since taking hormonal birth control can avert a previously begun pregnancy, this implies that it has abortifacient qualities.

Here is a contraceptive failure chart explaining the working of different birth control methods and their associated side effects and risks:

Method Usage Failure Rate

(actual use)

Condom (male) A latex rubber sheath put on over an erect penis to block the sperm’s channel 18% No side effects

(except if allergic)

Condom (female) A latex rubber sheath placed in the vagina to block the sperm’s passage 21% No side effects

(except if allergic)

Cervical Cap A barrier made of soft rubber that protects the cervix by preventing sperm from getting into the uterus 12%

(more after childbirth)

No side effects

(except if allergic)

Depo-Provera contraceptive injection A shot of hormone progestin administered once in 3 months averts pregnancy by preventing ovulation and thickening the cervical mucus 6% Breast tenderness, headaches, abdominal pain, weight gain, irregular or heavier menstrual cycle, allergic reaction
IUD (Intrauterine Device)- Copper IUDs and Hormonal IUDs The IUD is a T-shaped device inserted into the uterus to alter the movement of sperm cells and to prevent them from fertilizing an egg 0.2% – 0.8% Heavier bleeding during menstruation, severe cramping, ectopic pregnancy, PID (Pelvic Inflammatory Disease)
Diaphragm A dome-shaped barrier used to cover the cervix to hinder the sperm’s passage 12% No side effects

(except if allergic)


Implant – Hormonal


A thin, tiny rod about a matchstick’s size is implanted in the arm which releases hormones to prevent pregnancy 0.05% Painful menstruation, depression, weight gain, ectopic pregnancy, blood clots, ovarian cysts
Fertility Awareness Keeping track of the menstrual cycle and predicting ovulation and observing abstinence from intercourse during the fertile period 25% No side effects
Oral Contraceptive Oral contraceptive may have a blend of hormones progestin and estrogen or progestin alone which inhibits ovulation and prevents pregnancy 9% Headaches, irregular bleeding, weight gain, nausea, blood clots, breast tenderness
Spermicide (only) Spermicide contains chemicals that prevent sperm from fertilizing an egg when put in the vagina before sex 28% No side effects

(except if allergic)

Ortho-Evra Patch This contraceptive patch is a transdermal patch which sticks to the skin and releases hormones estrogen and progestin to prevent pregnancy 9% (higher if above 198 lbs) Nausea, mood swings, skin irritation, irregular bleeding, menstrual cramps, breast tenderness
Sponge Contraceptive sponge uses spermicidal and barrier methods to prevent pregnancy 20% (about 40% after childbirth) No side effects

(except if allergic)

Vaginal Ring- Hormonal A small flexible ring which is placed in the vagina once a month to prevent conception 9% Mood swings, acne, blood clots, weight gain, gallbladder or liver problems, nausea, TSS
Withdrawal Pull-out method where a man withdraws his penis before ejaculation during sexual intercourse 22% No side effects

What to Do If Your Contraceptive Fails?

You may like to keep the following things in mind if your contraceptive fails:

  • In case your contraceptive fails you can reduce the risk of an accidental pregnancy by taking emergency contraception pill which is easily available over-the-counter at most drugstores.
  • If you are sexually active and missed your period take a home pregnancy test immediately to ascertain any likely
  • Contact your doctor if the results are positive.

You can lower the failure rate of contraceptive methods by making sure that you use them consistently and correctly. In the instance of birth control failure, it is advisable to act immediately to deal with an unplanned pregnancy.

Also Read: Risks of taking Birth Control Pills

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