1. Contraception
Source
WebMD.com

2. Least Effective Methods
Without using any form of birth control, 85% of sexually active couples will get pregnant within a year. Even the least effective birth control options reduce that number considerably.

3. Abstinence Birth Control: How to Decide
With so many options, choosing a form of birth control can be daunting. Begin with a few questions: Do you need to protect against STDs? How important are convenience and cost? What about effectiveness? Only abstinence is 100% effective, but other methods come close -- as our effectiveness chart shows in a glance. Review this slideshow, then ask your doctor which options are best for you.

4. Rhythm Method Fertility Awareness
Also called natural family planning, fertility awareness means avoiding sex when the woman is most fertile. The most reliable way to do this is to watch for changes in cervical mucus and body temperature. To use this method correctly, it’s best to get training from a health care professional.
Pros: No drugs or devices, inexpensive. Cons: Limits spontaneous sex, 25% of typical users get pregnant.

5. Spermicide Spermicide
Spermicide contains a chemical that kills sperm. It comes in the form of foam, jelly, cream, or film that is placed inside the vagina before sex. Some types must be put in place 30 minutes ahead of time. Frequent use may cause tissue irritation, increasing the risk of infections and STDs. Spermicides are most often used along with other birth control methods.
Pros: Easy to use, inexpensive ($1 per use). Cons: May increase the risk of STDs, 29% get pregnant.

6. Male Condom Male Condom
The latex condom is the classic barrier method. It prevents sperm from entering the woman’s body, protecting against pregnancy and STDs. Of couples who rely only on male condoms, 15% get pregnant in a year.
Pros: Widely available, protects against STDs, inexpensive (under $1 each). Cons: Only effective if used correctly every time. Can’t be reused.

7. Female Condom Female Condom
The female condom is a thin plastic pouch that lines the vagina and can be put in place up to 8 hours before sex. Users grasp a flexible, plastic ring at the closed end to guide it into position. It's somewhat less effective than the male condom.
Pros: Widely available, some protection against STDs, conducts body heat better than a male condom. Cons: Can be noisy, 21% of users get pregnant, not reusable. Should not be used with a male condom, to avoid breakage.

8. Diaphragm
Diaphragm
The diaphragm is a rubber dome that is placed over the cervix before sex. It is used with a spermicide. Effectiveness compares to the male condom – 16% of average users get pregnant, including those who don’t use the device correctly every time. Pros: Inexpensive (a $15-$75 device lasts two years.) Cons: Must be fitted by a doctor, no STD protection. Can’t be used during your period due to a risk of toxic shock syndrome.

9. Cervical Cap Cervical Cap
A cervical cap is similar to a diaphragm, but smaller. The FemCap slips into place over the cervix, blocking entry into the uterus. It is used with spermicide. The failure rate for the cervical cap is 15% for women who have never had children and 30% for those who have.
Pros: Can stay in place for 48 hours, inexpensive. Cons: Must be fitted by a doctor, no protection against STDs. Can’t be used during your period.

10. Birth Control Sponge Birth Control Sponge
The birth control sponge, sold as the Today Sponge, is made of foam and contains spermicide. It is placed against the cervix up to 24 hours before sex. The sponge is about as effective as the cervical cap, with a failure rate of 16% for women who have never had children and 32% for those who have. But unlike the diaphragm or cervical cap, no fitting by a doctor is required.
Pros: No prescription, effective immediately. Cons: Difficult to insert correctly, no STD protection. Can't be used during your period.

11. Birth Control Pill Birth Control Pill
The most common type of birth control pill uses the hormones estrogen and progestin to prevent ovulation. When taken on schedule, the pill is highly effective. About 8% of typical users get pregnant, including those who miss doses. Like all hormonal contraceptives, the pill requires a prescription.
Pros: More regular, lighter periods, or no periods, depending on the type of pill. Less cramping. Cons: Cost ($15-$50 per month), no STD protection. May cause side effects, including breast tenderness, spotting, serious blood clots, and raised blood pressure. Some women should not use birth control pills.

12. Birth Control Patch Birth Control Patch
Women who have trouble remembering a daily pill may want to consider the birth control patch. The Ortho Evra patch is worn on the skin and changed only once a week for three weeks with a fourth week that is patch-free. The patch releases the same types of hormones as the birth control pill and is just as effective.
Pros: More regular, lighter periods with less cramping, no need to remember a daily pill. Cons: Cost ($15-$50 per month), may cause skin irritation or other side effects similar to birth control pills. Doesn’t protect against STDs.

13. Vaginal Ring Vaginal Ring
The NuvaRing is a soft plastic ring that is worn inside the vagina. The ring releases the same hormones as the pill and patch and is just as effective. But it only needs to be replaced once a month.
Pros: Lighter, more regular periods, only replaced once per month. Cons: Cost ($30-$50 per month), may cause vaginal irritation or other side effects similar to pills and the patch. Doesn’t protect against STDs.

14. Birth Control Shot Birth Control Shot
The birth control shot, known as Depo-Provera, is a hormonal injection that protects against pregnancy for three months. For the typical couple, it is more effective than the birth control pill -- only 3% of users get pregnant in a year.
Pros: Only injected four times per year, highly effective. Cons: Cost (about $240 per year), may cause spotting and other side effects. Doesn’t protect against STDs.

15. Birth Control Implant Birth Control Implant
The birth control implant (Implanon) is a matchstick-sized rod that is placed under the skin of the upper arm. It releases the same hormone that's in the birth control shot, but the implant protects against pregnancy for 3 years. The failure rate is less than 1%.
Pros: Lasts three years, highly effective. Cons: More expensive upfront ($400-$800 for exam, implant, and insertion), may cause side effects, including irregular bleeding. Doesn't protect against STDs.

16. IUD
IUD
IUD stands for intrauterine device, a T-shaped piece of plastic that is placed inside the uterus by a doctor. The copper IUD, ParaGard, works for as long as 12 years. The hormonal IUD, Mirena, must be replaced after 5 years. Both types make it more difficult for sperm to fertilize the egg. Fewer than eight in 1,000 women get pregnant.
Pros: Long-lasting, low-maintenance. Cons: Irregular or heavier periods. More expensive upfront, may slip out, may cause side effects.

17. Tubal Ligation Tubal Ligation
If you're sure you won't want biological children in the future, you may be ready for permanent birth control. The traditional method for women is called tubal ligation or "having your tubes tied." A surgeon closes off the fallopian tubes, preventing eggs from making their journey out of the ovaries. (The banding method is shown here.)
Pros: Permanent, nearly 100% effective. Cons: Requires surgery, may not be reversible, expensive. Doesn't protect against STDs.

18. Vasectomy
Vasectomy
Besides condoms, a vasectomy is the only birth control option available to men. It involves surgically closing the vas deferens – the tubes that carry sperm from the testes, through the reproductive system. This prevents the release of sperm but doesn’t interfere with ejaculation.
Pros: Permanent, cheaper than tubal ligation, almost 100% effective. Cons: Requires surgery, not effective immediately, may not be reversible.

19. Emergency Contraception
Emergency contraception works after sex to help avoid pregnancy. This is an option if no birth control was used or if a woman suspects her usual method failed. Plan B, Plan B One-Step, and a generic version of Plan B called Next Choice all contain a high dose of a hormone found in many birth control pills. No prescription is needed for women aged 17 and older. These types must be used within 72 hours. Ella uses a non-hormonal drug and requires a doctor's prescription. It can be taken up to five days after sex.

20. Withdrawal Withdrawal
Nearly six in 10 American women report that a partner has used "pulling out," the age-old method that relies on the man withdrawing his penis from the vagina before ejaculation. Newer reviews show that when it's done correctly every time, about 4% of users get pregnant in a year. With more typical use, about 18% get pregnant.
Pros: Free, no need for devices or hormones. Cons: May be hard to do correctly. No protection against STDs.

21. Most Effective Methods
Although barrier methods, such as the condom or diaphragm, are moderately effective with typical patterns of use, hormonal contraceptives have a better track record for effectiveness. There are also several options for couples that prefer the lowest possible odds of getting pregnant. Two of these are reversible -- the IUD and hormonal implant. Of course, the only birth control method that is 100% effective is abstinence.