Contraception is a term used to describe the methods people use to prevent pregnancy. There are a number of widely used contraception methods, also known as birth control. Some are designed for use by a man, such as the male condom, but most contraception methods are created for use by women. According to the Food and Drug Administration (FDA), 62 percent of women aged 15 to 44 use some form of contraception.
Contraceptive methods prevent pregnancy by keeping the sperm from meeting the egg or preventing a fertilized egg from implanting itself in the uterus and developing. To accomplish these goals, the methods either:
Inhibit the development and release of the egg
Create a physical or chemical barrier between sperm and the egg
Alter the ability of the fertilized egg to implant itself and develop
Most contraceptives are used during sexual intercourse. However, emergency contraceptives (e.g., the morning after pill) may be used to prevent pregnancy after intercourse when other contraceptive methods have failed or no contraception was used at all.
Most contraceptive methods are reversible, but some are considered permanent. Reversible contraceptive methods are techniques that do not permanently alter a woman’s ability to become pregnant. For men, reversible contraception does not permanently alter their ability to impregnate a woman. Fertility typically returns shortly after temporary methods are discontinued. The amount of time, however, varies from method to method and among women.
With the exception of continuous abstinence (not having sexual intercourse at all), no method of contraception is 100 percent effective. All methods can fail, resulting in an unplanned pregnancy. This risk can be greatly decreased by using the method correctly and using it with every act of intercourse.
In addition, most forms of birth control do not offer protection against human immunodeficiency virus (HIV) or other sexually transmitted diseases (STDs), including chlamydia, gonorrhea and genital herpes. Continuous abstinence offers the best protection against STDs. The next best option is the male latex condom. To prevent the transmission of these diseases, a male latex condom should always be used in combination with other forms of birth control (except female condoms).
Researchers are working to develop contraceptive methods that are both spermicidal and microbicidal (killing bacteria). This combination would prevent both pregnancy and the transmission of STDs. Additional research is focused on minimizing the side effects of contraceptives.
The U.S. Centers for Disease Control and Prevention (CDC) estimates that more than 98 percent of women between the ages of 15 and 44 who have ever had intercourse have used at least one contraceptive method. According to a CDC survey conducted in 2002, birth control pills are the most commonly used method among women in the United States (11.6 million women). The pill is followed by female sterilization (10.3 million women) and the male condom (9 million women).
What are barrier methods of birth control?
Barrier contraceptive methods provide a physical or chemical barrier between sperm and the egg. They do not have a long-lasting or permanent effect on fertility. For maximum effectiveness, these methods should be used with every sexual encounter. Examples include:
A sheath, or cover, placed over an erect penis before intercourse. Designed for one-time use, a condom prevents pregnancy by blocking the passage of sperm into the vagina. The condom, which collects the semen, is removed from the penis after intercourse. Available without a prescription, male condoms can be made of latex rubber, polyurethane (a type of plastic) or lamb intestines (natural or lambskin condom). Using condoms with a lubricant will reduce the chance of breakage and subsequent leakage of sperm. Aside from abstinence (refraining from sexual intercourse), male condoms are the most effective contraceptive method of preventing sexually transmitted diseases. They can be used with all other forms of contraception, except for female condoms because breakage may occur. The U.S. Food and Drug Administration (FDA) estimates that the failure rate for this method is 11 percent.
Shaped similarly to the male condom, the female condom is a polyurethane sheath with an open and closed end. Before intercourse, the closed end is inserted into the vagina and the open end remains outside the body partially covering the labia. It is available without a prescription and is intended for one-time use. The female condom should never be used in combination with the male condom because breakage may occur. According to the FDA, the failure rate for this method is 21 percent.
A reusable dome-shaped rubber disk that covers the cervix to prevent sperm from reaching the uterus and fertilizing the egg. When used correctly, spermicide is placed in the device and around its edges. A diaphragm is available only with a prescription and women must be fitted for the device by a healthcare professional. A diaphragm may be used for multiple acts of intercourse, but additional spermicide must be added before each act. In addition, it must be left in place for at least six hours after the last act of intercourse. To prevent complications, the device should not remain in the body for longer than a total of 24 hours. The FDA estimates that the failure rate for this method is 17 percent when used with spermicide.
Like the diaphragm, a cervical cap is a reusable thimble-shaped latex cup used to cover the cervix and prevent sperm from reaching the uterus and fertilizing the egg. It should be used in combination with spermicide. It is available only by prescription and requires fitting by a healthcare professional. It may be used for multiple acts of intercourse, but it should not remain in the body for longer than a total of 48 hours. When used in combination with spermicide, the FDA estimates that the failure rate for this method is 17 to 23 percent, depending on the brand.
Cervical shield (Lea’s shield)
A reusable cup-shaped device with a valve and a loop. Made of silicone, it is used to cover the cervix and prevent sperm from entering the uterus. It is held in place by pelvic muscles and the vaginal wall. It should be used in combination with spermicide, and may be inserted up to eight hours before intercourse. It may be used for multiple acts of intercourse, but it should not remain in the body for longer than a total of 48 hours. Cervical shields come in one size and they are available only by prescription. The FDA estimates that the failure rate for this method is 15 percent.
A disk-shaped device made of soft polyurethane. It contains spermicide and has a woven polyester loop attached to it for easy removal. It is placed in the vagina and used to cover the cervix. It may be used for multiple acts of intercourse. However, it must remain in the body for at least six hours after the last act of intercourse. It should not sit in the body for longer than a total of 30 hours. The sponge was removed from the marketplace in the United States in 1995, but has recently been re-approved for sale. They are available without prescription in most pharmacies or drug stores. The FDA estimates that the failure rate for this method is 14 to 28 percent.
A chemical designed to destroy sperm when placed in the vagina. It is available in the form of a foam, cream, jelly, film, suppository or tablet. It may be used alone or in combination with other forms of contraception. The tablet, film and suppository forms must be inserted at least 15 minutes before intercourse. Typically, each dose is effective for one hour. For multiple acts of intercourse, additional spermicide must be used. Following intercourse, the spermicide must remain in the body for six to eight hours, therefore, women should not douche during this time. Spermicides are widely available without a prescription. According to the FDA, the failure rate of this method is between 20 and 50 percent.
Copper-containing intrauterine devices (ParaGard T 380A)
Also known as an IUD, this small T-shaped device is inserted into a woman’s uterus by a healthcare professional, typically an obstetrician-gynecologist (ObGyn). It prevents pregnancy by stopping sperm and the egg from joining on their way to the fallopian tubes, or by altering the endometrium to prevent the fertilized egg from implanting. It can remain in place for up to 10 years, but requires monitoring by a healthcare professional. In some cases, an IUD may be placed in the uterus within seven days of unprotected sex as a form of emergency contraception. The FDA estimates that the failure rate for this method is less than 1 percent.
Hormonal methods of contraception
Hormonal methods of contraception use hormones to prevent ovulation (the monthly release of an egg from the ovaries). They also work to thicken the mucus in the cervix, preventing sperm from traveling to the uterus. They are very effective in preventing pregnancy when used regularly. Examples include:
Combined birth control pills
Also known as combined oral contraceptives, these drugs use synthetic hormones (estrogen and progestin) to prevent ovulation. One pill must be taken at the same time every day for 21, 28 or 91-day cycles. They are available only by prescription and are manufactured under several different brands. The U.S. Food and Drug Administration (FDA) estimates that the failure rate for this method is 1 to 2 percent.
Also known as progestin-only pills (POPs), this type of birth control pill contains only the hormone progestin. These pills prevent pregnancy by thickening the mucus in the cervix and preventing sperm from reaching the egg. They also prevent the endometrium (the lining of the uterus) from thickening, which makes it difficult for a fertilized egg to implant itself in the uterus. One pill must be taken at the same time every day for 28 days. They are available only by prescription. According to the FDA, the failure rate for this method is 2 percent.
Contraceptive patch (Ortho Evra)
A skin patch that releases progestin and estrogen into the bloodstream to prevent ovulation and to thicken the mucus in the cervix. It is worn on the abdomen, buttocks or upper torso or upper outer arm. A new patch is applied once a week for three weeks. During the fourth week (the week of menstruation), no patch is worn. It is available only by prescription. The FDA estimates that the failure rate for this method is 1 to 2 percent.
Contraceptive ring (NuvaRing)
Inserted high into the vagina, this flexible ring releases progestin and estrogen to prevent ovulation and thicken the mucus in the cervix to keep sperm from reaching the egg. Measuring approximately 2 inches (5 centimeters) in diameter, the ring is worn for three weeks and removed for the week the woman is menstruating. After menstruation, a new ring is inserted. It is available only by prescription. The FDA estimates that the failure rate for this method is 1 to 2 percent.
Contraceptive injections (Depo-Provera)
An injection of the hormone progestin. It prevents pregnancy by preventing ovulation, thickening the cervical mucus to keep sperm from reaching the egg and preventing the fertilized egg from implanting itself in the uterus by thickening the endometrium. It is injected into the woman’s buttocks or arm muscle by a health professional. An injection is required once every three months. According to the FDA, the failure rate for this method is less than 1 percent.
Hormone-releasing intrauterine devices (IUD)
Small T-shaped devices inserted into a woman’s uterus by a healthcare professional. They prevent pregnancy by stopping sperm and the egg from joining on their way to the fallopian tubes, or by altering the endometrium so the fertilized egg cannot become implanted. A levonorgestrel (a progestin) releasing version (Mirena), which must be replaced every five years, is available. According to the FDA, the failure rate for this method is less than 1 percent.
Morning after pill
Also known as the emergency contraceptive pills or post-coital contraceptives, this drug is used to prevent pregnancy after intercourse when other contraceptive methods failed or no contraception was used. The product contains the same type of hormones as oral contraceptives but is a high-dose combination of progestin and estrogen or progestin alone. It prevents pregnancy by delaying or preventing ovulation, or by preventing a fertilized egg from implanting itself in the wall of the uterus. For maximum effectiveness, the first dose should be taken no more than 72 hours after intercourse. The second dose must be taken within 12 hours of the first. The FDA approved the sale of the emergency contraceptive drug levonorgestrel (Plan B) without prescription for women aged 18 and older in August 2006. The morning after pill should not be confused with the abortion pill (RU486), which can terminate a pregnancy up to nine weeks after conception.
Estrogen-progestin injections (Lunelle)
This form of contraception uses synthetic hormones to prevent the ovaries from releasing eggs and to keep sperm from reaching the egg. The injection is given by a healthcare provider on a monthly basis in the arm, buttocks or thigh. The FDA reports a failure rate of less than 1 percent when Lunelle is used correctly.
This method uses capsules surgically implanted by a physician under the skin of the upper arm, where it gradually releases hormones to prevent pregnancy for years. An earlier type of implant called Norplant was removed from the U.S. market in 2002. Another implant, called Implanon, was approved in 2006.
Researchers are currently investigating male hormonal contraception. This form of contraception works by preventing the production of sperm. While it is not available yet, the results in early animal studies are promising.
Other methods of contraception
A wide variety of other techniques may also be used to prevent pregnancy. These include:
Also known as behavioral methods, these methods do not require use of prescription or over-the-counter hormones or devices. The effectiveness of these methods is quite low. Examples include:
Natural family planning. Also known as the rhythm method, fertility awareness or periodic abstinence, this method requires a woman to abstain from sexual intercourse or use a barrier method of contraception (e.g., male or female condom, diaphragm) on the days when she is most likely to become pregnant. The menstrual cycle, changes in cervical mucus and changes in body temperature are used to approximate the days the woman is fertile. This method requires long-term monitoring of the menstrual cycle and daily monitoring of temperature and body changes (e.g., cramps, sore breasts). Over-the-counter ovulation indicator testing kits are also available. These kits determine when a woman is most likely to ovulate by measuring the amount of luteinizing hormone (LH) in a woman’s urine. The U.S. Food and Drug Administration (FDA) estimates the failure rate for this method to be 20 percent or higher.
Lactational amenorrhea. This method is based on the idea that women may not ovulate when they are breastfeeding for up to six months after childbirth. It requires that a woman does not substitute any other food for breast milk, suckles the baby on demand and at least six times a day on both breasts.
Withdrawal. Also known as coitus interruptus, this method requires the man to remove his penis from his partner’s vagina before ejaculation. However, sperm are found in pre-ejaculate fluid, so pregnancy can occur without a man ejaculating. This method requires that a man recognize when he is going to ejaculate and have sufficient control to withdraw beforehand. According to the FDA, the failure rate for this method is between 4 and 19 percent.
These contraceptive options prevent pregnancy by surgically altering or blocking the reproductive organs to prevent sperm and eggs from meeting. They are considered permanent because reversal requires major surgery that is frequently unsuccessful.
Tubal ligation. Surgically cutting or blocking the fallopian tubes to prevent the egg from traveling to the uterus. It is also known as a female sterilization. According to the FDA, the failure rate for this method is less than 1 percent.
Vasectomy. Also known as a male sterilization, this procedure surgically seals, ties or cuts a man’s vas deferens to prevent sperm from traveling from the testicles to the penis. According to the FDA, the failure rate for this method is less than 1 percent.
Sterilization implant (Essure). A tiny, spring-like device is thread through the vagina and uterus and into each fallopian tube. The device is temporarily anchored inside the fallopian tube with flexible coils. A mesh material embedded in the coils is used to irritate the lining of the fallopian tube, causing scar tissue to grow. As a result, the fallopian tubes become permanently plugged. This is also known as nonsurgical sterilization or a selective tubal occlusion procedure (STOP). According to the FDA, the failure rate for this method is less than 1 percent.
Not having sexual intercourse at any time. This is the only method of contraception that is 100 percent effective.
In addition to these standard methods of birth control, there are other natural methods that are sometimes used, including vaginal douching after intercourse and urinating after intercourse. These methods, however, are not recommended because they have no contraceptive effect. Sperm can reach the cervix and uterus minutes after ejaculation.
Choosing a method of contraception
There are numerous methods of contraception available. To choose the best method, a person should consider a variety of factors, including:
Overall health. Some methods of contraception are not recommended for women with certain health conditions (e.g., risk for certain cancers). Women and their physician need to consider each method in regards to the patient's well-being.
Frequency of sexual activity and need for birth control.
Number of sexual partners. Having multiple partners increases the risk of contracting a sexually transmitted disease (STD). Certain forms of contraception are best used with individuals who are in a long-term, committed relationship.
Desire to have children in the future. Permanent methods of contraception are not recommended for people who may choose to have children in the future. These methods are difficult to reverse. Also, some forms of birth control may delay ovulation for a longer period of time than others after women stop using it. Women should consider when they plan on becoming pregnant in choosing the type of contraception.
Effectiveness of each method in preventing pregnancy. The U.S. Food and Drug Administration (FDA) rates the effectiveness of each method. However, the FDA estimates the effectiveness of the natural methods (e.g., rhythm method) based on reports in literature and not actual reported usage. The effectiveness based on typical use may therefore be lower.
Potential risks and side effects. Different forms of contraception have different risks and side effects, such as increasing the risk of blood clots.
Comfort level with using the method. Being uncomfortable with using a method may result in improper use or lack of use.
Other factors to consider include the cost, convenience and availability of the methods. In addition, some women have cultural, religious and social considerations that affect their choice of contraception or may not feel confident that they can maintain the strict regimens that some forms of contraception (e.g., daily contraceptive pills, rhythm method) may require. Women are encouraged to discuss all of their options with their obstetrician-gynecologist (ObGyn).
Questions for your doctor on contraception
Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about contraceptives:
Based on my lifestyle and health, which method might be best for me?
Which form of hormone-based birth control is the most effective?
Which birth control method that does not use hormones is most effective?
Do I have any conditions that prevent me from using hormone-based birth control?
Am I a candidate for an intrauterine device (IUD)?
Which form of birth control has the greatest risk for serious medical conditions?
How does the pill affect my fertility?
When should I stop using the pill If I want to become pregnant?
Can an IUD create problems for becoming pregnant?
What should I do if I failed to use birth control during intercourse?
How can I obtain the morning after pill?
What can be done if I decide I want to become pregnant after surgical sterilization?
Which method should I use if I am breastfeeding?
Can you provide information about natural family planning?
Can you refer me to community resources for contraception assistance?