Contraception

Malaysian poster explaining the use of the pill. Source: World Health Organization (WHO), National Library of Medicine.

Contraception is the use of a method or a product to prevent pregnancy. There are many different types of contraception. Some are permanent, while others are temporary. Contraceptives exist as devices, hormones that may be taken orally or delivered by the skin or mucus membranes, permanent surgical procedures, or barrier methods. Contraception may also involve using an understanding of the timing of conception to avoid pregnancy.

Other Names

• Birth Control

Why Contraception Is Used

Contraception is used to prevent unintended pregnancy. According to the Centers for Disease Control and Prevention (CDC), ^[1] almost half of all pregnancies in the United States are unintentional. ^[2] More than 98% of sexually active women in the United States have used at least one form of contraception. ^[3] Contraception is not as readily available in many other countries. Although contraceptive use has steadily increased throughout the world, access to contraceptives is still not universal and unplanned pregnancies continue to occur. ^[4]

Types

Contraception can be placed into several categories.

• Barrier methods
• Hormonal Contraception
• Intrauterine Devices
• Permanent Sterilization
• Natural family planning
• Emergency Contraception

Barrier methods

Photograph showing rolled up condom. Source: Wikimedia Commons.

Male condom

Condoms are called barrier methods of birth control because they put up a block, or barrier, which keeps the sperm from reaching the egg. Only latex or polyurethane (because some people are allergic to latex) condoms are proven to help protect against STDs, including HIV. "Natural” or “lambskin” condoms made from animal products also are available, but lambskin condoms are not recommended for STD prevention because they have tiny pores that may allow for the passage of viruses like HIV, hepatitis B and herpes. Male condoms are 84 to 98% effective at preventing pregnancy. Condoms can only be used once. They can be purchased at a drug store.

Female condom

Worn by the woman, this barrier method keeps sperm from getting into the female body. It is made of polyurethane, is packaged with a lubricant, and may protect against STDs, including HIV. It can be inserted up to 24 hours prior to sexual intercourse. Female condoms are 79 to 95% effective at preventing pregnancy. There is only one kind of female condom, called Reality which can be purchased at a drug store.

Diaphragm, cervical cap or cervical shield

These are barrier methods of birth control, where the sperm are blocked from entering the cervix and reaching the egg.

• The diaphragm is shaped like a shallow latex cup.
• The cervical cap is a thimble-shaped latex cup.
• The cervical shield is a silicone cup that has a one-way valve that creates suction and helps it fit against the cervix.

The diaphragm and cervical cap come in different sizes and require a doctor to “fit” them. The cervical shield comes in one size and does not require a fitting. These products should be used in conjunction with spermicide (to block or kill sperm) and placed inside the vagina to cover the cervix (the opening to the uterus, or womb). Spermicide gel or foam is available over the counter at most drug stores. Some women can be sensitive to an ingredient called nonoxynol-9 and will need to carefully read the label.

The diaphragm is 84 to 94% effective at preventing pregnancy.

The cervical cap is 84 to 91% effective at preventing pregnancy for women who have not had a child and 68 to 74% for women who have had a child.

The cervical shield is 85% effective at preventing pregnancy.

Barrier methods must be left in place for 6 to 8 hours after intercourse to prevent pregnancy and removed by 24 hours for the diaphragm and 48 for cap and shield. A visit to the doctor is required for a proper fitting for the diaphragm or cervical cap and for a prescription for the cervical shield.

Contraceptive sponge

This is a barrier method of birth control that was re-approved by the Food and Drug Administration in 2005. It is a soft, disk shaped device, with a loop for removal. It is made out of polyurethane foam and contains the spermicide nonoxynol-9.

Before intercourse, the sponge is placed, loop side down, inside the vagina to cover the cervix. The sponge is 84 to 91% effective at preventing pregnancy in women who have not had a child and 68 to 80% for women who have had a child. The sponge is effective for more than one act of intercourse for up 24 hours. It needs to be left in for at least six hours after intercourse to prevent pregnancy and must be removed within 30 hours after it is inserted.

There is a risk of getting Toxic Shock syndrome or TSS if the sponge is left in for more than 30 hours. The sponge does not protect against STDs or HIV. There is only one kind of contraceptive sponge for sale in the United States, called the Today Sponge, and it can be purchased at a drug store. Women who are sensitive to the spermicide nonoxynol-9 should not use this birth control method.

Spermicides

Spermicides (literally "sperm killers") work by killing sperm and come in several forms – foam, gel, cream, film, suppository, or tablet. They are inserted or placed in the vagina no more than one hour before intercourse. If a contraceptive film, suppository, or tablet is used, at least 15 minutes should be allowed to pass before intercourse so the spermicide can dissolve. Douching or rinsing of the vagina should be avoided for at least six to eight hours after intercourse. More spermicide should be inserted before each act of intercourse.

More protection against pregnancy will result if spermicide is used in combination with a male condom, diaphragm, or cervical cap. There are spermicidal products made specifically for use with the diaphragm and cervical cap.

All spermicides have sperm-killing chemicals in them. Some spermicides also have an ingredient called nonoxynol-9 that may increase the risk of HIV infection when used frequently because it irritates the tissue in the vagina and anus which can cause the virus to enter the body more freely. Some women are sensitive to nonoxynol-9 and need to use spermicides without it.

Spermicides alone are about 74% effective at preventing pregnancy. Medications for vaginal yeast infections may decrease effectiveness of spermicides.

Hormonal contraception

Photograph of a half-used blister pack of Levlen®ED oral contraceptive pill. Source: Wikimedia Commons.

Combination pill

Also called “the pill,” this type of birth control contains the hormones estrogen and progestin and is available in different hormone dosages. The pill is taken daily to block the release of eggs from the ovaries and prevent pregnancy. Oral contraceptives can also lessen menstrual flow and can reduce the risk of pelvic inflammatory disease (PID), ovarian cancer, benign ovarian cysts, endometrial cancer, and iron deficiency anemia. It does not protect against STDs or HIV.

The pill may add to the risk of heart disease, including high blood pressure, blood clots, and blockage of the arteries, especially in smokers. Women who are over the age of 35 and smoke, or have a history of blood clots or breast, liver, or endometrial cancer may not be good candidates for this type of birth control. The pill is 95 to 99.9% effective at preventing pregnancy. Some antibiotics may reduce the effectiveness of the pill in some women and a back-up method of birth control may be prescribed in addition to antibiotics.

Most oral contraceptives are swallowed in a pill form. One brand, called Femcon, can either be swallowed or chewed.

Extended cycle pills

There are also extended cycle pills, brand name Seasonique, which have 12 weeks of pills that contain hormones (active) and 1 week of pills contain a low dose of estrogen. The week of low level estrogen is given to reduce problems with breakthrough bleeding. While taking Seasonique, women only have their period 4 times a year.

Progestin-only pill (mini-pill)

Unlike the regular combination pill, the mini-pill only has one hormone, progestin, instead of both estrogen and progestin. Taken daily, the mini-pill thickens cervical mucus to prevent sperm from reaching the egg. It also prevents a fertilized egg from implanting in the uterus (womb). The mini-pill also can decrease the menstrual flow. It does not protect against PID and ovarian and endometrial cancer.

Mothers who breastfeed can use the minipill as it is not believed to affect the milk supply.

Mini-pills are 92 to 99.9% effective at preventing pregnancy if used correctly. The mini-pill needs to be taken at the same time each day. A back-up method of birth control is needed if the pill is taken more than three hours late. Some antibiotics may reduce the effectiveness of the pill in some women.

Contraceptive patch

The contraceptive skin patch (called Ortho Evra) is worn on the lower abdomen, buttocks, or upper body. It releases the hormones progestin and estrogen into the bloodstream. A new patch is placed once a week for three weeks, and then not worn during the fourth week so that menses occur. The patch is 98 to 99% effective at preventing pregnancy, but appears to be less effective in women who weigh more than 198 pounds. It does not protect against STDs or HIV. ^[5]

Vaginal ring

Image of vaginal birth control device NuvaRing. Source: Wikimedia Commons.

The hormonal vaginal contraceptive ring (NuvaRing) is a thin, flexible ring that releases the hormones progestin and estrogen. It has become a very popular method of birth control since the woman only needs to think about birth control once per month.

The ring is inserted it into the vagina by the patient. The ring is worn for three weeks, and is then taken it out for the week of the woman's period. A new ring is then placed for the next month.

The ring is 98 to 99% effective at preventing pregnancy. It does not need to be removed during intercourse. It will not fall out. The vaginal muscles hold the ring in place like a tampon is held in place.

Injection (Depo-Provera)

Depo-Provera – With this method women get injections, or shots, of the hormone progestin in the buttocks or arm every 3 months. It does not protect against STDs or HIV.

Women should not use Depo-Provera for more than 2 years in a row because it can cause a temporary loss of bone density that increases the longer this method is used. The bone does start to grow after this method is stopped, but it may increase the risk of fracture and osteoporosis if used for a long time. It is 97% effective at preventing pregnancy. The shots are given in a clinic or doctor's office.

Hormonal contraceptive implant

The contraceptive implant, Implanon, is a small rod ( about the size of a matchstick), that is put under the skin on the inside of a woman's upper arm. It is made of soft, flexible plastic. The rod contains a hormone called a progestin, which is slowly released into the woman’s body in very small amounts.

The hormone works to prevent pregnancy in several ways. First, the progestin prevents an egg from being released from the ovary in some women. Second, the hormone thickens the cervical mucus in all women, making it difficult for sperm to enter the uterus.

The most common side effect is unexpected bleeding during the first 6 to 12 months. Some women have longer periods and some women have lighter and less frequent periods. After one year, about 1/3 of women who use the implant will have no period at all.

The implant is highly effective. When a woman has the implant removed her ability to become pregnant returns quickly. It is very convenient since there is nothing to remember, or buy, or clean. The implant has no serious or life-threatening side effects. It provides up to 3 years of birth control.

Intrauterine devices

The copper intrauterine device

An intrauterine device {IUD} is a small device that is shaped in the form of a “T.” A health care provider places it inside the uterus. The arms of the copper T IUD contain some copper, which stops fertilization by preventing sperm from making their way up through the uterus into the fallopian tubes. If fertilization does occur, the IUD would prevent the fertilized egg from implanting in the lining of the uterus. The copper T IUD can stay in the uterus for up to 12 years. It does not protect against STDs or HIV and is 99% effective at preventing pregnancy.

The intrauterine system

The Intrauterine System (IUS) is a small T-shaped device like the IUD and is placed inside the uterus by a doctor. Each day, it releases a small amount of a hormone similar to progesterone called levonorgestrel that causes the cervical mucus to thicken so sperm cannot reach the egg. The IUS stays in the uterus for up to five years. It does not protect against STDs or HIV. The IUS is 99% effective. The Food and Drug Administration approved this method in December 2000. It needs to be inserted in a doctor's office.

Side effects include irregular bleeding for the first 3 to 6 months of use, lower abdominal pain or cramping. Side effects occurring in fewer than 5% of women include acne or other skin problems, back pain, breast tenderness, headache, mood changes, and nausea.

Permanent sterilization

Postpartum tubal ligation

This procedure is done in the hospital after the delivery of a baby. A small cut is made in or near the belly button to reach the fallopian tubes. A part of each tube is cut and tied or stitched with special medical thread.

Laparoscopic tubal sterilization

This method uses bipolar coagulation, a carefully controlled electrical current to seal the tubes shut. The surgeon makes a tiny cut in the abdomen and then inserts the laparoscope to see the fallopian tubes. Another instrument is used to apply the electrical current to part of the fallopian tubes.

Another laparoscopic methods use an elastic band to close off the fallopian tubes. Using a laparoscope and a tiny incision, the surgeon inserts an applicator to stretch the ring, pick up a loop of the tube, and place the device over the loop. Spring clips can also be used instead of elastic bands.

Hysteroscopic sterilization (Essure)

In this type of sterilization, called Essure, tiny spiral coils are put in the tubes by way of the vagina and through the cervix (no cut is made in the abdomen). The coils create scar tissue and block the tubes. This type of sterilization is new in the United States.

Vasectomy

Vasectomy is a highly effective type of male birth control that is designed to be permanent. In a vasectomy, a small portion of the tubes that carry sperm (vas deferens) from the testicles is cut and sealed . This prevents pregnancy because sperm cannot get into the ejaculate (semen) of the man.

Vasectomy is safer, simpler, and less expensive than tubal sterilization for a woman. The procedure has never caused a death in the United States and has a less than 1% complication rate. The operation is most commonly done in a doctor’s office or clinic using local anesthetic (numbing medicine) and the man can go home afterwards. The time to recovery is usually a few days of rest before resuming normal activities.

Natural family planning

The Standard Days Method works for women who always have menstrual cycles between 26 and 32 days in length. Avoiding sexual intercourse on the days labeled 'fertile' results in a pregnancy rate of 5% per year. The method can also be used to achieve pregnancy - the woman has sexual intercourse on the days labeled 'fertile'. Source: Wikimedia Commons.

Continuous abstinence

This means not having sexual intercourse (vaginal, anal, or oral intercourse) at any time. It is the only sure way to prevent pregnancy and protect against HIV and other STDs. This method is 100% effective at preventing pregnancy and STDs.

Periodic abstinence or fertility awareness methods

A woman who has a regular menstrual cycle has about seven or more fertile days or days when she is able to get pregnant, each month. Periodic abstinence means not having sexual intercourse on the days that fertility is likely.

The fertile days are approximately 5 days before ovulation, the day of ovulation, and one or more days after ovulation. Fertility awareness means either being abstinent or using a barrier method of birth control to keep sperm from getting to the egg. Barrier methods include condoms, diaphragms, or cervical caps, used together with spermicides, which kill sperm. These methods are 75 to 99% effective at preventing pregnancy.

Practicing these methods requires learning about the menstrual cycle. This generally involves keeping a written record of when you the menstrual cycle starts, what it is like (heavy or light blood flow), and any symptoms (sore breasts, cramps). The character of the cervical mucus is noted and the basal body temperature are recorded daily. The changes in the above signs and symptoms can predict periods of fertility.

Emergency contraception

Emergency Contraception is not a regular method of birth control. Emergency contraception, or emergency birth control, is used to keep a woman from getting pregnant when she has had unprotected vaginal intercourse. Women over the age of 18 may buy emergency contraception called Plan B without a prescription.

Unprotected intercourse can mean that no method of birth control was used. It can also mean that a birth control method was used but did not work – like a condom breaking. Or, a woman may have forgotten to take her birth control pills, or may have been abused or forced to have sex when she did not want to.

Emergency contraception consists of taking two doses of hormonal pills taken 12 hours apart and started within 72 hours after having unprotected sex. These are sometimes wrongly called the morning after pill. The pills are 75 to 89% effective at preventing pregnancy.

Another type of emergency contraception is having the copper T IUD put into the uterus within seven days of unprotected sex. This method is 99.9% effective at preventing pregnancy. Neither method of emergency contraception protects against STDs or HIV.

Research

Recent discoveries

• Patient satisfaction and ease of use of oral contraceptives and injectible contraceptives were compared. ^[6]
• Several methods of estimating births averted nationally by contraception were compared. For 156 countries and areas around the world the estimated number of births that would have occurred in a recent year in the absence of contraception (the average of the estimates of the three methods) is approximately 230 million, which is more than the estimated 129 million births that actually occurred. ^[7]
• The use of contraception in HIV-positive women and management strategies for these women is discussed. ^[8]
• The inadvertent use of contraceptives during pregnancy was studied. No increased risk of fetal death was noted with the use of oral contraceptives before or during pregnancy. ^[9]
• Methods and prevalence of physician counselling about emergency contraception in the United States were reviewed. ^[10]

Ongoing research

• A study is being conducted into whether or not having a greater supply of birth control pills leads to greater compliance. ^[11]
• A randomized trial of IUD versus hormonal contraception in HIV-infected women in Zambia is being conducted. Hormonal methods of birth control may increase the viral load in HIV, so alternative forms of birth control are being studied. ^[12]
• The potential for birth control to be dispensed by a pharmacist without a physician's prescription is being evaluated. This practice may increase access to birth control. ^[13]
• The bleeding pattern and user satisfaction with Mirena (IUD) is being studied. ^[14]

Clinical Trials

A list of ongoing clinical trials is available at ClinicalTrials.gov: contraceptive trials

Controversy

Most of the controversy surrounding the use of contraception involves religious objection. The Catholic church states that every church in Christendom condemned contraception until 1930, when, at its decennial Lambeth Conference, Anglicanism gave permission for the use of contraception in a few cases. Soon all Protestant denominations had adopted the secularist position on contraception. Today not one stands with the Catholic Church to maintain the ancient Christian faith on this issue. ^[15] Contraception was banned in Pope Paul VI's Humanae Vitae. Recently, a number of Catholic groups published a letter to the current Pope, Benedict, asking him to give permission for Catholics to use birth control. ^[16]

Another point of contention is the prescribing of birth control to teens. Many birth control methods do not require a prescription. Some states allow teens as young as 14 to be given birth control pills at Family Planning Clinics. Legislation varies by state.

The teaching of birth control methods to children is another issue. The only completely foolproof method of birth control is abstinence. Some parents would like children taught only abstinence as a birth control method (usually in religious schools). Others would like children to be presented with information about many birth control options.

History

Contraception has a long and varied history.

How contraception was developed

Many years ago, possibly as far back as ancient Egypt, people reportedly used herbs, coitus interruptus (withdrawl of the penis prior to ejaculation), and pessaries for birth control. Through the years, many different devices and substances were used in an attempt to prevent pregnancy.

In 1914, Margaret Sanger (1869-1966), a nurse, became the first birth control advocate. She wrote a series of educational articles and pamphlets ^[17] Some of Ms. Sanger's achievements:

• Started the first family planning clinic (in 1916), which was shut down by the police after a few days
• Started the periodical publication Birth Control Review in 1917
• Founded the American Birth Control League in 1921
• Lectured extensively in Europe and Asia in the 1920s and 1930s.
• Organized the Birth Control International Information Centre in 1930.
• Started the International Planned Parenthood Federation (IPPF)in 1952.

Margaret McCormick, a wealthy widow and one of the first women to attend Massachusetts Institute of Technology (MIT) met Margaret Sanger in 1917. In 1947, after the death of Mrs. McCormick's husband, she paired up with Margaret Sanger and financed the research and development of the birth control pill.

The two women approached physician and researcher Gregory Pincus in 1957 about developing a new birth control method. The birth control pill was approved by the FDA for use as a contraceptive in 1960. The first pill, called Enovid, was marketed by the G. D. Searle Company of Chicago. It cost the consumer about ten dollars a month. Pincus is also credited with the development of the morning after pill, for emergency contraception.

The pill has been credited with beginning the sexual revolution in the 1960s as women could, for the first time, have more control over their fertility and less concern about unintended pregnancy. This claim is debatable, however, since women had reportedly been using other forms of birth control for many years. ^[18]

The Supreme Court legalized contraception for married couples (Griswold v. Connecticut) shortly prior to Ms. Sanger's death. This decision involved overturning the Comstock Act, passed in 1873. Congress passed the Comstock Act to stop or control pornography (in print) as well to control or stop the passage of information on birth control devices, sexually transmitted diseases, human sexuality, and abortion.

References

1. ↑ Centers for Disease Control and Prevention. Unintended Pregnancy Prevention: Contraception
2. ↑ Finer LB, Henshaw SK. Disparities in rates of unintended pregnancy in the United States, 1994 and 2001. Perspect Sex Reprod Health. 2006 Jun;38(2):90-6. Abstract | PDF
3. ↑ Mosher WD, Martinez GM, Chandra A, Abma JC, Willson SJ. Use of contraception and use of family planning services in the United States: 1982-2002. Adv Data. 2004 Dec 10;(350):1-36. Abstract | PDF
4. ↑ Sitruk-Ware R. Contraception: an international perspective. Contraception. 2006 Mar;73(3):215-22. Epub 2005 Nov 14. Abstract
5. ↑ U.S. Food and Drug Administration. Update to Label on Birth Control Patch
6. ↑ Berenson AB, Odom SB, Breitkopf CR, Rahman M. Am J Obstet Gynecol. 2008 Jul 2. (Epub ahead of print). Abstract
7. ↑ Liu L, Becker S, Tsui A, Ahmed S. Three methods of estimating births averted nationally by contraception. Popul Stud (Camb). 2008 Jul;62(2):191-210. Abstract
8. ↑ Womack J, Richman S, Tien PC, Grey M, Williams A. Hormonal Contraception and HIV-positive women: metabolic concerns and management strategies. J Midwifery Womens Health. 2008 Jul-Aug;53(4):362-75. Abstract
9. ↑ Jellesen R, Strandberg-Larsen K, Jorgensen T, Olsen J, Thulstrup AM, Andersen AM. Maternal use of oral contraceptives and risk of fetal death. Paediatr Perinat Epidemiol. 2008 Jul;22(4):334-40. Abstract
10. ↑ Kavanaugh ML, Schwarz EB. Counseling about and use of emergency contraception in the United States. Perspect Sex Reprod Health. 2008 Jun;40(2):81-6. Abstract
11. ↑ ClinicalTrials.gov. The Impact of Pack Supply on Birth Control Pill Continuation (SixPack)
12. ↑ ClinicalTrials.gov. A Randomized Trial of IUD Versus Hormonal Contraception in HIV-Infected Women in Zambia
13. ↑ ClinicalTrials.gov. The Direct Access Study: Access to Hormonal Birth Control Through Community Pharmacies
14. ↑ ClinicalTrials.gov. Bleeding Pattern and User Satisfaction During Second Consecutive MIRENA® in Contraception and Treatment of Menorrhagia
15. ↑ Catholic.com. Contraception and Sterilization
16. ↑ AOL news. Critics Urge Pope to Lift Birth Control Ban
17. ↑ Department of History, New York University. The Margaret Sanger Papers Project. The Selected Papers of Margaret Sanger
18. ↑ American Heritage.com. The Pill: Did It Really Change How We Live?

External Links

The National Women’s Health Information Center

American College of Obstetricians and Gynecologists

World Health Organization: Promoting Family Planning

Planned Parenthood Federation of America

Contraception Online: Published by Baylor School of Medicine, has a series of patient handouts on the various methods of birth control.