Birth control guide

Welcome to Birth control guide

A typical U.S. woman is fertile about 40 years — half of her expected life span. If you choose not to have children at any point during that time, it's important that you select a birth control method that you find comfortable and appealing to your lifestyle.

This guide is intended to help you select a method of birth control that's appropriate for you. As you'll see, numerous contraceptive options are available. Your decision about what works best for you and your partner will be based on a number of factors, such as whether the method is reversible, what the potential side effects are and whether it protects you from sexually transmitted diseases (STDs).

As you make your way through this guide, you'll become familiar with the various birth control options: how they work, their effectiveness and the health risks associated with each. You can also read answers to frequently asked questions about birth control, from a Mayo Clinic specialist in obstetrics and gynecology. After reviewing the guide, you'll be better prepared to make a decision about which birth control method suits your needs.

Birth control options

Given all the options available, you may find choosing a birth control method confusing. You can make it a little easier by considering your lifestyle, goals and health status. Consider these factors as you decide on a birth control method that's right for you:

• How you feel about planning for sex
• Your comfort level with inserting contraceptive devices into your body
• Your diligence in following directions, whether it's taking a pill every day or tracking your fertile days
• How effective the method is at preventing pregnancy
• Whether you plan to have children someday
• How often you have sex
• Whether you have a monogamous partner
• How the method alters your sexual experience
• Whether you smoke

As you make your decision, you may find it helpful to know what birth control methods are most widely used. In the United States, the birth control pill is the most common contraceptive method, followed by tubal ligation and the male condom.

To help you understand the many birth control options available, this guide provides an overview of each, beginning with condoms and other barrier methods.

Condoms and other barrier methods

Barrier methods of contraception prevent sperm and egg from meeting by physically blocking the two. Barrier methods are the oldest and most widely used forms of contraception worldwide. They include:

• Male condom
• Female condom
• Cervical cap
• Diaphragm
• Shield
• Spermicide
• Sponge

Male condom

Male condoms, commonly called rubbers, provide a nonpermanent method of contraception for men. The condom is a thin covering made of latex, plastic (polyurethane) or animal membrane that's unrolled over an erect penis before sex. The covering prevents semen from entering a woman's vagina.

Effectiveness rate. The typical effectiveness rate of the male condom by itself is 85 percent. This means if 100 couples use male condoms for one year, 15 will get pregnant. The effectiveness of male condoms increases when used with vaginal spermicide; using both together is the most effective barrier method available. However, male condoms can fail due to improper use, nonuse, breakage or slippage.

Side effects and health risks. Some people are allergic to latex condoms. But condoms made of polyurethane (plastic) or animal skin also are available. Male condoms may decrease sensation during sex for both men and women.

The male condom is the most effective contraceptive method available for avoiding sexually transmitted diseases (STDs) and reducing the risk of HIV infection. Condoms made from animal skin don't offer as much protection from STDs, however, because they have tiny pores that may allow viruses such as HIV, hepatitis B and herpes to pass through them. Condoms containing the spermicide nonoxynol-9 sometimes irritate the skin. If this happens, your risk of HIV infection could go up. Skin irritation — leading to increased HIV risk — can also happen when condoms are used in combination with vaginal spermicide.

How to use the male condom. If you decide to use a male condom, put it on before the penis comes in contact with the vagina. It's important to use condoms carefully, correctly and consistently. Here are some additional tips for purchasing, storing and using condoms:

• Check the expiration date. Don't use the condom if the expiration date has passed.
• Open the package carefully. Don't use your teeth or fingernails.
• If the condom doesn't have a built-in nipple, leave a quarter inch of space at the tip to hold the semen.
• If necessary, use a water-based lubricant (K-Y, Astroglide, others). Oil-based lubricants may cause the condom to leak or break.
• Place the tip of the rolled-up condom over the erect penis. The rolled rim should be on the outside.
• Hold the tip of the condom while unrolling the condom down to the base of the penis.
• Smooth out any air bubbles to make sure the condom fits correctly. An air bubble could cause the condom to tear or come off.
• If the man is uncircumcised, make sure the foreskin is pulled back before putting on the condom.
• Store condoms in a cool, dry place because condoms exposed to air, heat and light are more likely to break. Don't keep condoms in a billfold, back pocket or glove compartment for an extended period of time.
• Remove the condom immediately after sex. You must use a new condom each time you have intercourse.

Cost and availability. Condoms are widely available and relatively inexpensive. In the United States, you pay less than $1 per condom. They come in a range of sizes and styles and are available without a doctor's prescription. They're sold in pharmacies, drugstores and some bathroom vending machines.

Female condom

The female condom is a soft, loosefitting polyurethane (plastic) pouch with two O-rings on the ends. One ring is inserted into the vagina and holds the female condom in place, and the open-end ring remains outside the vagina. Only one female condom, the FC female condom, is available in the United States at this time. A second-generation model, the FC2, is used in other countries but doesn't have Food and Drug Administration (FDA) approval in the U.S. Other models are currently being tested as well.

Effectiveness rate. The typical effectiveness rate of the female condom is 79 percent. In other words, 21 out of 100 women who use the female condom for one year will get pregnant.

Side effects and health risks. Some women may experience vaginal irritation or irritation of the vulva by the outer ring. Some couples have experienced decreased sensation, and some say that it's noisy during intercourse. Because female condoms are made out of polyurethane (plastic), people who are allergic to latex can use them. Female condoms protect against STDs, including HIV.

How to use the female condom. If you decide to use a female condom, insert it before the penis comes in contact with the vagina. First, lubricate the closed end of the condom. Squeeze the closed (inner) ring at one end and insert it into the vagina like a tampon. Push it into the vagina as far as it can go. It will be resting against the cervix. The outer ring will hang out of the vagina about an inch. If needed, you may use more lubricant during intercourse. The female condom can be used with water- or oil-based lubricants. During intercourse, movement of the condom from side to side is normal.

To remove the female condom, first twist the outer ring so that the semen is contained in the condom. Gently pull it out of the vagina and throw it in the trash. You must use a new female condom every time you have intercourse.

Cost and availability. Female condoms are widely available without a prescription at drugstores and some supermarkets for about $3 each.

Cervical cap

The cervical cap is a reusable, deep rubber cup shaped like a sailor's hat that fits over the cervix. By covering the cervix, the cap prevents sperm from entering the uterus and coming in contact with the egg. Only the FemCap cervical cap is available in the United States at this time.

Effectiveness rate. For women who've never had children, the typical effectiveness rate of the cervical cap is 86 percent. In other words, 14 out of 100 women using the cap for one year will get pregnant. The typical effectiveness rate for the cap in women who have had children declines to 71 percent, because the cervical shape changes after childbirth, making cap fitting more difficult. These rates are based on an older version of the FemCap cervical cap. No published studies document the effectiveness rates for the second generation of the FemCap — the one that's currently marketed in the United States — but the manufacturer claims that the newer device is likely more effective than was the original device. How much more effective isn't precisely known.

The most common cause of cervical cap failure is dislodgement of the cap from the cervix during sex.

Side effects and health risks. Side effects are infrequent. Some women may experience vaginal irritation from the spermicide that's applied to the cap. Though rare, risks include:

• Urinary tract infection
• Vaginal infection
• Toxic shock syndrome with prolonged use

Cervical caps do not provide protection against STDs.

How to use the cervical cap. If you decide on the cervical cap, your doctor fits you with one of the available sizes and demonstrates how to insert and remove the device. The fitted cervical cap is held in place by the cervix, and includes a strap for removal. To be most effective, the cervical cap is used with a sperm-destroying (spermicidal) cream, foam or gel. Insert the cervical cap no more than six hours before sex.

Here are some additional tips for cervical cap insertion:

• Before insertion, fill the dome of the cap one-third full with spermicide.
• Separate your labia with one hand. With the other hand, squeeze the rim of the cap between your thumb and index finger.
• Slide the cap into your vagina and push it along the rear wall of the vagina as far as it will go. This can be done standing, with one foot propped up, squatting or lying on your back.
• Using your finger to locate your cervix, press the rim of the cap around the cervix until you've completely covered it.
• Check the cap position by pressing the dome of the cap to make sure your cervix is covered. Sweep your finger around the cap rim. You should not be able to feel the cervix outside the cap.

After sex, leave the cap in place for at least six hours and up to two days. After removal, wash the cap with mild soap and warm water and let it air-dry. With proper care, the cap can last one to two years, but you should examine it regularly for holes, tears or leaks.

Some women may not be suited for the cervical cap due to:

• The size or position of their cervix
• Poor vaginal muscle tone
• An infection or, in rare circumstances, a scar from a cut or tear in the pelvic area

Don't wear the cervical cap during any kind of vaginal bleeding, including your menstrual period.

Cost and availability. Cost of a cap starts at about $72. The cervical cap is available only with a doctor's prescription. The initial examination that's required for a cervical cap fitting costs $50 to $200. You may need to replace the cap every year or so, depending on whether the cap shows signs of wear.

Diaphragm

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Diaphragm placement

The diaphragm is a reusable, dome-shaped rubber cup with a flexible rim. It's inserted into the vagina so that it fits behind the cervix and also behind the pelvic bone (symphysis pubis), completely covering the cervix and holding spermicide against the cervix. It's held in place by vaginal muscles.

Effectiveness rate. With the use of spermicide, the typical effectiveness rate for the diaphragm is 84 percent. In other words, 16 out of 100 women using the diaphragm for one year will get pregnant.

Side effects and health risks. Women rarely experience side effects while using the diaphragm. Some women report vaginal irritation caused by the latex rubber or the spermicides used with the device. Other risks include:

• Urinary tract infection
• Vaginal infection
• Toxic shock syndrome with prolonged use

How to use the diaphragm. If you decide on the diaphragm, your doctor determines which size diaphragm best fits your body. Weight gain, weight loss or changes in vaginal tone affect how the diaphragm fits. Have your doctor reassess your diaphragm's fit each year at the time of your regular pelvic exam. With proper care, your diaphragm could last up to two years before it needs to be replaced.

The diaphragm must be used with spermicide. It does not provide protection against pregnancy without the use of spermicide. The diaphragm may be inserted up to an hour before sex. Once in place, it provides effective contraceptive protection for up to six hours.

Here are some additional tips for diaphragm insertion:

• Hold the diaphragm with the dome down. Squeeze about 1 teaspoon of spermicide into the dome and spread a little bit around the rim with your finger.
• Squeeze the diaphragm so that it folds. Spread your labia with your other hand and insert the folded diaphragm into your vaginal canal. This can be done standing, with one foot propped up, squatting or lying on your back.
• Push the diaphragm downward and along the back wall of your vagina as far as it will go. Then tuck the front rim up along the roof of your vagina behind your pubic bone.
• If the diaphragm is correctly placed, the back rim is below and behind the cervix and the front edge of the rim is tucked up behind the pubic bone. You shouldn't be able to feel it except with your fingers.

After sex, leave the diaphragm in place for at least six hours but for no more than 24 hours. After removal, wash the diaphragm with mild soap and warm water and allow it to air-dry. Use only water-based lubricants with the diaphragm, and examine it regularly for holes, tears or leaks.

Some women may not be suited for the diaphragm due to:

• Frequent urinary tract infections
• Poor vaginal muscle tone
• An infection or, in rare circumstances, a scar from a cut or tear in the pelvic area

Don't wear the diaphragm during any kind of vaginal bleeding, including your menstrual period.

Cost and availability. The diaphragm itself generally costs $30 to $50. The initial examination that's required for a diaphragm fitting costs $50 to $200.

Cervical shield

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Shield placement

The shield (Lea's Shield) is a reusable, cup-shaped device that fits over the cervix and is held in place by suction and support from the vaginal wall. Because it's not held in place by the cervix like the cervical cap is, the silicone shield is one-size-fits-all. A valve on the device vents air during insertion, creating a suction effect for a snug fit. A control loop attached to the cup assists with insertion and removal.

Effectiveness rate. Based on projections from a study of women who used the shield for six months, the effectiveness rate is 85 percent. That means that of every 100 women who use the shield for one year, 15 will get pregnant. Because childbirth can alter how the shield fits, this method may have a higher failure rate for women who have given birth.

Side effects and health risks. Serious side effects associated with the device are rare. Some women may be sensitive to spermicide or silicone. Using the shield may increase the risk of the following:

• Urinary tract infection
• Vaginal infection
• Toxic shock syndrome with prolonged use

The shield doesn't protect against STDs.

How to use the shield. The shield comes in one size, so custom fitting isn't necessary. If you decide on the shield, your doctor demonstrates how to insert and remove it. Use the shield with spermicide. Insert the device anytime before sex.

Here are some additional tips for shield insertion and removal:

• Coat the inside of the bowl, the leading edge of the bowl (the part away from the loop) and the valve with spermicide.
• Press the rims on each side of the bowl together between your thumb and index finger. While holding the shield with the valve facing downward and the loop outward, use your fingers to insert the folded shield. This can be done standing, with one foot propped up, squatting or lying on your back.
• Insert the shield into the vagina, pushing it upward as far as it will comfortably go. It should sit over the cervix.
• For correct placement, all of the air between the cervix and the device must be vented through the valve to create the proper seal.
• To remove the shield, grasp the loop with your index finger and gently twist until the suction is broken.

After sex, leave the shield in place for at least eight hours and up to a maximum of 48 hours. After removal, wash the shield with mild soap and warm water and then let it air-dry. With proper care, the shield can last up to six months before it needs to be replaced, but examine it regularly for holes, tears or leaks.

Some women may not be suited for the shield due to:

• Frequent urinary tract infections
• Poor vaginal muscle tone
• An infection or, in rare circumstances, a scar from a cut or tear in the pelvic area

Cost and availability. The cost of the Lea's Shield is $65. The initial examination to learn how to insert and remove the device can range in cost from about $50 to $200.

Spermicides

Spermicides are substances that inactivate sperm before they enter the uterus. They come in a variety of forms: cream, gel, foam, vaginal contraceptive film, suppository and tablet. All spermicides sold in the United States contain the chemical nonoxynol-9, which kills sperm.

Effectiveness rate. Spermicides can be used alone but are more effective when used with another barrier method, such as a condom, diaphragm or cervical cap. The typical effectiveness rate of spermicides alone is 71 percent, which means that 29 out of 100 women using it for one year will get pregnant. Vaginal douches containing spermicide aren't reliable contraceptives because they're used after sex, when it's too late to prevent the ascent of sperm into the cervix.

Side effects and health risks. Spermicidal agents may irritate the vagina. Some women are sensitive to nonoxynol-9. Spermicides may also disrupt the normal bacterial colonies in the vagina and urethra, leading to an increased incidence of urinary tract infection. Spermicides containing nonoxynol-9 don't protect against HIV/AIDS and other STDs. Vaginal irritation from spermicides may actually increase the risk of STDs.

How to use the spermicide. If you decide to use spermicide, you insert the spermicidal agent into the vagina using either your fingers or the applicator, according to the product directions. All forms of spermicide are effective when applied less than one hour before sex. Foams and gels offer immediate protection, whereas suppositories and vaginal contraceptive films must be inserted at least 15 minutes before sex.

Here are some additional tips for spermicide use:

• Gel, cream or foam. Fill the applicator and insert it in your vagina as far as it will comfortably go. Push the plunger on the applicator to release the gel, cream or foam. The spermicide should be close to your cervix.
• Suppository. Remove the wrapping and slide the suppository into your vagina. Slide it along the back wall of your vagina as far as you can so that the suppository lies on or near your cervix.
• Film. Be sure your fingers are dry. Place one sheet of film on your fingertip and slide it along the back wall of your vagina as far as you can so that the film rests on or near your cervix.

Before each sex act, another application is needed. Don't wash away spermicides, especially not for at least six hours after intercourse.

Cost and availability. Spermicides cost about $1 to $1.50 per use, depending on the type of spermicide you use. They're available without a prescription and may be purchased in pharmacies and drugstores.

Contraceptive sponge

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Sponge placement

The sponge is a soft, disk-shaped device made from polyurethane foam that fits over a woman's cervix. It releases spermicide slowly over 24 hours and serves to block and absorb semen.

Effectiveness rate. For women who have never had children, the typical effectiveness rate of the sponge is 84 percent, meaning 16 out of 100 women using it for one year will get pregnant. Some reports suggest a decline in effectiveness in women who've had children.

The contraceptive sponge fits over the cervix to block and absorb semen and kill sperm.

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Side effects and health risks. Some sponge users complain of vaginal dryness, itching or soreness. Others experience allergic reactions to sponge materials or difficulty removing the sponge. Sponges don't provide protection against STDs.

How to use the sponge. If you decide to use the sponge, insert it just before intercourse or up to 24 hours ahead of time. Here are some additional tips for sponge insertion:

• Remove the sponge from its package, moisten it with about 2 tablespoons of clean water and squeeze it once.
• Insert the sponge into the vagina and slide it along the vagina until it rests against your cervix.
• Check with your finger to make sure you can feel your cervix covered by the sponge. Once inserted, the sponge offers protection for up to 24 hours.

After sexual activity, leave the sponge in place for at least six hours.

Cost and availability. A single contraceptive sponge costs about $2.50. The Today Sponge is available in the United States at local retailers and online. Other sponges, such as the Protectaid Sponge, are available outside the United States and online.

Barrier methods of birth control: Pros and cons

Barrier methods offer both advantages and disadvantages. To help you decide if they're right for you, keep the following points in mind:

The pill and other hormonal contraceptives

Hormonal contraceptives, a popular method of birth control, offer highly effective, reversible pregnancy prevention. These methods prevent pregnancy by inhibiting ovulation, by altering cervical mucus to decrease sperm mobility and by impairing embryo implantation in the uterus. Besides preventing pregnancy, hormonal contraceptives have other beneficial effects, including regular, shorter and less painful menstrual periods — or for some methods, no periods at all. The first hormonal contraceptive was the combination birth control pill, which appeared on the U.S. market in the early 1960s. Since then, hormonal contraceptive options have expanded to include the following:

• Skin patch
• Vaginal ring
• Minipill
• Injection
• Implant

Choosing among the pill, the patch and the ring
Combined estrogen and progestin hormonal methods — the pill, the patch and the ring — all provide comparable effectiveness, side effects and benefits. So how do you decide which of these three methods to use? The key to making this decision is deciding which method best suits your lifestyle. For example, if you have difficulty remembering to take a pill every day, you might want to use the ring or the patch, which you don't have to think about daily. If your skin is sensitive or easily irritated, you might not want to use the patch. Or if you're uncomfortable inserting a vaginal ring, you may want to consider the other two options instead.

Birth control combination pill

The combination birth control pill is an oral contraceptive taken daily that contains estrogen and progestin ("the pill").

Effectiveness rate. With perfect use — if you follow the directions and never miss any pills — the effectiveness rate of the pill tops 99 percent. However, among typical users of the combined estrogen and progestin pill, the effectiveness rate is 92 percent, meaning that eight out of 100 women taking it for one year will get pregnant. Other medications can interfere with the pill's effectiveness, so talk to your doctor before taking the pill with any other drug.

Side effects and health risks. Side effects may include headaches, breast tenderness, nausea, vomiting, bloating, decreased sex drive (libido) and depression. Research has not shown any link between taking the pill and weight gain. The most serious potential complication is a slightly increased risk of heart disease, high blood pressure and blood clots. Talk to your doctor about how your health history and age may affect your risks with hormonal contraception.

Women with the following characteristics should not take combination estrogen and progestin pills:

• Age 35 or older and currently smoke
• A history of cardiovascular disease
• A history of breast, uterine or liver cancer
• A history of blood clots in the legs or lungs

The pill doesn't provide protection against sexually transmitted diseases (STDs).

How to use the pill. The pill is available in a range of hormonal concentrations. If you decide on the pill, your doctor will determine which formula best meets your needs. Take the pill according to the most recent package insert, which provides instructions on when to begin the pill, whether you need backup contraception at certain times and what to do if you miss a pill. Using the pill to decrease the number of menstrual periods you have in a year, or to eliminate regular periods completely except for occasional breakthrough spotting, has been demonstrated to be safe and is a feature of some oral contraceptive regimens.

Cost and availability. Costs vary widely, depending on which product you use, what your insurance covers and what your doctor charges for the initial visit. Pill costs range from $9 to $60 a month, and initial visits cost $35 to $175.

Skin patch for birth control

Applied to skin, the birth control patch is about as long and wide as the length of a large paper clip.

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The first skin patch for birth control, Ortho Evra, was introduced in 2001. The patch is a 1 3/4-inch adhesive square that slowly releases the hormones estrogen and progestin through the skin and into the bloodstream.

Effectiveness rate. The effectiveness rate of the patch is around 98 percent, which means that two out of 100 women using the patch over one year will get pregnant. There's some evidence to suggest that Ortho Evra may be less reliable in women who weigh more than 198 pounds.

Side effects and health risks. The most common side effects are skin irritation, headaches, breast tenderness, nausea, vomiting, bloating, decreased sex drive and depression. Women who use the patch may be at a slightly increased risk of heart attack, stroke and blood clots. Users of the patch are exposed to higher levels of estrogen — about 60 percent greater — than are users of contemporary birth control pills. Increased exposure to estrogen may increase the risk of side effects, but that hasn't yet been demonstrated.

If any of these characteristics describes you, don't use the patch:

• Age 35 or older and currently smoke
• A history of cardiovascular disease
• A history of breast, uterine or liver cancer
• A history of blood clots in the legs or lungs

The patch doesn't protect against STDs.

How to use the patch. If you decide on the patch, apply a patch weekly for three consecutive weeks. The fourth week is patch-free, which allows you to have your menstrual period. Place the patch on your buttocks, lower abdomen or upper body, but not on your breasts. Here are a few additional tips for patch use:

• Don't apply oils, creams or cosmetics near the patch.
• You may participate in your regular activities, including swimming and bathing, while wearing the patch.
• If your patch becomes detached, replace it with a new patch immediately. Review your package insert for information on whether you need to use a backup method of birth control.

Cost and availability. Ortho Evra costs about $50 for a month's supply of three patches. The initial examination costs $35 to $175.

Vaginal ring

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Vaginal ring

The vaginal ring (NuvaRing) is a flexible, transparent plastic device that slowly releases the hormones estrogen and progestin. This device, which measures 2 inches in diameter, is inserted into the vagina to prevent pregnancy. Each ring provides pregnancy protection for one month.

Effectiveness rate. The effectiveness of the vaginal ring is similar to that of other hormonal contraceptives. The effectiveness rate among typical vaginal ring users is 92 percent, meaning that eight out of 100 women using it for one year will get pregnant.

Side effects and health risks. Side effects of the vaginal ring may include vaginal infections and irritation, irregular vaginal bleeding, headaches, breast tenderness, weight gain or loss, nausea, vomiting, bloating, decreased sex drive, and depression. Women who use the vaginal ring may be at a slightly increased risk of heart attack, stroke and blood clots. If any of these characteristics describes you, don't use the vaginal ring:

• Age 35 or older and smoke
• A history of cardiovascular disease
• A history of breast, uterine or liver cancer
• A history of blood clots in the legs or lungs

The vaginal ring doesn't protect against STDs.

How to use the vaginal ring. If you decide on the vaginal ring, you insert the ring in your vagina and leave it in place for three weeks. Here are some additional tips for ring use:

• You may insert the vaginal ring anywhere in your vagina, but placing it deeply makes you less likely to feel it once inserted.
• An additional method of birth control must be used during the first week of use.
• If the ring falls out, it should be rinsed with warm water and reinserted within three hours.
• If the ring is out of the vagina for more than three hours during the first three weeks of the cycle, pregnancy prevention is compromised, and you must use a backup method of birth control for one week.

The fourth week should be ring-free, which allows you to have your menstrual period.

Cost and availability. Each monthly vaginal ring costs $35 to $50. The initial examination costs $35 to $175.

Combined estrogen and progestin contraceptives: Pros and cons

Combined estrogen and progestin contraceptives (the pill, patch and ring) are a highly effective birth control method, but they're not suitable for everyone. To help you decide if these contraceptives are right for you, keep the following points in mind:

Progestin-only birth control pill

The progestin-only birth control pill, also known as the minipill, is an oral contraceptive taken daily that contains only one hormone, progestin. This is the only type of oral contraceptive recommended for breast-feeding mothers because it contains no estrogen, which is known to interfere with milk supply.

Effectiveness rate. The failure rate of the minipill is low, especially if the user follows the directions and misses no pills. Among typical users of progestin-only pills, the effectiveness rate is 92 percent, meaning that eight out of 100 women taking it for one year will get pregnant.

Side effects and health risks. The major side effect associated with the progestin-only pill is irregular menstrual bleeding. Periods often become short and light, and some women don't bleed for several months at a time. However, some women experience persistent spotting. Other side effects include weight gain, breast tenderness and depression. Women who take the minipill don't experience the side effects caused by estrogen, such as an increased risk of blood clots and cardiovascular disease. The minipill doesn't protect against STDs.

How to use the minipill. If you decide on the minipill, your doctor determines which formula best meets your needs. Take the pill according to the most recent package insert, which provides instructions on when to begin the pill, whether you need backup contraception at certain times and what to do if you miss pills.

Cost and availability. Progestin-only pills cost $30 to $60 a month. The initial examination costs $35 to $175.

Depo-Provera injectable contraceptive

Depo-Provera is the only injectable contraceptive available in the United States. Each injection contains high doses of the hormone progestin, which prevents pregnancy for up to three months.

Effectiveness rate. Depo-Provera is highly effective in preventing pregnancy, even if a woman is a few days late in receiving a scheduled dose. It's also ideal for women who aren't likely to, or don't want to, take a pill every day. The typical effectiveness rate among users is 97 percent, meaning that three out of 100 women using the injection for one year will get pregnant.

Side effects and health risks. You'll experience changes in your menstrual periods while using Depo-Provera. Periods may become irregular or unpredictable, or you may not bleed at all. The absence of periods isn't harmful, and periods typically return to normal after you stop using Depo-Provera. Other side effects may include weight gain, breast tenderness and depression. However, women who take Depo-Provera don't experience the side effects of estrogen exposure, such as an increased risk of blood clots and cardiovascular disease. The injection doesn't protect against STDs.

Prolonged use of Depo-Provera may result in bone loss, during use, but bone density returns to normal when you stop using Depo-Provera.

The return of normal menstrual periods after Depo-Provera can be delayed, sometimes for months. As a result, you may not experience a prompt return to fertility after stopping the injections.

How to use Depo-Provera. If you decide on Depo-Provera, you receive an injection in your upper arm or buttocks every three months. You should get the first injection within the first five days of your menstrual period for immediate effectiveness. If you get the first injection later than that, use a backup method of birth control for two weeks.

Cost and availability. Depo-Provera costs between $30 and $75 per injection, which lasts three months. The initial examination costs $35 to $125. Further office visits cost $20 to $40.

Implantable contraceptive device

Implanon, an implantable contraceptive device, was approved in 2006. The matchstick-sized device releases a low, steady dose of progestin to prevent pregnancy. The implant can be left in place for up to three years and removed at any time.

Another implantable contraceptive, Norplant, was available in the United States throughout the 1990s. In 2000, however, questions about the strength of certain lots of the drug led its manufacturer to stop U.S. distribution. Two years later, the company decided not to reintroduce Norplant to the U.S. market. Doctors continued to implant new Norplant devices until the already-distributed supply ran out. Unless your doctor recommends otherwise, you can safely use an existing Norplant insert for five years after implantation, when it loses its effectiveness.

Effectiveness rate. The manufacturer says Implanon is 99 percent effective in preventing pregnancy when implanted properly, which means that one out of 100 women using Implanon for one year will get pregnant.

Side effects and health risks. Implanon can cause irregular menstrual bleeding and spotting. For some women, Implanon stops menstruation entirely. Other side effects may include acne, headaches, breast tenderness and weight changes.

How to use the implant. If you decide on Implanon, a doctor will place the implant under the skin of your inner, upper arm. The implant is effective for up to three years, at which time you can get it removed and have a new one implanted.

Cost and availability. The implant costs $180, and the initial examination and implantation costs $50 to $200. The implant is not yet widely available. As more doctors are trained in implanting the device, it will be offered in more locations.

Progestin-only contraceptives: Pros and cons

Progestin-only contraceptives (the minipill, injection and implant) are an effective birth control method, but they're not suitable for everyone. To help you decide if these contraceptives are right for you, keep the following points in mind:

Intrauterine device

Intrauterine devices (IUDs) are among the safest contraceptive devices, and are commonly used worldwide. They were used extensively in the United States until the 1980s, when a significant number of pelvic infections were observed in women using a specific IUD called the Dalkon Shield. It turned out that the thread going from the lower end of the device through the cervix and into the vagina acted as a wick, carrying bacteria from the vagina into the cervix and uterus. Not long after the discovery, the Dalkon Shield was pulled from the market. As a result, IUDs fell out of favor in the U.S., despite the proven safety and effectiveness of other IUDs. In recent years, however, IUDs have made a comeback and are again a popular method of birth control.

Copper IUD

Named after the contraceptive substance released, the copper IUD is highly effective at preventing pregnancy.

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Intrauterine devices (IUDs) are a reversible method of birth control. The copper IUD (ParaGard) is one of two IUDs available by prescription in the United States. The other IUD is a hormonal version (Mirena).

The copper IUD is a T-shaped plastic frame with two threads attached. It's inserted into the uterus to prevent pregnancy. Once in place, it inhibits fertilization, as the IUD impedes the sperm's journey to the fallopian tubes. If fertilization occurs, the device prevents the embryo from attaching to the uterine wall. ParaGard also slowly releases copper, which inactivates the sperm in the cervical mucus.

Effectiveness rate. The effectiveness rate for the copper IUD is between 99.2 percent and 99.4 percent, meaning that six to eight women out of 1,000 who use it for one year will get pregnant. The copper IUD may remain in place for up to 10 years.

Side effects and health risks. Common side effects associated with the copper IUD are increased vaginal bleeding and menstrual pain. Taking nonsteroidal anti-inflammatory drugs (Advil, Motrin, others) helps with these symptoms. Some women may also experience a pelvic infection within the first three weeks of placement, as the insertion process may introduce bacteria into the uterus. Your doctor may prescribe antibiotics before insertion to reduce the risk of such infections. The copper IUD doesn't protect against STDs. IUDs also carry a risk of spontaneous expulsion — which leaves you unprotected against pregnancy — or piercing (perforation) of the uterine wall during insertion.

How to use the copper IUD. If you decide on the copper IUD, your doctor will insert the device and give you information on its use. When ParaGard needs to be removed, your doctor gently withdraws it by pulling on the IUD string. In rare instances the strings on the device may break, making IUD removal a more complicated procedure. After removal, normal fertility returns promptly.

Cost and availability. The copper IUD costs $200 to $300 every ten years plus the cost of an office visit for insertion and a follow-up appointment.

Hormonal IUD

The hormonal IUD (Mirena) is a T-shaped plastic frame with thread attached. The device is inserted into the uterus and can remain in place for up to five years. It prevents pregnancy in a few different ways. The IUD frame contains a progestin called levonorgestrel, which inhibits sperm motility and makes the uterine lining thin and unsuitable for a pregnancy. The shape of the IUD impedes the sperm's journey to the fallopian tubes, inhibiting fertilization. If fertilization occurs, the device prevents the embryo from attaching to the uterine wall.

Effectiveness rate. The effectiveness rate for Mirena is 99.9 percent, so one woman out of 1,000 using the device for one year will get pregnant. Mirena must be replaced every five years.

Side effects and health risks. Unlike the copper IUD, the hormonal IUD decreases the amount of menstrual blood flow and menstrual cramping. The major side effect of hormonal IUD use is abnormal vaginal bleeding. Some women have unpredictable, light menstrual flow, while many may have no flow at all. Most women report discomfort and cramping during and after IUD insertion. Rarely, IUD users may experience a pelvic infection within the first three weeks of placement, as the insertion process can introduce bacteria into the uterus. Although most of the risk of infection with IUDs occurs at the time of insertion, many care providers continue to weigh risk of infection in their patients. Mutually monogamous relationships are the best defense against infection.

Hormonal IUDs don't protect against STDs. IUDs also carry a risk of spontaneous expulsion — which leaves you unprotected against pregnancy — or piercing (perforation) of the uterine wall during insertion. The risks of expulsion and perforation are extremely low.

How to use the hormonal IUD. If you decide on the hormonal IUD, your doctor will insert the device and give you information on its use. There's no maintenance required, but you should feel for the IUD string once a month to ensure the device hasn't been expelled. When the IUD needs to be removed, your doctor withdraws it by pulling on the IUD string. After removal, normal fertility returns promptly.

Cost and availability. The Mirena hormonal IUD costs between $300 and $400 every five years plus the cost of an office visit for insertion and a follow-up appointment.

IUD: Pros and cons

The IUD is a long-lasting, safe and reversible means of birth control, yet there are downsides. To help you decide if it's right for you, keep the following points in mind:

Natural family planning

Natural family planning — more accurately referred to fertility-awareness-based birth control — is a means of preventing pregnancy by avoiding unprotected intercourse during a woman's fertile period, when she's most likely to become pregnant. For highly motivated and diligent couples, one or more fertility-awareness-based methods may prove an effective means of birth control. Examples of fertility-awareness-based methods are:

• Basal body temperature
• Calendar
• Cervical mucus
• Lactational amenorrhea
• Standard days
• Symptothermal

Basal body temperature birth control method

The basal body temperature (BBT) is your body temperature at the time you wake up each day. By measuring this temperature each day and noting the day that it changes, a woman can determine when she's least and most likely to ovulate and conceive.

Effectiveness rate. The typical effectiveness rate among users of the BBT method is 80 percent, so 20 out of 100 women practicing this method for one year will get pregnant. The reliability of this method can be disrupted by:

• Illness
• Emotional distress
• Interrupted sleep cycles
• Smoking tobacco or drinking alcohol
• Using an electric blanket

Side effects and health risks. The major downside associated with using BBT as a means of natural family planning is the requirement for prolonged abstinence or use of barrier methods. Also, this method of birth control doesn't protect against STDs.

How to use the basal body temperature method. Before relying on this method, you have to familiarize yourself with your cycle by charting your BBT for three months. During that time — and for as long as you continue to use the BBT method — you take your temperature with a special BBT thermometer every morning before getting out of bed. For the method to work, you need to predict when you'll ovulate, not just to realize when you have ovulated. To do that, keep a log of each day's BBT, and watch for it to rise slightly (less than one degree) at some point between menstrual periods. This BBT increase means you have ovulated in the past 24 hours.

It's necessary to abstain from intercourse or use a barrier contraceptive every time you have sex during the three months of BBT charting. Then, when you begin to rely on the BBT method, you should either abstain from intercourse or use a barrier method on the days when conception may occur. Because sperm can live for three days in your reproductive tract, the "unsafe" interval has to include at least three days before and three days after ovulation. In other words, unprotected intercourse is off limits from your menstrual period until the night of the third day after your temperature rises, every month.

Cost and availability. Basal body temperature thermometers cost around $10. Classes that teach this technique may charge fees, which vary from region to region.

Calendar birth control method

The calendar method attempts to predict ovulation using a woman's menstrual history. By keeping a written record of each cycle, you can determine when you're least likely to conceive.

Effectiveness rate. The typical effectiveness rate among users of the calendar method is 87 percent. This means that 13 out of 100 women practicing this method for one year will get pregnant. The calendar method isn't dependable if your cycles vary in length.

Side effects and health risks. The downside of using the calendar method is the requirement for prolonged abstinence or use of barrier methods and the need to monitor your cycle for several months before using the method. This method doesn't protect against STDs.

How to use the calendar method. If you decide to use the calendar method, you'll calculate which days you're likely to become pregnant. During that time, abstain from sex or use barrier methods. Here are some tips for using this method:

• Keep a record of the number of days in each cycle, counting from the first day of one period to the first day of the next period. When bleeding starts, circle that day.
• Check your record of previous months, find the shortest cycle and subtract 18 from the total number of days. For example, if your shortest cycle is 26 days, 26 - 18 = 8.
• Starting with the day that you circled, count ahead eight days and draw an X through that day. That's the first day you're likely to be fertile. That's also the first day to practice abstinence or use barrier methods.
• To find the last day you're likely to conceive, subtract 11 days from your longest cycle. If your longest cycle is 30 days, 30 - 11 = 19. Starting from the first circle, count ahead 19 days and draw an X through that date. That's the last day you need to practice abstinence or use barrier methods.

Keep a cycle record for at least eight of your cycles before relying on this method. You must not be using hormonal contraception while you keep these records.

Cost and availability. Using the calendar method costs nothing, but classes that teach this technique may charge fees, which vary from region to region.

TwoDay birth control method

The TwoDay method is similar to the cervical mucus method, but it was devised to simplify the process of determining fertile days by only monitoring the presence — not the quality — of cervical mucus.

Effectiveness rate. The typical effectiveness rate among those using the TwoDay method is 86 percent. In other words, out of 100 women using the TwoDay method over one year, 14 will get pregnant.

Side effects and health risks. As with the cervical mucus method, the most significant disadvantage of the TwoDay method is prolonged periods of abstinence or the use of barrier methods. This method doesn't protect against STDs.

How to use the TwoDay method. If you decide to use the TwoDay method, check for cervical mucus at the vulva or on toilet paper two times each day: once in the afternoon, and once before bed. Ask yourself two questions. Do I have any secretions today? Did I have any secretions yesterday? If the answer to either of these questions is yes, then you should avoid unprotected intercourse, because you might be fertile. If the answer to both questions is no, then you're not in a fertile part of your cycle and can have unprotected intercourse.

Many women use a chart to mark fertile and infertile days, as well as the start of each cycle. It's important for women using this method to know how to recognize cervical mucus.

Cost and availability. Using the TwoDay method costs nothing, but classes that teach this technique may charge fees, which vary from region to region.

Lactational amenorrhea birth control method

Lactational amenorrhea refers to the normal cessation of menstrual periods for the first few months a woman is exclusively breast-feeding. During this time, ovulation doesn't occur and so birth control is essentially automatic. The method is only effective in preventing pregnancy under the following conditions:

• The mother is exclusively breast-feeding.
• The baby is less than 6 months old.
• The mother's period hasn't yet returned.

Effectiveness rate. When lactational amenorrhea is used as a means of birth control, the effectiveness rate is 98 percent. In other words, two out of 100 women will get pregnant while using this method during the six months after childbirth. After the first six months, ovulation and fertility may return before the onset of a period.

Side effects and health risks. Many women notice that they need to use extra lubrication during sex to be comfortable. This method doesn't protect against STDs.

How to use the lactational amenorrhea method. If you decide to use the lactational amenorrhea method, you must breast-feed your baby at least eight to 10 times a day, including at least once a night, on both breasts. Don't allow more than six hours to pass between any two feedings.

Cost and availability. Using the lactational amenorrhea method costs nothing, but classes that teach this technique may charge fees, which vary from region to region.

Standard days birth control method

The standard days method requires abstaining from unprotected sex on certain days of your menstrual cycle — the days you're most likely to conceive. You keep track of your cycle by using a special string of beads, known as CycleBeads. The standard days method works for a woman who:

• Has regular menstrual cycles
• Has menstrual cycles not shorter than 26 days or longer than 32 days
• Has a cooperative partner
• Avoids unprotected sex on days eight through 19 of her menstrual cycle

Effectiveness rate. The typical effectiveness rate among users of the standard days method is 88 percent. That means that 12 out of 100 women practicing this method for one year will get pregnant.

Side effects and health risks. The major downside of using the standard days method is the requirement for prolonged abstinence. This method doesn't protect against STDs.

How to use the standard days method. If you decide to use the standard days method, CycleBeads can help you keep track of which days you're most fertile. This string of beads contains 32 colored beads that each represent one day of your cycle. Here are some tips on using these beads effectively:

• On the first day of your period, move the rubber ring attached to the string of CycleBeads to the red bead.
• Advance the rubber ring one bead for each day that passes.
• If the rubber ring is on a brown-colored bead, you're unlikely to get pregnant if you have unprotected sex on that day.
• If the rubber ring is on a white-colored bead, pregnancy is likely on that day, so you should abstain from unprotected sex.

In your late 30s or early 40s, your menstrual cycles tend to shorten. In that case, the fertile phase may begin on day five rather than day eight.

Cost and availability. The standard days method uses CycleBeads — at a cost of about $14 — to help you keep track of your fertile days.

Symptothermal birth control method

The symptothermal method involves combining several of the natural family planning methods — including, at least, the basal body temperature and mucus methods — to prevent pregnancy. These methods can be checked against each other to determine the beginning and the end of the fertile period. Using a combination of methods increases the effectiveness rate, compared with other natural methods.

Effectiveness rate. The effectiveness rate among users of the symptothermal method is typically 98 percent, meaning that two women out of 100 will get pregnant while using this method for one year. Women who have unpredictable periods, irregular body temperature patterns or recurrent reproductive tract infections shouldn't rely on this method.

How to use the symptothermal method. If you decide to use the symptothermal method, use the basal body temperature and cervical mucus methods at the same time. The calendar method, the position and feel of your cervix, and any pain during ovulation, any breast tenderness, or both, can be other indicators of fertility.

Side effects and health risks. The downside to the symptothermal method is the requirement for a prolonged period of abstinence or barrier methods and the time used to perform the monitoring methods. The method doesn't protect against STDs.

Cost and availability. Using the symptothermal method costs nothing, but classes that teach this technique may charge fees, which vary from region to region.

Natural family planning: Pros and cons

Natural family planning helps you gain self-awareness and knowledge of your fertility. But it requires considerable diligence and training. To help you decide if it's right for you, keep the following points in mind:

Sterilization

The reproductive life span for men and women encompasses many years. Healthy women are fertile until about the age of 50. Healthy men are fertile essentially throughout adult life. Sterilization was first introduced as a means of family planning for women 40 and older who had eight or more children. Sterilization became more common by the late 1960s, and today, many couples opt for sterilization as a permanent means of birth control.

Sterilization methods include:

• For women — tubal ligation and Essure coils
• For men — vasectomy

Essure

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Placing the Essure coil

Essure is a permanent birth control method in which tiny metal coils are placed in a woman's fallopian tubes. Over time, scar tissue grows in and around these coils, which block the tubes so that sperm can't reach a woman's eggs. It's unlike other sterilization procedures because it doesn't require incisions.

The flexible coil is 4 centimeters in length. It expands to a diameter of 1 to 2 millimeters once in place.

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Effectiveness rate. Essure has an effectiveness rate of 99.7 percent to 99.8 percent. That means two to three women out of 1,000 who rely on this method will get pregnant. Essure isn't intended for women who might wish to become pregnant in the future.

Side effects and health risks. The most commonly reported side effects in the clinical studies included mild to moderate pain during the procedure and vaginal bleeding for a few days afterward. The rare pregnancy that occurs after the Essure procedure is more likely to be a tubal ectopic pregnancy, one in which the fertilized egg starts developing in the fallopian tube. Ectopic pregnancies require immediate surgical removal, or the fallopian tube could rupture. Essure doesn't protect against STDs.

What to expect. Before the coils are placed, you receive a local anesthetic. Your doctor then inserts a narrow instrument called a hysteroscope into your vagina, through your cervix and into your uterus. The hysteroscope is connected to a video monitor, allowing your doctor to see the openings of your fallopian tubes and place the tiny coils inside them, using a small catheter attached to the hysteroscope. During the three months following the procedure, you must use another type of birth control. After three months, you get an X-ray to confirm that your fallopian tubes are blocked. If the procedure is successful, you can stop using backup birth control.

Cost. The cost of Essure ranges from about $1,300 to $3,500.

Tubal ligation

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Tubal ligation

Tubal ligation is a permanent birth control procedure commonly known as "having your tubes tied." The procedure prevents pregnancy by preventing transport of the egg to the uterus and by blocking the passage of sperm up the fallopian tube to the egg.

Effectiveness rate. In the first year after tubal ligation, the effectiveness rate of this procedure is greater than 99 percent, meaning that less than one woman out of 100 may get pregnant. However, over time it's possible that the tubes could fuse back together. Effectiveness rates of 98 percent have been reported 10 years after the procedure.

Reversal. Although tubal sterilization may be reversible, doing so is difficult. A reversal requires microsurgery to reconnect tiny fallopian tubes. Generally, women who wish to become pregnant after having a tubal ligation will be offered in vitro fertilization, a procedure in which eggs are removed from a woman, fertilized by a man's sperm in the laboratory and implanted in the uterus.

Side effects and health risks. After surgery you may experience temporary side effects, such as fatigue, abdominal pain, dizziness, nausea, gassiness and shoulder pain. Rare complications from the surgery include a reaction to the anesthesia drugs, pelvic infection, bowel or bladder injury, and injury to blood vessels in the abdomen. The rare pregnancy that occurs after a tubal ligation procedure is more likely to be an ectopic pregnancy, in which the fertilized egg starts to develop in a fallopian tube. Ectopic pregnancies require immediate surgical removal, or the fallopian tube could rupture. Tubal ligation doesn't protect against STDs.

What to expect. For tubal ligation, one or two small incisions are made near your navel and above your pubic bone while you're under anesthesia. A laparoscope — a small, lighted magnifying device — is inserted through the incision next to your navel. Using instruments passed through the laparoscope, your doctor cauterizes and seals the fallopian tubes or closes them with plastic rings or clips. Tubal ligation can also be performed immediately after childbirth through a small incision near the navel, during a Caesarean section or through a small incision in the vagina.

Cost. The procedure costs between $2,500 and $4,000.

Vasectomy

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Vasectomy

A vasectomy provides permanent birth control for men. This procedure averts pregnancy by preventing the transport of sperm out of the testes.

Effectiveness rate. The effectiveness rate of a vasectomy is greater than 99 percent. Fewer than two men out of 1,000 who have this procedure will father a child. However, the procedure doesn't provide immediate protection against pregnancy, because a man's sperm count decreases gradually after the procedure rather than all at once. It takes about three months after vasectomy before sperm are no longer present in the semen. A semen specimen must be examined and found to be completely free of sperm before you can rely on a vasectomy for birth control.

Reversal. Most men who have a surgical reversal procedure are able to have children. However, vasectomy reversal is a complicated procedure requiring general anesthesia and a lengthy operation. Vasectomy should be performed only if a man is certain he never wants to father another child.

Side effects and health risks. Serious side effects with a vasectomy are extremely rare, although swelling and bruising of the scrotum occasionally occur. One rare complication is an infection, which is characterized by a fever, blood or pus oozing from the incision site, and excessive pain, swelling or both. An infection is treatable with antibiotics. The surgery doesn't affect a man's ability to achieve an erection, to have an orgasm or to ejaculate. A vasectomy doesn't protect against STDs.

Although a few researchers have suggested that vasectomy increases the risk of prostate or testicular cancer, many recent and carefully designed studies have found no such association.

What to expect. If you decide on a vasectomy, a small incision is made in the upper part of the scrotum after you receive a local anesthetic. The vasa deferentia may be tied off, cauterized or blocked with surgical clips.

Cost. The cost of a vasectomy generally ranges between $250 and $1,000.

Sterilization: Pros and cons

Sterilization provides permanent birth control. This may be desirable if you don't want to have children, but it's difficult to reverse if you later change your mind. To help you decide if sterilization is right for you, keep the following points in mind:

Withdrawal birth control method

Withdrawal, formally known as coitus interruptus, is the pseudo-contraceptive practice in which a man removes his penis from a woman's vagina and away from her external genitalia before ejaculating. This method attempts to prevent sperm from entering a woman's vagina.

Effectiveness rate. Sperm are often released before ejaculation, rendering the technique ineffective. The typical effectiveness rate is 73 percent, so about 27 out of 100 women relying on this method will get pregnant.

Cost and availability. The withdrawal method costs nothing, requires no devices and is available in any situation. But it's not an effective birth control option when used without a backup means of contraception.

Withdrawal: Pros and cons

Withdrawal isn't a reliable method of preventing pregnancy. But it's better than no method at all. Keep the following points in mind:

Emergency birth control

Emergency birth control is a method of preventing pregnancy used after a contraceptive method fails or after unprotected sex. It prevents pregnancy by inhibiting ovulation, fertilization or implantation.

Two types of emergency birth control are available:

• Emergency contraceptive pills (ECPs)
• Intrauterine device (IUD)

A number of oral contraceptives can be used for emergency contraception in the United States, but Plan B is the only FDA-approved product specifically marketed for such purposes.

Plan B. The first Plan B tablet is taken as soon as possible within three days of intercourse, and the second tablet must be taken 12 hours later. When taken properly, Plan B is effective at preventing pregnancy. On average, eight out of 100 women who have unprotected sex during the fertile part of their cycles will become pregnant. But only one to two women out of 100 will become pregnant after taking Plan B. Occasional side effects include nausea, abdominal pain, fatigue, headache and menstrual changes. Plan B is available to women and girls age 17 and older without a prescription at most pharmacies. You must show proof of age to purchase Plan B. For girls age 16 and younger, Plan B is available only with a doctor's prescription.

Copper IUD. The copper IUD (ParaGard) is another method of emergency contraception. The device must be inserted within five days of unprotected sex. The effectiveness rate is 99 percent after insertion. That means that one out of 100 women using ParaGard may get pregnant. The IUD can be removed after a woman's next menstrual period or left in place for up to 10 years as a continual birth control system.

Emergency contraception: Pros and cons

Emergency contraception shouldn't be a substitute for regular use of safe and effective birth control. But unplanned and unprotected sex do occur, so emergency contraception fills an important need. Keep the following points in mind:

Emerging birth control methods

A number of promising birth control methods are currently in development. These include innovations in the following:

• Chemical barriers
• Hormonal implants
• Transcervical sterilization
• Immunocontraceptives
• Fertility computers
• Male contraception

Chemical barriers. Three contraceptive microbicides — Pro 2000 or Pro 2000/5, Carraguard and cellulose sulfate — work by inhibiting sperm function and the attachment of disease-causing organisms to healthy cells. They are used like traditional spermicides, but are also being evaluated for their ability to prevent the spread of HIV. Other products, such as BufferGel, maintain an acidic environment in the vagina, disabling sperm.

Hormonal implants. Jadelle — the second generation of Norplant — consists of two progestin-releasing rods instead of Norplant's six capsules. Jadelle has effectiveness rates similar to those of Norplant, but it's easier to insert and remove than Norplant. Although not for sale in the United States at this time, Jadelle may be available in the future if a U.S. distributor is found. Another type of hormonal contraceptive is Nestorone, which is specifically designed for breast-feeding women. It's being tested as an implant, vaginal ring and patch.

Transcervical sterilization. Similar to the Essure system, two other methods to block the fallopian tubes by way of the cervix are being investigated. The first method involves a drug called quinacrine, which traditionally was used to treat malaria. Quinacrine pellets inserted in the fallopian tubes may effectively block the tubes and provide sterilization. The second method, known as the Adiana procedure, uses low-level radiofrequency energy to create lesions in the fallopian tubes. Plastic implants inserted into the lesions cause scar tissue to develop, blocking the tubes to provide sterilization.

Immunocontraceptives. Immunocontraceptives are vaccines that stimulate the body's defense system to interrupt the reproductive process. A vaccine intended to inhibit a hormone called human chorionic gonadotropin, which is necessary for pregnancy to occur, has undergone preliminary clinical studies.

Fertility computers. There are minicomputers currently on the market that indicate which days a woman is fertile based on the hormone levels in her urine. Fertile days are indicated by a red light and infertile days with a green light, for example. The effectiveness of these devices hasn't been demonstrated by scientific testing. A similar device, the Clearblue Easy Fertility Monitor, also is available, but it's used to achieve pregnancy. Some people use the fertility monitor to avoid pregnancy, but it hasn't been evaluated as an aid in natural family planning methods.

Male contraception. Developing reversible birth control for men is difficult. Here are a few potential contraceptive methods under investigation:

• Hormones — monthly or bimonthly injections with testosterone undecanoate, a hormone that reduces sperm production, greatly reduce sperm counts
• Battery-powered capsules — capsules implanted in each vas deferens that emit low-level electrical currents, immobilizing sperm
• Silicone plugs — tiny silicone cylinders inserted into each vas deferens to block them
• Sperm-blocking gel — injected into the vasa deferens, the gel partially blocks the tubes that carry sperm and disables any sperm that do get through

Things to consider about birth control

Your age, health, emotional maturity, marital status and even your religious convictions come into play when you choose a contraceptive method. Knowing your options is part of the decision process, but an honest assessment of yourself, your partner and your relationship is just as important. Most people have to make some trade-offs. They will, for instance, deal with the mild side effects of some hormonal contraceptives in exchange for superior effectiveness, or forgo the convenience of an IUD for the low cost of a barrier method. Ideally, you and your partner can discuss the options and reach a mutually beneficial decision. For complete information, consider raising the following questions with your health care professional.

What is the method's effectiveness?
The efficacy of any method depends on whether it's used consistently and correctly. Still, the failure rates of some methods are significantly higher than others'. Different people are satisfied with varying levels of effectiveness.

Is it reversible?
The method you choose depends on your life stage and reproductive goals. If you plan to have children at some point in the future, you may want a method that's easily stopped or quickly reversible. If you're certain that you would never desire pregnancy, you may prefer a permanent method.

Is it convenient?
The word "convenient" can be defined in a number of ways, depending on your perspective. For some, convenience means fewer trips to a health care professional. If your schedule is chaotic, you might want to select a method that doesn't require much planning or adhering to a rigid schedule. In that case, a method that's long-acting might fit more easily into your daily routine. For others, the idea of convenience suggests ease of use, no bothersome side effects or no disruption of the sexual experience. It's important to decide what type of birth control is best tailored to your lifestyle.

Can you afford it?
Some methods are inexpensive, while others can be more costly. Consult with your insurance provider if you're unsure about your coverage, and then weigh the expense factor in your choice.

Are health risks involved?
You may want to consider your tolerance for the possible side effects associated with a particular birth control method. Allergic responses to various components of contraceptives could be another determining factor. Some methods, particularly those that contain estrogen, pose the risk of rare but serious side effects. These may occur more often in women with specific characteristics, such as those who smoke and are 35 or older. Consider whether your medical history or lifestyle conflicts with the use of these methods.

Will the birth control method provide protection from STDs?
Unless you're in a mutually monogamous relationship, use condoms to protect yourself from contracting infections such as HIV/AIDS, genital herpes and gonorrhea.

Is the method acceptable to your sexual partner?
Your partner may have birth control preferences that are similar to or different from your own. Discussing all the birth control options with him or her helps you determine which method is acceptable to both of you.

Is the method compatible with your religious beliefs or cultural practices?
Some forms of birth control may be considered a violation of certain religious laws or cultural traditions. Weigh the techniques described here against your particular convictions.

Does the method offer any noncontraceptive benefits?
Besides preventing pregnancy, some contraceptives provide additional benefits such as more predictable, lighter menstrual cycles or a decreased risk of STDs. If these benefits are important to you, they may influence your birth control decision.

At-a-glimpse comparison of birth control methods

*Note: OTC means "over the counter."

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