With so many birth control methods available, women who do not want to become pregnant have a wide variety of safe, highly effective choices. These include a number of approaches that use the actions of the female hormones estrogen and progestin to suppress ovulation (the monthly release of an egg from the ovaries), thus preventing fertilization.
In Update on Contraception, Part 1 we explored traditional birth control techniques, barrier methods and surgical options. Here in Part 2 we will discuss some of the more complex prescription birth control choices: birth control pills, injectable hormone contraceptives and intrauterine devices. Unlike barrier methods that must be inserted or worn immediately before and during intercourse, hormone methods provide continuous protection day and night. All these methods require a physician’s prescription.
“The Pill”
By far the most popular form of reversible birth control in the United States is the birth control pill, commonly called “the pill,” which was introduced more than 40 years ago. “When used appropriately, oral contraceptives have a low failure rate,” says Kathy A. King, MD, Assistant Professor of Obstetrics and Gynecology at the Medical College of Wisconsin. “But women must remember to take a pill every day,” she adds.
Women using the pill typically take one pill containing hormones every day for three weeks, then stop for one week, during which they have a menstrual period. They continue this cycle each month.
A new pill, Seasonale, has taken the traditional pill-taking method a step further. Instead of taking the pill for 21 days and stopping for a week, women would take it for 84 consecutive days, then stop for a week before resuming the cycle. Thus, women using this drug would only menstruate every three months, reducing the number of menstrual periods from 12 or 13 a year to four or five. Seasonale is not available yet, pending approval from the U.S. Food and Drug Administration (FDA), but Dr. King says physicians are already advising some women to take their pills for longer stretches of time.
“Seasonale is the same drug as standard combination pills. The only difference is how they are packaged,” says Dr. King. “The main reason the pill is traditionally taken on a monthly cycle is to reassure the patient every month that she’s not pregnant. The continuous pill regimen is advantageous for women with endometriosis, heavy periods or severe menstrual cramps.”
For the majority of women, continuous pill use (also known as tricycling) is highly effective and well-tolerated, says Dr. King, although some women may have problems with breakthrough bleeding or spotting. This occurs more frequently in women who smoke.
“And of course there are insurance issues,” she adds, “since policies that cover prescription drugs typically limit patients to one month’s supply.” Some insurance companies exclude birth control pills from coverage altogether. “And that’s a whole other problematic issue,” Dr. King says.
Less Hormone, Fewer Side Effects, Equal Efficacy
Today’s birth control pills use greatly reduced amounts of hormones, compared with the strength of pills used 20 to 40 years ago. Today’s pills contain 20 to 35 micrograms of estrogen, compared with the 50- to 100-microgram pills used in the past. These lower dose pills result in a safer, better tolerated pill with few side effects, Dr. King says. The most common initial side effects with today’s pill are irregular bleeding or spotting, nausea or breast tenderness. Other side effects such as headache, weight gain and depression are much less common. A study of pill use and acne showed a significant decrease in acne but no difference in headache frequency or weight gain for women taking the combined birth control pill vs. a placebo. “If women gain weight on the pill,” she says, “it is much more likely due to diet and exercise issues.”
“Because more than 50 different birth control pills are on the market,” Dr. King continues, “women who are having problems with side effects should contact their physicians and consider changing to a different pill, rather than stopping entirely.”
Breast Cancer Link ‘Controversial’
Whether the pill influences breast cancer risk remains controversial, with conflicting results from a number of studies, Dr. King says. The largest study to date, a 1996 meta-analysis of more than 50 studies, showed a small increase in the diagnosis of breast cancer in current pill users. This increased risk disappeared 10 years after stopping the pill. The risk of breast cancer was no greater among women who stopped using the pill 10 years earlier compared with the risk for women who never used the pill.
“Among pill users who were diagnosed with breast cancer, it was a less advanced and more treatable type,” she says. One interpretation of this is that the women who have taken the pill may be more likely to have an existing breast cancer diagnosed earlier because of their more frequent encounters with health care providers. ”There’s still not a lot of good evidence on this subject.”
Who Should Not Use the Pill
Women over 35 who smoke should not use the pill. And women with any of the following conditions are not candidates for the combined pill and should speak with their physicians about other birth control options, Dr. King says:
- A history of blood clots, including pulmonary embolism or genetic disorders that could produce blood clots
- Uncontrolled hypertension
- A history of stroke or heart attack
- Severe liver disease
- Migraine headaches with a neurological component
- Diabetes with retinopathy or kidney problems (diabetes alone does not preclude the use of the pill)
- Estrogen-dependent cancer of the breast or endometrium
Some women who have contraindications to the combined pill may be able to take progestin-only pills, sometimes called minipills. “Minipills are also an excellent option for women who are breast feeding,” Dr. King says, adding that there is a downside to minipills: “They’re unforgiving. They are only effective for 27 hours, so it’s important for women to take them faithfully at the same time every day. If they forget and are more than three hours late taking the pill, they should use a backup form of contraception for 48 hours." And because the minipill does not consistently prevent ovulation, women may have more problems with irregular bleeding.
The Pill and Drug Interactions
Certain medications may decrease the effectiveness of birth control pills, Dr. King notes. Women who take antiseizure drugs such as phenobarbital and Dilantin, the antibiotic rifampin or the antifungal griseofulvin may need the levels of their birth control pills adjusted, or they may need to use backup contraception methods. Women taking birth control pills may need the levels of certain other medications adjusted, including tricyclic antidepressants, antianxiety drugs such as Valium and Xanax, and bronchodilators like theophylline for asthma relief.
Additional Benefits, But No STD Protection
In addition to their convenience, oral contraceptives can provide benefits beyond pregnancy prevention. They can decrease menstrual bleeding and cramps, lower the risk of endometrial and ovarian cancer, and reduce the risk or lessen the effects of pelvic inflammatory disease. The pill can also help relieve the symptoms of perimenopause. However, the pill does not provide protection from sexually transmitted diseases (STDs), and at-risk pill users still need to protect themselves against them, Dr. King advises.
Emergency Contraception
Women who have had intercourse but have missed taking their regular contraceptive pills may, under their physician's direction, help prevent pregnancy by taking increased doses of their usual pills. This method can be used by women who normally take combination pills as well as by women taking progestin-only pills. Emergency contraception pills are usually taken in two doses, 12 hours apart. Women using the progestin-only contraceptive pill Ovrette would have to take 20 Ovrette pills as an emergency contraception dose.
Some women may find it simpler to use prepackaged emergency contraceptive pills, which are available by prescription under the brand names Preven and Plan B. Preven is a combination tablet; Plan B is a progestin-only pill. Preven is typically taken along with an anti-nausea medication. The risk of nausea is less with Plan B.
“Without emergency contraception, approximately 8% of women who had just one act of unprotected sex would be expected to become pregnant. If they used emergency protection, that declines to 1 to 2%,” Dr. King says. This method is most effective if used within 72 hours of unprotected intercourse, but a recent study showed that the method is still reasonably effective for up to five days.
'User-Friendly' Ring and Patch
Women may find two new hormonal birth control methods even easier to use than the pill, which might further reduce the likelihood of failure. A new contraceptive skin patch, the Ortho Evra, has just been introduced, and later this year a vaginal ring called the Organon NuvaRing is expected to be available. Women replace the skin patch once a week over three weeks, then stop for one week and have a menstrual period. The patches are reapplied after the fourth week, and the cycle starts over again. Similarly, the vaginal ring is worn for three weeks, and then stopped for a week for menstruation. Both methods are approximately 99% effective.
“Some methods are definitely more user-friendly and more reliable than others,” Dr. King says, “and pharmaceutical companies keep introducing new contraceptives that are easier than ever to use.”
Non-Pill Hormone Birth Control Methods
Injectable progestins. Depo-Provera, made from a progestin, is injected by a health professional into the buttocks or arm muscle every three months. “It offers up to 13 weeks of protection, although we instruct women to repeat their injection after 11 to12 weeks,” Dr. King says. “As long as patients remember to come back for their next injection, it’s highly effective and convenient.” The FDA estimates effectiveness at more than 99%.
But Depo-Provera can have side effects, Dr. King says. “Some women have irregular spotting and bleeding. Up to 25% discontinue Depo-Provera within the first year for that reason. There can be weight gain of 5 pounds over the first year; mood changes, including depression; and loss of bone density. Women who stop the injections so they can become pregnant may require 12 to 18 months before their baseline fertility returns, although the average is 10 months after the last injection.”
Depo-Provera prevents pregnancy three ways: It completely inhibits ovulation, it changes the cervical mucus to help prevent sperm from reaching the egg, and it changes the uterine lining to prevent the fertilized egg from implanting in the uterus.
A monthly injectable, Lunelle, has been available for more than a year. “The only downside is that it requires a regular monthly clinic visit,” Dr. King says. “Otherwise it is more than 99% effective and provides good menstrual cycle control.
Implantable progestins. No longer available is Norplant, a progestin-only contraceptive that was surgically implanted under the skin of the upper arm, and provided protection for up to five years. The FDA took it off the market in September 2000. “It appears that Norplant will never be reintroduced in the United States,” says Dr. King. “A single capsule implant called Implanon is in use in other countries, and it may be introduced into the United States within the next couple of years.”
Intrauterine Devices. Intrauterine devices, or IUDs, are inserted into the uterus by a health-care professional to provide long-term protection against pregnancy. IUDs are highly effective – 98 to 99%, according to the FDA. Two types are available in the United States: the Paragard Copper IUD, which can remain in place 10 years, and the Mirena – introduced about 18 months ago – which maintains its efficacy for five years.
“IUDs are an excellent option for women wanting long-term contraception but are uncertain if they want another child or want to avoid surgical sterilization,” says Dr. King. “I am very pro-IUD.”
Today’s IUDs have little risk of side effects. “According to the most recent data,” Dr. King says, “Paragard has not been associated with either an increased risk of PID (pelvic inflammatory disease) or infertility. The greatest risk of PID occurs within the first 20 days after insertion; otherwise, it is not a significant long-term risk.”
Mirena uses hormonal effects that may reduce PID risk. It’s important to screen patients beforehand to rule out whether they have some type of STD or other condition that affects their cervix or uterine lining, which may rule out an IUD, Dr. King says. She notes that IUDs provide no protection against STDs.
The copper IUD prevents pregnancy by its spermicidal effects. The Mirena IUD prevents pregnancy by its progestin effects. Until recently, Dr. King says, less than 1% of U.S. women used IUDs, although worldwide, more than 100 million women use them. “With the introduction of the Mirena IUD, the number is growing here. In addition, Mirena is effective in reducing menstrual blood loss and menstrual cramping.”
Article Created: 2002-06-13
Article Updated: 2002-06-19
MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.
