WEDNESDAY, May 23, 2012 (HealthDay News) -- New research suggests that long-term birth control options, such as intrauterine devices (IUDs) and under-the-skin implants, are 20 times more effective for preventing pregnancy than short-term contraceptives, such as birth control pills, patches and rings.
"IUDs and implants are very effective; they rival tubal ligation in terms of preventing pregnancy," said study co-author Dr. Jeffrey Peipert, vice chair of clinical research at Washington University School of Medicine in St. Louis.
"Birth control pills work about 90 percent of the time," Peipert added. "When you think about the millions of women taking them, that's a lot of unintended pregnancies."
Results of the study are published in the May 24 issue of the New England Journal of Medicine.
In the United States, about half of all pregnancies are unplanned, according to the researchers. That rate is significantly higher than the rate in other developed nations, and it results in more than 1 million abortions each year. About half the unintended pregnancies occur because of contraceptive failure, often because of inconsistent or improper use, the study said.
The birth control pill, the most commonly used form of contraception in the United States, should be taken at the same time every day for best results. However, not everyone remembers to do that. "We're human, and we all make mistakes," said Peipert.
Those mistakes reduce the pill's effectiveness by about 9 percent, on average. In teenagers, failure rates are about 13 percent for the pill, according to the study. Other short-term birth control options include the birth control patch, the vaginal ring and a hormone shot that works for about three months.
Long-term, reversible birth control options include IUDs and implants. An IUD is a small, T-shaped device inserted into your uterus. "It's a simple office procedure that you can have the same day you talk to your doctor about it. It's inserted through a small tube, and it takes about 30 seconds," said Dr. Sarah J. Betstadt, an assistant professor in the department of obstetrics and gynecology at the University of Rochester Medical Center in New York.
The risk of complications is low, she said, adding that there's a slight risk of infection for about three weeks after IUD insertion. When a woman decides she wants to become pregnant, the device is easily removable. Some women who can't use birth control pills or other hormonal options, perhaps because of high blood pressure or a history of blood clots, can often use an IUD, she said.
A significant drawback to an IUD is often the up-front cost -- $500 to $1,000, according to Planned Parenthood -- which some insurance companies may not cover. But Peipert said other methods of birth control often cost more than that over the course of a year, so an IUD may actually be more cost-effective.
The other long-term contraceptive is an implant placed under your skin that releases the hormone progestin, which changes the cervical mucus and helps prevents the sperm and egg from joining.
Peipert's study included almost 7,500 women with an average age of about 24, who were counseled about the use and reliability of various contraceptives. They were nearly evenly divided between black and white, with between 7 percent and 8 percent from other races. Around 40 percent had completed at least some college.
The contraceptive failure rate for pills, patches and rings was 4.55 per 100 participant years. For the hormone shot, the failure rate was 0.22 per 100 participant years, and for IUDs and subdural implants, it was 0.27.
The risk of accidental pregnancy was 21.8 times higher for those using short-term methods, the authors said.
Women under 21 had about twice the rate of unplanned pregnancy as did older women using the same methods, reported the study.
"I recommend long-term options to all women who want to avoid pregnancy first. They should be the first-line option," said Peipert.
Peipert added it's extremely important for insurers to cover all contraceptive choices. "Part of family planning is prevention," he said. "We're already paying for a very high rate of unintended pregnancy through abortions, pre-term birth and the higher risk of complications women face in pregnancy. And young women who get pregnant might not finish their education or achieve as much in their careers."
Betstadt noted that many more contraceptive options are available now than in the past. "All of these options are safer than pregnancy," he said, "especially if you have any medical conditions."
IUDs fell out of favor in the 1970s, because of safety concerns linked to one model called the Dalkon Shield, which was withdrawn from the market. The IUDs on the market today are much improved, and the American College of Obstetricians and Gynecologists and other organizations consider them safe for most women.
More information
Learn more about available birth control options from the U.S. Department of Health and Human Services Office on Women's Health.
