Long-acting reversible contraceptive ( LARC ) methods—namely intrauterine devices ( IUDs ) and implants—are the most effective forms of reversible contraception available and are safe for use by almost all reproductive-age women, according to a Practice Bulletin released by The American College of Obstetricians and Gynecologists ( The College ). The new recommendations offer guidance to ob-gyns in selecting appropriate candidates for LARCs and managing clinical issues that may arise with their use.
"LARC methods are the best tool we have to fight against unintended pregnancies, which currently account for 49% of US pregnancies each year," said Eve Espey, MD, MPH, who helped develop the new Practice Bulletin. "The major advantage is that after insertion, LARCs work without having to do anything else. There's no maintenance required."
More than half of women who have an unplanned pregnancy were using contraception. The majority of unintended pregnancies among contraceptive users occur because of inconsistent or incorrect contraceptive use. LARCs have the highest continuation rates of all reversible contraceptives, a key factor in contraceptive success.
IUDs and contraceptive implants must be inserted in a doctor's office. Two types of IUDs—small, T-shaped devices that are inserted into the uterus—are available. The copper IUD, which effectively prevents pregnancy for 10 years, releases a small amount of copper into the uterus, preventing fertilization. In addition, copper interferes with the sperm's ability to move through the uterus and into the fallopian tubes. The device can also be used for emergency contraception when inserted within five days of unprotected sex.
Women using the copper IUD will continue to ovulate, and menstrual bleeding and cramping may increase at first. Though data suggest that these symptoms lessen over time, heavy menstrual bleeding and pain during menstruation ( dysmenorrhea ) are main causes of discontinuation among long-term copper IUD users. Women considering IUDs should be informed of this adverse effect beforehand.
The hormonal IUD releases progestin into the uterus that thickens cervical mucus and thins the uterine lining. It may also make the sperm less active, decreasing the ability of egg and sperm to remain viable in the fallopian tube. The hormonal IUD may make menstrual cycles lighter and is also FDA-approved for the treatment of heavy bleeding. The hormonal IUD prevents pregnancy for five years.
The contraceptive implant is a matchstick-sized rod that is inserted under the skin of the upper arm and allows the controlled release of an ovulation-suppressing hormone for up to three years. It is the most effective method of reversible contraception available with a pregnancy rate of 0.05%.
Despite the many benefits of LARC methods, the majority of women in the US who use birth control choose other methods. Fewer than 6% of women in the US used IUDs between 2006 and 2008. According to The College, lack of knowledge about LARCs and cost concerns may be to blame. "Women need to know that today's IUDs are much improved from earlier versions, and complications are extremely rare. IUDs are not abortifacients—they work before pregnancy is established—and are safe for the majority of women, including adolescents and women who have never had children. And while upfront costs may be higher, LARCs are much more cost-effective than other contraceptive methods in the long run," Dr. Espey said.
According to a December 2009 Committee Opinion released by The College, LARCs should be offered as first-line contraceptive methods and encouraged as options for most women. "The benefits of IUDs and the contraceptive implant in preventing unplanned pregnancy could be profound with widespread adoption of these methods, and ob-gyns are in a great position to effect change," Dr. Espey said.
Practice Bulletin #121 "Long-Acting Reversible Contraception: Implants and Intrauterine Devices" is published in the July 2011 issue of Obstetrics & Gynecology.