IUDs Most Effective

ACOG: IUDs, Implants Are Most Effective Reversible Contraceptives


Print This Post Print This Post
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 Congress of Obstetricians and Gynecologists (ACOG). The new recommendations offer guidance in selecting appropriate candidates for LARCs and managing clinical issues that may arise with their use.

More than half of the women who have an unplanned pregnancy were using contraception at the time they conceived. 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 United States who use birth control choose other methods. Less than 6% of U.S. women used IUDs between 2006 and 2008. According to ACOG, lack of knowledge about LARCs and cost concerns may be to blame. A spokesperson for ACOG notes, “Women need to know that today’s IUDs are much improved from earlier versions, and complications are extremely rare. They 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.”

Jill Shuman, MS, ELS
Published on July 12, 2011

Source: Practice Bulletin No. 121: Long-Acting Reversible Contraception: Implants and Intrauterine Devices. Obstet Gynecol. 2011;118(1):184-196.