Long-acting reversible contraceptives: a review
Because of the high number of unintended pregnancies and the effectiveness of LARCs, they should be a first-line contraceptive option for most women.
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Nearly half of all pregnancies in the United States are unintended.1 Although the teen pregnancy rate has decreased since the 1990s, it is still higher than the rates in other developed countries. Long-acting reversible contraceptives (LARCs) are excellent choices for women at increased risk for unintended pregnancies.1 LARCs include intrauterine devices (IUDs) and implants. LARC methods are highly effective, and there are no issues with patient adherence.2 With oral contraceptives, patients must remember to take their pills daily. With contraceptive injections, patients must obtain their injections regularly. Even though the up-front costs are higher, LARCs are among the most cost-effective methods available because of their low failure rate.1 However, the rate of LARC use is low in the United States, at less than 10%.3 In the past, some providers discouraged adolescents and nulliparous women from using LARCs. The purpose of this article is to provide information on the available LARCs, discuss the 2016 US Medical Eligibility Criteria for Contraceptive Use (US MEC), and describe effective counseling strategies for patients wishing to use LARCs.
In addition to the high level of effectiveness of LARCs, the continuation rates for LARCs exceed those for non-LARC methods.4 The continuation rate at 12 months for the levonorgestrel IUD was 88%; similarly, 85% of women continued to use the nonhormonal copper IUD at 1 year.5 In comparison, the continuation rate for non-LARC methods was 57%. The satisfaction rate for the was 86% at 1 year and was 81% for the nonhormonal copper IUD. In contrast, 53% of women were satisfied with their chosen non-LARC method.5 An important aspect of LARC continuation and satisfaction rates is effective counseling. It is important to assist women in choosing contraceptive methods that meet their reproductive needs.1
The 2 classes of IUDs are the nonhormonal and hormonal IUDs (Table 1). The nonhormonal IUD is the copper IUD, Paragard, which is 32 by 36 mm in size. It has been approved for 10 years of use.6 The nonhormonal copper IUD is more than 99% effective. Some women have longer menstrual periods and heavier bleeding with this type of IUD, but the side effect may decrease after the first year of use.7
Currently, 4 hormonal IUDs are available. The Mirena IUD contains 52 mg of levonorgestrel, is 32 by 32 mm in size, and is approved for 5 years of use.6 Like the nonhormonal copper IUD, it is more than 99% effective. In addition, the Mirena IUD has been approved for the treatment of heavy menstrual bleeding, and approximately 20% of women have amenorrhea after 1 year of use.8 The Liletta IUD also contains 52 mg of levonorgestrel, is 32 by 32 mm in size, and is approved for 3 years of use. The Liletta IUD is more than 99% effective. It is now available with a single-handed insertion device to facilitate insertion.9
The Skyla IUD contains 13.5 mg of levonorgestrel,6 is 28 by 30 mm in size, and is more than 99% effective. The Skyla IUD is approved for 3 years of use. Nulliparous women were included in the clinical trials for Skyla, so it is approved for use in women regardless of their childbearing status. Fewer women have amenorrhea with the Skyla IUD because of the lower dose of levonorgestrel.8 The newest IUD is the Kyleena IUD, which became available in October 2016. The Kyleena IUD contains 19.5 mg of levonorgestrel and is 28 by 30 mm in size. It is more than 98.5% effective at preventing pregnancy, The Kyleena IUD is approved for 5 years of use. With the Kyleena IUD, irregular bleeding and spotting may occur for 3 to 6 months. However, with time, periods may be shorter and lighter, or even stop entirely.6