Long-Acting Reversible Contraception
Long-Acting Reversible Contraception
Abstract & Commentary
By Rebecca H. Allen, MD, MPH, Assistant Professor, Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, Women and Infants Hospital, Providence, RII, is Associate Editor for OB/GYN Clinical Alert.
Dr. Allen reports no financial relationships relevant to this field of study.
Synopsis: In this large prospective cohort study, women using the pill, patch, or ring were 22 times more likely to experience a contraceptive failure than those using the IUD, subdermal implant, and DMPA injection.
Source: Winner B, et al. Effectiveness of long-acting reversible contraception. N Engl J Med 2012;366:1998-2007.
The authors performed a prospective cohort study, the contraceptive CHOICE Project, in which women in the St. Louis, Missouri, region received a reversible contraceptive method of their choice for up to 3 years at no cost. The participants were read a standardized counseling script that stated that IUDs and the subdermal implant were the most effective methods of contraception. The women then chose their desired method and were followed prospectively so that contraception continuation and pregnancies could be ascertained. The first 7486 women who used an IUD, implant, depot medroxyprogesterone acetate (DMPA) injection, pills, patch, or ring were analyzed in this report, where the primary outcome was contraceptive failure. Contraceptive-method failure was defined as a pregnancy that occurred when the contraceptive method was actually being used. The women were divided into a long-acting reversible contraception (IUDs and implant) group, a DMPA group, and a pill/patch/ring (PPR) group.
Winner and her colleagues found 156 unintended pregnancies that were attributed to IUD, implant, DMPA, pill, patch, or ring failure. The failure rates for the PPR group were 4.8%, 7.8%, and 9.4% for years 1, 2, and 3, respectively. The corresponding rates for the long-acting reversible contraception (LARC) group were 0.3%, 0.6%, and 0.9% (P < 0.001) and the DMPA group was similar (0.1%, 0.7%, and 0.7% for years 1, 2, and 3, respectively). The risk of unintended pregnancy for the PPR group remained higher than the LARC group after controlling for age, educational level, and number of previous unintended pregnancies (hazard ratio 21.8, 95% confidence interval 13.7 to 34.9). The authors also determined that women younger than 21 years of age in the PPR group had almost twice the risk of unintended pregnancy as older women using these methods after controlling for educational level and previous unintended pregnancy (hazard ratio 1.9, 95% CI 1.2 to 2.8). Age did not impact contraceptive failure in the DMPA and LARC group.
Commentary
The authors conducted this study to provide reliable prospective data on contraceptive failure rates for different methods of reversible contraception. Previous estimates of contraceptive failure rates had been based on retrospective studies. Given that the pill, patch, and ring are user-dependent compared to the IUD and implant, it is not surprising that more contraceptive failures occurred in the PPR group. Having to remember to use a medication daily, weekly, or even monthly can be challenging, especially for the adolescents. Interestingly, the DMPA injection group did not differ from the LARC group in this study. This is likely because the authors categorized a pregnancy in DMPA users as a true contraceptive failure only in those compliant with injections. Therefore, this represents "perfect" use of DMPA rather than "typical" use where women might not adhere to injection schedules and failure rates will be higher.
In the United States, the unintended pregnancy rate currently stands at 49% and is a major public health problem.1 The most common reversible methods of contraception used in the United States are oral contraception and male condoms.2 As noted above, condoms and oral contraceptives are dependent on user adherence and therefore have higher failure rates among typical users. In contrast, LARC, due to its high efficacy and continuation rates, is considered in the top tier of contraceptive efficacy, as this study confirms. Rather than presenting all contraceptive options as equal alternatives, we should now be offering LARC as first-line contraceptive agents for women.3 The Contraceptive CHOICE Project investigators have previously reported continuation rates at 12 months of 88% for the levonorgestrel IUD, 84% for the copper IUD, and 83% for the subdermal implant.4 Satisfaction rates were also higher for LARC methods compared to other methods of contraception, such as oral contraceptives and DMPA. Unfortunately, as of 2008 in the United States, only 5.5% of women practicing contraception used IUDs, and implant users were even fewer.2 The advantages of LARC also include few contraindications and cost-effectiveness. Current guidelines for LARC use have expanded IUD eligibility to nulliparous and adolescent women.5 Therefore, almost all women are candidates for these methods and we need to do a better job of making LARC more accessible.
Of course, sometimes the question is how to convince our patients to try IUDs or the subdermal implant when they may fear side effects or having something "foreign" in their body. This study showed that with standardized counseling 5781 (77%) of 7486 women chose LARC methods. Adolescents in this project also had high uptake of both IUDs and implants.6 So what does their counseling script say?
One of our objectives is to be sure women are aware of all contraceptive options, especially the most effective, reversible, long-acting methods. These methods include intrauterine contraception (the IUD) and the subdermal implant called Implanon. IUDs are completely reversible contraceptive methods placed in the uterus. There are two types of IUD. One is hormonal and lasts up to 5 years (Mirena). The other, ParaGard, is nonhormonal, contains copper, and can last up to 10 years. Both may be removed at any time if you wish to become pregnant or want to switch to a new method. They are very safe and have the highest satisfaction and continuation rates of any contraceptive method. Implanon is a single flexible plastic rod placed under the skin of your upper arm. It is hormonal and lasts up to 3 years. It may also be removed if you wish to become pregnant or would like to switch to a different method. Do you have any questions about these methods?
I try to use this counseling message with my patients and also emphasize the fact that they should at least try an IUD or implant. If they don't like it, then it can be removed, but they will never know if they don't try.
References
- Finer LB, Henshaw SK. Disparities in rates of unintended pregnancy in the United States, 1994 and 2001. Perspect Sex Reprod Health 2006;38:90-96.
- Mosher WD, Jones J. Use of contraception in the United States: 1982-2008. Vital Health Statistics 2010;23:1-44.
- ACOG Committee Opinion no. 450: Increasing use of contraceptive implants and intrauterine devices to reduce unintended pregnancy. Obstet Gynecol 2009;114:1434-1438.
- Peipert JF, et al. Continuation and satisfaction of reversible contraception. Obstet Gynecol 2011;117:1105-1113.
- ACOG Committee Opinion No. 392: Intrauterine device and adolescents. Obstet Gynecol 2007;110:1493-1495.
- Mestad R, et al. Acceptance of long-acting reversible contraceptive methods by adolescent participants in the Contraceptive CHOICE Project. Contraception2011;84:493-498.
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