From Medscape Ob/Gyn > Viewpoints
Effectiveness of Long-Acting Reversible Contraception
Winner B, Peipert JF, Zhao Q, et al
N Engl J Med. 2012;366:1998-2007
N Engl J Med. 2012;366:1998-2007
Contraceptive Methods
Contraception is used for 2 reasons. First for birth control, but also because most methods offer noncontraceptive benefits. For example, oral contraceptives can be used to manage hirsutism, dysmenorrhea, and menorrhagia; a progesterone intrauterine device (IUD) is also highly effective in treating menorrhagia.
The efficacy of different contraceptive methods in preventing pregnancy varies and is influenced by whether the method is used "perfectly" or "typically." The efficacy of a few methods of contraception (tubal ligation, subdermal implants) is independent of the user, but most methods are dependent on the level of compliance. Compliance is generally not perfect; therefore, in a small proportion of users, the contraceptive method will fail and pregnancy can ensue. Contraceptive failure is the most common reason for undesired pregnancy. About half of all pregnancies are unplanned, and about half of these are terminated. This puts the patient at risk and is associated with psychological consequences and significant healthcare expenses
Women can select from numerous contraceptive options. Patients with different backgrounds (eg, age, socioeconomic status, education, parity) typically choose different methods, but the healthcare provider plays an equally important role in decision-making. Contraception is expensive; therefore, insurance coverage also influences the decision.
The study by Winner and colleagues compared the efficacy of long-acting, reversible methods of contraception (subdermal implant, IUD) in a large group of women at risk for pregnancy with that of depot medroxyprogesterone acetate injection (DMPA; Depo-Provera®; Pfizer, New York, New York) and other shorter-acting hormone preparations (pill, patch, vaginal ring).
Study Summary
A total of 7486 women participated in the study. All contraceptive methods were free for 2-3 years. The patient was allowed to select the method (and to switch methods if needed) after appropriate counseling. Conception that occurred while using the method was considered a contraceptive failure.
Women who chose the pill, patch, or ring were more likely to be nulliparous and to have private insurance. These women also had fewer previous unintended pregnancies. DMPA users were more likely to be black and to have less education and lower socioeconomic status. Women who selected IUDs or implants were more likely to be older and to be parous.
During the study period, the participants had a total of 156 unintended pregnancies. These women were younger, had lower socioeconomic status, were more likely to be black, and were more likely to have previous undesired pregnancies. Women who used IUDs or implants had a level of risk for unintended pregnancy similar to that of DMPA users. Risk for unintended pregnancy was significantly higher in pill, patch,and ring users (hazard ratio. 21; 95% confidence interval, 13.67-34.88). Younger (under 21 years of age) pill users had a 2-fold increased risk for unintended pregnancy than older pill users. Winner and colleagues concluded that the effectiveness of long-acting reversible contraception is superior to that of the contraceptive pill, patch, or ring and is not altered in adolescents and young women.
Viewpoint
No contraceptive method provides 100% efficacy, but with perfect use, hormonal contraception, long-acting implants, IUDs, and tubal ligation are associated with failure rates of less than 1%. Most methods are associated with higher failure rates with ordinary (typical) use.
The choice of contraception depends on several factors. Reversibility and interference with everyday life are important considerations for some women, whereas other women need a method that also protects them from sexually transmitted infections. Multiparous women typically choose longer-acting methods or may decide on tubal ligation. Parous women also more often select IUDs. Younger women are more likely to choose short-acting hormonal or barrier contraception. They are also more likely to be noncompliant and thus at higher risk for unintended pregnancy. Multiparous women tend to be more compliant, and because pregnancy rates also decline with age, the risk for undesired pregnancy diminishes over time.
Unintended pregnancies should be prevented in all age groups, and especially among nulliparous women who tend to have more psychological consequences. Longer-acting methods that are less user-dependent may be the best options for these women. In well-screened cases, IUDs or subdermal implants may be good choices. DMPA is another option, but the patient needs to be educated about the potential side effects to improve long-term compliance. All women who select long-acting methods should be educated about the prevention of sexually transmitted infections because these options do not protect against these diseases.
Finally, the method must be affordable to the patient. Inability to pay might be a reason for lack of contraception or noncompliance. The costs of contraception should be balanced against the expenses associated with pregnancy termination. This study shows the huge difference in unintended pregnancy rates with short- and long-acting contraceptive methods in favor of the long-acting methods. Counseling should include a discussion of the benefits of long-acting reversible contraception when patients seek medical advice with regard to their contraceptive options
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