Contraceptive injection offers effective option
Executive Summary
Injectable contraception in the form of depot medroxyprogesterone acetate (DMPA) provides birth control for women who desire convenience, but are unable to use or do not want to commit to a long-acting reversible contraceptive.
• The perfect use first-year failure rate for DMPA has been reported as two per 1,000 women. In large Phase 3 trials of the subcutaneous formulation, no pregnancies have been reported.
• While routine repeat DMPA injections should be administered every three months or 13 weeks, injections can be provided before this time when needed, and repeat injections can be given up to two weeks late (15 weeks from the last injection) without requiring additional contraceptive protection.
The next patient in your office is a 17-year-old young mother whose busy schedule conflicts with remembering to take a daily birth control pill, the method she chose at her postpartum visit. She is not interested in using such top-tier effective methods as the contraceptive implant and intrauterine device. What methods might offer the best fit for her?
Injectable contraception in the form of depot medroxyprogesterone acetate (DMPA) provides birth control for women who desire convenience, but are unable to use or do not want to commit to a long-acting reversible contraceptive. According to a new commentary on the subject, among users who return for repeat injections, DMPA represents an effective contraceptive.1 The perfect use first-year failure rate for DMPA, including the weighted average of the results from seven trials of the intramuscular (IM) formulation (available in the United States as generic) and two trials of the 104 mg subcutaneous (SC) formulation, has been reported as two per 1,000 women.2 In large Phase 3 trials of the SC formulation, no pregnancies have been reported.3
Whether a woman chooses to use the intramuscular or subcutaneous formulation of DMPA, clinicians have traditionally counseled for return for reinjections every three months. Reinjections do get missed. The percentage of women experiencing an unintended pregnancy during the first year of typical use with DMPA is 6%.1,2
Good news: The grace period for repeat injections is longer than previously thought. The 2013 "Selected Practice Recommendations for Contraceptive Use" (SPR)4 indicates that while routine repeat DMPA injections should be administered every three months or 13 weeks, injections can be provided before this time when needed, and repeat injections can be given up to two weeks late (15 weeks from the last injection) without requiring additional contraceptive protection.5 The SPR goes on to state that a woman more than two weeks late (beyond 15 weeks from the last injection) can have the shot if it is reasonably certain she is not pregnant. Such women should abstain from sexual intercourse or use back-up contraception for the next seven days.4
Self-injection option?
What if women could administer their own shots of SC DMPA? In the first reported randomized trial of self-administration versus office-based administration of SC DMPA, findings were consistent with earlier reports that many U.S. DMPA users are interested in self-administration.6
Although several small studies were published prior to the trial, the study was conceived during the annual Fellowship in Family Planning Meeting in 2008, says Anitra Beasley, MD, MPH, assistant professor in the Department of Obstetrics and Gynecology in the Baylor College of Medicine in Houston.
"The thought behind the study was that DMPA is an incredibly effective contraceptive and has great uptake with a good portion of the population; however, its use is greatly limited by the need for regular provider visits," observes Beasley. "The hope was that we could show that self-administration was acceptable to users, feasible, and that eliminating the need for provider visits would increase method continuation."
A total of 137 women ages 18 and older enrolled in the study; of these, 91 were allocated to self-administration, and 90 out of 91 were able to correctly self-administer SC DMPA. Eighty-seven percent completed follow-up. DMPA use at one year was 71% for the self-administration group and 63% for the clinic group (p = 0.47). Uninterrupted DMPA use was 47% and 48% for the self and clinic administration groups at one year (p = 0.70), respectively. Serum analyses confirmed similar mean DMPA levels in both groups and therapeutic trough levels in all participants, demonstrating that efficacy in women who self-injected SC DMPA should be as high as that seen with injections given in an office setting.1
Although DMPA represents a second-tier contraceptive when compared with IUDs and the implant, some women seeking effective contraception don’t have access to these latter methods or choose not to use them, observes Andrew Kaunitz, MD, professor and associate chair in the Obstetrics and Gynecology Department at the University of Florida College of Medicine — Jacksonville. Kaunitz served as a co-author of the current commentary.
"The safety, effectiveness experienced by women who return for repeat injections, convenience — along with the potential for self-administration of SC DMPA, and noncontraceptive benefits underscore injectable contraception’ s importance for women in the U.S. and worldwide," states Kaunitz.
While DMPA does cause declines in bone density, such declines are reversible, he states. DMPA has not been found to cause osteoporosis or fractures.6-9
"The Food and Drug Administration’s addition of the black box warning label, which is not evidence-based, has inappropriately prevented many clinicians from recommending and patients from using/continuing DMPA," states Kaunitz. "Skeletal health concerns should not prevent initiation or continuation of DMPA contraception." (To read more on the warning label, see the Contraceptive Technology Update article, "DMPA: Time to repeal black box warning?" October 2011, p. 112.)
- Kaunitz AM, Peipert JF, Grimes DA. Injectable contraception: issues and opportunities. Contraception 2014; doi: 10.1016/j.contraception.2014.03.014.
- Trussell J. Contraceptive failure in the United States. Contraception 2011; 83:397-404.
- Jain J, Jakimiuk AJ, Bode FR, et al. Contraceptive efficacy and safety of DMPA-SC. Contraception 2004; 70:269-275.
- Centers for Disease Control and Prevention. U.S. Selected Practice Recommendations for Contraceptive Use, 2013. MMWR Early Release 2013; 62:1-60.
- Steiner MJ, Kwok C, Stanback J, et al. Injectable contraception: what should the longest interval be for reinjections? Contraception 2008; 77:410-414.
- Beasley A, White KO, Cremers S, et al. Randomized clinical trial of self versus clinical administration of subcutaneous depot medroxyprogesterone acetate. Contraception 2014; doi:10.1016/j.contraception.2014.01.026.
- Cundy T, Cornish J, Roberts H, et al. Menopausal bone loss nd less than 7% of males ages 13-17 completed the shot series.
- Orr-Walker BJ, Evans MC, Ames RW, et al. The effect of past use of the injectable contraceptive depot medroxyprogesterone acetate on bone mineral density in normal postmenopausal women. Clin Endocrinol (Oxf) 1998;49:615-618.
- Viola AS, Castro S, Marchi NM, et al. Long-term assessment of forearm bone mineral density in postmenopausal former users of depot medroxyprogesterone acetate. Contraception 2011; 84:122-127.
