Levonorgestrel vs. Copper Intrauterine Devices for Emergency Contraception

Two methods of emergency contraception are currently available in the United States. One is the copper intrauterine device (IUD) and the other is the morning after pill — as either oral levonorgestrel or ulipristal acetate. Unlike the copper IUD, the oral emergency contraception options do not provide long-term contraception.

For long-term contraception, the levonorgestrel IUD is preferred over the copper IUD because the copper IUD is associated with dysmenorrhea and discomfort. However, limited data are available regarding the efficacy of the levonorgestrel IUD for use as emergency contraception.  

In a noninferiority trial conducted at family planning clinics in Utah, researchers randomized 711 women who requested emergency contraception, after at least one episode of unprotected intercourse in the previous 5 days, to receive the levonorgestrel IUD or the copper IUD. The prespecified noninferior margin was 2.5 percentage points.  

The levonorgestrel IUD was noninferior to copper IUD for emergency contraception; the 1-month positive pregnancy test rate after IUD insertion was 1 in 317 (0.3%, 95% confidence interval [CI], 0.01 to 1.7) in the levonorgestrel IUD group and 0 in 321 (0%; 95% CI, 0 to 1.1) in the copper IUD group (between-group absolute difference, 0.3 percentage points; 95% CI, -0.9 to 1.8). Adverse events during the first month of IUD placement (including bleeding, cramping and pain) occurred in 5.2% of participants in the levonorgestrel IU group and 4.9% in the copper IUD group.

This trial indicates that the levonorgestrel IUD was noninferior to the copper IUD for use as emergency contraception after unprotected sexual intercourse in the previous 5 days.

The following NEJM Journal Watch summary further explains the study.

Eleanor Bimla Schwarz, MD, MS reviewing Turok DK et al. N Engl J Med 2021 Jan 28

In the U.S., levonorgestrel IUDs are preferred over copper IUDs for long-term contraception because they reduce menstrual bleeding and cramping. How do these options measure up when used for emergency contraception? To assess the effectiveness of levonorgestrel versus copper IUDs, researchers in Utah conducted a randomized noninferiority study involving 711 women who had unprotected intercourse within 5 days prior to placement of either IUD and who wished to avoid pregnancy for at least 1 year.

Regardless of type of IUD placed, pregnancy rates were low (≤0.3%) and satisfaction was high among all participants.

Comment: Women of reproductive age should routinely be counseled about emergency contraception, including the option of prompt IUD placement. Whereas over-the-counter access to a levonorgestrel pill (Plan B) has some benefit in preventing pregnancy, a prescription for an ulipristal acetate pill (ella) is twice as effective — and placement of a levonorgestrel or copper IUD reduces risk for pregnancy tenfold. Thus, “door-to-device time” as a quality metric applies to both cardiac and contraceptive emergencies.

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Dr. Fernandes is an Endocrinologist at Rhode Island Hospital and Assistant Professor of Medicine at the Warren Alpert Medical School of Brown University. She was an NEJM editorial fellow from 2018-2019. She completed her fellowship in Endocrinology at the University of Vermont.