Levonorgestrel IUD shows potential as emergency contraception

A levonorgestrel intrauterine device (IUD) may be a suitable alternative to a copper IUD for emergency contraception, according to results of the RAPID EC* trial from the US.

“As an emergency contraceptive, [the levonorgestrel IUD] appears to be no worse than a copper IUD and is way better than the morning-after pill,” noted study lead author Associate Professor David Turok from the University of Utah Health Sciences Center, Salt Lake City, Utah, US.

The study, conducted in six clinics in Utah, US, involved 711 women aged 18–35 years (mean age 24 years) who requested emergency contraception following ≥1 incidents of unprotected sexual intercourse within the past 5 days (average 2.1 incidents). They were randomized 1:1 to receive a levonorgestrel 52-mg or copper T380A IUD. The analysis comprises the 317 and 321 women in these respective groups who received the assigned IUDs and had outcomes at 1-month post-IUD insertion.

One-month following insertion of IUD, pregnancy rates did not significantly differ between women who received the levonorgestrel and copper IUDs (0.3 percent vs 0 percent; n=1 vs 0; between-group absolute difference, 0.3 percentage points, 95 percent confidence interval, -0.9 to 1.8). [N Engl J Med 2021;384:335-344]

Ultrasound examination at 10 weeks suggested that the pregnancy in the woman who received the levonorgestrel IUD was due to emergency contraception failure. Conception occurred due to a single incident of unprotected sexual intercourse 48 hours prior to IUD insertion and ended in spontaneous abortion at 10 weeks with IUD still inserted.

One woman who received the copper IUD experienced IUD expulsion on day 11 and underwent same-day reinsertion, while one levonorgestrel IUD recipient switched to a copper IUD on day 28.

Medical care for adverse events in the first month following IUD insertion was requested by 5.2 and 4.9 percent of women (n=17 and 16, respectively) who received the levonorgestrel and copper IUDs, respectively.

A comparable proportion of levonorgestrel and copper IUD recipients experienced IUD-associated pain (68.2 percent vs 67.7 percent). In the first month of IUD use, levonorgestrel and copper IUD recipients experienced a mean 10.8 and 7.2 bleeding days, respectively, and 11.0 and 5.7 spotting days.

“[P]ersons selecting an IUD for long-term contraception have shown a strong preference for the levonorgestrel IUD over the copper IUD, probably because the levonorgestrel IUD reduces menstrual bleeding and discomfort,” said the authors.

“[Findings of the present study] support using hormonal IUDs as a safe and viable alternative for women seeking to prevent pregnancies up to 5 days after intercourse,” said Turok.

The authors noted that while the study did not compare the levonorgestrel IUD with other emergency contraceptive options, pregnancy incidence with the levonorgestrel IUD in this study was “favourable” compared to that of oral emergency contraception (1.4–2.6 percent). [Lancet 2010;375:555-562; Lancet 2002;360:1803-1810]

Furthermore, the efficacy of the levonorgestrel IUD did not appear to be affected by BMI, in contrast to oral levonorgestrel, they continued.

“[U]nlike emergency contraception pills, hormonal IUDs can continue to provide highly effective contraception for up to 7 years,” added Turok.

“This finding is exciting because it will give people more options for both emergency and ongoing contraception and decrease barriers to same-day IUD placement when patients want one,” highlighted study co-author Assistant Professor Lori Gawron, also from the University of Utah.