No difference in 1-year usage, pregnancy rates between hormonal, copper IUD users

Pregnancy rates and continued use of IUDs at 1 year after placement were similar between people using levonorgestrel and copper IUDs, according to data published in the American Journal of Obstetrics & Gynecology.

Although the copper IUD “revolutionized” the options available for emergency contraception by also providing protection against future pregnancy, many people searching for an IUD for nonemergency contraception opt to use the levonorgestrel IUD, according to study background.

“Outside of emergency contraception use, previous studies that randomized participants to IUD type do not provide long-term follow up pregnancy or continuation rates,” Jennifer E. Kaiser, MD, an assistant professor of OB/GYN and a family planning specialist at the University of Utah in Salt Lake City, and colleagues wrote. “However, one study that randomized participants to long-acting or short-acting methods did report that 78.4% continued their self-selected IUD for 1 year, and 0.7% experienced an unintended pregnancy.”

Kaiser and colleagues conducted a secondary analysis of the Randomized Controlled Trial Assessing Pregnancy for IUDs as Emergency Contraception (RAPID EC), which enrolled and randomly assigned participants 1:1 to levonorgestrel 52 mg or CuT380A (copper) IUD from August 2016 to December 2019.

In total, 327 participants were assigned to levonorgestrel IUD and 328 were assigned to copper IUD during presentation to one of six Utah family planning clinics for emergency contraception within 5 days of having unprotected intercourse. At 1 month, participants were informed of their type of IUD and were able to switch to the other type or have their IUD removed at no cost.

There were no significant differences in pregnancy rates at 1 year between participants assigned to levonorgestrel and copper IUD (2.8% vs. 3%). One pregnancy in each group was attributed to device failure. Five of nine participants using a levonorgestrel IUD and six of 10 participants in the copper group had the device removed in order to pursue pregnancy; of these, two in the levonorgestrel and three in the copper IUD groups conceived.

At 1 year, 62.4% of levonorgestrel IUD participants and 55.8% of copper IUD participants were still using their device. The difference in continuation rates was not significant.

Among participants who discontinued use, those assigned to levonorgestrel IUD were less likely to report excessive bleeding (RR = 0.6; 95% CI, 0.4-0.8) or excessive cramping (RR = 0.7; 95% CI, 0.6-0.9) as the reason for discontinuation compared with copper IUD users.

“The 1-year data we report demonstrates that 59% of IUD emergency contraception users continued IUD use for 1 year and this population, including those who discontinued the IUD, had low 1-year pregnancy rates,” Kaiser and colleagues wrote. “This further supports the levonorgestrel 52 mg IUD as an important option for emergency contraception and shows favorable IUD continuation and pregnancy rates over 1 year for users of both IUD types following emergency contraception placement.”

The researchers said future studies should investigate IUD use and pregnancy rate beyond 1 year after placement.