Researchers and clinicians have long known that copper intrauterine devices (IUDs) work extremely well for emergency contraception. But few bothered to examine the possibility of using hormonal IUDs for the same purpose.
Now, in a first-of-its-kind study, University of Utah Health scientists found that hormonal IUDs were comparable to copper IUDs for use as emergency contraceptives. The researchers say the finding supports adding hormonal IUDs to current emergency contraception options. They conclude that using hormonal IUDs could have dramatic effects on emergency contraception, including reducing menstrual bleeding and cramping associated with copper IUDs.
The study appears in the Jan. 28 issue of the New England Journal of Medicine.
"These findings support using hormonal IUDs as a safe and viable alternative for women seeking to prevent pregnancies up to five days after intercourse," says David Turok, M.D., M.P.H., lead author of the study and an associate professor in the Department of Obstetrics and Gynecology at U of U Health. "As an emergency contraceptive, it appears to be no worse than a copper IUD and is way better than the morning-after pill."
He adds, "And, unlike emergency contraception pills, hormonal IUDs can continue to provide highly effective contraception for up to seven years."
The risk of pregnancy after using morning-after pills is about 2%, Turok says. In comparison, the 0.1% risk of pregnancy with copper IUDs is far less. In this study, the risk with hormonal IUDs was 0.3% and statistically was not less effective than the copper IUD.
All hormonal IUDs approved in the U.S. contain a synthetic version of the hormone progesterone called levonorgestrel (LNG). This study used the Liletta IUD; Mirena, another type of hormonal IUD, uses the same amount of LNG as Liletta.
When people are offered both hormonal and copper IUDs, they more frequently choose the LNG IUD. However, unlike copper IUDs, little or no research had been conducted on the LNG IUD use as an emergency contraceptive device. As a result, few, if any, medical providers have used LNG IUDs for this purpose.
To address this concern, the U of U Health researchers decided to test the effectiveness of LNG IUDs versus copper IUDs. Over a three-year period beginning in August 2016, they recruited more than 700 people, ages 18 to 35, who were seeking emergency contraception at six Utah Planned Parenthood clinics.
All of the participants had unprotected intercourse at least once in the previous five days. In addition, they had regular menstrual cycles, knew the date of their last menstrual period, had a negative urine pregnancy test, wanted to prevent pregnancy for at least a year, and were interested in using an IUD. The participants were randomly assigned to receive either an LNG or copper IUD. One month later, none of the 321 participants who received a copper IUD were pregnant. Pregnancy occurred in only one of the 317 participants who received LNG IUDs.
"While I assumed the hormonal IUD would work for emergency contraception, I was surprised to see it worked just as well as the copper IUD," says Lori Gawron, M.D., M.P.H., a study co-author and an assistant professor in the Department of Obstetrics and Gynecology at U of U Health. "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."
Turok adds that this research supports providing IUDs to those who want one at any point in the menstrual cycle, regardless of recent unprotected intercourse, giving women more opportunity for intervention than current medical recommendations.
The researchers obtained urine pregnancy tests from about 93% of the participants. They ruled out pregnancy in the remaining 7% based on survey information and clinical reports. Among other study limitations was that although participants were unaware which device they received in the first month of use, the nurse practitioners who placed them knew which device was implanted in each patient. That's because of distinct differences in the appearance of these IUDs.
The last new method of emergency contraception was approved for use by the Food & Drug Administration nearly 15 years ago. According to the researchers, LNG IUDs may become an attractive choice because they are used widely and are already FDA-approved for use as birth control.
"This is all about increasing access and options for people," Turok says. "It's about supporting their opportunity to live the life they want and have meaningful sexual relationships in ways that are not tied to pregnancy."
More information: New England Journal of Medicine (2021). DOI: 10.1056/NEJMoa2022141
Journal information: New England Journal of Medicine
Provided by University of Utah Health Sciences