Menstrual Cup Users at Increased Risk of IUD Displacement

Menstrual cup use was associated with a higher risk of intrauterine device (IUD) expulsion, according to an ongoing contraceptive efficacy trial of two copper IUDs.

Women that used a menstrual cup had a nearly fourfold increased risk of IUD displacement compared with non-users (odds ratio 3.81, 95% CI 2.45-5.92), reported Jill Long, MD, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, Maryland, and colleagues.

Two years after trial enrollment, around 17% of cup users experienced IUD expulsion compared with 5% of non-users, Long and colleagues reported in an abstract in Obstetrics & Gynecology. The study had been scheduled to be presented today at the American College of Obstetricians and Gynecologists (ACOG) annual meeting, which was canceled due to COVID-19.

The researchers also noted that around one-third of menstrual cup users who experienced expulsion said their IUD was dislodged during cup removal.

In an interview with MedPage Today, Long said her team was surprised by the rate of IUD expulsions they were seeing in the trial, and that the findings on increased risk may have new clinical implications for providers counseling women on the concurrent use of copper IUDs and menstrual cups.

She noted that although there are no official guidelines about the use of menstrual cups with an IUD, current advice is to break the seal of the menstrual cup before removing it from the vaginal canal to help lessen the chance of IUD displacement.

"That is something that providers have been telling patients to do -- but from what we see here, we don't know if that actually works," Long said

Asked for her perspective, Gabriela Aguilar, MD, MPH, of the Family Planning, Obstetrics, Gynecology & Reproductive Sciences Service of Yale School of Medicine in New Haven, Connecticut, who was not involved with the research, said that although the original intention of the study was not to evaluate the risk of IUD expulsion with menstrual cup use, the findings do "shine a light on a potential issue."

"For many of these individuals, they are probably using the copper IUD specifically for contraception, since we know that it doesn't have the added benefit of improving abnormal uterine bleeding," Aguilar told MedPage Today. The biggest risk, she said, is people thinking they are protected from pregnancy when they may not be -- especially if they are unaware of IUD displacement.

There are still a few unknowns about the study, Aguilar continued, such as the type of menstrual cup participants used; the type of copper IUD associated with greater expulsion rates; and the string length of the IUD, which may catch on menstrual cups and cause displacement.

Regarding the clinical implications, she said: "I think it's an important piece to consider in the family planning world, because now when we are counseling our patients, we need to be asking them more about what products they are using for their menstrual hygiene."

The study by Long and colleagues was a prospective 3-year efficacy trial of two copper IUDs, which were successfully placed in 1,092 women. Participants attended follow-up visits during the first year at 6 weeks after insertion, and then every 3 months thereafter.

Nine months after initiating enrollment, the investigators advised trial participants against concurrent menstrual cup and IUD use. That recommendation, however, Long said, did not impact the number of women who used a menstrual cup.

At the end of the first year of the study, the researchers found that IUD expulsion rates were 14.3% among cup users, and 4.7% among non-users. Rates at the second year were 23.2% and 6.5%, respectively.

Comment