VANCOUVER, B.C. – Use of tampons or menstrual cups does not increase the risk of early expulsion of an intrauterine device, according to findings of a retrospective cohort study of nearly 1,000 women.
In the study, the overall rate of IUD expulsion within 2 months of insertion was low (3.5%), and was statistically no higher for women who used tampons or cups than it was for their counterparts who used pads.
"Women can be reassured that they can use whatever their usual menstrual product is and not increase their risk of expelling the IUD," said coinvestigator Dr. Ellen Wiebe of the department of family practice at the University of British Columbia, Vancouver.
She noted that it is a common concern that vaginal menstrual products will tug on the IUD strings protruding from the cervix, thereby pulling the device out. And most IUD expulsions in the first year occur within a month of insertion (Hum. Reprod. Update 2008;14:197-208).
"Every day, I would get asked the question, ‘Is it okay to use tampons with the IUD?’ And every week or so, I would get asked the question, ‘Is it okay to use a cup with the IUD?’ " she said in an interview at the annual meeting of the Society of Obstetricians and Gynaecologists of Canada. "And I looked in the literature, and there were no answers."
Moreover, IUD package inserts are inconsistent on the issue. For example, of the four IUDs on the market in Canada, the Mirena package insert says that tampons can be used, the Liberté insert notes that tampons can be used (but is silent on the use of menstrual cups), and the Flexi-T and Nova-T inserts do not mention menstrual products at all, she said.
She further noted that little is known about the prevalence of menstrual cup use today, as most studies on this product were done in the 1960s and focused on acceptability.
Dr. Wiebe and her colleague retrospectively reviewed the charts of 999 women who underwent IUD insertion at two reproductive health clinics in 2009.
Study results, reported in a poster session at the meeting, showed that about half the women had the hormonal Mirena IUD inserted and about half had one of the copper IUDs inserted. Among the 930 women having data on the type of menstrual product used, 74% used tampons, 43% used pads, and 10% used menstrual cups, with many using more than one product.
Cup users were more likely than pad users and tampon users to be younger than 30 years of age (77% vs. 51% and 61%, respectively) and nulliparous (88% vs. 54% and 69%, respectively). Additionally, cup users were more likely than pad users to be white (85% vs. 69%).
Among the 620 women who had adequate follow-up, the rate of early IUD expulsion (defined as within 2 months of insertion) was 3.5% overall, and was statistically indistinguishable among women who used pads (4%), tampons (2%), and menstrual cups (6%).
Based on anecdotal evidence, "I knew it was fine, and most of our colleagues thought it was fine" to use tampons and menstrual cups with an IUD, said Dr. Wiebe.
"But that’s not the evidence you want to give your patient," she added. "You’d rather say, ‘Well, we looked at 1,000 women and it didn’t make any difference what they used.’ "
Dr. Wiebe reported that she had no relevant conflicts of interest.