Concern menstrual cups causing rise in IUD expulsion

The use of menstrual cups might be associated with IUD expulsion, an Australian chart review suggests.

Menstrual cups are becoming increasingly popular in Australia because of their reduced environmental impact, financial benefits and convenience, Dr Matilda-Jane Oke from Sexual Health Quarters in Perth told delegates at the RACGP conference (GP20).

“We became interested in menstrual cups because clinic staff reported an anecdotal increase in IUD expulsion following concurrent menstrual cup use,” she said in the online presentation earlier this week.

“There were two mechanisms posited; one was that menstrual cup removal may catch the IUD strings and the second was the menstrual cup removal may apply a negative pressure to the cervix which would dislodge the IUD.”

Her team reviewed their clinic’s data, finding that 520 patients had an IUD inserted in the 12 months from 31 January 2019, with the majority of those being Mirena hormonal IUDs (67%) followed by Copper T standard IUDs (28%).

By the end of follow-up in June, 22 of the IUDs had been expelled, with 10 expulsions (45%) being associated with menstrual cup use

The majority, but not all, expulsions in women using menstrual cups were reported by the patient as being associated with removal of the cup, she said.

Of the 10 expulsions in women using cups, six were Copper T standard IUDs and four were Mirena IUDs.

“The reason we think that there were more Copper Ts expelled rather than Mirenas is because Copper Ts tend to make the menstrual flow heavier and longer and so menstrual cup users may opt to keep using their menstrual cup,” Dr Oke said.

“However, because the Mirena tends to make menstrual flow lighter, people who use menstrual cups may opt not to continue using.”

Dr Oke said her team had since begun routinely asking patients about the menstrual products they used and counselling those using menstrual cups about the importance of breaking the seal and not catching the IUD strings when removing the cup.

Further research was needed to support the association, she said, adding that the next stage of their own investigation was to determine the proportion of menstrual cup users among the study population.

This article first appeared in Australian Doctor, 19 November 2020.