Copper IUDs such as T-Safe, Multi-Safe and Flexi-T are safe and effective contraceptive methods. When using a copper IUD, you maintain your own cycle and have a period every month. The first months after placement, periods may be heavier, after which the natural cycle recovers. Sometimes, after this acclimatisation period, there may be permanently slightly more blood loss during menstruation. Copper IUDs are therefore often not recommended for women who naturally menstruate heavily. But is this justified?

There has been little research into whether copper IUDs are well tolerated by women who naturally have more ample blood loss during their periods. US researchers therefore wanted to know whether women who already had heavy periods before having a copper IUD had a higher risk of early removal of their IUD than women without heavy periods.

The researchers used data from the CHOICE project, a prospective observational cohort study in which women were allowed to choose a contraceptive method free of charge. Women could self-report prior to placement how they had experienced their periods in the past year. Of the 918 participants, 165 women were then assigned to the heavy menstrual group, while 753 had no heavy menstruation. The two groups did not differ in terms of age, ethnicity, education, relationship status or socioeconomic status. In the 12 months after placement, records were kept of how many women from each group had their IUDs removed.

The researchers found no significant difference in continued use between the two groups 12 months after copper IUD placement. In the heavy menstruation group, 80.2% still had her IUD, compared to 85.0% in the non-heavy menstruation group. It is possible that women who are already used to having heavy periods are more tolerant of blood loss and therefore less likely to have a copper IUD removed. The researchers therefore think that women who menstruate heavily should not be discouraged from choosing a copper IUD as an effective form of hormone-free contraception.

Wanting to compare their results, the researchers found only one other study that included baseline blood loss in the analysis. Therefore, the researchers stress that more studies are needed with larger groups of women with heavy periods to improve contraceptive counselling for them.

The full article can be found here (Hobby, J. H., Zhao, Q., & Peipert, J. F. (2018). Effect of baseline menstrual bleeding pattern on copper intrauterine device continuation. American Journal of Obstetrics and Gynecology, 219(5), 465.e1-465.e5). Earlier, we also wrote a blog On another part of the CHOICE project. This study was about the association between bleeding and cramping patterns in LARC methods and satisfaction.