Background: Intrauterine devices (IUDs) are safe and effective methods of long-term reversible contraception. The design and copper content as well as placement of the copper on IUDs could affect their effectiveness and side effect profile. We compared different copper IUDs for their effectiveness and side effects.
Study design: We searched multiple electronic databases with appropriate keywords and names of the IUDs known to be on the market. We searched the reference lists of papers identified and contacted authors when possible. There was no language restriction. Randomized controlled trials comparing different IUDs that reported on clinical outcomes were considered for inclusion. Two reviewers independently extracted data on outcomes and trial characteristics. We combined the trial results in meta-analyses and expressed results as rate difference (RD) using a fixed-effects model with 95% confidence interval (CI). In the presence of significant heterogeneity, a random-effects model was applied.
Results: We included 35 trials, resulting in 18 comparisons of 10 different IUDs in approximately 48,000 women. TCu380A was more effective in preventing pregnancy than MLCu375 (RD 1.70%, 95% CI 0.07-2.95% after 4 years of use). TCu380A was also more effective than MLCu250, TCu220 and TCu200. There tended to be fewer pregnancies with TCu380S compared to TCu380A after the first year of use, a difference which was statistically significant in the fourth year (RD -1.62%, 95% CI -3.00% to -0.24%). This occurred despite more expulsions with TCu380S (RD 3.50%, 95% CI 0.36-6.63% at 4 years). MLCu375 was no more effective than TCu220 at 1 year of use, or MLCu250 and NovaT up to 3 years. Compared to TCu380A or TCu380S, none of the IUDs showed any benefits in terms of bleeding or pain or any of the other reasons for early discontinuation. None of the trials that reported events at insertion found one IUD easier to insert than another or caused less pain at insertion. There is no evidence that uterine perforation rates vary by type of device. There are minimal randomized data on IUD use in nulliparous women.
Conclusions: TCu380A and TCu380S appear to be more effective than other IUDs. No IUD showed consistently lower removal rates for bleeding and pain in comparison to other IUDs. There is no evidence that any particular framed copper device is better suited to women who have not had children.