Progestin intrauterine devices versus copper intrauterine devices for emergency contraception

Background: The copper intrauterine device (Cu-IUD) is a highly effective method of contraception that can also be used for emergency contraception (EC). It is the most effective form of EC, and is more effective than other existing oral regimens also used for EC. The Cu-IUD provides the unique benefit of providing ongoing contraception after it is inserted for EC; however, uptake of this intervention has been limited. Progestin IUDs are a popular method of long-acting, reversible contraception. If these devices were also found to be effective for EC, they would provide a critical additional option for women. These IUDs could not only provide EC and ongoing contraception, but additional non-contraceptive benefits, including a reduction in menstrual bleeding, cancer prevention, and pain management. Objectives: To examine the safety and effectiveness of progestin-containing IUDs for emergency contraception, compared with copper-containing IUDs, or compared with dedicated oral hormonal methods. Search methods: We considered all randomized controlled trials and non-randomized studies of interventions that compared outcomes for individuals seeking a levonorgestrel IUD (LNG-IUD) for EC to a Cu-IUD or dedicated oral EC method. We considered full-text studies, conference abstracts, and unpublished data. We considered studies irrespective of their publication status and language of publication. Selection criteria: We included studies comparing progestin IUDs with copper-containing IUDs, or oral EC methods for emergency contraception. Data collection and analysis: We systematically searched nine medical databases, two trials registries, and one gray literature site. We downloaded all titles and abstracts retrieved by electronic searching to a reference management database, and removed duplicates. Three review authors independently screened titles, abstracts, and full-text reports to determine studies eligible for inclusion. We followed standard Cochrane methodology to assess risk of bias, and analyze and interpret the data. We used GRADE methodology to assess the certainty of the evidence. Main results: We included only one relevant study (711 women); a randomized, controlled, non-inferiority trial comparing LNG-IUDs to Cu-IUDs for EC, with a one-month follow-up. With one study, the evidence was very uncertain for the difference in pregnancy rates, failed insertion rates, expulsion rates, removal rates and the difference in the acceptability of the IUDs. There was also uncertain evidence suggesting the Cu-IUD may slightly increase rates of cramping and the LNG-IUD may slightly increase bleeding and spotting days. Authors' conclusions: This review is limited in its ability to provide definitive evidence regarding the LNG-IUD’s equivalence, superiority, or inferiority to the Cu-IUD for EC. Only one study was identified in the review, which had possible risks of bias related to randomization and rare outcomes. Additional studies are needed to provide definitive evidence related to the effectiveness of the LNG-IUD for EC.