Effectiveness and Safety of Extending Intrauterine Device Duration: A Systematic Review

Abstract Objective To systematically review the literature to determine if extended use of intrauterine devices including the copper or levonorgestrel intrauterine device beyond approved durations is effective and safe for preventing pregnancy. Data sources We searched PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, and Global Index Medicus from inception through June 2019. Study eligibility criteria We considered primary studies of women using the T380A Copper or currently available levonorgestrel intrauterine devices past their approved duration (extended use). The primary outcome was pregnancy. Safety outcomes included adverse events and side effects that led to discontinuation. Study appraisal and synthesis methods We abstracted study data into evidence tables and assessed study quality as related to the risk of bias, precision, and external validity. For each intrauterine device type, we calculated a pooled pregnancy rate during the first two years of extended use using the Poisson inverse variance method. Results Of 4,068 studies identified by our search, four good to poor quality studies of the 52 mg levonorgestrel intrauterine device (approved for five years) with a total of 2098 women starting extended use, and two good to fair quality studies of the T380A copper intrauterine device (approved for 10 years) with 245 women starting extended use met inclusion criteria. For the levonorgestrel intrauterine device, the pooled pregnancy rate was 0.02 per 100 person-years (95% confidence interval 0.00-0.45) in year six, 0.03 per 100 person-years (95% confidence interval 0.00-0.71) in year 7, and 0.02 per 100 person-years (95% confidence interval 0.00-0.29) in years six and seven combined. During this same time, annual rates of adverse events or discontinuation due to side effects ranged from 0-3.7 per 100 participants. For the copper intrauterine device, the pooled pregnancy rate for years 11 and 12 was 0.0 per 100 person-years (95% confidence interval 0.0-0.8), and annual rates of adverse events and discontinuation due to side effects during extended use ranged from 0-4.6 per 100 participants. Conclusion The available evidence suggests that rates of pregnancy, adverse events, and discontinuation due to side effects during the first two years of extended use of the 52 mg levonorgestrel intrauterine device and the T380A copper intrauterine device are low and comparable to rates during approved duration of use. Data were limited in quantity and quality, and may not be generalizable to all intrauterine device users.