Relationship of parity and prior cesarean delivery to levonorgestrel 52 mg intrauterine system expulsion over 6 years.

ABSTRACT Objective Assess the relationship between parity and prior route of delivery to levonorgestrel 52 mg intrauterine system (IUS) expulsion during the first 72 months of use. Study Design We evaluated women enrolled in the ACCESS IUS multicenter, Phase 3, open-label clinical trial of the Liletta® levonorgestrel 52 mg IUS. Investigators evaluated IUS presence at three and six months after placement and then every six months and during unscheduled visits. We included women with successful placement and at least one follow-up assessment. We evaluated expulsion rates based on obstetric history; for prior delivery method sub-analyses, we excluded 12 participants with missing delivery data. We determined predictors of expulsion using multivariable regression analyses. Results Of 1,714 women with IUS placement, 1,710 had at least one follow-up assessment. The total population included 986 (57.7%) nulliparous women. Sixty-five (3.8%) women experienced expulsion within 72 months, 50 (76.9%) within the first 12 months. Expulsion rates among nulliparous women (22/986 [2.2%]) or parous women with any pregnancy ending with a Cesarean delivery (6/195 [3.1%]) differed from parous women who only experienced vaginal deliveries (37/517 [7.2%]) (p Conclusion IUS expulsion occurs in less than 4% of users over the first six years of use and occurs mostly during the first year. Expulsion is more likely among obese and parous women. Implications Levonorgestrel 52 mg intrauterine system expulsion occured more commonly in parous than nulliparous women; the increase in parous women is primarily in women who had vaginal deliveries only. The association between obesity, delivery route, and IUS expulsion needs further elucidation.