biostudies-literatureBrown JEBill &amp; Melinda Gates FoundationNICHD NIH HHSNational Institute of Child Health and Human Development110415https://www.ebi.ac.uk/biostudies/studies/S-EPMC11081833biostudies-literatureUnknown134<h4>Objective</h4>To evaluate menstrual cup use and intrauterine device (IUD) expulsion.<h4>Study design</h4>We performed a secondary analysis of a 3-year contraceptive efficacy trial comparing two copper 380 mm² IUDs. Investigators randomized participants approximately 1:4 to the TCu380A or NTCu380-Mini IUD. Approximately 12 months after enrollment began, we advised participants against menstrual cup use due to observed IUD expulsions in cup users. We evaluated IUD expulsion (including spontaneous partial and complete expulsion and accidental self-removal) at 12 and 36 months. We used multivariable logistic regression to evaluate IUD expulsion by age, baseline menstrual volume, body mass index, IUD type, menstrual cup use, parity, and uterine length.<h4>Results</h4>This analysiContraceptionMenstrual cup use and intrauterine device expulsion in a copper intrauterine device randomized trial.PMC11081833HHSN275201200002CHHSN275201600001IHHSN275201200002ICreinin MDSchreiber CAKaneshiro BHubacher DBrown JENanda KBlithe DLWu HfalseMenstrual cup use and intrauterine device expulsion in a copper intrauterine device randomized trial.<h4>Objective</h4>To evaluate menstrual cup use and intrauterine device (IUD) expulsion.<h4>Study design</h4>We performed a secondary analysis of a 3-year contraceptive efficacy trial comparing two copper 380 mm² IUDs. Investigators randomized participants approximately 1:4 to the TCu380A or NTCu380-Mini IUD. Approximately 12 months after enrollment began, we advised participants against menstrual cup use due to observed IUD expulsions in cup users. We evaluated IUD expulsion (including spontaneous partial and complete expulsion and accidental self-removal) at 12 and 36 months. We used multivariable logistic regression to evaluate IUD expulsion by age, baseline menstrual volume, body mass index, IUD type, menstrual cup use, parity, and uterine length.<h4>Results</h4>This analysi2024-01-01T00:00:00Z2024 Jun2026-06-02T20:17:23.147Z2026-04-20T03:10:04.475ZS-EPMC110818333843125710.1016/j.contraception.2024.110415