title: Transmural migration and perforation of a levonorgestrel intrauterine system: a case report and review of the literature.
abstract: BACKGROUND
  Uterine perforation is an uncommon yet well-known complication of copper intrauterine devices and the levonorgestrel intrauterine system (IUS). While initial extrauterine placement at the time of insertion is felt to be the cause of perforation in most cases, some hypothesize that delayed transmural migration and subsequent perforation can occur with slightly malpositioned or even properly placed devices.
  
  
  METHODS
  A 46-year-old female had a 52-mg levonorgestrel IUS inserted for menstrual management and contraception. We arranged a follow-up ultrasound as the uterus was enlarged on bimanual examination and the cavity sounded to 11cm. This ultrasound was completed 6days after insertion and reported the IUS to be in the "upper uterine cavity". Over time, transmural displacement and perforation of the horizontal arms of the device occurred. Computed tomography scans performed over 2years for nongynecologic indications document this gradual migration. A retrospective review of initial ultrasound images showed no evidence of uterine defect, embedment or perforation but the cavity length did appear to be less than 11cm.
  
  
  CONCLUSIONS
  While initial extrauterine placement at the time of insertion is the most common mechanism of perforation, delayed transmural migration is another mechanism that can occur.
authors.affiliation: Contraception Advice Research and Education Fellowship, Department of Obstetrics and Gynaecology, Queen's University, Kingston, ON, Canada K7L 3N6. Electronic address: carrie.ferguson@queensu.ca.
authors.forename: Carrie Anne
authors.initials: CA
authors.lastname: Ferguson
authors.affiliation: Department of Obstetrics and Gynaecology, McMaster University, Hamilton, ON, Canada L8S 4L8.
authors.forename: Dustin
authors.initials: D
authors.lastname: Costescu
authors.affiliation: Department of Obstetrics and Gynaecology, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: Mary Anne
authors.initials: MA
authors.lastname: Jamieson
authors.affiliation: Department of Radiology, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: Lisa
authors.initials: L
authors.lastname: Jong
mesh_terms: D000328:Adult; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D058736:Intrauterine Device Migration / Q000009:adverse effects*; D007436:Intrauterine Devices, Medicated / Q000009:adverse effects*; D016912:Levonorgestrel / Q000008:administration & dosage*; D014595:Uterine Perforation / Q000209:etiology*
chemical_list: D003271:Contraceptive Agents, Female; D016912:Levonorgestrel
keywords: Embedment; Intrauterine device; Intrauterine system; Migration; Uterine perforation