title: In vitro study of fracture forces associated with the Copper 7, Nova T and MLCu 250/375 intrauterine devices.
abstract: In the literature there is a paucity of reports of cases of intrauterine breakage of IUDs. In this study the forces required to break the Copper 7, Nova T and Multiload (MLCu) devices were measured. New and used devices were examined in vitro. The devices were broken in a water bath at body temperature. The mean rupture force of new and used Copper 7 devices was 30.4 newtons. The mean rupture forces for new Nova T and MLCu 250/375 IUDs was 6.8 and 15.7 newtons, respectively, and for used Nova T and MLCu 250/375 devices was 16.8 and 8.7 newtons, respectively. The decreased fracture forces associated with used as opposed to new MLCu devices may explain the reports of intrauterine breakage with this type of device.
authors.affiliation: Department of Obstetrics and Gynaecology, University of the Witwatersrand, Johannesburg Hospital, South Africa.
authors.forename: N D
authors.initials: ND
authors.lastname: Goldstuck
authors.forename: G J
authors.initials: GJ
authors.lastname: Hofmeyr
authors.forename: E W
authors.initials: EW
authors.lastname: Sonnendecker
authors.forename: A
authors.initials: A
authors.lastname: Butchart
mesh_terms: D066298:In Vitro Techniques; D007435:Intrauterine Devices, Copper; D010969:Plastics; D013314:Stress, Mechanical
chemical_list: D010969:Plastics