title: Location of the missing intra-uterine contraceptive device. Examination by ultrasound B-technique and the Beolocator method.
mesh_terms: D005260:Female; D006801:Humans; D007047:Hysterosalpingography / Q000379:methods; D007434:Intrauterine Devices; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014567:Urography