The 'lost' or 'unknown' IUD.
D005260:Female; D005547:Foreign Bodies / Q000209:etiology*; D005548:Foreign-Body Migration / Q000209:etiology*; D006801:Humans; D007434:Intrauterine Devices / Q000009:adverse effects*; D011247:Pregnancy; D014595:Uterine Perforation / Q000209:etiology*; D014597:Uterine Rupture / Q000209:etiology*