Studies on intrauterine contraceptive devices (polyethylene ring, polyethylene-metal combined ring and rubber wing). I. Effectiveness and side-effects.
D005260:Female; D006801:Humans; D007434:Intrauterine Devices / Q000009:adverse effects; D008670:Metals; D011095:Polyethylenes; D011247:Pregnancy; D012408:Rubber
D008670:Metals; D011095:Polyethylenes; D012408:Rubber