title: Polypropylene loops: a research report.
mesh_terms: D000475:Alkenes; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007434:Intrauterine Devices / Q000009:adverse effects / Q000592:standards / Q000706:statistics & numerical data; D010969:Plastics; D011095:Polyethylenes; D011108:Polymers; D011247:Pregnancy; D012828:Silicones; D013223:Statistics as Topic
chemical_list: D000475:Alkenes; D010969:Plastics; D011095:Polyethylenes; D011108:Polymers; D012828:Silicones