title: Alternative estimates of ectopic pregnancy risks during contraception.
authors.forename: I
authors.initials: I
authors.lastname: Sivin
mesh_terms: D003270:Contraceptive Agents / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007434:Intrauterine Devices / Q000009:adverse effects*; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000453:epidemiology*; D012307:Risk Factors; D014481:United States
chemical_list: D003270:Contraceptive Agents