Heterotopic pregnancy: reappraisal of incidence.
D000028:Abortion, Induced; D000293:Adolescent; D000328:Adult; D005187:Fallopian Tubes / Q000601:surgery; D005260:Female; D006801:Humans; D007813:Laparotomy; D009820:Ohio; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D011271:Pregnancy, Ectopic / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D011274:Pregnancy, Tubal / Q000175:diagnosis / Q000453:epidemiology; D014429:Twins, Dizygotic; D014463:Ultrasonography