title: Tubal pregnancies in women using progestagen-only contraception.
mesh_terms: D000328:Adult; D003280:Contraceptives, Oral, Synthetic; D005260:Female; D006801:Humans; D009640:Norethindrone / Q000008:administration & dosage; D009664:Norway; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000209:etiology*; D013997:Time Factors
chemical_list: D003280:Contraceptives, Oral, Synthetic; D009640:Norethindrone