title: Oral contraceptives and estrogen combinations (excluding progestogens) during the first trimester--clearly increased the risk of overall birth defects.
authors.forename: M L
authors.initials: ML
authors.lastname: Martínez-Frías
authors.forename: E
authors.initials: E
authors.lastname: Rodríguez-Pinilla
authors.forename: E
authors.initials: E
authors.lastname: Bermejo
authors.forename: L
authors.initials: L
authors.lastname: Prieto
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000453:epidemiology / Q000209:etiology*; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000009:adverse effects*; D006801:Humans; D011247:Pregnancy; D012307:Risk Factors
chemical_list: D003278:Contraceptives, Oral, Hormonal; D012739:Gonadal Steroid Hormones