title: Methotrexate embryopathy after exposure to low weekly doses in early pregnancy.
abstract: OBJECTIVE
  Methotrexate (MTX) is a potent teratogen when used in high doses for cancer or termination of tubal pregnancy. In contrast, it has been perceived as safe when used once weekly at low dose for rheumatological conditions.
  
  
  METHODS
  A prospective observational controlled study of women exposed to low dose MTX. The control group were women exposed to MTX only before conception.
  
  
  RESULTS
  Among the 8 MTX-exposed pregnancies, there was a case of typical MTX embryopathy, the first to be described to date at this lower once weekly dose Schedule.
  
  
  CONCLUSIONS
  This case has important implications for rheumatologists treating women of reproductive age, as the assumption of fetal safety of MTX, implied from small cohorts, is premature.
authors: María Cecilia
authors: MC
authors: Martín
authors: Pablo
authors: P
authors: Barbero
authors: Boris
authors: B
authors: Groisman
authors: Miguel Ángel
authors: MÁ
authors: Aguirre
authors: Gideon
authors: G
authors: Koren
mesh_terms: D000015:Abnormalities, Multiple / Q000139:chemically induced*; D000293:Adolescent; D000328:Adult; D018501:Antirheumatic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D019465:Craniofacial Abnormalities / Q000139:chemically induced*; D005260:Female; D005315:Fetal Diseases / Q000139:chemically induced*; D006801:Humans; D008431:Maternal-Fetal Exchange; D008727:Methotrexate / Q000009:adverse effects* / Q000627:therapeutic use; D011247:Pregnancy; D012216:Rheumatic Diseases / Q000188:drug therapy; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents; D008727:Methotrexate