title: Caesarean scar pregnancy: a diagnosis to consider carefully in patients with risk factors.
abstract: BACKGROUND
  Caesarean scar pregnancy is rare. A high index of suspicion is necessary to make the right diagnosis early.
  
  
  METHODS
  Two women, each with a history of 1 previous caesarean delivery, were initially diagnosed with spontaneous abortion in progress when ultrasonography scan revealed the gestational sac to be in the lower uterine cavity. Subsequent ultrasound scans showed that the gestational sac was actually in the anterior uterine wall at the level of the uterine isthmus.
  
  
  METHODS
  Both women were managed successfully with intrasac methotrexate injection.
  
  
  RESULTS
  We report 2 cases of caesarean scar pregnancies mistaken for spontaneous abortions by experienced ultrasonographers.
  
  
  CONCLUSIONS
  This highlights the difficulty in differentiating between these 2 diagnoses and the importance of having a high index of suspicion in women with risk factors.
authors.affiliation: Department of Obstetrics and Gynaecology, National University of Hospital, Singapore. geraldinetpl@pacific.net.sg
authors.forename: G
authors.initials: G
authors.lastname: Tan
authors.forename: Y S
authors.initials: YS
authors.lastname: Chong
authors.forename: A
authors.initials: A
authors.lastname: Biswas
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000008:administration & dosage; D000028:Abortion, Induced; D000022:Abortion, Spontaneous; D000328:Adult; D002585:Cesarean Section; D002921:Cicatrix; D005260:Female; D006801:Humans; D008727:Methotrexate / Q000008:administration & dosage; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy*; D016216:Ultrasonography, Prenatal
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D008727:Methotrexate