title: How should success be defined when attempting medical resolution of first-trimester missed abortion?
abstract: OBJECTIVE
  There is currently no consensus on how success should be defined after medical management of first-trimester missed abortion. The aim of this study was to determine the transvaginal ultrasound criterion associated with highest success rate and, at the same time, lowest long-term complications.
  
  
  METHODS
  Prospective observational study of consecutively enrolled patients.
  
  
  METHODS
  A tertiary care university hospital in northern Portugal.
  
  
  METHODS
  Forty-four women submitted to medical management of first-trimester missed abortion using a regimen of vaginal misoprostol, with histologically confirmed conception products passed vaginally. A transvaginal ultrasound scan was performed by an experienced sonographer in the morning after treatment, to characterise uterine content. Patients were provided with a chart for daily registration of axillary temperature, vaginal bleeding and lower abdominal pain. Transvaginal ultrasound was repeated 2-3 weeks later, and again after the following menses.
  
  
  METHODS
  Success rates of medical management when post-treatment transvaginal ultrasound criteria for subsequent expectant management were: absence of intra-uterine sac, largest anteroposterior diameter of hyperechogenic content, and maximum area of hyperechogenic intra-uterine content in a sagittal view. Self-reported duration of vaginal bleeding and abdominal pain after medical treatment.
  
  
  RESULTS
  Success rate was 86% (38/44) when absence of gestational sac on the 12 h transvaginal ultrasound was used as the main criterion for subsequent expectant management and there was no need for further intervention. The success rate using the ultrasound criterion anteroposterior diameter < or = 15 mm was 51% (22/43), and with maximum sagittal plane area under 7.5 cm(2), 72% (31/43). Mean duration of vaginal haemorrhage was 9 days (minimum 2 days, maximum 14 days) and of lower abdominal pain 6 days (minimum 0 days, maximum 14 days). No patient recorded an axillary temperature exceeding 37 degrees C. No apparent relationship between the size of ultrasound-estimated intra-uterine content and duration of symptoms was observed.
  
  
  CONCLUSIONS
  Absence of gestational sac on transvaginal ultrasound should be the criterion used to document success after medical management of first-trimester missed abortion, as it is associated with the highest short and long-term success rates, as well as mild and self-limited symptoms in the days following treatment.
authors.affiliation: Departamento de Ginecologia e Obstetríca, Faculdade de Medicina da Universidade do Porto, Hospital de São João, Portugal. sisporto@med.up.pt
authors.forename: A
authors.initials: A
authors.lastname: Reynolds
authors.forename: D
authors.initials: D
authors.lastname: Ayres-de-Campos
authors.forename: M A
authors.initials: MA
authors.lastname: Costa
authors.forename: N
authors.initials: N
authors.lastname: Montenegro
mesh_terms: D015746:Abdominal Pain; D000030:Abortion, Missed / Q000000981:diagnostic imaging / Q000628:therapy*; D000282:Administration, Intravaginal; D000293:Adolescent; D000328:Adult; D005113:Extraction, Obstetrical; D005260:Female; D005865:Gestational Age; D006801:Humans; D016595:Misoprostol / Q000008:administration & dosage; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D014592:Uterine Hemorrhage
chemical_list: D016595:Misoprostol