title: Ultrasound detection of placenta accreta in the first trimester of pregnancy.
abstract: BACKGROUND
  Placenta accreta is considered a life-threatening condition and the main cause of maternal mortality. Prenatal diagnosis of placenta accreta usually is made by clinical presentation, imaging studies like ultrasound and MRI in the second and third trimester.
  
  
  OBJECTIVE
  To determine accuracy of ultrasound findings for placenta accreta in the first trimester of pregnancy.
  
  
  METHODS
  In a longitudinal study 323 high risk patients for placenta accreta were assessed. The eligible women were examined by vaginal and abdominal ultrasound for gestational sac and placental localization and they were followed up until the end of pregnancy. The ultrasound findings were compared with histopathological examinations as a gold standard. The sensitivity, specificity, positive and negative predictive value of ultrasound were estimated for the first trimester and compared with other 2 trimesters in the case of repeated ultrasound examination.
  
  
  RESULTS
  Ultrasound examinations in the first trimester revealed that 28 cases had the findings in favor of placenta accreta which ultimately was confirmed in 7 cases. The ultrasound sensitivity and specificity for detecting placenta accreta in the first trimester was 41% [95% CI: 16.2-62.7] and 88% [95% CI: 88.2-94.6] respectively.
  
  
  CONCLUSIONS
  Ultrasound screening for placenta accreta in the first trimester of pregnancy could not achieve the high sensitivity as second and third trimester of pregnancy.
authors: Perinatalogy Devision, Department of Obstetrics and Gynecology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Fatemeh
authors: F
authors: Rahimi-Sharbaf
authors: Perinatalogy Devision, Department of Obstetrics and Gynecology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Ashraf
authors: A
authors: Jamal
authors: Perinatalogy Devision, Department of Obstetrics and Gynecology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Elaheh
authors: E
authors: Mesdaghinia
authors: Trauma Nursing Research Center, Kashan University of Medical Sciences, Kashan, Iran.
authors: Masoumeh
authors: M
authors: Abedzadeh-Kalahroudi
authors: Perinatalogy Devision, Department of Obstetrics and Gynecology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Shirin
authors: S
authors: Niroomanesh
authors: Trauma Research Center, Kashan University of Medical Sciences, Kashan, Iran.
authors: Fatemeh
authors: F
authors: Atoof
keywords: Placenta accreta; Screening; Sensitivity; Specificity; Ultrasonography