• Sally L Collins, Gordon N Stevenson, Abdulla Al-Khan, Nicholas P Illsley, Lawrence Impey, Leigh Pappas, and Stacy Zamudio.
• Nuffield Department of Obstetrics & Gynaecology, University of Oxford, and the Fetal Medicine Unit, John Radcliffe Hospital, Oxford, and the Evelyn Perinatal Imaging Centre, Rosie Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom; and the Center for Abnormal Placentation, Division of Maternal Fetal Medicine and Surgery, Department of Obstetrics and Gynecology, Hackensack University Medical Center, Hackensack, New Jersey.
• Obstet Gynecol. 2015 Sep 1; 126 (3): 645-653.

ObjectiveTo test an objective ultrasound marker for diagnosing the presence and severity of abnormally invasive placenta.MethodsWomen at risk of abnormally invasive placenta underwent a three-dimensional power Doppler ultrasound scan. The volumes were examined offline by a blinded observer. The largest area of confluent three-dimensional power Doppler signal (Area of Confluence [Acon], cm) at the uteroplacental interface was measured and compared in women subsequently diagnosed with abnormally invasive placenta and women in a control group who did not have abnormally invasive placenta. Receiver operating characteristic curves were plotted for prediction of abnormally invasive placenta and abnormally invasive placenta requiring cesarean hysterectomy.ResultsNinety-three women were recruited. Results were available for 89. Abnormally invasive placenta was clinically diagnosed in 42 women; 36 required hysterectomy and had abnormally invasive placenta confirmed histopathologically. Median and interquartile range for Acon was greater for abnormally invasive placenta (44.2 [31.4-61.7] cm) compared with women in the control group (4.5 cm [2.9-6.6], P<.001) and even greater in the 36 requiring hysterectomy (46.6 cm [37.2-72.6], P<.001). Acon rose with histopathologic diagnosis: focal accreta (32.2 cm [17.2-57.3]), accreta (59.6 cm [40.1-89.9]), and percreta (46.6 cm [37.5-71.5]; P<.001 analysis of variance for linear trend). Receiver operating characteristic analysis for prediction of abnormally invasive placenta revealed that with an Acon of 12.4 cm or greater, 100% sensitivity (95% confidence interval [CI] 91.6-100) could be obtained with 92% specificity (95% CI 79.6-97.6); area under the curve is 0.99 (95% CI 0.94-1.0). For prediction of abnormally invasive placenta requiring hysterectomy, 100% sensitivity (95% CI 90.3-100) can be obtained with an Acon of 17.4 cm or greater with 87% specificity (95% CI 74.7-94.5; area under the curve 0.98 [0.93-1.0]).ConclusionThe marker Acon provides a quantitative means for diagnosing abnormally invasive placenta and assessing severity. If further validated, subjectivity could be eliminated from the diagnosis of abnormally invasive placenta.Level Of EvidenceII.

32 keywords...

hide…