Abnormally invasive placenta (AIP) is a clinical term used to describe a placenta that does not separate spontaneous during normal delivery and cannot be removed without causing high blood loss. Maternal outcome in cases with AIP is improved by antenatal diagnosis that currently relies on subjective interpretation of imaging signs. There is no accepted consensus on the definition of the commonly used ultrasound markers for AIP. The studies included in a recently published systematic review of antenatal sonographic diagnosis of AIP were analysed for the ultrasound descriptors. Different wordings used for each sign were identified, analysed and discussed by an expert panel (European Working Group on AIP). Consensus was reached, leading to a unified, detailed descriptor for each sign. Characteristic ultrasound images of these descriptors and normal findings are provided. Twenty-three papers were examined for wording used to describe AIP signs. These were extracted and grouped by ultrasound modality, and synonymous or identical terms identified. The group agreed on six unified descriptors for 2D greyscale signs, four for 2D colour Doppler and one for 3D power Doppler. Four papers included descriptions that were considered to be not sufficiently comprehensive or not clear regarding their meaning. We present an analysis of terms describing the sonographic appearance of AIP commonly used in the literature. We unified these terms and propose unambiguous descriptors accompanied by characteristic ultrasound images to promote understanding and guide future use in AIP.
Ultrasound in Obstetrics and Gynecology : the Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2016, Vol 47, Issue 3, p. 271-5