Accuracy of Sonographic Amniotic Fluid Volume Assessments in Diamniotic Dichorionic Twin Pregnancies: A Literature Review

Abstract

This literature review is meant to bring to light the controversy over the most accurate method to assess the amniotic fluid volumes (AFV) in diamniotic-dichorionic (di-di) twin gestations. It is hoped that this may initiate consideration of a standardized method so that all sonographers and interpreting physicians will consistently use the same method. There is no definitive standard method for sonographers to obtain an accurate amount of amniotic fluid. Commonly, sonographers and interpreting physicians agree that the most practical and accurate methods for sonographers to use are the amniotic fluid index, largest vertical pocket, and the two-diameter pocket methods. Although these measurements are fast, noninvasive, and relatively consistent in evaluating the relative amount of AFV, only the dye-determined technique is 100% accurate, especially when the AFV is outside the subjective normal ranges and either oligohydramnios or polyhydramnios is present.