Amniotic Fluid Assessment: Amniotic Fluid Index Versus Maximum Vertical Pocket

Abstract

Amniotic fluid assessment is vital to fetal well-being. Accurately diagnosing an amniotic fluid abnormality can aid in the proper management of a pregnancy at risk for an adverse outcome. Sonography is the most common way to assess amniotic fluid volume throughout a pregnancy; however, the most accurate technique, amniotic fluid index or maximum vertical pocket, is yet to be determined. Dye-dilution techniques are the most accurate way to measure amniotic fluid volume, but they are invasive and can be performed only at the time of a cesarean delivery. Multiple studies have been performed to determine the accuracy of the amniotic fluid index and maximum vertical pocket methods when diagnosing amniotic fluid volume abnormalities. Based on the studies reviewed in this article, neither method stands out as superior to the other when it comes to diagnosing amniotic fluid abnormalities during pregnancy. However, the maximum vertical pocket should also always be considered when an amniotic fluid abnormality is suspected because the amniotic fluid index overdiagnoses amniotic fluid abnormalities, leading to increased rates of pregnancy intervention and the potential for adverse pregnancy outcomes.