Amniotic fluid index

The amniotic fluid index (English Amniotic fluid index or AFI) denotes a semiquantitative sonographic measurement method for determining the amount of amniotic fluid. To measure the belly of the pregnant woman is divided into four quadrants, and measured in each quadrant of the largest vertical amniotic fluid. The four values ​​(in cm) are then added. The classification, whether it is polyhydramnios or oligohydramnios is dependent upon the week of pregnancy. Decisive for the diagnosis of an oligo - or polyhydramnios, accordingly, the 5th and 95th percentiles of the AFI table. After the due date, for example, shows an AFI less than 7 cm from too little amniotic fluid.

An alternative determination of the amount of amniotic fluid, the vertical measurement of the largest depots (SDP - single deepest pocket ), where as the lower and upper limits of standard values ​​of 2 and 8 cm are considered. According to a Cochrane Review tend to determine the AFI compared with the SDP to überdiagnostizieren oligohydramnios, leading to more frequent medical intervention without significant clinical advantage. Other sources consider the AFI measurement to be better suited, or speak neither of the two methods, a reliable high accuracy.