<P> Amniotic fluid index (AFI) is a quantitative estimate of amniotic fluid and an indicator of fetal well - being . It is a part of the biophysical profile . </P> <Ul> <Li> AFI is the score (expressed in cm) given to the amount of amniotic fluid seen on ultrasonography of a pregnant uterus . To determine the AFI, doctors may use a four - quadrant technique, when the deepest, unobstructed, vertical length of each pocket of fluid is measured in each quadrant and then added up to the others, or the so - called "Single Deepest Pocket" technique . </Li> <Li> An AFI between 8 - 18 is considered normal . Median AFI level is approximately 14 from week 20 to week 35, when the amniotic fluid begins to reduce in preparation for birth . </Li> <Li> An AFI <5 - 6 is considered as oligohydramnios . The exact number can vary by gestational age . The fifth percentile for gestational age is sometimes used as a cutoff value . </Li> <Li> An AFI> 20 - 24 is considered as polyhydramnios . </Li> </Ul> <Li> AFI is the score (expressed in cm) given to the amount of amniotic fluid seen on ultrasonography of a pregnant uterus . To determine the AFI, doctors may use a four - quadrant technique, when the deepest, unobstructed, vertical length of each pocket of fluid is measured in each quadrant and then added up to the others, or the so - called "Single Deepest Pocket" technique . </Li>

What is the normal range of afi in pregnancy