amniotic fluid index
Also written as: AFI — Amniotic Fluid Index
Ultrasound measurement technique that quantifies amniotic fluid volume by summing the deepest vertical pockets in four quadrants of the uterus.
Full Definition
The amniotic fluid index (AFI) is a standardized ultrasound method for assessing amniotic fluid volume during pregnancy. The measurement involves dividing the uterus into four equal quadrants and measuring the deepest vertical pocket of amniotic fluid in each quadrant, then summing these measurements. Normal AFI ranges from 5-25 cm, with values below 5 cm indicating oligohydramnios and values above 25 cm suggesting polyhydramnios. This measurement is crucial in fetal surgery planning as fluid volume affects surgical visibility, fetal positioning, and procedural safety.
Usage
Usage note: Always report with units (cm) and gestational age for proper interpretation.
In Context
- "The amniotic fluid index of 3.2 cm indicated severe oligohydramnios requiring amnioinfusion prior to surgery." — Ultrasound report
- "Serial AFI measurements tracked the effectiveness of the therapeutic amniocentesis." — Prenatal care notes