Amniotic fluid index

Amniotic Fluid Index (AFI) is a quantitative estimate of amniotic fluid volume and is an integral part of the antenatal care procedure. It is a significant aspect of fetal health and well-being.

Overview

The Amniotic Fluid Index is a score calculated from the depths of fluid in four quadrants of the pregnant uterus. The depth of the fluid in each quadrant is measured, and the sum of these four measurements is the AFI. The AFI helps to determine if there are potential issues with the pregnancy, such as oligohydramnios (low levels of amniotic fluid) or polyhydramnios (high levels of amniotic fluid).

Measurement

The AFI is typically measured using ultrasound during the second and third trimesters of pregnancy. The uterus is divided into four quadrants, and the vertical depth of the deepest, unobstructed, fluid-filled area in each quadrant is measured. The sum of these four measurements gives the AFI.

Interpretation

The normal range for the AFI is 5-25 cm. An AFI < 5cm is considered oligohydramnios, and an AFI > 25cm is considered polyhydramnios. Both conditions can pose risks to the fetus and may require further monitoring or intervention.

Clinical Significance

The AFI is an important tool in assessing fetal well-being. Abnormal AFI levels can indicate potential complications such as intrauterine growth restriction (IUGR), preterm birth, and perinatal mortality. It is also used in the management of high-risk pregnancies, such as those with diabetes mellitus or hypertension.

See Also

• Biophysical profile
• Oligohydramnios
• Polyhydramnios
• Ultrasound