Methods for measuring the amount of amniotic fluid

The amount of amniotic fluid contained in the amniotic sac during pregnancy cannot be measured directly. However, there are two methods to assess the amount of amniotic fluid by ultrasound:

• Maximum vertical column (MCV): the maximum vertical column of amniotic fluid is measured.
• Amniotic fluid index (AFI): the uterus is divided into 4 quadrants and the maximum vertical columns of amniotic fluid in each quadrant are added together.

Generally, MCV is the most commonly used method in low-risk pregnancies. However, ILA is used when any pathology has been detected in the pregnancy.