The normal maximum depth of amniotic fluid is 3-7 cm. If the maximum depth of amniotic fluid is less than 2 cm, the amniotic fluid is too small. If the maximum depth of amniotic fluid is greater than 8cm, it is too much amniotic fluid. The mother, the fetus, and the amniotic fluid are in balance. Amniotic fluid is the fluid that fills the amniotic cavity. In late pregnancy, the circulation of amniotic fluid is swallowed by the fetus and then expelled from the fetal urine, which is a cycle of amniotic fluid. So amniotic fluid is dynamic and not constant. In late pregnancy, if you find too little amniotic fluid or too much amniotic fluid, be on high alert for abnormalities in the fetal digestive and urinary systems. It is also important to observe the dynamic changes of the amniotic fluid and to combine fetal heart monitoring to determine the fetal well-being.