The vertical depth of the amniotic pool is generally standardized against 2-8cm. The amount of amniotic fluid is determined by ultrasound testing to find out how much amniotic fluid is present and also to find out how the fetus is growing and developing. If there is an abnormality in the amniotic fluid, then it may lead to fetal growth restriction, fetal kidney agenesis, abnormal ureter or spina bifida. Generally during pregnancy, if the maximum vertical depth of amniotic fluid is more than 8cm, then it can be diagnosed as excessive amniotic fluid and timely intervention is needed to avoid affecting the normal development of the fetus. Amniotic fluid has a protective effect on both the fetus and the mother, and the mother and child can exchange fluids through the amniotic cavity to keep the amount relatively constant, and amniotic fluid plays an important role in maintaining the growth and development of the fetus. Therefore keeping the amount of amniotic fluid constant is of great significance to the growth and development of the fetus.