The normal range of amniotic fluid index at 25 weeks of pregnancy is 8-25 cm, and strictly speaking the amniotic fluid index should be kept within this range throughout pregnancy. The amniotic fluid index is the result of measuring the depth of amniotic fluid in the four quadrants and summing them up by drawing two lines perpendicular to each other through the navel and dividing the amniotic cavity into four 90 degree right angle quadrants. During pregnancy, the production and absorption of amniotic fluid is in a dynamic balance, and an imbalance in production or absorption will result in an abnormal amount of amniotic fluid. A general amniotic fluid index of ≤5 cm indicates low amniotic fluid and an amniotic fluid index of ≥25 cm indicates excess amniotic fluid. When the amniotic fluid index is abnormal, it may affect the normal growth and development of the fetus and requires fetal heart monitoring, ultrasound for abnormalities and other tests. The role of amniotic fluid is to protect the fetus and provide a suitable environment for his growth, development and maturation, and to participate in metabolism. It should be monitored regularly during pregnancy to see if the amount and clarity of amniotic fluid is normal. Pregnant women should drink no less than 1-1.5L of water every day, eat a light diet, avoid cold and spicy stimulating foods, eat more vegetables and fruits, and take appropriate slow walks to promote metabolism and facilitate the circulation and renewal of amniotic fluid, which is beneficial to both the pregnant woman and the fetus.