The umbilical level line and the abdominal white line are used to mark the right angle of the uterus into four quadrants, and the vertical diameter of the largest amniotic fluid pool in each quadrant is measured, and the sum of the four is the amniotic fluid index. If the amniotic fluid index is less than 50 mm, it is too little amniotic fluid, and if the amniotic fluid index is more than 250 mm, it is too much amniotic fluid, and too much or too little has an impact on the growth and development of the fetus. Excessive amniotic fluid is mostly associated with fetal malformations, pregnancy complications such as gestational diabetes, and can increase the risk of gestational hypertension and even lead to weak contractions, prolonged labor and premature delivery. Low amniotic fluid is mostly associated with fetal urinary tract malformations, placental dysfunction, maternal dehydration, etc. It can increase the morbidity of the perinatal fetus, which is susceptible to disease and even death due to various factors during intrauterine, delivery and after birth. During pregnancy, pregnant women are advised to have timely and regular health checkups and to treat any abnormalities promptly. In daily life, pregnant women should pay attention to their emotions and try to maintain a positive and optimistic mood, as well as pay attention to maintaining a light diet and getting enough sleep for good fetal development.