Excessive amniotic fluid is defined as a person whose amniotic fluid volume reaches or exceeds 2000 ml or more during any period of pregnancy. In recent years, with the development of medical career and improvement of diagnostic techniques, the incidence has increased. In general, the more severe the amniotic fluid is, the higher the perinatal mortality rate, and the prognosis for newborns is poorer in patients with significant amniotic fluid. Patients with excessive amniotic fluid are prone to placental abruption, weak contractions, postpartum hemorrhage, etc. The causes of excessive amniotic fluid are still not clear, but it is believed that the causes are: (1) fetal malformations and chromosomal abnormalities account for 18% to 40%; (2) twin fetuses combined with excessive amniotic fluid account for 10%; (3) excessive amniotic fluid combined with diabetes mellitus account for 10% to 25%; (4) maternal and child RH blood type incompatibility, anemia, edema, increased urine volume, etc., may be the cause of excessive amniotic fluid; ( (5) Placental factors, placenta enlargement, placental prolactin (HPL) receptor reduction, placental chorionic hemangioma, etc. may be accompanied by excessive amniotic fluid. (2) Clinical manifestations of amniotic fluid overload are divided into chronic and acute amniotic fluid overload, and acute amniotic fluid overload is prone to preterm labor and placental abruption. (1) Acute amniotic fluid overload occurs in 20-24 weeks of pregnancy. In severe cases, due to the huge uterus compressing the bilateral ureters, and the large amount of body fluid sinks to the amniotic cavity, the pregnant woman has little urine and can be in an emergency state without urine. Due to the compression of the inferior vena cava, the blood return to the lower limbs and vulva is obstructed and edema is obvious. The uterine wall is tense and the fetus may not be palpated and the fetal heart cannot be heard. Shun to cannot lie flat and cannot walk. (2) Chronic hyperhydramnios often occurs in late pregnancy, due to the gradual increase of amniotic fluid, the symptoms of compression are mild, and sometimes the patient can not feel. Only during prenatal examination, the uterus is found to be larger than the normal gestational week, and it is not easy to find the fetus or feel that the fetus is floating in a large amount of amniotic fluid, the fetal position is unclear, and the fetal heart is light or unclear. 3.Diagnosis At present, the clinic is mostly based on ultrasound examination: it can diagnose excessive amniotic fluid and exclude fetal malformation, which is a simple and effective way to diagnose excessive amniotic fluid. Method: When the maximum amniotic fluid vertical depth (AFV) is greater than 7cm, the diagnosis of excessive amniotic fluid can be made.