If the pregnancy examination reveals excessive amniotic fluid, and after repeated re-examination, all of them are manifestations of excessive amniotic fluid, the main thing is to find the causes, mainly including the following aspects: 1, fetal causes: the most common, such as fetal organ structure abnormalities, with gastrointestinal anomalies more common, especially esophageal or duodenal atresia; neurological abnormalities, such as anencephaly, spina bifida are also prone to excessive amniotic fluid; some Fetal chromosomal and genetic abnormalities or congenital metabolic diseases, fetal tumors, and fetal diseases may lead to excessive amniotic fluid; 2. Multiple fetuses: among them, twin fetus transfusion syndrome is prone to excessive amniotic fluid in one fetus and significantly too little amniotic fluid in the other; 3. Placental factors may also lead to excessive amniotic fluid, such as placental chorionic villous hemangioma, a relatively large placenta; some sail placentas may also increase amniotic fluid; 4. Maternal comorbidities: For example, maternal diabetes mellitus, poor blood sugar control, or maternal and child Rh blood type incompatibility, fetal immune edema can also lead to excessive amniotic fluid. The risk of excessive amniotic fluid is that it can easily induce premature rupture of the fetal membranes, which can lead to placental abruption or umbilical cord prolapse, which are more serious complications in obstetrics and threaten the safety of both the pregnant woman and the fetus, so excessive amniotic fluid carries a great risk.