The normal amniotic fluid index at 32 weeks of pregnancy is 8-18 cm. The amniotic fluid index is an important indicator of the amount of amniotic fluid measured by ultrasound, which can determine the development of the fetus in the uterine cavity. The 32nd week of pregnancy is a late stage of pregnancy and too much or too little amniotic fluid can have an impact on the health of the fetus. First, if the amniotic fluid index is <8cm, it is considered as low amniotic fluid. If the amniotic fluid index <5cm, it can be diagnosed as low amniotic fluid. 1, placental problems: such as partial abruption of the placenta, which cannot supply the fetus with enough blood and nutrients, resulting in interruption of amniotic fluid circulation; 2, fetal malformations: the fetus may have congenital heart defects, or abnormal kidney development or urethral obstruction, which cannot produce enough urine to maintain the amniotic fluid volume; 3, twin or multi-cell pregnancy: there may be one of One fetus has too little amniotic fluid while the other has too much; 4, other: if the pregnant woman has ruptured amniotic membrane, or has her own chronic hypertension, pre-eclampsia, diabetes and lupus, all of which can lead to a decrease in amniotic fluid. Second, if the amniotic fluid index > 18cm, which is an increase in amniotic fluid, there may be the following cases: 1, fetal developmental malformations: common abnormalities of the digestive tract and nervous system, individual fetuses may be tracheoesophageal fistula, need to do ultrasound for screening. When ultrasound suggests abnormalities in the fetus, it is recommended to do cord blood or amniotic fluid puncture to check whether there are abnormalities in fetal chromosomes and genes; 2. Gestational diabetes: it is recommended to do glucose tolerance test. If gestational diabetes is diagnosed, pregnant women lower their blood sugar by controlling diet and exercise, if blood sugar cannot be controlled well through diet and exercise, amniotic fluid may continue to increase and insulin is needed for control. When too much amniotic fluid leads to breathing difficulties and other symptoms, you can consider amniocentesis to release some of the amniotic fluid, and regularly review the ultrasound to pay attention to changes in the amount of amniotic fluid; 3, other: the fetus is huge, mother and child blood type incompatibility may also lead to increased amniotic fluid, need to check to confirm the diagnosis.