Dark zone of amniotic fluid around 30 to 80mm is normal and the amniotic fluid index range is around 80 to 180mm within the normal range. The normal value of dark area of amniotic fluid is 30 to 80mm: if it is less than 30mm it is critical hyponatremia, if it is less than 20mm it is diagnosed as hyponatremia. If it is more than 80mm it is considered excessive amniotic fluid. Amniotic fluid index is the sum of the maximum depth of the four amniotic fluid dark zones, the range of normal values is 80 to 180mm, amniotic fluid index less than 80mm belongs to the amniotic fluid is low, less than 50mm for the amniotic fluid is too little, more than 180mm for the amniotic fluid is too much, more than 220 to 240mm when the indication of amniotic fluid is too much. Once the amniotic fluid dark zone test result is abnormal after pregnancy, you need to clarify the cause of the disease with the help of your doctor and carry out targeted treatment or therapy.