In 35 weeks of pregnancy, if the depth of amniotic fluid is 6 centimeters, this is normal and not serious. However, if the amniotic fluid index is 6 centimeters, it means that the amount of amniotic fluid is low and relatively serious. In clinical practice, the amount of amniotic fluid is usually calculated based on the depth of amniotic fluid or amniotic fluid index. The depth of amniotic fluid, which refers to the vertical depth of the dark zone of maximum amniotic fluid water, should be between 3 and 8 centimeters. The amniotic fluid index, which refers to the sum of the vertical diameters of the largest pools of amniotic fluid in each of the four quadrants, should be between 8 and 18 centimeters. Now 35 weeks pregnant, if the depth of amniotic fluid by ultrasound is 6 centimeters, that is, within the range of 3~8 centimeters, this is a normal phenomenon, not serious, and will not affect the growth and development of the fetus. If the index of amniotic fluid measured by ultrasound is 6 centimeters, it means that the amount of amniotic fluid is on the low side, which is relatively serious because it may lead to fetal structural abnormalities or limb shortages, etc., and the rate of surgical deliveries and the rate of induced deliveries will also increase.