A low risk Down’s syndrome is the probability of screening for Down’s syndrome and is not so much related to low amniotic fluid. The main reasons for the decrease in amniotic fluid may be placental hypoplasia, fetal growth restriction or side effects caused by medication. 1. Placental hypoplasia: Placental hypoplasia is mainly caused by elevated blood pressure during pregnancy, overdue pregnancy, etc.; this needs to be examined to determine the cause and then determine whether medication is needed. 2. Fetal growth restriction: Fetal growth restriction may be caused by redistribution of blood circulation due to chronic hypoxia in the uterine cavity of the fetus, which may result in decreased urination of the fetus and low amniotic fluid volume. 3. Drugs: taking some drugs during pregnancy can also cause a decrease in amniotic fluid volume, such as indomethacin, aspirin and so on. The amount of amniotic fluid can drink more water to see if it can promote the recovery, in addition to the need for timely pregnancy test, clear its specific causes, and under the guidance of the doctor to give targeted treatment.