Low amniotic fluid in 31 weeks of pregnancy is recommended to be improved by food rehydration, infusion rehydration, and also can be helped by injection of amniotic fluid. 1. Food rehydration: everyone’s lifestyle is different, if you usually drink less water, it may lead to low amniotic fluid. It is recommended to increase the amount of water you drink, eat more food with high water content and drink more soup, which can help to replenish amniotic fluid. 2. Infusion rehydration: 31 weeks of pregnancy has reached the late stage of pregnancy, if the amniotic fluid is low, it is recommended to go to the hospital, can be supplemented by infusion of amniotic fluid, such as through the intravenous input of dextrose injection or saline rehydration. 3. Injection of amniotic fluid: if the amniotic fluid at 31 weeks of pregnancy is particularly low and cannot be improved by the above methods, it can also be injected directly into the amniotic membranes through the outflow of amniotic fluid by the professional instruments under the operation of professional doctors, which can achieve the effect of replenishing the amniotic fluid quickly. If the amniotic fluid in 31 weeks of pregnancy is particularly low, it is recommended to go to the obstetrics department of the hospital in time to find out the cause of the low amniotic fluid, if it is due to insufficient intake of amniotic fluid by the pregnant woman can be used in the above way, if it is due to the pregnant woman’s disease, pregnancy complications and other reasons, active treatment of the original disease, comorbidities, etc., and combined with the doctor’s advice to deal with.