Low amniotic fluid at 31+5 weeks with a two-week small fetus is considered an abnormality and the cause needs to be identified. Normally, the amount of amniotic fluid is between 300 and 2000 milliliters, if there is low amniotic fluid, then it is considered to be abnormal, which may lead to the growth and development of the fetus is limited, as well as the phenomenon of intrauterine oxygen deficiency. It is necessary to consult a doctor in time. If the amniotic fluid is low, accompanied by fetal development of two weeks, then it is necessary to see whether the pregnant woman’s menstrual cycle is prolonged, resulting in a small gestational period, or fetal development is delayed. Therefore, if you find that the amniotic fluid is low and the fetus is two weeks small, you need to consult a doctor in time to find out the cause and treat the symptoms.