In the fifth month of pregnancy, the fetus weighs about 300-350g and the amniotic fluid is about 500ml, weighing about 500g, so the total weight of the fetus and amniotic fluid is about 800-850g. During pregnancy, the fetus will continue to grow and develop with the growth of gestational age, and its weight will gradually increase. The rate of fetal growth and development has individual differences, influenced by genetic factors, nutritional factors, environmental factors and other aspects, the fetal weight in a certain pregnancy week is not completely consistent, and is not an exact value, in the fifth month of pregnancy, the fetal weight is about 300-350g, there will be some individual differences. Amniotic fluid is the environment in which the fetus lives in the uterus. Amniotic fluid includes maternal serum filtered through the fetal membrane to form dialysis fluid, fetal urine and exudate from the amnion, umbilical cord and fetal skin. During pregnancy, the amount of amniotic fluid generally increases gradually. In the fifth month of pregnancy, the amount of amniotic fluid is about 500ml and weighs about 500g. In the fifth month of pregnancy, the volume of amniotic fluid is about 500 ml and weighs about 500 g. The maximum volume of amniotic fluid is reached at 38 weeks of gestation, about 1000 ml, after which the volume gradually decreases.