What causes pregnant women to have polyhydramnios?

Pregnant women with polyhydramnios are considered to be caused by fetal malformation, maternal and infant blood group incompatibility, placenta or umbilical cord disease, diabetes, multiple pregnancy, etc. It is recommended to go to the hospital for alpha-fetoprotein determination, but also to detect blood sugar and blood type. When the patient's blood sugar is relatively high, insulin treatment is required according to the doctor's advice.