Hydrocephalus during pregnancy is mainly caused by three reasons, excluding the baby’s own central nervous system developmental abnormalities, resulting in cerebrospinal fluid flow and triggered by hydrocephalus, the common clinical preterm labor or uterine infection during pregnancy, easy to cause hydrocephalus in babies: 1, preterm labor: if a pregnant woman is hit by an external force during pregnancy to appear the stress response, which may cause uterine contractions and trigger preterm labor. In addition, by the excessive dilatation of the uterine cavity or the influence of other diseases, there may also be preterm delivery, triggering the baby to have ventricular hemorrhage, thus causing hydrocephalus; 2, uterine infection: if the pregnant woman during pregnancy in the uterus or the uterus of other parts of the infection, the baby was not born, may be infected with germs through the amniotic fluid, resulting in infection of baby, which leads to inflammation of the brain tissue, triggering hydrocephalus. Hydrocephalus; 3. Others: Pregnant women who do not take folic acid on time may lead to abnormalities in the baby’s neurodevelopment, thus triggering the emergence of hydrocephalus. In addition, exposure to strong physical radiation or chemical substances during pregnancy may also lead to hydrocephalus and even more serious consequences.