All fetuses have cerebrospinal fluid.
Normal fetuses have cerebrospinal fluid, which circulates continuously through the fetal ventricles as well as the subarachnoid space.
Physiologically, the lateral ventricles of the fetus usually measure within 10mm, and there are no abnormalities in the circulation of cerebrospinal fluid in the brain, which will not lead to hydrocephalus, and there will not be excessive fluid dark areas in the brain during obstetric ultrasound.
If there is excessive cerebrospinal fluid, there is a possibility of hydrocephalus, and the fetus should be investigated for developmental malformations of the brain, and amniocentesis is needed to confirm the chromosomal status of the fetus. When chromosomal abnormalities or developmental malformations of the brain are found, the pregnancy needs to be terminated.