There is no research to prove that fetal choroid plexus cysts are caused by radiation, common causes of choroid plexus cysts include the following: 1, chromosomal abnormalities: such as 21-trisomy, 18-trisomy, etc., can cause the choroid plexus to occupy normal brain tissue; 2, brain diseases: brain diseases, such as brain tumors, can also cause cerebrospinal fluid circulation obstruction, causing the occurrence of this disease; 3, benign structures Tissue: choroid plexus cysts are more common in 14-24 weeks fetuses, with an incidence of 1%, and the vast majority of them can gradually disappear after 24 weeks with the growth of the fetus. Fetal lateral ventricular choroid plexus cysts detected by ultrasonography in mid-pregnancy, usually unilateral ≥3 mm in diameter, are recommended to undergo amniocentesis or non-invasive DNA testing to exclude chromosomal abnormalities such as trisomy 21 and trisomy 18. If the chromosomes are normal, no special treatment is needed and most of them resolve after 24 weeks and almost all of them disappear by 32 weeks. Only a few choroid plexus cysts are progressively enlarged, and MRI can be done at this time to understand the specific situation, which can persist until childhood if no intervention is done and may cause acute hydrocephalus in the child. If chromosomal abnormalities are present, they need to be interpreted adequately depending on the severity of the chromosomal abnormality phenotype to decide on fetal retention.