Fetal choroid plexus cysts and chromosomal abnormalities

Background: The risk of chromosomal abnormalities in fetuses with choroid plexus cysts was investigated to determine if cytogenetic study is warranted in these fetuses. Materials and Methods: During a 31-month period, 45 fetuses with choroid plexus cysts were identified. The fetuses were carefully scanned for any structural abnormalities. The number, size and laterality of the choroid plexus cysts were recorded. Genetic counseling concerning the risk of chromosomal abnormalities was offered. All 45 patients elected to undergo amniocentesis. Follow-up ultrasound studies were performed. Results: Five (11% ) of the fetuses had chromosomal abnormalities, one had trisomy 21 and the other four had trisomy 18; no associated abnormality was identified in the fetus with trisomy 21. All four fetuses with trisomy 18 had one or more associated abnormalities. Two out of 40 fetuses with normal karyotype were structurally abnormal, one had hydrocephalus and the other had diaphragmatic hernia. Conclusion: Our study supports the association between fetal choroid plexus cysts and chromosomal abnormalities, including trisomy 18 and trisomy 21. It is reasonable to offer genetic counseling and cytogenetic studies to those patients who have had fetal choroid plexus cysts identified.