A Sonographic Finding and Chromosomal Study of Prenatally Diagnosed Fetal Choroid Plexus Cyst

Moon, S E; Yang, Y H; Cho, J S; Park, Y W

Abstract

OBJECTIVE
To evaluate the risk of fetal aneuploidy in the presence of fetal choroid plexus cyst and to compare the relationship between sonographic findings and aneuploidy.
METHODS
From Jan 1984 through Dec 1997, We retrospectively reviewed 96 patients who had shown fetal choroid plexus cysts while sonographic examination followed by genetic amniocentesis.
RESULTS
4 cases of fetal trisomy 18 were revealed [4.1%]. Two of them had isolated choroid plexus cysts and remaining 2 cases had risk factors of chromosomal anomaly. The risk factors included advanced maternal age, positive triple test screening and additional ultrasonographic abnormalities, especially cardiac defect. The sonographic findings of choroid plexus cyst were as following; The size of cysts varied from 2.0 to 13.0 mm. The cysts were unilateral in 75 of 96 cases [78.1%] and bilateral in 21 cases [21.9%]. Most of cysts [89.5%] were solitary. All cases of trisomy 18 had the cyst more than 5.0 mm in size and 3 of them had bilateral cyst.
CONCLUSION
It was concluded although the cysts are apparently isolated, the risk for trisomy 18 cannot be excluded, especially bilateral, large [> or =5mm] cysts. The risk factors associated with trisomy 18 were advanced maternal age, positive triple screening and additional abnormalities[cardiac defect]. For these cases, genetic counselling and prenatal chromosomal analysis would be offered. But numerous conflictiong reports need a prospective study in a large unselected population.