Prenatal chromosomal microarray analysis and karyotyping in fetuses with isolated choroid plexus cyst: A retrospective case-control study

Objectives To evaluate the the diagnostic yield of chromosomal microarray analysis (CMA) in fetuses with isolated CPC (iCPC). Methods A total of 315 fetuses with iCPC (iCPC group) and 364 fetuses without abnormal ultrasound findings (control group) were recruited between July 2014 to March 2018. Results The overall diagnostic yield of chromosomal abnormalities by CMA and karyotyping in iCPC group was up to 4.1 %, higher than 1.4 % in the control group, p < 0.05. The detection rate of pathogenic or likely pathogenic copy number variants (CNVs) with clinical significance by CMA in iCPC group (1.3 %) was higher than in control group (0 %), p < 0.05. According to the type of chromosome abnormalities, the missed diagnosis rate of non-invasive prenatal testing (NIPT) was 1.6 % in our study. Conclusions The presence of iCPC on ultrasound examination suggests a potential indication for genetic counseling. Karyotyping and chromosomal microarray analysis may be considered for fetuses with iCPC. It is important to be aware of the limitations of non-invasive prenatal testing, as there is a possibility of residual risk.