Cytogenetic microarray in structurally normal and abnormal foetuses: a five year experience elucidating increasing acceptance and clinical utility

The aim of the present study was to evaluate the diagnostic yield of prenatal cytogenetic microarray (CMA) in structurally normal and abnormal foetuses and record the acceptance rate of CMA for prenatal diagnosis over a course of five year. In 128 structurally normal and abnormal foetuses, CMA was performed along with foetal karyotype, after exclusion of aneuploidy by quantitative fluorescence polymerase chain reaction. The microarray was able to detect the pathogenic variants in 5.5% cases; the diagnostic yield in structurally abnormal foetuses was 8.8% and 4.7% in foetuses with a high aneuploidy risk. Balanced and unbalanced translocations, and low level mosaicism were detected. Reanalysis of variants of uncertain significance identified pathogenic variant. The study shows higher diagnostic yield in structurally abnormal cases, the importance of foetal karyotype and reanalysis in microarray. The acceptance rate of prenatal CMA increased five-fold over a period of five year.