Application of digital polymerase chain reaction technology for noninvasive prenatal test

the chromosomal abnormalities, it was reported that Down syndrome (trisomy 21) occurs in 1 in 800 [3,4], Edward syndrome (trisomy 18) in 1 in 6,000 [5], and Patau syndrome (trisomy 13) in 1 in 10,000 fetal subjects [6]. Moreover, birth defects from Down syndrome comprise about 26% of all congenital birth defects [7,8]. As maternal age increases, fetal chromosomal aneuploidy becomes more prevalent [9]. The prevalence of fetal aneuploidy has rapidly increased over the last decade in Korea because of the increasing age of marriage and childbearing (Table 1). Application of digital polymerase chain reaction technology for noninvasive prenatal test