Chromosomal disorders with a prevalence of 4 in 1,000 live births are among the important determinants of paediatric health and a healthy population. Trisomies constitute almost half of all chromosomal abnormalities (Wellesley et al., 2012). Down syndrome is the most common non-lethal trisomy and occurs one per 740 live births in the United States (Parker et al., 2010), indicating an increase of approximately 33% compared with the late 1970s (Shin et al., 2009). This increase in prevalence is associated with increased maternal age in this period. According to the guidelines of the American College of Obstetrics and Gynecology, all pregnant women should be offered aneuploidy screening or diagnostic testing in early pregnancy (ACOG & May, 2016).