Just 30 years ago, Merkatz et al1 reported an association between low maternal serum alpha-fetoprotein and trisomy 18, proving in principal that information about a fetus could be learned prenatally. Today, genetic testing directly on fetal cells can provide a complete karyotype, and use of chromosomal microarray analysis (CMA) can generate information regarding more than 80 syndromes caused by microdeletions and microduplications.2 Noninvasive prenatal testing on cell-free fetal DNA in maternal serum is also being integrated into prenatal care, providing, as early as the first trimester, highly sensitive screening for the common trisomies, sex chromosome aneuploidies, and syndromes such as velocardiofacial syndrome (22q11 deletion).3Â Read more.