Non-invasive prenatal testing using cell-free fetal DNA in maternal circulation

•NIPT using fetal DNA has been successfully implemented into clinical practice.•Digital PCR and MPS have advanced NIPT development.•Testing includes fetal sex assessment, RhD genotyping, and fetal aneuploidy.•NIPT of many single-gene disorders will be available in the near future.•NIPT provides a tremendous opportunity to advance prenatal genetic testing.

The identification of cell-free fetal DNA (cffDNA) in maternal circulation has made non-invasive prenatal testing (NIPT) possible. Maternal plasma cell free DNA is a mixture of maternal and fetal DNA, of which, fetal DNA represents a minor population in maternal plasma. Therefore, methods with high sensitivity and precision are required to detect and differentiate fetal DNA from the large background of maternal DNA. In recent years, technical advances in the molecular analysis of fetal DNA (e.g., digital PCR and massively parallel sequencing (MPS)) has enabled the successful implementation of noninvasive testing into clinical practice, such as fetal sex assessment, RhD genotyping, and fetal chromosomal aneuploidy detection. With the ability to decipher the entire fetal genome from maternal plasma DNA, we foresee that an increased number of non-invasive prenatal tests will be available for detecting many single-gene disorders in the near future. This review briefly summarizes the technical aspects of the NIPT and application of NIPT in clinical practice.