Noninvasive prenatal testing beyond genomic analysis: what the future holds

Purpose of reviewThe discovery of cell-free fetal DNA in maternal blood enabled the development of DNA-based noninvasive prenatal testing. Noninvasive prenatal testing for chromosomal aneuploidy detection was first applied for clinical use a few years ago, resulting in a paradigm shift in prenatal testing. Apart from the use of cell-free fetal nucleic acids for the detection of fetal genetic or chromosomal diseases, we predict that the analysis of cell-free placental RNA and DNA methylation signatures would allow the noninvasive monitoring of placental function. These developments would potentially allow the screening and identification of a range of pregnancy-associated diseases, providing a holistic approach to prenatal management.Recent findingsThis article covers the advancement of techniques in measuring cell-free fetal RNA and fetal-specific methylation patterns in maternal blood. Recently, genome-wide fetal transcriptome and methylome can be obtained from maternal plasma, which allow the identification of novel biomarkers and the elucidation of the pathogenesis of maternal and fetal diseases. In fact, some studies demonstrated the feasibility of applying the RNA and DNA methylation analysis techniques for prenatal disease assessment.SummaryThis study reviews the evidence that demonstrates the potential utilities of cell-free fetal transcriptomic and methylomic analysis for the future assessment of pregnancy-associated disorders.