Cell-free fetal DNA and RNA in maternal blood: implications for safer antenatal testing

#### Summary points The landmark discovery that cell-free fetal DNA circulates in maternal blood during pregnancy has stimulated research worldwide into many potential applications in obstetric care.1 Improvements in molecular genetic technology over the same period have enabled the translation of cell-free fetal DNA testing into clinical practice for early non-invasive prenatal identification of some genetic traits. However, complex wider ethical, legal, and social problems associated with the technology, as well as implications for clinical and laboratory services, still need careful consideration. This article gives an overview of recent developments in cell-free fetal nucleic acid technology and its implications for non-invasive prenatal diagnosis and screening. #### Sources and selection criteria We searched PubMed, the Cochrane Collaboration, and Science Direct using the terms “non-invasive prenatal diagnosis” and “free fetal DNA” (and common variations), in addition to using personal archives of references. We also led a working group of experts and key stakeholders in the United Kingdom to review the area and make recommendations for implementation of this technology in the NHS. Prenatal screening and diagnosis form a routine part of antenatal …