**1. Introduction**

The analysis of the fetal genome by an indirect approach from maternal blood during preg‐ nancy has been the focus of research in prenatal medicine for decades. The only option to investigate the genetic condition of the fetus so far had been an invasive procedure such as chorionic villous sampling and amniocentesis, which carries a 1% risk of miscarriage.

The basis of the current concepts to this non-invasive approach was the detection of cell-free fetal DNA (cffDNA) in maternal blood in 1997 [1]. It finally was the development of the

technique of next-generation sequencing (NGS) that lead to the transfer of this research into clinical practice. After the clinical availability and introduction of cell-free DNA analysis for the most common fetal aneuploidies (Trisomy 21, 13, and 18) in 2011, there has been an extremely high demand by pregnant women and to date approximately 1.4 million analyses have been performed worldwide assuming that there will be around 1 million/year in 2015 [2]. Most current tests count DNA fragments, map them to the chromosomes, and quantitatively compare the cell-free-DNA in maternal blood with a euploid reference genome. This new screening tool in prenatal diagnostics has marked the beginning of a new era in prenatal care and has significantly reduced the rate of invasive prenatal procedures such as chorionic villous sampling and amniocentesis.

With the broad availability of non-invasive prenatal genetic testing, a number of new issues have emerged concerning its reasonable clinical application, ethical concerns, integration into current public healthcare plans, counseling issues, and the role of prenatal ultrasound screening. In the following, we will discuss the current and future concepts of prenatal cellfree fetal DNA testing and show the current impact on clinical care among different risk groups taking into account medical, social, and ethical aspects.
