Question

1. Non-invasive prenatal testing (NIPT) is fundamentally based on DNA sequencing the blood of a pregnant person.  We have had the technical capacity to sequence DNA for decades.  Why was NIPT only developed in 2008?  

Answer 1

Prenatal screening for aneuploidy has changed dramatically since the 1970s. Non-invasive methods developed in the 1980s and 1990s, combined measurements of maternal serum analytes and ultrasonography. The problem with those methods was not just a high false-negative rate of 12% to 23%, a high positive rate of 5% and a poor sensitivity, ranging from 50% to 95%. Uncertain results frequently led to invasive procedures such as amniocentesis or chorionic villi sampling to perform karyotyping on fetal samples. Both of those procedures carry a risk of miscarriage.

The discovery of fetal cells in 1979 and fetal DNA in maternal blood in 1997 were key to the development of an alternative screening method using cell-free fetal DNA (cfDNA) for non-invasive prenatal testing (NIPT). However, it took until 2008 to demonstrate that trisomy can be identified in maternal blood by using next-generation sequencing (NGS). This opened-up a race to develop the best NIPT tests using NGS to offer as a more accurate and safer method aiming to avoid invasive test follow up.