Fetal Cells Offer Promise in Prenatal Testing (MIT Technology Review)

A scientist says a blood test that can discern a fetus’s entire genome is coming

by Bonnie Rochman|August 18, 2016

The year Led Zeppelin released its first album, in 1969, doctors in California found that they could sometimes spot Y chromosomes in some cells collected from a pregnant woman’s blood. It meant the cells came from the baby, assuming it was a boy.

The presence of fetal cells circulating in maternal blood immediately suggested that capturing and analyzing them could be a way to test fetuses for genetic abnormalities. But the race to do so turned into 50-year ordeal, and most scientists involved in the effort abandoned it. As it turns out, fetal cells in a pregnant woman’s blood are fairly rare. An ounce of blood might have 10 of them, or sometimes none, and they are hard to find.