Sequenom and Biocept researchers have built noninvasive prenatal genetic tests that can detect defects with a simple blood-draw from the mother, rather than invasively sampling amniotic fluid.

They have adapted methods from Chinese University of Hong Kong scientists in finding free-floating nucleic acids to diagnose Down syndrome and Rh-encoding genes to diagnose HR incompatibility syndrome.

Biocept uses microfluidics and sticky antibodies to capture fetal cells that leak into the mother’s bloods. These are rare–a milliliter of maternal blood contains fewer than five fetal cells.

Amniocentesis and chorionic villus sampling, the standard testing methods now used, are invasive and can cause miscarriages.