At the moment, pregnant women in the United Kingdom are offered an ultrasound scan and a blood test to assess the chances that their developing child will have a genetic abnormality. If the test comes back and shows that an abnormality is likely, then diagnostic tests must be performed to confirm the existence of any genetic conditions.
Many women eschew the more invasive diagnostic tests because they carry a risk of miscarriage and must be performed after the first trimester. But all that may change very soon if non-invasive prenatal testing (NIPT) becomes available for all pregnant women through the National Health Service, the U.K.'s nationalized health care system.
I've written extensively about NIPT and what it may mean for families in the United States. NIPT involves examining the DNA fragments of the fetus present in the mother's maternal plasma during pregnancy. This is called cell-free DNA. Once extracted, the DNA is analyzed for abnormalities. NIPT allows for detection of Down syndrome and a host of other chromosomal and genetic conditions.
NIPT is vastly superior to the old way of testing pregnancies. It's more than 98 percent accurate, carries no risk to the baby and can be performed as early as 10 weeks gestation, earlier than the old tests, which generally started around 12 weeks.