Pregnancy blood test can identify Down's syndrome

http://www.newscientist.com/article/dn21887-pregnancy-blood-test-can-identify-downs-syndrome.html


Blood tests for fetal syndromes remove the risk of miscarriage (Image: Neil Bromhall/Science Photo Library)

TESTING whether a fetus has Down's syndrome is getting easier - and less risky. Several companies, all based in California, are launching tests that work on a pregnant woman's blood, rather than requiring an invasive procedure.

The tests are already proving controversial, with opponents of abortion concerned that more women will decide to terminate their pregnancy. "We oppose testing for the purpose of killing unborn children who are found to have disabilities," says Jessica Rodgers, spokeswoman for the National Right to Life Committee.

Brian Skotko, a Down's syndrome researcher at Harvard Children's Hospital in Cambridge, Massachusetts, says this isn't an unreasonable concern. The new tests will see prenatal diagnoses skyrocket, he says. "Unless the healthcare community ensures that these women receive accurate information about Down's syndrome, I think that a reasonable prediction is that fewer babies with the syndrome will be born."

Down's syndrome, caused by an extra copy of chromosome 21, is generally detected by amniocentesis, which involves inserting a needle into a pregnant woman's belly to sample cells from the fluid bathing her fetus. It carries a 1 per cent risk of miscarriage and is usually performed between 15 and 20 weeks into pregnancy - which in some US states is right up against the legal time limit for abortion. Chorionic villus sampling, which samples tissue from the placenta, can be performed earlier, but has an even higher risk.