New Blood Screening Can Detect Down Syndrome in Fetuses Earlier

A new blood screening test can detect Down’s syndrome in a fetus nearly two months earlier than previously possible, potentially reducing complications for pregnant women, according to a report in today’s New England Journal of Medicine. Young women in North America and Europe usually take blood tests between 16 and 18 weeks of pregnancy to learn if their fetus has the genetic defect, which is marked by mental retardation and physical defects. Older women or those at high risk usually undergo amniocentesis.

But researchers in Maine and Massachusetts have identified three new proteins secreted by the fetus or the placenta. They are present in the blood in about 60% of Down cases between nine and 14 weeks of pregnancy, about the same percentage as the protein now used in the later test.

--Compiled by Times medical writer Thomas H. Maugh II