A new non-invasive test may determine if an unborn baby has Down syndrome during the first trimester of a pregnancy.

Researchers at the Harris Birthright Centre at King's College in London developed a test that analyzes a baby's DNA that is present in its mother's blood to determine chromosomal disorders. The test was published in Ultrasound in Obstetrics and Gynecology.

Currently, if women want to determine if their unborn child has a genetic disease, they are faced with invasive procedures like amniocentesis or chorionic villus sampling.

During the amniocentesis test, a long needle is inserted into the belly to pull fluid from the sac that surrounds the baby. Chorionic villus sampling involves testing a small sample of the placenta. Both invasive procedures have a one in 100 risk of miscarriage. The new blood test could help women know if their child is facing any genetic conditions without putting the fetus at risk.

"This test is nearly diagnostic. It tells you almost certainly your baby has Down's or almost certainly it does not," lead researcher professor Kypros Nicolaides told BBC News. "From a woman's perspective, that is a much more clear message about what to do next."

According to the National Down Syndrome Society, one in every 691 babies in the United States is born with Down syndrome. Approximately 400,000 Americans currently have Down syndrome and about 6,000 babies with Down syndrome are born in the United States each year. Down syndrome is caused by the presence of an extra copy of chromosome 21 in 90 percent of cases.

"The test results from Nicolaides and his team at King's College show that the use of an early non-invasive blood test that could be used throughout the national screening program is still a fair way off," said Carol Boys, chief executive of the Down’s Syndrome Association UK. "The test is becoming more accurate. There are still small but significant anomalies that make it difficult to see how this could replace the current screening process."

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