A simple, completely noninvasive DNA analysis of a mother-to-be's blood may be able to replace the current, riskier procedure used to identify possible birth defects, say researchers at the University of Pittsburgh Medical Center.

Currently, if birth defects are suspected, a sample of the fluid surrounding the fetus is drawn through a needle inserted in the pregnant woman's abdomen in a process called amniocentesis. But this type of invasive procedure carries risks.

"There is a pretty significant, if small, level of risk to the health of the fetus associated with those tests," said David Peters, lead researcher at Magee-Womens Research Institute. "So there's been a strong push to try and reduce that risk."

Researchers were able to accurately identify one specific defect -- a chromosomal irregularity called "fetal microdeletion syndrome" -- in an unborn child using a DNA test of a maternal blood sample at 35 weeks into the pregnancy. Tests for Down syndrome and other fetal anomalies are also being developed, according to an article in the New England Journal of Medicine.

About 1 in every 150 babies in the U.S. are born with a chromosomal abnormality, according to the March of Dimes. These are typically diagnosed via invasive procedures, such as amniocentesis.