BOSTON -- Research initiated at a Boston hospital and published in the New England Journal of Medicine may change the way doctors screen pregnant women for Down syndrome and other genetic disorders.

NewsCenter 5's Heather Unruh reported Wednesday that Christina O'Donnell is expecting her third child in March. Like all pregnant women, she hopes for a healthy baby. But unlike most women who get screened for Down syndrome and other potential risks in their second trimester, O'Donnell knew just 11 weeks into her pregnancy that her baby's risk was low.

"It was important for me to know, and I wanted to know as soon as I could," O'Donnell said.

O'Donnell was one of 38,000 women who took part in a national study of prenatal screening methods. Researchers found that screening for Down syndrome with blood testing and ultrasound in the first trimester was more accurate in predicting if a baby would have Down syndrome than when done in the second trimester.

"The current standard of care only detects 81 percent of the fetuses with Down syndrome," Tufts New England Medical Center's Dr. Diana Bianchi said.

Screening in the first trimester detected 87 percent of down syndrome babies, and combined screening in the first and second trimesters resulted in 95 percent detection.

"The combined is the best route if you want to have the safest combination of tests," Bianchi said.

The findings mean women who used to rely on invasive and potentially dangerous procedures like amniocentesis no longer have to put their unborn child at risk.

"It's a no-brainer to do that over doing something that could potentially harm your baby," O'Donnell said.

First trimester testing can also detect congenital heart disease and other genetic disorders earlier. Critics say the information may lead to more parents deciding to abort fetuses with potential problems.

Doctors say past studies show the information will give parents a chance to adjust and physicians a chance to address any health concerns sooner.