Columbia University Medical Center researchers at NewYork-Presbyterian Hospital/Columbia evaluated the new screening method in more than 38,000 pregnant women at 15 US centers. The new test offers a significant advantage over the current standard screening, a blood test performed in the second trimester of pregnancy.

"These results will undoubtedly change national practice," says Mary E. D'Alton, MD, principal investigator of the study. "All pregnant women should have the option of early screening for Down syndrome in their first trimester." Dr. D'Alton is Chair of the Department of Obstetrics and Gynecology at Columbia University College of Physicians and Surgeons, and Chief of Obstetrics and Gynecology at NewYork-Presbyterian Hospital/Columbia.

"Down syndrome screenings based on either maternal age alone, or an ultrasound or sonogram alone, are no longer justified protocols," she maintains.

Results Available in Five Days

Down syndrome, one of the leading causes of mental retardation and birth defects, occurs in one out of every 660 pregnancies. Persons with this condition have distinct physical features and commonly have certain birth defects and medical problems.

Any woman can have a baby with Down syndrome, regardless of her age, race, health, economic status or family history. For this reason, most pregnant women undergo testing to determine their potential to have a baby with this syndrome.

The new screening approach uses a blood test that analyzes the level of a protein and hormone in the mother's blood, combined with an ultrasound or sonogram picture of the thickness of skin on the back of the baby's neck (known as the nuchal translucency or NT).

Results are available within five days, often before starting the second trimester of pregnancy. This combination approach determines the odds that the baby might have Down syndrome, allowing pregnant women the option of prenatal diagnosis for Down syndrome and other chromosomal abnormalities within the first trimester or pregnancy.

The new first-trimester method offered a higher rate of detection, at 87 percent, compared to the best second-trimester screening method, which resulted in 81 percent detection, the researchers found.

Of the 38,167 women who underwent first-trimester screening, 117 were found to have a fetus with Down syndrome. The patients who received positive results from this screening could opt for a diagnostic exam -- chorionic villus sampling (CVS) or amniocentesis -- for confirmation. Both of those tests carry risks of complication leading to miscarriage.

Appropriate Training

The new screening method should be administered only by qualified, trained physicians, say the researchers. Dr. D'Alton and other experts working with the Society of Maternal Fetal Medicine recently have formed the Maternal Fetal Medicine Foundation to facilitate physician training and quality review for the screening.

So far, 1,600 physicians and sonographers nationwide have undergone training, and more are scheduled to do so. Information about the training and quality review program can be found at http://www.MFMF.org.

Women who want this early screening should seek healthcare professionals with appropriate ultrasound training and who participate in ongoing quality-monitoring programs. Programs should provide sufficient information and resources for counseling regarding the different screening options and limitations of these tests. Additionally, the services should provide access to an appropriate diagnostic test when the screening test is positive.

"This study was a wonderfully collaborative effort between researchers, including four leading Obstetrics and Gynecology centers in New York City," says Dr. D'Alton. "This incredible achievement would not have been possible without the hard work of the 15 centers that comprised the FASTER (First and Second Trimester Evaluation of Risk) Research Consortium and the 38,167 women who participated in this clinical trial."

The study was funded by a $13 million grant -- one of the largest ever awarded for obstetrical research -- from the National Institutes of Health and the National Institute of Child Health and Human Development.