Study shows test in the first trimester of pregnancy is effective in identifying birth defects

Huntington Station, New York -- A study in the August 2000, issue of Obstetrics and Gynecology shows that a new screening test which combines a blood test and an ultrasound exam can identify over 90% of cases of Down syndrome in the first trimester of pregnancy. This early screening test is an alternative to the commonly used "Triple Test" and has the advantage of being performed 6-8 weeks earlier in pregnancy while detecting more cases of Down syndrome. Down syndrome is one of the most common birth defects, affecting about one in every 600 new-born babies.

The study, entitled "First-Trimester Down Syndrome Screening Using Dried Blood Biochemistry and Nuchal Translucency", was a collaboration of NTD Laboratories, Huntington Station, New York; Centro Di Diagnosi Prenatale, Palermo, Italy; GeneCare Medical Genetics Center, Chapel Hill, North Carolina; and The George Washington University Medical Center, Washington, D.C.

Patients in the study underwent an ultrasound exam in which the amount of fluid accumulation behind the neck of the baby, called nuchal translucency, was measured. Additionally, a blood test was performed on each patient in which two chemicals called free Beta hCG and PAPP-A were measured. The results of the ultrasound measurement and blood test were then entered into a mathematical formula to determine the risk that the patient was carrying a baby with Down syndrome. The screening test identifies approximately 5% of patients most at risk for Down syndrome. These increased-risk patients are then offered a diagnostic procedure, such as chorionic villus sampling (CVS) or amniocentesis, which can determine, definitively, if the patient is carrying a baby with Down syndrome. The study showed that 91% of women carrying a baby with Down syndrome were in the increased-risk group.

The advantages of the new test, marketed as Ultrascreen® by NTD Laboratories, Huntington Station, New York, include increased detection of Down syndrome, earlier reassurance to pregnant women who have normal test results, more time and more diagnostic options for patients with increased risk results, and the ability to detect Down syndrome cases in patients destined to have a miscarriage.