First-trimester screening was conducted between 10 3/7 weeks" and 13 6/7 weeks" gestation, although the optimal time for testing was 11 weeks, because nuchal translucency
was shown to deteriorate rapidly as a marker between 11 and 13 weeks.
The future trend for first-trimester screening for DS could combine the measurements of PAPP-A, free [beta]-human chorionic gonadotropin, and nuchal translucency
in a near-patient environment.
already has a proven sensitivity and is cost-effective, so this screening could be an added component of aneuploidy studies."
A rapid first trimester screening program for Down syndrome using nuchal translucency
, free beta hCG and PAPP-A.
In such cases, there is no added benefit in performing serum screening or in using the nuchal translucency
(NT) value for developing a risk assessment algorithm because a measurement of at least 4 mm is indicative of extremely high aneuploidy risk, said Dr.
The first large study of screening using fetal nuchal translucency
in 95,000 women showed a detection rate of 77% with a 5% false-positive rate using that test alone, and 18 studies have reported similar results.
Second, we must ensure the quality of obstetric ultrasound and, specifically, the measuring of nuchal translucency
WASHINGTON -- First-trimester nuchal translucency
screening shows great promise for the early detection of Down syndrome and other aneuploidies, but its detection rate is highly variable and remains dependent on the skill of the individual sonographer.
Wapner, who collaborated with members of the Biochemistry, Ultrasound, and Nuchal Translucency
At least seven studies now have shown that detection of aneuploidy can be improved by analyzing a combination of risk factors in the first trimester: maternal age, nuchal translucency
measured on ultrasound, and serum testing for [beta]-HCG and PAPP-A.
They used ultrasound to evaluate 701 fetuses that were considered to be at risk for the chromosomal abnormality because of advanced maternal age and a previous finding of nuchal translucency
Aneuploidy screening in the first trimester relies on an algorithm incorporating four pieces of data: maternal age, blood levels of pregnancy-associated plasma protein A (PAPP-A), blood levels of free [beta]-human chorionic gonadotrophin (free [beta]-hCG), and ultrasound measurements of fetal nuchal translucency