Of the 160 patients, 100 were referred because of nuchal translucency
greater than the 95th percentile, 51 because of a family history of congenital cardiac defects, and 9 because of the presence of extracardiac lesions.
Ellen Mozurkewich analyzed 27 studies including 163,450 subjects and reported that nuchal translucency
measurements identified 78% of fetuses affected by trisomy 21, 82% of those with trisomy 18, 90% of those with trisomy 13, and 96% of those with monosomy X.
When nuchal translucency
thickness found on ultrasound in the first trimester is at least 2 multiples of the appropriate gestational median (MoM), the risk of a major congenital heart defect is 14 times higher than normal, Lynn L.
Studies indicate that nuchal translucency
has a detection rate of about 82% for Down syndrome, which compares with a 60% detection rate for serum screening.
Second-trimester ultrasound can be as sensitive and specific as first-trimester nuchal translucency
in predicting Down syndrome.
Aside from the first trimester biochemistry and nuchal translucency
approach, another option to keep in mind is second-trimester noninvasive screening, which up to now has consisted of testing maternal serum for alpha-feto-protein, human chorionic gonadotropin, and unconjugated estriol.
Amniocentesis, chorionic villus sampling (CVS), maternal serum screening, and nuchal translucency
(NT) scan have been the primary diagnostic and screening methods for chromosomal abnormalities.
During the 13[sup]th week of pregnancy, ultrasound test indicated that fetal nuchal translucency
Following the demonstration of a correlation between abnormal ductal flow and nuchal translucency
(NT), it has been proposed that a combined assessment of DV and NT thickness may increase the efficacy of early sonographic screening of trisomy 21.
CFTS incorporates maternal characteristics, a first-trimester nuchal translucency
ultrasound scan, and serum biochemical investigations (measurement of serum free beta human chorionic gonadotrophin and pregnancy-associated plasma protein A).
Increased nuchal translucency
at 10 to 14 weeks or increased nuchal translucency
along with scoliosis at 15 weeks of gestational age also signifies arthrogryposis multiplex congenita.
Also, NTD's first trimester non-invasive prenatal screening test for Down Syndrome is the only high sensitivity screen that uses the free Beta hCG biomarker, along with PAPP-A and Nuchal Translucency
measurement, in assessing risk for Down syndrome.