Impact of Including or Removing Nuchal Translucency Measurement on the Detection and False-Positive Rates of First-Trimester Down Syndrome Screening

Abstract

Introduction: First-trimester Down syndrome (DS) screening combining maternal age, serum markers (pregnancy-associated plasma protein-A and beta-human chorionic gonadotropin) and nuchal translucency (NT) gives an 85% detection rate for a 5% false-positive rate. These results largely depend on quality assessment of biochemical markers and of NT. In routine practice, despite an ultrasound quality control organization, NT images can be considered inadequate. The aim of the study was to evaluate the consequences for risk calculation when NT measurement is not taken into account. Material and Method: Comparison of detection and false-positive rates of first-trimester DS screening (PerkinElmer, Turku, Finland), with and without NT, based on a retrospective study of 117,126 patients including 274 trisomy 21-affected fetuses. NT was measured by more than 3,000 certified sonographers. Results: There was no significant difference in detection rates between the two strategies including or excluding NT measurement (86.7 vs. 81.8%). However, there was a significant difference in the false-positive rates (2.23 vs. 9.97%, p < 0.001). Discussion: Sonographers should be aware that removing NT from combined first-trimester screening would result in a 5-fold increase in false-positive rate to maintain the expected detection rates. This should be an incentive for maintaining quality in NT measurement.

Study on the Effect of B-Ultrasound NT Scan in Early Pregnancy Combined with Serum Screening in Early and Middle Pregnancy for Down Syndrome

“…The main clinical manifestations are obvious mental retardation, special face, growth and development disorders, and multiple malformations. Studies have shown that most patients with the disease are accompanied by deformities, mental retardation, difficult to take care of themselves, and need long-term care from their families, which not only brings heavy economic and spiritual burden to the family and society but also has become a major public health problem of widespread concern in the world [ 3 , 4 ]. At the same time, a foreign literature that combined the artificial termination of pregnancy and live birth of children with DS showed that the incidence of DS could be as high as 2.32%, indicating that it is urgent to seek better methods to prevent and reduce the birth of children with DS [ 5 ].…”

Predicting first-trimester outcome of embryos with cardiac activity in women with recurrent spontaneous abortion

“…Previous studies have demonstrated that pelvic ultrasonography and biochemical analysis of maternal serum or urine can allow earlier detection of pregnancy and lead to more accurate diagnosis of its complications. 9,10 However, these studies mainly delineated normal outcomes of miscarriage. [11][12][13] The findings of research focusing on predicting pregnancy outcomes in women with RSA after the presence of fetal heart motion are sparse and the results are often conflicting.…”

Prenatal Diagnosis Nomograms: A Novel Tool to Predict Fetal Chromosomal Abnormalities in High-Risk Patients

“…However, NT thickening is currently recognized as the most closely associated sonographic index with trisomy 21 at 11-13 +6 weeks of gestation. 35,36 The 99 th percentile value of NT is 3. while the 95 th percentile value is 2.7 mm. 37 Some fetuses with chromosomal abnormalities of aneuploidy may also be missed with this technique.…”