Fetal nuchal translucency thickness in different cut‐off points for aneuploidy screening in the south of Vietnam

Abstract

Aims: The purpose of this study was to define the most suitable cut-off point for fetal nuchal translucency thickness in a screening program for aneuploidy and trisomy 21 in the south of Vietnam. Material & Methods: Two thousand and five hundred cases of singleton pregnancies were followed prospectively from the first trimester to the delivery. The rate of aneuploidy was calculated by seeking a relationship to increased fetal nuchal translucency thickness then calculating the sensitivity and specificity of different cut-off points in thickness measurement to find the most suitable point for screening. Results:The prevalence of fetal abnormality was 1.5% (95% CI 1.1-2.1), and 1.2% (95% CI 0.8-1.7) of aneuploidy cases found and the commonest was trisomy 21. A cut-off point at 2.4 mm showed the highest level of sensitivity and specificity for the detection of aneuploidy (65.5 and 95.7%) and trisomy 21 (75.0 and 95.1%), with a false-positive rate of 4.3 and 4.9%, respectively. Conclusion:Using a cut-off point of nuchal translucency at 2.4 mm has potential for aneuploidy and trisomy 21 screening in the south of Vietnam.

United States' experience in nuchal translucency measurement: variation according to provider characteristics in over five million ultrasound examinations

“…The majority (98.4%) of paired data were submitted to the NTQR program by the laboratories performing the analyte assessment. Therefore, if a patient chose not to undergo combined first-trimester screening after the first-trimester ultrasound examination, for example, in case of markedly increased NT or structural anomaly, their data were not included, as those with NT ≥ 3 mm or with fetal abnormalities visualized were probably counseled on alternative testing strategies [21][22][23] . It is therefore likely that the data presented here represent those that were in the more 'normal' range.…”