Donald School Journal of Ultrasound in Obstetrics and Gynecology

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VOLUME 5 , ISSUE 2 ( April-June, 2011 ) > List of Articles


Analysis of Quality of Nuchal Translucency Measurements

Mónica Echevarria, Carmen Comas, Bernat Serra, Ignacio Rodríguez, Joan Sabrià

Keywords : Prenatal screening,Down syndrome,Quality control,CUSUM,Fetal medicine

Citation Information : Echevarria M, Comas C, Serra B, Rodríguez I, Sabrià J. Analysis of Quality of Nuchal Translucency Measurements. Donald School J Ultrasound Obstet Gynecol 2011; 5 (2):127-132.

DOI: 10.5005/jp-journals-10009-1187

License: CC BY-NC 4.0

Published Online: 01-03-2012

Copyright Statement:  Copyright © 2011; The Author(s).



Quantitative analysis of the quality of nuchal translucency (NT) measurements.


This is a retrospective single-center study. NT was measured according to the Fetal Medicine Foundation (FMF) criteria by 20 trained obstetricians (October 2003-November 2009). The performance of NT measurements was analyzed with regard to several quality control standards. Accuracy according to experience, professional profile, crown-rump length (CRL) values and FMF certification was statistically tested.


A total of 14,978 NT measurements were assessed. (1) The mean operator-specific median NT-MoM values was 0.98. (2) Mean percentage of cases >95th and <5th percentiles were 5.0 and 4.2% respectively. (3) Logarithmic mean and SD of the NT-MoM values were 0.00 and 0.13 respectively. (4) The DR for trisomy 21 at screening time was 90.7% for a FPR of 6.7% for standard screening strategy. (5) According to cumulative SUM (CUSUM) figures, the performance was more acceptable in FMF-certified operators. Operator experience, exclusive dedication to FM, FMF certification and a range of CRL values > 60 mm had a statistical impact improving these standards.


Overall quality standards show optimal NT measurements in our unit. Experience a dedicated profile to fetal medicine ultrasound, CRL over 60 mm and FMF certification has a significant positive impact on the quality standards.

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