Quality assessment of uterine artery Doppler measurement in first-trimester combined screening for pre-eclampsia.
OBJECTIVE
To assess the quality of mean uterine artery (UtA) pulsatility index (PI) measurement in a first-trimester pre-eclampsia screening program.


METHODS
Consecutive women with a singleton pregnancy attending first-trimester screening for fetal chromosomal abnormalities also had combined screening for pre-eclampsia based on the Fetal Medicine Foundation (FMF) algorithm, at a large practice in Sydney, Australia, from May 2014 to February 2017. Distributions of mean UtA-PI multiples of the median (MoM) on a logarithmic scale were plotted in relation to the normal median with 95% CI for each operator and for each month. Central tendency and dispersion and cumulative sum charts were produced. Mean UtA-PI MoM values between 0.95 and 1.05 were considered ideal and those between 0.90 and 1.10 were considered acceptable. The screen-positive rates for preterm pre-eclampsia in different groups of sonographers according to their mean log10 UtA-PI MoM were calculated and compared using the chi-square test.


RESULTS
A total of 21 010 women attended for first-trimester ultrasound and had screening for pre-eclampsia. The overall median UtA-PI MoM was 1.042 (interquartile range (IQR), 0.85-1.26). Of 46 sonographers, 42 (91.3%) performed more than 50 examinations and, of those, 41 (97.6%) measured UtA-PI within the acceptable range. Sonographers measuring UtA-PI MoM on average below 0.95 and those measuring it above 1.05 had, respectively, lower and higher screen-positive rates when compared with those with measurements within the 0.95-1.05 UtA-PI MoM interval (7.2% and 13.2% vs 11.2%, respectively, P < 0.001).


CONCLUSION
UtA Doppler is measured well among trained operators when following an established protocol. While slight variations are expected, systematic error in this measurement impacts on the screen-positive rate. Therefore, a quality control process should be in place and retraining of staff may be required. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
['Rolnik|D L|DL|0000-0002-2263-3592', 'da Silva Costa|F|F|', 'Sahota|D|D|0000-0002-3755-2701', 'Hyett|J|J|', 'McLennan|A|A|']
D000328:Adult D003951:Diagnostic Errors D005260:Female D006801:Humans D008403:Mass Screening D011225:Pre-Eclampsia D011247:Pregnancy D011261:Pregnancy Trimester, First D011446:Prospective Studies D011673:Pulsatile Flow D018615:Ultrasonography, Doppler, Color D016216:Ultrasonography, Prenatal D055988:Uterine Artery
quality assessment uterine artery Doppler screening pre-eclampsia first trimester