Perinatal Services, Monash Medical Centre, Melbourne, Australia.
Department of Obstetrics and Gynaecology, Monash University and Monash Ultrasound for Women, Melbourne, Australia.
Ultrasound Obstet Gynecol. 2019 Feb;53(2):245-250. doi: 10.1002/uog.19116. Epub 2019 Jan 11.
To assess the quality of mean uterine artery (UtA) pulsatility index (PI) measurement in a first-trimester pre-eclampsia screening program.
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 log UtA-PI MoM were calculated and compared using the chi-square test.
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).
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.
评估早孕期子痫前期筛查项目中子宫动脉平均搏动指数（UtA-PI）测量的质量。
2014 年 5 月至 2017 年 2 月，澳大利亚悉尼一家大型诊所连续纳入接受早孕期胎儿染色体异常联合筛查的单胎妊娠女性，采用胎儿医学基金会（FMF）算法进行子痫前期联合筛查。每位操作人员和每个月的子宫动脉平均搏动指数（UtA-PI）对数正态分布的中位数倍数（MoM）均与正常中位数的关系进行绘图。制作中心趋势和离散度以及累积和图。将 0.95-1.05 之间的平均 UtA-PI MoM 值视为理想值，将 0.90-1.10 之间的平均 UtA-PI MoM 值视为可接受值。根据他们的平均 UtA-PI MoM，计算不同超声医师组的早产子痫前期筛查阳性率，并使用卡方检验进行比较。
共有 21010 名女性接受了早孕期超声检查并进行了子痫前期筛查。总的中位数 UtA-PI MoM 为 1.042（四分位距（IQR），0.85-1.26）。46 名超声医师中，42 名（91.3%）进行了超过 50 次检查，其中 41 名（97.6%）在可接受范围内测量了 UtA-PI。与 UtA-PI MoM 测量值在 0.95-1.05 之间的医生相比，平均 UtA-PI MoM 低于 0.95 的医生和平均 UtA-PI MoM 高于 1.05 的医生的筛查阳性率分别较低和较高（分别为 7.2%和 13.2%，vs 11.2%，P<0.001）。
在遵循既定方案的情况下，经过培训的操作人员可以很好地测量 UtA 多普勒。虽然会有轻微的变化，但这种测量的系统误差会影响筛查阳性率。因此，应建立质量控制过程，可能需要对员工进行再培训。
