Reference ranges for uterine artery mean pulsatility index at 11–41 weeks of gestation
O Gómez, F Figueras, S Fernández… - … in Obstetrics and …, 2008 - Wiley Online Library
Ultrasound in Obstetrics and Gynecology: The Official Journal of …, 2008•Wiley Online Library
Objectives To construct gestational age (GA)‐based reference ranges for the uterine artery
(UtA) mean pulsatility index (PI) at 11–41 weeks of pregnancy. Methods A prospective cross‐
sectional observational study was carried out of 20 consecutive singleton pregnancies for
each completed gestational week at 11–41 weeks. UtAs were examined by color and pulsed
Doppler imaging, and the mean PI, as well as the presence or absence of a bilateral
protodiastolic notch, were recorded. Polynomials were fitted by means of least‐square …
(UtA) mean pulsatility index (PI) at 11–41 weeks of pregnancy. Methods A prospective cross‐
sectional observational study was carried out of 20 consecutive singleton pregnancies for
each completed gestational week at 11–41 weeks. UtAs were examined by color and pulsed
Doppler imaging, and the mean PI, as well as the presence or absence of a bilateral
protodiastolic notch, were recorded. Polynomials were fitted by means of least‐square …
Objectives
To construct gestational age (GA)‐based reference ranges for the uterine artery (UtA) mean pulsatility index (PI) at 11–41 weeks of pregnancy.
Methods
A prospective cross‐sectional observational study was carried out of 20 consecutive singleton pregnancies for each completed gestational week at 11–41 weeks. UtAs were examined by color and pulsed Doppler imaging, and the mean PI, as well as the presence or absence of a bilateral protodiastolic notch, were recorded. Polynomials were fitted by means of least‐square regression to estimate the relationship between the mean UtA‐PI and GA.
Results
A total of 620 women were included. A second‐degree polynomial (Loge mean UtA‐PI = 1.39 − 0.012 × GA + GA2 × 0.0000198, with GA measured in days), after a natural logarithmic transformation, was selected to model our data. There was a significant decrease in the mean UtA‐PI between 11 weeks (mean PI, 1.79; 95th centile, 2.70) and 34 weeks (mean PI, 0.70; 95th centile, 0.99). It then became more stable up until 41 weeks (mean PI, 0.65; 95th centile, 0.89).
Conclusions
The mean UtA‐PI shows a progressive decrease until the late stages of pregnancy. Reference ranges for mean UtA‐PI may have clinical value in screening for placenta‐associated diseases in the early stages of pregnancy, and in evaluating patients with pregnancy‐induced hypertension and/or small‐for‐gestational age fetuses during the third trimester. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
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