[DSRP Evidence](https://dsrpevidence.org/)

# Interobserver and intraobserver variability of fetal and maternal Doppler measurements: systematic review and meta-analysis

## Details

**Authors** Prins et al.

**Year** 2026

**Publisher** Ultrasound in Obstetrics & Gynecology

**Discipline** Medicine

[Read it at the publisher](https://doi.org/10.1002/uog.70287) 
10.1002/uog.70287

## In authors' words

### Abstract

Objectives To evaluate the variability and reproducibility of umbilical artery (UA), fetal middle cerebral artery (MCA) and uterine artery (UtA) Doppler ultrasound measurements in pregnancy. Methods A systematic search of MEDLINE, EMBASE and the Cochrane Library (CENTRAL) was conducted from inception to 17 June 2024. Studies were included if they reported intra‐ or interobserver variability of UA, MCA or UtA Doppler ultrasound measurements in singleton or multiple pregnancies, using the intraclass correlation coefficient (ICC), concordance correlation coefficient, Cohen's kappa or limits of agreement. Data extraction was performed using standardized data‐extraction forms. A meta‐analysis was conducted using a random‐effects model to account for heterogeneity, and variability estimates were pooled using Fisher's Z ‐transformation. Reproducibility was categorized according to the True Reproducibility of Ultrasound Techniques (TRUST) criteria. Results In total, 2426 records were screened. Of these, 26 studies including 2457 patients met the inclusion criteria; eight studies described UA Doppler, 11 described MCA Doppler and 11 described UtA Doppler results; two of the studies described cerebroplacental ratio results. The pooled intraobserver ICC for UA pulsatility index (PI) was 0.88 (95% CI, 0.77–0.94) and the pooled interobserver ICC was 0.68 (95% CI, 0.55–0.79). For MCA‐PI, these values were 0.85 (95% CI, 0.69–0.93) and 0.80 (95% CI, 0.62–0.90), respectively, and for mean UtA‐PI they were 0.90 (95% CI, 0.85–0.93) and 0.84 (95% CI, 0.78–0.89), respectively. Findings across studies suggested generally poor‐to‐moderate reproducibility according to the strict TRUST criteria. Conclusions Our results emphasize that there is room for improvement regarding the reproducibility of Doppler ultrasound in routine obstetric practice. By standardizing ultrasound measurement protocols, advancing technologies such as artificial‐intelligence‐supported measurement applications and training programs, as well as obtaining multiple measurements per session and performing quality audits when outliers are detected, the field could move towards more accurate and reliable fetal assessments. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

### What they found (results)

A meta-analysis of 26 studies (2,457 patients) found poor-to-moderate reproducibility of umbilical- and uterine-artery Doppler pulsatility-index measurements, with intraclass correlation coefficients differing substantially between inter-observer and intra-observer comparisons (e.g. uterine artery PI: 0.90 vs. 0.84).

## Commentary

### In short

The same physiological signal yields a different measured value depending on which observer takes the measurement, showing the reading is partly a function of observing perspective rather than purely intrinsic to the object.

**Patterns it shows** P

**Added** 2026-08-12

**How to cite this** Prins et al. (2026). Interobserver and intraobserver variability of fetal and maternal Doppler measurements: systematic review and meta-analysis. Ultrasound in Obstetrics & Gynecology.