First trimester uterine artery Doppler for the prediction of preeclampsia and foetal growth restriction.

Feasibility and reproducibility of uterine artery Doppler (UAD) at 11-14 gestational weeks was recently confirmed. Normal range values were established for resistance and pulsatility indexes. A body of evidence supports that the risk of developing preeclampsia or foetal growth restriction is highest when UAD impedance (evaluated by sus-mentioned indexes or uterine artery notch persistence) remains bilaterally high from first to second trimester, whereas the risk is lowest when UAD impedance is low from 11 to 14 gestational weeks. In unselected women, the sensitivity of 11-14 weeks-UAD is high but the positive predictive value is low, and data do not support its introduction as the sole predictive test. In models using maternal history and 11-14 weeks-UAD, the negative predictive value is high while abnormal UAD may identify a high proportion of women that will develop early-onset preeclampsia. Algorithms combining biochemical markers could still improve this prediction rate at higher cost and complexity.