Ultrasound markers for the detection of women at risk of developing pre-eclampsia

Pre-eclampsia (PE) is a consequence of an abnormal placental invasion. Uterine artery Doppler (Ut-AD) is directly related to trophoblastic invasion of the spiral arteries, which occurs before 18 weeks' gestation. A correct interpretation of Ut-AD indices and waveform patterns requires a rigorous and standardized methodology, in particular for the definition of notches. To date, aspirin is the only treatment associated with a decreased incidence of PE, and early identification of women at risk is crucial to optimize its use. The diagnostic performance of Ut-AD as a screening test should take into account the characteristics of the population studied. In women at high-risk of PE (i.e., women with a previous history of PE), results vary from a detection rate of 63%, with 25% false-positive results for all forms of PE, to 91% detection with 5% false-positive for early PE if repeated measurements, combined with maternal characteristics, are performed. Multicenter randomized clinical trials failed to demonstrate a benefit from administering aspirin in low-risk women with abnormal Ut-AD. In unselected populations, the use of Ut-AD, alone or integrated into algorithms including maternal characteristics, cannot be recommended for clinical practice at any gestational age. Combination with biological markers is a new field of research that could improve the performance of Ut-AD.