Pulse wave analysis: a preliminary study of a novel technique for the prediction of pre-eclampsia

Objective  To investigate whether first-trimester arterial pulse wave analysis (PWA) can predict pre-eclampsia.
Design  This was a prospective screening study.
Setting  The Homerton University Hospital, a London teaching hospital.
Population  Two hundred and ten low-risk women with a singleton pregnancy were analysed.
Methods  Radial artery pulse waveforms were measured between the 11⁺⁰ and 13⁺⁶ weeks of gestation and the aortic waveform derived by applying a generalised transfer function. Augmentation pressure (AP) and augmentation index at heart rate of 75 beats per minute (AIx-75), measures of arterial stiffness, were calculated. The multiple of the gestation-specific median in controls for AP and AIx-75 were calculated. Logistic regression models were developed and their predictive ability assessed using the area under the receiver operator curve.
Main outcome measures  Prediction of pre-eclampsia by AIx-75.
Results  Fourteen (6.7%) women developed pre-eclampsia, and 196 remained normotensive. Eight of the 14 women developed pre-eclampsia before 34 weeks of gestation (early-onset pre-eclampsia). For a false-positive rate of 11%, AIx-75 had a detection rate of 79% for all cases of pre-eclampsia and 88% for early-onset pre-eclampsia.
Conclusion  First-trimester arterial PWA can play a significant role in understanding the pathophysiology of pre-eclampsia and may play a role in early screening.