Introduction: Early pregnancy prediction for the development of pre-eclampsia can be improved. Currently, a number of logistic regression models are employed internationally to perform this task. Women planning to deliver within our institution undertake one such risk assessment. This is performed at 11-13+6 weeks of gestation, and is based upon the UK Fetal Medicine Foundation model. Parameters assessed include mean arterial blood pressure, uterine artery pulsatility index, serum PAPP-A and previous maternal history. However, the main issue with these models is their poor positive predictive value. In addition, markers of arterial stiffness have been found to be elevated in pre-eclamptic pregnancies compared to normal pregnancies, providing a potential means of further identifying women who go on to develop pre-eclampsia.
Objectives: To determine if cuff-based pulse-wave analysis can improve the performance of a currently employed first-trimester risk prediction model for pre-eclampsia.
Methods: A prospective cohort study of all women undertaking first-trimester assessment also had their pulse-wave analysis performed using a cuff-based device.
Results: 1,793 women underwent first-trimester screening at Royal Prince Alfred Hospital, between June 2013 to May 2014. Central systolic and diastolic blood pressure (CSP, CDP) was higher in women who developed pre-eclampsia (CSP 109.5mmHg vs 102.5mmHg, p<0.01; CDP 79.9mmHg vs 74.4mmHg, p<0.01). There was no significant difference in augmentation pressure (AP) or heart-rate adjusted augmentation index (AIx75) in women who developed pre-eclampsia versus those who did not (AP 4.2 vs 4.3, p=0.76; AIx75 18.6 vs 18.3, p=0.88). When attempting to determine if an elevated AP or AIx75 improved the model, we found that the addition of either did not improve the positive predictive value of the current model (PPV ranged from 0-11.4%).
Conclusions: Cuff-based pulse-wave analysis does not appear to improve the ability of the current model to identify women who will go on to develop pre-eclampsia.