PAPPA and hypertensive disorder: Amongst these three models, the Odibo 2011a model with ethnicity, BMI, history of hypertension, and PAPP-A as predictors showed the highest discrimination (summary C-statistic 0.72, 95% CI 0.51 to 0.86), with a summary calibration slope of 1.20 (95% CI 0.24 to 2.00) due to heterogeneity in calibration performance across the three cohorts.