PGF and Hypertension: Two previous retrospective analyses by our group suggested a role for uteroplacental flows and for two serum biomarkers, soluble Fms-like tyrosine kinase 1 (sFlt-1) and Placental Growth Factor (PlGF), in distinguishing between PE and chronic kidney disease (CKD) in patients with hypertension and proteinuria during pregnancy [16, 17].