Abstract
BACKGROUND: PlGF (placental growth factor) concentrations are lower in preeclampsia, a major cause of maternal death; testing improves diagnosis and outcomes. We evaluated 2 novel, whole blood, point-of-care PlGF tests (RONIA and Lepzi Quanti) in a low-resource setting for predicting adverse outcomes. METHODS: A prospective observational cohort study was conducted in women with hypertension in Sierra Leone, each of which were 24 to 36(+6) weeks of gestation. Eligible women underwent concealed RONIA and Lepzi Quanti PLGF testing. Optimal rule-out and rule-in thresholds were determined for predicting maternal (death and eclampsia) and perinatal (stillbirth, termination pre-viability, and neonatal death) composite outcomes. Sensitivity, specificity, negative predictive values, and positive predictive values were assessed. RESULTS: Analysis included women with RONIA (n=488) and Lepzi Quanti (n=140) PlGF tests. Optimal thresholds were >60 or >90 pg/mL (rule-out) and <20 or <12 pg/mL (rule-in) for RONIA and Lepzi Quanti, respectively. For tests <34 weeks, RONIA <60 pg/mL had high sensitivity and negative predictive value for ruling out maternal (94.9% and 94.6%) and perinatal (100%) composite outcomes. RONIA <20 pg/mL indicated higher risk (positive predictive values, 16.3% and 40.9% respectively). Lepzi Quanti <90 pg/mL had 100% sensitivity and negative predictive value for ruling out maternal and perinatal composites. Conversely, with Lepzi Quanti <12 pg/mL, nearly a quarter and a half of pregnancies experienced the maternal and perinatal composites (positive predictive values, 22.0% and 48.0%). Performance declined slightly at later gestations. CONCLUSIONS: Point-of-care PlGF testing shows accurate rule-out performance for serious outcomes, with potential for risk stratification in low-resource settings. For both tests, a minority of cases fell into an intermediate category, which would warrant increased surveillance to determine progress.