Prognostic indicators of severe disease in late preterm pre-eclampsia to guide decision making on timing of delivery: the PEACOCK study
Chappell LC., Brocklehurst P., Green M., Hardy P., Hunter R., Beardmore-Gray A., Bowler U., Brockbank A., Chiocchia V., Cox A., Duhig K., Fleminger J., Gill C., Greenland M., Hendy E., Kennedy A., Leeson P., Linsell L., McCarthy FP., O’Driscoll J., Placzek A., Poston L., Robson S., Rushby P., Sandall J., Scholtz L., Seed PT., Sparkes J., Stanbury K., Tohill S., Thilaganathan B., Townend J., Juszczak E., Marlow N., Shennan A.
Objective To assess the diagnostic performance of angiogenic biomarkers in determining need for delivery in seven days in women with late preterm preeclampsia. Study design In a prospective observational cohort study in 36 maternity units across England and Wales, we studied the diagnostic accuracy of placental growth factor (PlGF) and sFlt-1 in determining the risk of complications requiring delivery in late preterm (34+0 to 36+6 weeks' gestation) preeclampsia. Angiogenic biomarkers were measured using the Quidel (PlGF) and Roche (sFlt-1 : PlGF ratio) assays. Additional clinical data was obtained for use within the established ʻPrediction of complications in early-onset pre-eclampsiaʼ (PREP)-S prognostic model. Biomarkers were assessed using standard methods (sensitivity, specificity, Receiver Operator Curve areas). Estimated probability of early delivery from PREP-S was compared to actual event rates. Main outcome measures Clinically indicated need for delivery for pre-eclampsia within seven days. Results PlGF (Quidel) testing had high sensitivity (97.9%) for delivery within seven days, but negative predictive value was only 71.4%, with low specificity (8.4%), with similar results from sFlt-1/PlGF assay. The area under the curve for PlGF was 0.60 (SE 0.03), and 0.65 (0.03), and 0.64 (0.03) for PREP-S in combination with PlGF, and sFlt-1 : PlGF, respectively. Conclusions Angiogenic biomarkers do not add to clinical assessment to help determine need for delivery for women with late preterm pre-eclampsia. Existing models developed in women with early-onset pre-eclampsia to predict complications cannot be used to predict clinically indicated need for delivery in women with late preterm pre-eclampsia.