New prognostic prediction tool for suspected early-onset pre-eclampsia:
model development and performance evaluation.
Abstract
Objectives (1) To develop a risk score for early-onset pre-eclampsia
leading to delivery within one week from repeated marker determinations
on pregnancies with an sFlt-1/PlGF ratio above 38, and (2) to compare it
(i) with sFlt-1/PlGF ratio model and (ii) with the sFlt-1/PlGF ratio 655
cut-off. Design Retrospective cohort study. Setting Oviedo, Spain.
Sample 522 blood samples from 363 singleton pregnancies with clinical
suspicion of pre-eclampsia between 27 and 34 weeks of gestation. Methods
NT-proBNP, sFlt-1 and PlGF were combined using linear mixed models with
random intercept based on 213 samples from 123 pregnancies with an
sFlt-1/PlGF ratio above 38. Main outcome measures Early-onset
pre-eclampsia diagnosis leading to delivery within one week from
assessment. Results None of the 253 pregnancies with an sFlt-1/PlGF
ratio of 38 or below developed early-onset pre-eclampsia. The prognostic
prediction tool included sFlt-1 MoM, NT-proBNP and gestational age at
time (GA) of repeated measurements. The area under the ROC curve (AUC)
for early-onset pre-eclampsia diagnosis leading to delivery within one
week was 88.247 (95% CI 0.822-0.934) for the prediction tool and 82.639
(95% CI 0.752-0.892) for the sFlt-1/PlGF + GA model (P=0.04). At an
sFlt-1/PlGF ratio 655 cut-off the detection ratio was 31.9% (19.1-47.1)
with false positive rate of 4.2% (1.7-8.5). With the same false
positive rate, the detection rate with the prognostic prediction tool
was 53.2% (38.1-67.9) (P=0.03). Conclusions A prediction tool derived
from NT-proBNP, sFlt-1 MoM and gestational age linear mixed model
provided clinically useful prediction of early-onset pre‐eclampsia
prognosis when clinically suspected.