Dual-cutoff of sFlt-1/PlGF ratio in the stratification of preeclampsia: a systematic review and meta-analysis

Purpose To systematically review the approach of using two independent sFlt-1/PlGF cutoffs that has better sensitivity (cutoff-sen) and specificity (cutoff-spe) separately for risk stratification in the detection of preeclampsia. Methods PubMed and Embase databases and reference lists were searched up to June 2016. Inclusion criteria were blood samples for sFlt-1/PlGF with separate cutoffs (cutoff-sen and cutoff-spe) provided. Six relevant studies were identified. Pooling of results was done based on three studies and a systematic review was performed based on all six. Results The strategy of using a cutoff of ≤33 and ≥85 for early onset preeclampsia, and ≤33 and ≥110 for the late onset preeclampsia was proposed and examined. The pooled sensitivity for cutoff-sen was: 95.3% (90.6–98.1%) and 88.6% (82.9–92.9%) for early and late onset preeclampsia, respectively. The pooled specificity for cutoff-spe was: 97.6% (95.2–98.9%) and 94.2% (91.4–96.3%) for early and late onset preeclampsia respectively. The pooled estimation of the early onset pre-eclamptic pregnancies and control normal pregnancies classified in the equivocal zone was 4.9% (2.0–8.8%) and 32.4% (25.7–39.5%), respectively, and 26.8% (10.3–47.6%) and 8.7% (3.0–17.6%) for late onset patients. Conclusion The new dual-cutoff diagnostic system optimizes the predictive performance of the single cutoff system. Further studies are required to assess the performance of this system and to define the approach and frequency at which subjects in the equivocal zone should be screened.