Statistical analyses
The differentiating power of each gene in non-PE and PE placental
tissues from multiple GEO datasets was combined by meta-analysis. The
optimal Cer marker in women’s serum was determined by Mann–Whitney U
test P-value, fold change, and AUC in the testing cohort. Performance of
Lep, the optimal Cer marker, and Lep/Cer ratio in predicting PE was
measured in the validation cohort by calculating AUC, sensitivity,
specificity, PPV, and NPV. A time-to-event analysis was performed to
calculate the gap between the time of prediction and the time of
confirmatory diagnosis of PE. Results were compared with a reference
point sFlt-1/PlGF ratio. Statistical analyses were preformed using R
packages .