In the classification of PPROM, the areas under the curve (AUC) and cutoff values were determined: albumin (AUC = 0.735, cutoff < 36 g/dL), factor 12 (AUC = 0.732, cutoff < 207.4%), CRP (AUC = 0.698, cutoff > 4.3 mg/L), ferritin (AUC = 0.660, cutoff > 10.39 ng/mL), ceruloplasmin (AUC = 0.788, cutoff > 0.44 mg/dL), fibrinogen (AUC = 0.764, cutoff > 3.74 mg/dL), protein S (AUC = 0.656, cutoff > 42%). Here, PROS1 is linked to preterm premature rupture of the membranes.