However, it was reported that additional biomarkers and further research were needed to improve the screening performance of the combined model which would include maternal risk factors, PAPP-A and PlGF before any clinical application.[17] In the study conducted by Rosen et al, it was found that circulating maternal plasma thrombin-antithrombin (TAT) complexes predicted PPROM and the probability of PPROM was 6.0 times higher in patients with TAT level > 3.9 mcg/L in the second trimester. The gene discussed is PAPPA; the disease is preterm premature rupture of the membranes.