SERPINE1 and Bjornstad syndrome: NGAL concentrations (spontaneous PTD: median 398.0 ng/mL (IQR 165.7–502.0) vs term: median 325.5 ng/mL (IQR 228.3–499.8); p = 0.448) and PAI-1 concentrations (spontaneous PTD: median 41.4 ng/mL (IQR 26.4–54.8) vs term: median 40.1 pg/mL (IQR 22.4–59.4); p = 0.718) were not significantly associated with spontaneous PTD in the replication phase (Table 6).