The NT-proBNP levels of the preterm infants who had the above complications were not elevated compared with the NT-proBNP reference values (BPD: n = 16, median: 656 ng/l, IQR: 408–879 ng/l; BPD-related PH: n = 5, median: 469, IQR: 332–941; ROP stage 2 with plus disease or higher: n = 4, median: 645, IQR: 377–1567 vs. Reference group: n = 33, median: 824, IQR: 714–1232). Here, NPPB is linked to bronchopulmonary dysplasia.