NPPB and pulmonary hypertension: There is strong evidence that various preterm conditions affect NT-proBNP serum levels, including hemodynamically significant patent ductus arteriosus [6, 7], pulmonary hypertension, bronchopulmonary dysplasia [9], retinopathy of prematurity [10, 11], and inflammation or sepsis [12, 13].For other preterm diseases such as intestinal complications (NEC, FIP, gastric perforation) and IVH, the study evidence on their effects on NT-proBNP levels is less clear.