Fig. 2

Graphical representation of concomitant risk conditions in the study population

Early preterm: infants born at gestational age ≤ 29 weeks; Preterm: infants born at gestational age 30-35 weeks, Term: infants born at gestational age > 35 weeks. BPD Bronchopulmonary Dysplasia, RDS Respiratory Distress Syndrome, CHD Congenital Heart Diseases