This single-center prospective cohort study aims to describe the distribution of umbilical-cord blood vitamin A concentrations in extremely preterm infants (<32 weeks' gestation) and to evaluate whether low cord blood vitamin A is associated with increased risk of neonatal morbidities such as bronchopulmonary dysplasia (BPD), necrotising enterocolitis (NEC), severe intraventricular haemorrhage (IVH), retinopathy of prematurity (ROP), periventricular leukomalacia (PVL), high-grade patent ductus arteriosus (hsPDA), respiratory distress syndrome (RDS), sepsis and death before discharge.

Inclusion Criteria:

Gestational age <32 weeks Birth at First Hospital of Jilin University Umbilical cord blood sample obtained within 24 h Parental written informed consent

Exclusion Criteria:

Major congenital malformation or chromosomal abnormality Refusal of consent

Preterm neonates (gestational age <32 weeks)