Early postnatal blood pressure and intraventricular haemorrhage in very and extremely preterm neonates: a matched...

Background Immediate postnatal transition is a vulnerable phase, especially in preterm neonates. Arterial blood pressure (ABP) modulates cerebral perfusion and may contribute to intraventricular haemorrhage (IVH) when autoregulation is impaired. Evidence for its role during transition remains limited. We investigated associations between ABP and IVH. Methods We conducted a retrospective matched case-control study at the Medical University of Graz including neonates born < 32 weeks' gestation between 2009 and 2025. Cases with IVH grade ≥ II during the first week of life and an oscillometric ABP measurement at 15 minutes after birth were matched 1:1 to controls without IVH by gestational age (±3 days), birth weight (±70 g), sex, and cord clamping strategy. Systolic, mean, and diastolic ABP (SABP, MABP, DABP) were compared using paired analyses. Subgroup analyses were performed according to infection status and physiological-based cord clamping (PBCC). Results Forty-four neonates with IVH grade ≥II (median GA 25 weeks; BW 755 g) were matched to 44 controls. Baseline characteristics were similar. At 15 minutes after birth, IVH cases had lower SABP, MABP, and DABP (Holm-adjusted p=0.018, 0.012, 0.018, respectively), consistently below the 10th percentile. Infection occurred only among IVH cases. The association remained consistent across infection-stratified analyses, but no significant difference was detected in the exploratory PBCC subgroup. Conclusion Reduced ABP at 15 minutes after birth is strongly associated with IVH ≥ grade II. Values below the 10th percentile may indicate circulatory compromise. Early ABP assessment may improve risk stratification and monitoring.