Objective To evaluate lowest mean arterial blood pressure during the first 24 h of life (minMAP²⁴) in very-low-birthweight (VLBW) infants and to identify associations between hypotension and short-term outcome.

Design Retrospective cohort analysis of the minMAP²⁴ of 4907 VLBW infants with a gestational age <32 weeks in correlation with clinical data. Hypotension was defined as minMAP²⁴ being lower than the median value of all patients of the same gestational age.

Results MinMAP²⁴ values correlated with gestational age. Median minMAP²⁴ values of VLBW infants ≤29 weeks’ gestation were 1–2 mm Hg lower than gestational age in completed weeks. Hypotensive infants had a higher rate of intraventricular haemorrhage (IVH, 20.3% vs 15.9%, p<0.001), bronchopulmonary dysplasia (BPD, 19.2% vs 15.1%, p<0.001) and death (5.2% vs 3.0%, p<0.001). Multivariate logistic regression analyses, including potential confounders, confirmed these data. MinMAP²⁴ was an independent risk factor for IVH (OR 0.97/mm Hg, 95% CI 0.96 to 0.99, p=0.003), BPD (OR 0.96/mm Hg, 95% CI 0.94 to 0.98, p<0.001) and mortality (OR 0.94/mm Hg, 95% CI 0.90 to 0.98, p=0.003).

Conclusions Hypotension during the first 24 h of life is associated with adverse outcomes in VLBW infants. This underlines the need for randomised controlled trials on the use of vasoactive drugs in this vulnerable patient cohort.