ObjectiveEvaluate the relationship between initial haemostatic parameters and the frequency and severity of bleeding in neonates with hypoxic–ischaemic encephalopathy (HIE).DesignRetrospective observational cohort study.Setting2 academically affiliated level III neonatal intensive care units in Atlanta, Georgia.Participants98 neonates with moderate-to-severe HIE who underwent haemostatic testing within 12 hours of birth and were born from 1 January 2008 to 31 December 2013.Primary and secondary outcome measuresInitial haemostatic dysfunction was defined as one or more of the following: prothrombin time (PT) ≥18 s, platelet count <100×103/μL or fibrinogen <150 mg/dL. Bleeding assessed using the Neonatal Bleeding Assessment Tool and graded according to the WHO bleeding scale. The robust Poisson regression was used to evaluate the independent association between components of initial haemostatic dysfunction and bleeding.ResultsAmong the 98 neonates evaluated, the prevalence of initial haemostatic dysfunction was 69% (95% CI 59% to 78%). 27 neonates (28%; 95% CI 19% to 38%) had abnormal bleeding events and 56 (57%) received at least 1 blood product transfusion. 3 neonates died from bleeding complications. The most common products transfused were fresh-frozen plasma (71%), followed by packed red blood cells (24%) and platelets (21%). In multivariable analysis, fibrinogen <150 mg/dL (adjusted relative risk 2.41, 95% CI 1.09 to 5.36) and platelet count <100×103/μL (adjusted relative risk 2.59, 95% CI 1.30 to 5.16), but not initial PT, were associated with an increased risk of bleeding. The most severe bleeding occurred in neonates with a fibrinogen <150 mg/dL.ConclusionsAmong neonates with moderate-to-severe HIE, haemostatic dysfunction is prevalent and associated with an increased risk of bleeding and high transfusion burden. Further studies are needed to determine the appropriate transfusion approaches in this population to prevent bleeding.