OBJECTIVE: To assess the rate, location, risk factors, management, and outcomes of neonatal thrombosis (NT).

DESIGN: A retrospective study investigating infants admitted to NICUs in Canadian Neonatal Network between January 2014 and December 2016 and diagnosed with NT. Each infant with NT was matched with an infant without NT.

RESULTS: Of 39,971 infants, 587 (1.5%) were diagnosed with NT: 440 (75%) venous, 112 (19%) arterial, 29 (5%) both. NT rate was 1.4% in full-term and 1.7% in preterm infants. Venous thrombi occurred most commonly in the portal vein and arterial thrombi in the cerebral artery. Conservative management and low molecular weight heparin were the most common treatment modalities. Hospital stay was longer (p < 0.001) in the NT patients, but mortality was similar.

CONCLUSIONS: NT was diagnosed in ~15/1000 NICU admissions and most commonly in the portal vein and cerebral arteries. Management varied based on the type and location of thrombi. Large multicenter trials are needed to address the best management strategies.