Neonatal thrombo-embolism: risk factors, clinical features and outcome

Background: There are few data with respect to prothrombotic risk factors in neonates. Aim: To determine the associated risk factors, clinical features and outcome in newborn infants diagnosed with thrombo-embolism. Methods: Case records of 25 infants ( 17 full-term and eight preterm) diagnosed with thrombo-embolism between January 2005 and April 2008 in a neonatal intensive care unit were reviewed. Results: Of the 25 infants, 18 cases of venous (72%) and seven of arterial (28%) thrombo-embolism were recorded; in 18 it was associated with central catherisation. The sites of thrombosis were portal vein ( 15), right renal vein ( one), right femoral vein ( one), multiple veins ( one), right femoral artery ( 3), right iliac artery ( 2), bilateral iliac and renal arteries ( one) and left renal artery ( one). Hereditary thrombotic mutations were detected in three patients and anticardiolipin antibody was detected in one, none of whom had been catheterised. The remaining three non-catheterised patients had perinatal risk factors. Venous catheter placement was undertaken in 12 patients (48%), eleven of whom had: umbilical venous catheterisation for exchange transfusion ( 9), partial exchange transfusion ( one) and venous access ( one), and one had femoral venous catheterisation for an angiographic study. Arterial catheterisation was undertaken in seven patients ( 28%) ( one infant had both umbilical venous and arterial catheters) for angiographic studies ( 5) and blood sampling ( 2). Of the 18 catheterised patients ( 72%), thrombophilic studies were undertaken in 13 and none had abnormal results. Additional perinatal risk factors were present in 18 patients ( 72%) and included prematurity ( 8), congenital heart disease ( 8), septicaemia ( 5), dehydration ( 3), respiratory distress syndrome ( 3), polycythemia ( 2), meconium aspiration syndrome ( one), pneumonia ( one), maternal diabetes ( one), necrotising enterocolitis ( one) and perinatal asphyxia ( one). Although most of the patients recovered after anticoagulant or fibrinolytic therapy, the five (20%) deaths were associated mainly with underlying diseases. Conclusion: The most important risk factor for thrombo-embolic events in neonates is placement of central catheters and some perinatal prothrombotic conditions. Nevertheless, hereditary or acquired thrombophilic risk factors may also be a cause of thrombo-embolism