Thrombophilia
Neonatal thrombophilia can cause both arterial and venous thromboembolic events. Thrombophilia results from the disrupted hemostatic system that normally consists of 4 integrated components: the coagulation system, endothelium and regulatory proteins, platelets, and fibrinolysis.
The peak incidence of pediatric thromboembolic events occurs in neonates and infants < 1 year of age. The true incidence remains unknown, however, clinically apparent thrombosis is estimated to be present in 2 – 5 / 1000 live births.
Inherited thrombophilia
- permanent condition that can increase the risk for thrombosis formation in presence of other factors or triggers (see acquired conditions below)
- Leiden mutation of factor 5 = the most common inherited thrombophilia (autosomal dominant), present in 5% of population => mutated factor 5 is resistant to activated protein C
- antithrombin III deficiency = homozygous form (large thromboses after birth, survival practically impossible)
- protein C deficiency = homozygous form (purpura fulminans => acute (often fatal), thrombotic disorder which manifests as blood spots, bruising and skin discolouration (coagulation in small blood vessels) => rapidly leads to skin necrosis and disseminated intravascular coagulation)
Acquired thrombophilia
- central venous catheters
- sepsis
- polycythemia
- dehydration
- maternal factors (anti-phospholipid antibodies, diabetes mellitus)
- combination of factors (renal vein thrombosis – RVT; cerebral infarction)
Therapy
Treatment is required for large thrombosis or if there is a risk of organ damage. In case of thrombosis associated with central venous catheter, the catheter can be extracted after couple of days of anti-coagulation therapy (low molecular heparin – LMWH). The therapy is titrated based on anti-Xa levels (normal values 0.5 – 1.0 IU/ml).
References
① Rajagopal R, Thachil J, Monagle P. Disseminated intravascular coagulation in paediatrics. Arch Dis Child. 2017;102(2):187-193. doi:10.1136/archdischild-2016-311053
