Thrombophilia testing in neonates and infants with thrombosis.

In neonates and infants with idiopathic venous thrombosis (VTE) and in pediatric populations in which thromboses were associated with medical diseases, inherited thrombophilia (IT) have been described as risk factors. Follow-up data for VTE recurrence in neonates suggest a recurrence rate between 3% in provoked and 21% in idiopathic VTE. Apart from underlying medical conditions, recently reported systematic reviews on pediatric VTE have shown significant associations between factor V G1691A, factor II G20210A, and deficiencies of protein C, protein S and antithrombin, even more pronounced when combined IT were involved. Independent from the age at first VTE onset, the pooled odds ratios (OR: single IT) for VTE ranged from 2.4 for the factor II G20210A mutation to 9.4 in neonates and infants with antithrombin deficiency. The pooled OR for persistent antiphospholipid antibodies/lupus anticoagulants was 4.9 for pediatric patients with venous VTE. The factor II G20210A mutation (OR: 2.1), and deficiencies of protein C (OR: 2.4), S (OR: 3.1) and antithrombin (OR: 3.0) also played a significant role at recurrence. Based on these data, screening and treatment algorithms must be discussed.