Clinical and treatment characteristics of infants and toddlers less than 2 years of age with hemophilia.

Infants and toddlers (ITs) with hemophilia have unique bleeding features. Factor prophylaxis has been shown to decrease the risk of intracranial hemorrhage (ICH), which supports recommendations to begin at a young age. Clinical and demographic characteristics were analyzed for 883 ITs ≤2 years old with hemophilia A and B, seen at US Hemophilia Treatment Centers and enrolled in the Community Counts Registry, a surveillance program of the Centers for Disease Control and Prevention. ICH in the first 2 years of life was seen in 68 of 883 (7.7%) ITs, of whom 8 of 68 (11.8%) were on continuous prophylaxis at the time of ICH. ITs in this study usually started prophylaxis within the first year of life (mean, 10.3 months), with earlier ages of prophylaxis initiation in later birth cohorts in ITs with hemophilia A. Compared with those without a family history (FH) of hemophilia, known positive FH of hemophilia was associated with earlier age of diagnosis (P ≤ .0001) and decreased rates of vaginal delivery (P = .0006). The use of factor VIII mimetics and extended half-life clotting factor prophylaxis increased with later birth cohorts for ITs with hemophilia A and B. The study highlights that ICH rates in ITs with hemophilia remains substantial and underscores the need for further research to identify modifiable risk factors to prevent ICH by earlier diagnosis and initiating prophylaxis early, even within the first month of life.