Clinical and Treatment Characteristics of Infants and Toddlers Less Than Two Years of Age with Hemophilia

Authors: Han, JH; Dupervil, B; Mahajerin, A; Kulkarni, R; Manco-Johnson, MJ; Thornburg, CD

Affiliations: Indiana Hemophilia & Thrombosis Center (IHTC), Indianapolis, Indiana, United States. Center for Disease Control and Prevention, Atlanta, Georgia, United States. argenx, Boston, Massachusetts, United States. Michigan State University, Okemos, Michigan, United States. Hemophilia & Thrombosis Center, University of Colorado Anschutz Medical Campus and Children’s Hospital Colorado, Aurora, Colorado, United States. Rady Children’s Hospital San Diego, San Diego, California, United States.

Publication: Blood advances; 2024

Abstract: 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 (CDC). ICH in the first two years of life was seen in 8% of ITs, of whom 8 (12%) 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 to those without a family history (FH) of hemophilia, known positive FH of hemophilia was associated with earlier age of diagnosis (p =<0.0001) and decreased rates of vaginal delivery (p = 0.0006). The use of FVIII 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.