How to start prophylaxis in untreated children with severe and moderate haemophilia in 2025, opinion of paediatricians from the French Society of Thrombosis and Haemostasis.

Hemophilia is the most prevalent constitutional bleeding disorder. Management of severe and moderate hemophilia has completely evolved in recent years due to major therapeutic innovations, such as antihemophilic factors with a prolonged half-life and non-substituted treatments, particularly emicizumab. Initial treatment takes place as early as possible in infancy to limit bleeding incidents and their consequences. In light of recent therapeutic changes, the pediatricians of the French Society of Thrombosis and Hemostasis have therefore carried out a national practice survey. Based on the survey results and a literature review, this article proposes suggestions for the initial management, prophylaxis, and monitoring of children with severe or moderate hemophilia. We recommend establishing early and long-term prophylaxis for all patients with severe or moderate hemophilia and a severe phenotype who have not been previously treated. The choice of treatment and prophylaxis regimen should be made through a shared decision-making process with the family. Close monitoring is recommended after prophylactic treatment initiation.