This is the first published report documenting the successful use of intrauterine infusion of factor VIII (FVIII) in order to reduce the risk of intracranial haemorrhage in a foetus with documented haemophilia A. This approach provides another option for management of newborns with documented coagulation factor deficiency. The subsequent development of an inhibitor directed against FVIII is believed to be related to exposure to exogenous FVIII in the presence of an inversion mutation and not to the intrauterine procedure.