The aim of this single-centre study was to obtain data prospectively on when children are diagnosed as having severe haemophilia and when they start to bleed. Results of this 10-year PUP study suggest that severe haemophilia is nowadays diagnosed much earlier than in the Sixties. Patients with severe haemophilia (n = 37: FV III <0.01 U/ml) start to bleed at very different ages. While 44% of patients have their first bleeding episode within the first year of life, others do not bleed before the age of four. The onset of joint bleedings generally occurs about half a year later than other types of bleeding. While half our patients developed their first bleeding by the age of 1.22 years, the mean age for the first joint bleeding was 1.91 years.
Conclusion: Early-onset prophylactic therapy can prevent damage to the joints, but for rational therapy the age at onset of bleeding must also be taken into account. A non-bleeding child does not benefit from prophylactic treatment.