RESUMEN
We report a term newborn who presented on day 3 of life with unilateral, tender scrotal swelling with skin discolouration, which was subsequently diagnosed as haemophilia A at about 6 months of age. He received intramuscular vitamin K and hepatitis B vaccine at birth uneventfully. The scrotal swelling was treated as an infected hydrocoele, considering the absence of a family history of bleeding disorder and other risks of bleeding tendency, as well as the ultrasonographic features. He also had congenital pneumonia requiring venepuncture, non-invasive oxygen supplementation and intravenous antibiotics, without any complication. The swelling slowly improved over 2 months. He later developed post-trial vaccine injection haematoma at 4 months of age, and multiple non-traumatic bruises when he was 6 months old, leading to the diagnosis. This case demonstrates an uncommon, but a possible, early manifestation of haemophilia A at birth with a unilateral scrotal haematoma.