What are the causes? Pulmonary hypertension can persist after birth in the presence of a heart which is normal although this is unusual. More commonly, the high pressure is secondary to abnormalities or diseases of the heart or lungs. The child may have a congenital abnormality of the heart (see entry Heart Defects) in which too much blood goes to the lungs at a high pressure. Or the baby may have difficulties in breathing and be short of oxygen as a result of lung diseases. In any child with persistent pulmonary hypertension of the newborn, it is essential that an accurate diagnosis be made as rapidly as possible and appropriate treatment given. For babies in whom pulmonary hypertension persists, the UK Specialist Commissioning Advisory Group includes a pulmonary hypertension service; the paediatric service is based at Great Ormond Street Hospital, London. Inheritance patterns and prenatal diagnosis Inheritance patternsNone. Prenatal diagnosisNone. Is there support? Information and support in the UK for pulmonary hypertension of the newborn is provided by the Pulmonary Hypertension Association UK (see entry Idiopathic and Familial Pulmonary Arterial Hypertension).