Fetal haemoglobin Bart's disease in Hong Kong: why early diagnosis could not be made.

Pregnancies complicated by fetal haemoglobin (Hb) Bart’s disease are associated with poor perinatal outcomes, which include: early onset of hydrops fetalis, intrauterine or early neonatal death, and a higher risk of maternal pre-eclampsia.1 Even though there are case reports of survivors with or without intrauterine transfusion, postnatal regular transfusion is necessary until bone marrow transplantation can be successfully performed.2,3 As a result, affected pregnancies are usually terminated (after counselling) and hence early prenatal diagnosis is of great value.