LAUSR

High oxygen-affinity haemoglobin (Hb) is a heritable cause of secondary erythrocytosis that is associated with abnormality in haemoglobin oxygen release (McMullin et al. 2005). Increased erythropoietin and RBC production is a consequence of poor oxygen delivery to the kidneys. Although uncommon, haemoglobin Tak (HbTak) is one of the Hb variants with high oxygen affinity found in Thailand and Southeast Asia (Srivorakun et al. 2014). HbTak variant diseases have been reported in paediatric and adult patients (Charoenkwan et al. 2003; Teawtrakul et al. 2010). This is the first report on pregnant women who have a coinheritance of HbTak and b-thalassaemia (HbTak/b-thal). The aim of this report is to describe the pregnancy outcomes of pregnant woman complicated with secondary erythrocytosis caused by the HbTak/b-thal disease.