The Erythropoietic Response to Pregnancy in β‐Thalassaemia Minor

Summary. In 15 women with β‐thalassaemia minor, the haemoglobin concentration fell to a greater extent during pregnancy than in normal women. The lower haemoglobin level in the thalassaemics was caused by limited expansion of their red‐cell mass. Although the increase in red‐cell mass in iron‐sufficient thalassaemics was not influenced by iron supplementation, two of the unsupplemented women were in negative iron balance. Ideally, each thalassaemic patient should receive individual assessment prior to iron therapy. Iron supplementation is recommended, when there is evidence of a negative iron balance. There was great variability in the rise of red‐cell mass observed in the thalassaemic women. The rise correlated inversely with the morphological abnormality of the red cells, suggesting that the underlying disorder in haemoglobin synthesis was the main limiting factor. In the thalassaemic women foetal haemoglobin was significantly greater in the first half of pregnancy than in the puerperium. This raises the possibility that the increased production of γ‐chains could favourably influence haemoglobin synthesis in pregnant women with thalassaemia minor.