Effect of Folic Acid Supplementation in Pregnant Women Having Thalassaemia Trait

Folic acid supplementation has been recommended for prevention of neural tube defects in pregnancy when taken periconceptionally up to 12 weeks of gestation. A daily dose of 0.4mg has been endorsed by World Health Organisation to achieve a Red blood cell (RBC) folate level of 906nmol/L (400ng/mL) for reduction of neural tube defect. Hong Kong has no policy on food fortification. Research data conducted in countries with food fortification may not be applicable. It is therefore essential to study the baseline folate status in pregnant women locally.

For pregnant women with thalassaemia, they are believed to have a higher risk of folate deficiency because of an increased rate of erythropoiesis and chronic haemolysis. However, information on folate level of thalassaemia trait in pregnancy is scanty. Unmetabolized folic acid has been detected in maternal and fetal blood when daily dosage greater than 0.8-1mg was taken. In term of the dosage and duration of folic acid supplementation after 12 weeks of gestation, the practice varies widely among public hospitals and Maternity \& Child Health Care centres. It is therefore essential to study the optimal dosage of folic acid supplementation in women with thalassaemia.