Effects of Iron and Folic Acid Antenatal Supplements on Maternal Haematology and Fetal Wellbeing

Pregnant women received one of five supplement regimes throughout the second half of pregnancy: (i) placebo; (ii) ferrous sulphate, 60 mg of iron per day; (HI) folic acid, 0·5 mg per day; (iv) iron 60 mg and folic acid 0·5 mg per day; and (v) iron 60 mg and folic acid 5 mg per day. Fifteen out of 102 subjects developed moderate anaemia (haemoglobin (Hb) < 10·0 g/100 ml). Anaemia in 12 cases was due to iron deficiency, and 10 of these patients had not received iron supplements. Oral iron, 60 mg per day, raised the mean haemoglobin level progressively from after the 28th week of gestation, but was inadequate to prevent moderate anaemia In two subjects. Forty-six per cent of patients receiving iron had no stainable intracellular stores at the end of pregnancy, compared with 67% of those not receiving iron. Folic acid 0·5 mg per day prevented completely folic deficiency and 5 mg per day gave no further advantage. Seven subjects (18%) not receiving folic acid had frankly megaloblastic erythropoiesis, but in only one was folate deficiency the sole cause of mild anaemia (Hb < 11·0 g/100 ml). Iron and folic acid acted on maternal haematology independently and cumulatively, but not through Interaction. Mean urinary oestrogen excretion, placental weight, birthweight and Apgar score were not significantly different in the various supplement groups, but even mild anaemia was associated with decreased oestrogen excretion and larger placentas. Neither folic acid excess nor folate deficiency affected oestrogen excretion in the absence of anaemia. It is concluded that oral ferrous sulphate equivalent to elemental iron 60 mg per day is Insufficient as antenatal supplementation in this community, but that folic acid 0·5 mg per day is adequate.