Iron Deficiency Anaemia in Pregnancy

Iron deficiency anaemia in pregnancy is low haemoglobin (below 11 g/dL in the first and third trimesters and below 10.5 g/dL in the second) due to inadequate iron. It is the commonest cause of anaemia in Kenyan pregnancy, driven by poor diet, hookworm, malaria and closely spaced pregnancies. It raises the risk of preterm birth, low birth weight, postpartum haemorrhage and maternal death.

• Risk factors: poor diet, heavy periods, previous short interval, hookworm, malaria, HIV, vegetarian diet.
• Iron needs rise to about 27 mg daily in pregnancy.
• Treatment raises haemoglobin by about 1 g/dL every 2 to 3 weeks.

Women have fatigue, pallor, dizziness, palpitations, breathlessness, headache and pica, with pale conjunctivae, koilonychia and angular stomatitis. Check pulse, blood pressure and signs of heart failure.

• Palmar and conjunctival pallor.
• Tachycardia and flow murmur.
• Differential diagnosis: sickle cell disease, thalassaemia trait, anaemia of chronic disease, folate or vitamin B12 deficiency, malaria, haemorrhage, haemodilution of pregnancy.
• Complications: heart failure, preterm birth, low birth weight, postpartum haemorrhage, infection, maternal death, fetal anaemia.

The approach is blood count with ferritin and a search for the cause.

• Haemoglobin below 11 g/dL, MCV below 80 fL, ferritin below 30 micrograms/L (below 15 micrograms/L is definite), hypochromic microcytic film.
• Transferrin saturation below 16 percent; haemoglobin electrophoresis if microcytosis persists with normal ferritin.
• Malaria test, stool for hookworm eggs, urine dipstick, HIV test.
• Severity: mild 10 to 10.9 g/dL; moderate 7 to 9.9 g/dL; severe below 7 g/dL.

The principle is oral iron, treatment of causes, and IV iron or transfusion in severe or late disease.

• Supportive: iron rich diet (meat, liver, beans, dark leafy vegetables) with vitamin C foods; avoid tea with meals; insecticide treated net; take iron on an empty stomach or with orange juice.
• Pharmacological: ferrous sulphate 200 mg (65 mg elemental iron) oral 8-hourly, or 200 mg twice daily if not tolerated, for 3 months after haemoglobin normalises; ascorbic acid 250 mg oral with each dose; albendazole 400 mg oral single dose after 13 weeks for hookworm; artemether-lumefantrine 4 tablets (20 mg and 120 mg each) oral at 0, 8, 24, 36, 48 and 60 hours for uncomplicated malaria in the second and third trimesters; IV iron sucrose 200 mg diluted in 100 mL sodium chloride 0.9 percent over 30 minutes on alternate days to a total of 1000 mg, or ferric carboxymaltose 15 mg/kg (maximum 1000 mg) IV once, after 13 weeks for poor tolerance, poor response or haemoglobin below 8 g/dL after 34 weeks; folic acid 400 micrograms oral daily.
• Procedures: blood transfusion for haemoglobin below 7 g/dL with symptoms, or below 8 g/dL after 36 weeks.
• Special groups: women taking zidovudine are checked for anaemia; women with sickle cell disease use iron only if ferritin is low; preterm babies receive iron 2 mg/kg oral daily from 2 weeks.
• Red flags: haemoglobin below 7 g/dL, breathlessness at rest, chest pain, syncope, heart failure, ongoing bleeding.
• Follow-up: haemoglobin at 2 to 4 weeks; continue iron for 3 months after normal and for 3 months postpartum; haemoglobin at 28 and 36 weeks; plan delivery in a facility with blood if below 9 g/dL.