Anaemia

Question 1

How is anaemia in pregnancy defined

Answer 1

First trimester haemoglobin less than 110g/L, second trimester Hb less than 105g/L and postpartum Hb less than 100g/L.

Question 2

What is the cause of anaemia in pregnancy

Answer 2

• During pregnancy, plasma volume increases by 40%. This results in a reduction in haemoglobin concentration since the blood is dilated due to higher plasma volume

Question 3

When are women screened for anaemia in pregnancy

Answer 3

Women are routinely screened for anaemia TWICE during pregnancy using FBC:
* At the booking clinic
* At 28 weeks gestation

Question 4

When will pregnant women with anaemia become symptomatic

Answer 4

• Often anaemia in pregnancy is asymptomatic, and usually becomes symptomatic when Hb is less than 90g/L. Women may then present with SOB, fatigue, dizziness, pallor (rarely PICA develops- craving for non-food items such as ice)

Question 5

What are some characteristics and risks of IDA

Answer 5

• IDA is associate with increased susceptibility to infection, poor work capacity and disturbance in maternal cognition and emotions postpartum. The foetus is relatively protected from the effects of IDA by upregulation of placental iron transport proteins (does increase the risk of IDA in first 3 months of life)
• There is some evidence for the association between maternal iron deficiency and preterm delivery, low birth weight, possibly placental abruption and increased peripartum blood loss

Question 6

Investigations for anaemia in pregnancy

Answer 6

• FBC at booking clinic and at 28 weeks gestation
• Serum ferritin- best marker of iron stores in pregnancy (ferritin is an acute phase protein so has limitations)
• Women with known haemoglobinopathy should have serum ferritin checked and offered oral supplements if their ferritin level is < 30 ug/L
• Women with unknown haemoglobinopathy status or normocytic or microcytic anaemia, should have haemoglobinopathy screening (in accordance with sickle cell and thalassaemia programmes)

Question 7

Lifestyle advice (concerning aneamia) for pregnant women

Answer 7

• Smoking and drinking cessation
• For Fe deficiency- eat animal meat (red meat and avoid pre-cooked chilled meat), eggs, milk, to increase iron
• For macrocytic- folate rich food (lightly cooked or raw green vegetables)

Question 8

How can normocytic or microcytic anaemia be managed antenatally

Answer 8

• A trial of oral iron (oral ferrous sulphate 100-200mg) should be considered as the first step and further tests should be undertaken if there is no demonstrable rise in Hb at 2 weeks and compliance has been checked (B12, folate studies etc)
• Can be considered a first line diagnostic test (increment demonstrated within two weeks is diagnostic)
• Parenteral iron is indicated when oral iron is not tolerated or absorbed or the patient’s compliance is in doubt (or women is approaching term with limited time to stabilise anaemia- 2nd trimester onwards)
• For nausea and epigastric discomfort, preparations with lower iron content should be tried. Slow release and enteric coated forms should be AVOIDED
• Routine iron supplementation for all pregnancies is not recommended in the UK
• Referral to secondary care should be considered if there are significant symptoms and/or severe anaemia (< 70g/L) or late gestation (>34 weeks)
• Once Hb is in the normal range, supplementations should continue for 3 months and at least until 6 weeks postpartum to replenish iron stores

Question 9

How should macrocytic anaemia be managed in pregnancy

Answer 9

Consider hydroxocobalamin 1mg 3 times a week for 2 weeks

Question 10

Intrapartum management of anaemia

Answer 10

Anaemic women may require additional precautions for delivery including:
* Delivery in a hospital setting
* Available IV access
* Blood group-and-save- All women should have their blood group and antibody status checked at booking and at 28 weeks of gestation (but group and save samples used for provision of blood in pregnancy should be less than 3 days old)
* FFP at a dose of 12–15 ml/kg should be administered for every 6 units of red cells during major obstetric haemorrhage. Subsequent FFP transfusion should be guided by the results of clotting tests
* Active management in the third stage of labour with plans for excessive bleeding
* Cut off: <100g/L for delivery in hospital and <95g/L for delivery in an obstetrician-led unit

Question 11

Postpartum management of anaemia in pregnancy

Answer 11

• FBC should be checked within 48 hours of delivery in all women with an estimated blood loss greater than 500ml and in women with uncorrected anaemia in the antenatal period or symptoms suggestive of postpartum anaemia.
• Women with Hb<100 g/l, who are haemodynamically stable, asymptomatic, or mildly symptomatic, should be offered elemental iron 100-200mg daily for at least 3 months and a repeat FBC and ferritin to ensure Hb and iron stores are replete.