Anaemia

Question 1

What are the thresholds for iron supplementation for anaemia in pregnancy

Answer 1

British Committee for Standards in Haematology, BCSH
First trimester <110
Second/third <105
Postpartum <100

Question 2

What is the most common cause of anaemia in pregnancy

Answer 2

Iron deficiency anaemia (90%)
- Bleeding e.g. menstrual/GI
- Increased use e.g. growth/pregnancy, malignancy
- Dietary deficiency e.g. vegetarian
- Malabsorption e.g. coeliac, IBD

Question 3

What are the causes of anaemia

Answer 3

Microcytic: IDA, thalassaemia, sideroblastic
Normocytic: ACD, haemolytic anaemia, pregnancy, blood loss, aplastic anaemia
Macrocytic: B12/folate deficiency, Alcohol excess, haemolysis, liver disease, drugs

Question 4

What are the risk factors for anaemia in pregnancy

Answer 4

Increased use: Multiple pregnancy
Intake: Inadequate diet, Large volumes of vomit
Chronic anaemia
Blood loss: Short period of time between periods, Uterine fibroids, Previous menorrhagia
Young age (adolescent pregnancies)

Question 5

Describe the blood changes that occur in pregnancy

Answer 5

Pregnant women often gain a physiological anaemia: plasma volume increases out of proportion to the red cell increase (Lower Hct)

Plasma volume
- Increases by 10-15% at 6-12 weeks gestation
- Expands rapidly until 30-34 weeks
- Total plasma volume increases to 30-50% from non-pregnant state

Red Cell Volume
Increases by approximately 20% at term (even higher with folate and iron supplements)
Discrepancy between the rate of increase of plasma volume and red cell mass → relative haemodilution (physiological anaemia), from haemoglobin conc., haematocrit and red cell counts all decrease

Pregnancy causes a 2-3 fold increase in requirement of iron and 10-20 fold increase in folate requirement
300mg Foetus, 500mg Maternal

Question 6

What are the symptoms of anaemia in pregnancy

Answer 6

Lethargy/fatigue
Light-headedness/dizziness
Shortness of breath
Issues concentrating
Easy bruising
Night sweats
Weight loss
Fever

B12 specific: Glossitis, depression, psychosis/dementia, paraesthesia, peripheral neuropathy

Question 7

What investigations should be done for anaemia in pregnancy

Answer 7

FBC: ↓Hb, MCV
Iron studies (IDA):
- Serum iron ↓
- Iron binding capacity ↑
- Serum ferritin ↓
- Transferrin ↓
- Pregnancy: Iron ↑, TIBC ↑, Ferritin N
Blood film:
- IDA: microcytic, hypochromic RBC, anisocytosis, poikilocytosis, pencil cells, elliptocytes

No extra investigations if they are multiparous with no GI symptoms
Normal Hb + LOW MCV → check ferritin → if <30 → commence oral iron

Question 8

What is the management for anaemia in pregnancy

Answer 8

1. Diet and advice
2. If below threshold: oral ferrous sulfate (100-200mg daily)/ferrous fumarate (continue for 3 months after correction)
3. Consider folic acid if cause is not known and hydroxycobalamin for B12 deficiency
4. Measure again in 2 weeks to confirm positive response

<70 → Urgent referral to joint obstetric/haem clinic

Question 9

What is the intrapartum management for anaemia

Answer 9

Consultant led care
IV access and G&S on admission
Active management of third stage
Active management of PPH: Consider prophylactic syntocinon infusion
Postnatal FBC and serum ferritin on day 1

Question 10

What are the complications of anaemia in pregnancy

Answer 10

Preterm or LBW (Low Birth Weight) baby
Postpartum depression
Child with developmental delays
Spina bifida
Susceptibility to infections
Physical weakness
Postpartum haemorrhage
Increased risk of neonatal iron deficiency

Question 11

What are the signs of foetal anaemia antenatally

Answer 11

Note: these are not usually obvious unless foetal Hb < 60g/L

Polyhydramnios
Enlarged foetal heart
Ascites + pericardial effusions
Reduced foetal movements
Hyperdynamic foetal circulation (increased velocities in the MCA or aorta on Doppler)
Abnormal CTG with reduced variability, eventually a sinusoidal trace

Question 12

What dietary advice should be given for anaemia in pregnancy

Answer 12

Increase iron intake - green leafy vegetables, nuts, beans, seeds
B12 - meat and dairy
Folate - green leafy vegetables, nuts, yeast
Vit C enhances absorption of iron, whereas tea and coffee inhibit iron absorption

Question 13

When are women screened for anaemia in pregnancy

Answer 13

The booking visit (often done at 8-10 weeks)
At 28 weeks
Multiple pregnancy: additional FBC at 20-24 weeks

Question 14

What is the treatment for sickle cell anaemia in pregnancy

Answer 14

Consider induction later
Folic acid 5mg
Foetal growth scans
Penicillin V
Aggressive management of crisis

Question 15

What is the treatment for thalassaemia in pregnancy

Answer 15

Trait: Can have PO Iron but NOT parenteral

Major:
Need regular blood transfusion
(Pregnancy is rare)