Haemotology in Pregnancy

Question 1

What is the composition of blood?

Answer 1

2/3 Plasma

1/3 RBC’s

Question 2

What happens to blood volume during pregnancy?

Answer 2

Increases by 1.5L
Plasma volume increased
Red cell mass decreases
Overall Hb decreases

Question 3

What happens to RBC volume between weeks 0-10?

Answer 3

Dips then rises after 10 weeks

Question 4

When does Hb fall to lowest in pregnancy?

Answer 4

32-34 weeks

Question 5

What anaemia develops in pregnancy?

Answer 5

Physiological/dilutional anaemia 
MCV slightly increased
MCH normally unchanged 
Hb < 104
Ferritin < 15

Question 6

What is polycythaemia?

Answer 6

Increased Hb

Question 7

How is iron stored?

Answer 7

Most contained in Haemoglobin
Excess stored as
1) Ferritin in Liver
2) Haemosiderin in bone marrow

Question 8

What are normal ferritin levels?

Answer 8

> 15ug/L

Question 9

What can cause ferritin levels to increase?

Answer 9

Inflammation

Acute phase protein

Question 10

How is iron deficiency treated?

Answer 10

1st or 2nd trimester: oral Fe replacement

3rd trimester: IV iron

Question 11

What clinical conditions increase hepcidin levels?

Answer 11

CKD
RBC transfusions
Fe administration 
Replete Fe stores
Genetic factors
Infectious/inflam disorders

Question 12

What clinical conditions decrease hepcidin levels?

Answer 12

Ineffective erythropoiesis 
Hypoxia/anaemia
CLD
Alcohol abuse
HCV 
Genetic factors
Testosterone

Question 13

Who is B12 deficiency seen in?

Answer 13

Vegan/veggie
Pernicious anaemia
Post bariatric surgery

Question 14

What happens to serum B12 in pregnancy?

Answer 14

Falls

If true deficiency - homocysteine increases

Question 15

What are the risk factors for folic acid deficiency?

Answer 15

Hyperemesis

Twin preg

Question 16

What happens with WBC count in pregnancy?

Answer 16

Increases - mainly neutrophils

Lymphocyte count decreases

Question 17

What is thrombocytopenia?

Answer 17

Low platelets due to reduced production and increased consumption
< 115

Question 18

What are the differential diagnosis of thromocytopenia?

Answer 18

• Immune thrombocytopenia
• Familial thrombocytopenia
• Drugs
• Pseudothrombocytopenia
• Bone marrow infiltration
• Hypersplenism

Question 19

What happens in bone marrow failure?

Answer 19

• Aplastic anaemia - due to reduced production
• Leucopenia - too few WBC’s
• Thrombocytopenia
• Pancytopenia

Question 20

What causes increased consumption of platelets out of pregnancy?

Answer 20

• Immune
• Sepsis
• Massve haemorrhage
• Cardiac bypass surgery
• Hypersplenism

Question 21

What causes increased consumption of platelets in pregnancy?

Answer 21

• HELLP: haemolysis, elevated liver enzymes, low platelets
• Gestational thrombocytopenia
• TTP
• Disseminated intravascular coagulation: massive haemorrhage, amniotic fluid embolism

Question 22

What should you consider with low MCV?

Answer 22

Thalassaemia trait

But Fe deficiency anaemia most likely

Question 23

Why is there an increased risk of venous thromboembolism during pregnancy?

Answer 23

1) Stasis - venous, compression of left common iliac vein
2) Vessel wall injury
3) Hypercoagulability - increases pro-coagulant, reduced anticoagulant, reduced fibrinolysis

Question 24

What causes compression of left common iliac vein in pregnancy?

Answer 24

As uterus grows

= venous stasis = deep vein thrombosis

Question 25

What are antenatal risk factors for VTE in pregnancy?

Answer 25

• Previous DVT/PE
• Antiphospholipid syndrome
• Myeloproliferative disorder
• Sickle cell disease
• Systemic lupus erythematosis
• Obesity