Pregnancy

Question 1

What are increased haematological maternal demands in pregnancy?

Answer 1

1. increased iron requirement (plus 200mg for foetus + 500mg for increased red cell mass)
2. increased folate requirement

Question 2

What is the recommended dose for folic acid supplementation in pregnancy

Answer 2

400 microgram/day

Question 3

Why is the anaemia threshold in pregnancy?

Answer 3

Lower than ususal (due to increased
1. Hb <110 in 1st trimester
2. Hb <105 in 2nd +3rd
3. Hb <100 postpartum

Question 4

What is the physiological change in platelet count during pregnancy?

Answer 4

Thrombocytopenia (~ 10% decrease mainly 3rd trimester)

Due to Increased turnover and clearence of platelets (dilution + increased consuption)

Normalises 2-5 days post-delivery

Question 5

What are pathological causes of thrombocytopenia in pregnancy?

Answer 5

Especailly in low platelet counts (e.g. <100, <70)

1. pre-eclampsia
2. ITP (immunosuppression makes worth)
3. Microangiopathic syndromes
4. Other non-pregnancy specific reasons, e.g. leukaemia, BM failure

Question 6

What are safe levels for pt count for delivery?

Answer 6

• <50 sufficient for delivery
• > 70 for epidural (spinal haematoma)

Question 7

What are the characteristics of MAHA on blood film?

Answer 7

Microangiopathic haemolytic anaemia

1. schistocytes (due to platelet rich clots in small vessels)

Question 8

What are the coagulation changes in pregnancy?

Answer 8

Generally increase in coagulation (to limit blood loss during delivery)

Increase - Hypercoagulable
1. Factor VIII and vWF (3-5x)
2. Fibrinogen (2x)
3. Factor VII

Decrease - Hypofibrinolytic
Protein S
(increased D-dimern normal in pregnancy)

Placental
PAI 1 and PAI 2

Question 9

Why is there are higher incidence of VTE in pregnancy?
When is the highest risk?

Answer 9

Highest risk in 6 weeks post-partum period

All parts of Virchows triad effected
1. Hypercoaguable state
2. Change in Flow (reduced venous return, 85% of DVT in left side)
3. Hormonal changes in vascular wall

Question 10

What is the leading cause of maternal deaths in the UK?

Answer 10

PEs

Question 11

What is the highest risk factor for maternal mortality due to PE?

Answer 11

High BMI
(+ 2x likely in <35)

Question 12

How can Thromboembolic diseases be prevented in pregnancy?

Answer 12

Depending on risk asessment for VTE
1. Prophylactic hepatin + TED stockings
2. Very high risk: dose asjusted LMWH
2. Early mobilisation
3. Hydration

Question 13

What is the management for VTE in pregnancy?

Answer 13

1. LMWH (OD/ BD) - no placental crossing
2. NOT warfarin (crosses placenta)
3. After 1st trimester: monitor Xa

Question 14

What are the effects of warfarin during pregnancy?

Answer 14

1. Chondrodysplasia Punctata
   Very severe, absoloute contraindication

Question 15

What are the factors that will make Antiphospholipid syndrome more common?

Answer 15

Recurrent miscarriage
>3

Question 16

What are major risk factors for fatal maternal bleeding?

Answer 16

Placenta praevia
Placenta accreta

Other causes of PPH usually aren’t fatal

Question 17

What are th causes of postpartum haemorrhage

Answer 17

4Ts
1. Tone - less uterine contraction
2. Trauma
3. Tissue
4. Thrombin - usually more minor (e.g. dilutional coagulopathy after resuscitation, DIC in abruption, anmiotic fluid embolism)

Question 18

What haematological screening tests are done during pregnancy?

Answer 18

For
1. alpha (Hb barts) thalassaemia –> death in utero+ hydops fetalis)
2. ß thalassaemia major : transfusion dependant)
3. Sickle Cell

Question 19

How are haematological screening in pregnancy done?

Answer 19

1. Family origin quessionaire
2. Parental teting
3. Foetal testing
4. don’t have to do
   5.

Question 20

How can you differentiate between Iron deficiency and Thalassaemai trait on lab resultsß

Answer 20

Question 21

What are physiological changes on an FBC in pregnancy?

Answer 21

RBC/ HB

• Red cell mass rises (120 -130%)
• Plasma volume rises (150%)
• –> Dilution and fall in Hb (NR 115-130)

Platelets

• thrombocytopenia with increased pt size

Mild

• Neutrophilia
• Macrocytosis

Question 22

What is the clinical presentation of n amniotic fluid embolism?

Answer 22

1 in 20000-30000 births
* Sudden onset shivers, vomiting, shock. DIC
n 86% mortality (16 deaths in last triennium)

• almost all >25 years, usually in 3rd trimester
• Presumed due to Tissue Factor in amniotic fluid entering maternal bloodstream

Question 23

What is HELLP syndrome?

What are some lab findings?

Answer 23

HELLP syndrome = life-threatening complication that can develop 2nd to pre-eclampsia

1. Haemolysis (MAHA - reduced HB, increase LDH, increase bilirubin)
2. Elevated Liver Enzymes (↑↑AST, ↑↑ALT)
3. Low Platelets (but normal APTT, PT)

Question 24

What are differentials for a suspected HELLP syndrome?

Answer 24

DIC (↑APTT, ↑PT, ↓fibrinogen),

AFLP (marked transaminitis) - acute fatty liver of pregnancy

Question 25

How would haemolytic disease of the newborn present?

Answer 25

Haemolysis due to maternal antibodies (IgG crossing the placenta)

–> anaemia + Jaundice

Question 26

How is prevention of haemolytic disease of the newborn done in rhesus negative mothers?

Answer 26

Generally
1. Establish rhesus status of fetus (based on bloods)
2. If Mother -ve, fetus +ve: Give Anti-D

Give Anti-D at
* 28+34 weeks
* at delivery
* any event with hight risk of fetal blood entering maternal circulation (haemorrhage, miscarriage etc. )