Disorders of Pregnancy and Parturition Tutorial

Question 1

How common is pre-eclampsia?

Answer 1

Occurs in around 2-4% of pregnancies in USA and Europe (incidence rising?)

Question 2

Where is pre-eclampsia most common?

Answer 2

More common in Africa and Asia (8% to as high as 16%?)

Question 3

How many deaths does pre-eclampsia cause?

Answer 3

1. ~1/10 maternal deaths in Africa and up to 1/4 in South America are associated with gestational hypertensive disorders (including PE).
2. Estimated to cause 50,000-60,000 maternal deaths per year

Question 4

What is the cause of pre-eclampsia?

Answer 4

unknown

Question 5

What is the diagnosis of pre-eclampsia?

Answer 5

1. New onset hypertension (in a previously normotensive woman) BP ≥140 mmHg systolic and/or ≥90 mmHg diastolic
2. Occurring after 20 weeks’ gestation
   3, Reduced fetal movement and/or amniotic fluid volume (by ultrasound) in 30% cases
   4, Oedema common but not discriminatory for PE
3. Headache (in around 40% of severe PE patients)
4. Abdominal pain (in around 15% of severe PE patients)
5. Visual disturbances, seizures and breathlessness associated with severe PE and risk of eclampsia (seizures)

Question 6

What is early onset PE?

Answer 6

<34 weeks
·Associated with fetal and maternal symptoms
·Changes in placental structure

Question 7

What is late onset PE?

Answer 7

>34 weeks
·More common (90%)
·Mostly maternal symptoms
·Fetus generally OK
·Less overt/no placental changes

Question 8

What maternal risk factors pre-dispose to PE?

Answer 8

1. Previous pregnancy with pre-eclampsia
2. BMI >30 (esp >35)
3. Family history
4. Increased maternal age (>40, <20?)
5. Gestational hypertension or previous hypertension
6. Pre-existing conditions: diabetes, PCOS, renal disease, subfertility, autoimmune disease.
7. Non-natural cycle IVF?

Question 9

What are the risks to the mother in PE?

Answer 9

1. damage to kidneys, liver, brain and other organ systems
2. possible progression to eclampsia (seizures, loss of consciousness)
3. placental abruption (separation of the placenta from the endometrium)

Question 10

What are the risks to fetus in PE?

Answer 10

1. reduced fetal growth
2. preterm birth
3. pregnancy loss/stillbirth

Question 11

What happens in normal placenta?

Answer 11

1. EVT invasion of maternal spiral arteries leads to endothelial and smooth muscle breakdown
2. EVT become endothelial EVT and spiral arteries become high capacity

Question 12

What happens to placenta in PE (esp early)?

Answer 12

1. EVT invasion of maternal spiral arteries is limited to decidual layer
2. Spiral arteries are not extensively remodelled, thus placental perfusion is restricted

Question 13

What is PLGF (placental growth factor)?

Answer 13

VEGF related, pro-angiogenic factor released in large amounts by the placenta

Question 14

What is flt1 (soluble VEGFR1)?

Answer 14

Soluble receptor for VEGF-like factors which binds soluble angiogenic factors to limit their bioavailabliltiy

Question 15

What happens in PE?

Answer 15

1. excess production of Flt-1 by distressed placenta
2. leads to reduction of available pro-angiogenic factors in maternal circulation
3. resulting in endothelial dysfuction

Question 16

How can you predict onset of PE?

Answer 16

PLGR levels alone or FIt/PIGR ratio can be used

Question 17

What does PLGR alone allow?

Answer 17

e.g. triage test

rules out PE in next 14 days in women 20-36 weeks and 6 days

Question 18

How can PE be resolved?

Answer 18

PE can only be resolved by delivery of the placenta

Question 19

What happens if <34 weeks?

Answer 19

preferable to try and maintain the pregnancy if possible for benefit of the fetus

Question 20

What happens if >37 weeks?

Answer 20

delivery preferable

Question 21

What happens if in between?

Answer 21

case by case basis

Question 22

What treatment can you give?

Answer 22

1. Anti-hypertensive therapies.

2. Corticosteroids for <34 weeks to promote fetal lung development before delivery.

Question 23

What are the three main approaches for the prevention of PE?

Answer 23

1. Weight loss (esp if BMI >35)
2. Exercise throughout pregnancy (seems to work independent of BMI)
3. Low-dose asprin (from 11-14 weeks) for high risk groups – but may only prevent early onset

Question 24

What are the long term impacts of PE on maternal health?

Answer 24

1. Elevated risk of cardiovascular disease, type 2 diabetes and renal disease after PE
2. Roughly 1/8 risk of having pre-eclampsia in next pregnancy (greater if early onset)