Preg+Part disorders

Question 1

Outline the pathophysiology of pre-eclampsia

Answer 1

New onset hypertension (in a previously normotensive woman) BP ≥140 mmHg systolic and/or ≥90 mmHg diastolic

Occurring after 20 weeks’ gestation

-Causes reduced fetal movement in 30% of cases

Question 2

What does oedema mean when you suspect PE?

Answer 2

Oedema is common but not discriminatory/diagnostic

Question 3

Give some symptoms of PE

Answer 3

Oedema, Headache (in around 40% of severe PE patients), Abdominal pain (in around 15% of severe PE patients), Visual disturbances, seizures and breathlessness associated with severe PE and risk of eclampsia (seizures)

Question 4

What are the subtypes of PE and how are they different?

Answer 4

Early onset: <34 weeks
Associated with fetal and maternal symptoms
Changes in placental structure

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

Question 5

Give some risk factors of PE

Answer 5

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

Question 6

What are the risks to the mother in pre-eclampsia?

Answer 6

Mother: damage to kidneys, liver, brain and other organ systems

Possible progression to eclampsia (seizures, loss of consciousness)

Question 7

What are the risks to the fetus in pre-eclampsia?

Answer 7

Placental abruption (separation of the placenta from the endometrium)

Fetus: reduced fetal growth, preterm birth, pregnancy loss/stillbirth

Question 8

What is the major placental defect that causes PE?

Answer 8

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

Question 9

What is PLGF and what is its function?

Answer 9

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

Question 10

What is Flt1 and what is its function?

Answer 10

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

Question 11

What occurs to Flt1 production in PE?

Answer 11

Production of Flt1 is excess, so PLGF and VEGF bind to the soluble Flt1 instead of the membrane bound Flt1

This leads to reduction of available pro-angiogenic factors in maternal circulation, resulting in endothelial dysfunction.

Question 12

What is the function of PLGF and VEGF from the placenta?

Answer 12

Releases PLGF and VEGF into the maternal circulation. These growth factors bind receptors on the endothelial surface to promote vasodilation, anti-coagulation and ‘healthy’ maternal endothelial cells.

Question 13

How can PE onset be predicted through blood?

Answer 13

PLGF levels alone or Flt-1/PlGF ratio can be used to predict onset of PE

Low PLGF levels or raised Flt1/PLGF is characteristic of PE

Question 14

How can you treat pre-eclampsia?

Answer 14

If <34 weeks, preferable to try and maintain the pregnancy if possible for benefit of the fetus
If >37 weeks, delivery preferable
In between – case by case basis.

Anti-hypertensive therapies.
Corticosteroids for <34 weeks to promote fetal lung development before delivery.

Question 15

What are the 3 main approaches for preventing PE?

Answer 15

Weight loss (esp if BMI >35)

Exercise throughout pregnancy (seems to work independent of BMI)

Low-dose aspirin (from 11-14 weeks) for high risk groups – but may only prevent early onset.

Question 16

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

Answer 16

Elevated risk of cardiovascular disease, type 2 diabetes and renal disease after PE

Roughly 1/8 risk of having pre-eclampsia in next pregnancy (greater if early onset)