[18] Pre-eclampsia Flashcards
What is pre-eclampsia?
Pregnancy induced hypertension in association with proteinuria (>0.3g in 24 hours)
Why is pre-eclampsia important?
It is relatively common but can become life-threatening for mother and fetus
What is severe pre-eclampsia?
BP of ≥160/110 mmHg and/or symptoms and/or biochemical and/or haematology impairment
What is eclampsia?
The occurence of one or more convulsions superimposed on pre-eclampsia
What % of pregnancies in the UK are affected by pre-eclampsia?
6%
How dangerous are severe pre-eclampsia and eclampsia?
They are the second most common cause of direct maternal death in the UK
What proportion of pregnancies are affected by severe pre-eclampsia?
5/1000
What proportion of pregnancies are affected by eclampsia?
5/10,000
What proportion of stillbirths with no congenital abnormalities occur in women with pre-eclampsia?
20%
What proportion of women with severe pre-eclampsia deliver before 36 weeks?
50%
What is the common thought of what causes pre-eclampsia?
Poor placental perfusion due to abnormal placentation
What happens in normal placentation?
The trophoblast invades the myometrium and the spiral arteries, destroying the tunica muscularis media, rendering spiral arteries dilated and unable to constrict.
What is the result of normal placentation?
Provides pregnancy with a high flow, low resistance circulation
How is the remodelling of spiral arteries different in pre-eclampsia?
They are incompletely re-modelled
What is the result of incomplete spiral artery re-modelling in pre-eclampsia?
Development of a high resistance, low-flow uteroplacental circulation develops as the constrictive muscular walls of the spiral arterioles is maintained
How does the high resistance, low flow uteroplacental circulationof pre-eclampsia affect BP?
Causes an inccrease
What other pathophysiological factors are caused by inadequate uteroplacental perfusion in pre-eclampsia?
Hypoxia and oxidative stress
What is caused by the raised BP, hypoxia and oxidative stress caused by pre-eclampsia?
Systemic inflammatory response and endothelial cell dysfunction (resulting in leaky blood vessels)
What factors put women at high risk of pre-eclampsia?
- Previous pre-eclampsia
- Previous eclampsia
- Previous hypertension in pregnancy
- Pre-existing hypertension
- Pre-existing CKD
- Pre-existing diabetes
- SLE
- Antiphospholipid syndrome
What factors put women at moderate risk of pre-eclampsia?
- 10 years or more since last pregnancy
- First pregnancy
- Age 40 or more
- BMI >35 at presentation
- Family history
- Multiple pregnancy
What criteria should be met to be diagnosed with pre-eclampsia?
- Hypertension
- Significant proteinuria
- > 20 weeks gestation
What is classified as hypertension fulfilling the criteria of pre-eclampsia?
BP >140/90 mmHg on 2 occasions >4 hours apart
What is classified as significant proteinuria, fulfilling the criteria of pre-eclampsia?
> 300mg protein in a 24 hour urine sample or >30mg/mmol urinary protein:creatinine
Is the presentation of pre-eclampsia the same in everyone?
No
Why should proteinuria and hypertension be checked for at every antenatal appointment?
Some people with pre-eclampsia are asymptomatic
What are some possible clinical features of pre-eclampsia?
- Headaches
- Visual disturbance
- Epigastric pain
- Sudden onset non-dependent odema
- Hyper-reflexia
What visual disturbances can occur in pre-eclampsia?
- Blurred or double vision
- Halos
- Flashing lights