Hypertension in pregnancy Flashcards
Pre-eclampsia pathophysiology
abnormal trophoblast invasion of decidual spiral arteries and myometrium
placental hypoperfusion
diseased placenta releases pro-inflammatory proteins into maternal circulation
systemic vasoconstriction and endothelial dysfunction
hypertension and end organs damage
Risk factors for pre-eclampsia
high:
- hypertensive disease in previous pregnancy
- CKD
- T1DM/T2DM
- SLE/APLS/other autoimmune disease
- chronic HTN
- placental histology confirming placental dysfunction in previous pregnancy
moderate:
- first pregnancy
- age>=40y
- BMI>=35 at booking
- FH pre-eclampsia in 1st degree relative
- pregnancy interval >10y
- multiple pregnancy
1 high risk factor or 2 or more moderate risk factors = aspirin 150mg ON 12-36 weeks or delivery whichever is sooner
How can pre-eclampsia be prevented?
aspirin 150mg at night from 12/40 until delivery ir 36 weeks whichever is sooner
for women with any high risk factor or >=2 moderate risk factors
What is transient hypertension in pregnancy?
develops at any gestation and resolves without treatment during the pregnancy
What is gestational hypertension?
hypertension that develops >= 20 weeks gestation without any features of pre-eclampsia
What is pre-eclampsia?
hypertension develops >=20 weeks gestation in association with:
- proteinuria >= 300mg/day or protein/creatinine ratio >=30mg/mmol
other maternal organ dysfunction:
- AKI
- liver involvement
- neurological complications (eclampsia)
- haematological complications (thrombocytopaenia)
uteroplacental dysfunction
Signs and symptoms of pre-eclampsia
headache
visual disturbance
epigastric pain
nausea/vomiting
foetal growth restriction
placental abruption
proteinuria
increased reflexes
clonus
oedema
Maternal complications of pre-eclampsia
eclampsia
HELLP syndrome
intracranial haemorrhage
placental abruption + DIC
renal failure
pulmonary oedema
What is HELLP syndrome?
haemolysis
elevated liver enzymes
low platelets
Foetal complications of pre-eclampsia
intrauterine growth restriction
oligohydramnios
hypoxia from placental insufficiency
placental abruption
preterm birth
intrauterine death
When should BP be measured in pregnancy?
every visit
Blood pressure thresholds in pregnancy
hypertension = 140/90-159/109 mmHg
severe hypertension = >=160/110 mmHg
be alert to any rise from booking >30mmHg - irrespective of above thresholds
How should a woman with suspected pre-eclampsia be assessed?
history
serial BP
physical examination - chest, abdomen, neurological
test for proteinuria:
- dipstick
- protein creatinine ratio >30
- 24 urinary protein >0.3g/24h
bloods:
- U&Es
- FBC - Hb and platelets
- LFTs
- coagulation screen
regular foetal surveillance - USS growth + doppler + CTG
test PlGF (placental growth factor) - low = abnormal
BP target in pregnancy
<135/85 mmHg
What anti-hypertensives can be given in pregnancy?
labetalol
alternatives = nifedipine, methyldopa, hydralazine
What anti-hypertensives should be avoided in pregnancy?
diuretics
ACE-is
ARBs
Contraindications to labetalol
low HR <60bpm
severe asthma
Labetalol MOA
lowers blood pressure primarily by blocking both alpha-1 and beta-adrenergic receptors. This dual action leads to reduced peripheral resistance and heart rate, ultimately decreasing blood pressure
What is the only cure for pre-eclampsia?
delivery
Indications for delivery in pre-eclampsia
inability to control BP
HELLP syndrome - worsening liver/renal function, falling platelets
eclampsia
foetal distress/severe IUGR
Treatment of acute/severe hypertension in pregnancy
IV antihypertensive regimens aim <150/100-80
continuous foetal monitoring
strict input/output - catheterise, consider fluid restriction if risk of pulmonary oedema/fluid overload
consider MgSO4 infusion for seizure prevention (4g bolus followed by 1g/hour infusion)
What is given for seizure prevention in acute/severe hypertension in pregnancy?
MgSO4 infusion
4g bolus followed by 1g/hour infusion
When to consider magnesium sulphate in hypertension in pregnancy?
prophylactic anti-convulsant therapy
control of eclamptic seizure
neuroprotection for preterm infants (<30 weeks)
should be continued for 24h from starting, or for 24h after birth
Define eclampsia
generalised convulsions in any woman with signs and symptoms of pre-eclampsia, or in any woman who then presents with hypertension in pregnancy
