hypertension in pregnancy and pre-eclampsia Flashcards
what happens to blood pressure normally in pregnancy?
Blood pressure during pregnancy normally falls over the first two trimesters and then normalises within the last trimester.
what is the cause of pre-eclampsia?
- Pre-eclampsia is caused by abnormal placentation
- In pre-eclampsia, there is inadequate trophoblastic invasion which causes inappropriate remodelling of the maternal arterioles.
- The consequence is a high resistance, low flow blood flow maternal-foetal vascular interface
- Subsequently, inflammatory cytokines are released which cause systemic vasoconstriction and results in the symptoms and complications seen in pre-eclampsia
what is eclampsia?
a rare but severe complication of pre-eclampsia which presents with seizures.
what are moderate risk factors for pre-eclampsia?
- ≥ 40 years of age
- First pregnancy
- Pregnancy interval > 10 years
- BMI ≥ 35
- Family history of pre-eclampsia
- Multiple pregnancies
what are high risk factors for pre-eclampsia?
- Chronic hypertension
- Chronic kidney disease
- Hypertension during a previous pregnancy
- Type 1 or 2 diabetes
- Autoimmune disease: such as systemic lupus erythematosus or antiphospholipid syndrome
what is the risk of someone with pre-existing hypertension developing pre-eclampsia?
- 25%
how do you diagnose someone as having gestational HTN?
- Hypertensive after 20 weeks
- No proteinuria
- Resolves post-delivery
how would you diagnose someone as having pre-eclampsia?
Hypertensive after 20 weeks
Proteinuria (>0.3g /24 hours)- this isn’t usually done
Pre-eclampsia is diagnosed if the patient has new-onset hypertension (SBP ≥140 mmHg and/or DBP ≥90 mmHg) after 20 weeks of pregnancy AND proteinuria, as evidenced by:
- Urine protein:creatinine ratio ≥ 30 mg/mmol OR
- Albumin:creatinine ratio ≥ 8 mg/mmol OR
- Urine dipstick protein ++
what are the signs of pre-eclampsia?
- HTN
- proteinuria
- oedema (hands feet and face)
- creatinine > 100
- platelets <100
- ALT >50
- raised uric acid
- brisk reflexes and clonus
what are signs of pre-eclampsia?
- headache
- epigastric/ RUQP= may suggest HELP
- visual disturbance
- seizures- in eclampsia
when would you admit someone with pre-eclampsia to hospital?
if they had severe pre-eclampsia (>160/110 mmHg)
severe hypertension that does not respond to treatment OR is associated with [4]:
- Ongoing or recurring severe headaches
- Visual scotomata
- Nausea or vomiting
- Epigastric pain
- Oliguria and severe hypertension
- Blood test deterioration: rising creatinine or LFTs or - - - falling platelet count
- Failure of fetal growth
- Abnormal doppler findings
which bloods would you do for pre-eclampsia?
- Placental growth factor (PIGF): low in pre-eclampsia; used to rule out pre-eclampsia
- FBC: useful in the diagnosis of HELLP syndrome; Haemolysis, Elevated Liver enzymes, and Low Platelets
- LFTs: hypoalbuminemia due to proteinuria and deranged in HELLP syndrome
- U&Es: renal function can be deranged in pre-eclampsia
what is prophylaxis for pre-eclampsia and who should it be given to?
- Aspirin: women at risk of developing pre-eclampsia should be commenced on 150mg from 12 weeks
- Indicated if there is one high risk or two moderate risk factors (see risk factor section)
what are the drug txs for pre-eclampsia?
First line: labetalol
Second line: nifedipine
Third line: methyldopa
what is the treatment of eclampsia?
Magnesium sulphate: women with pre-eclampsia who are having seizures or developing neurological symptoms should be treated with IV magnesium sulphate
what monitoring should be done for women with moderate pre-eclampsia?
- blood pressure: Aim for <135/85 mmHg
Measure every 48 hours - blood tests: Twice a week: FBC, LFTs and renal function
what monitoring should be done for women with severe pre-eclampsia?
- blood pressure:Aim for <135/85 mmHg
Measure every 15-30 minutes until blood pressure is <160/110 mmHg - blood tests: FBC, LFTs and renal function
what is the definitive management for pre-eclampsia?
delivery of placenta
when should delivery be planned with preeclampsia?
- > 37 weeks
- before that should only be if there is maternal and foetal compromise
- < 34 weeks give magnesium sulphate and steroids
- 34-7 weeks give steroids
what are complications that can ossuary in the mother with pre-eclampsia?
- Stroke: there is an increased risk of stroke during pregnancies with pre-eclampsia
- Eclampsia: presents as pre-eclampsia with seizures, treated with magnesium sulphate
- HELLP: pre-eclampsia with thrombotic microangiopathy. Endothelial dysfunction in the liver leads to platelet aggregation and subsequent microangiopathic haemolytic anaemia. Characterised by Haemolysis, Elevated Liver enzymes, and Low Platelets
- Pulmonary oedema: secondary to proteinuria and subsequent hypoalbuminemia
what are complications that can occur in the foetus if there is preeclampsia?
- Intrauterine growth restriction: occurs in 30% of patients with pre-eclampsia
- Premature delivery: iatrogenic if there is evidence of foetal or maternal compromise
- Placental abruption
what is the most common underlying cause of death in women with pre-eclapsia?
pulmonary oedema
how does pre-eclampsia affect the liver?
- vasoconstriction of the hepatic bed
- can cause fibrin deposits haemorrhage and hepatocellular necrosis
- which leads to elevated liver enzymes and rarely hepatic infection, rupture and liver collapse
what is the target diastolic blood pressure when administering labetalol for pre-eclampsia?
80-100
what is an important sign to elicit in pre-eclapsia?
brisk tendon reflexes
increased ICP/oedema resultant from severe hypertension compresses descending UMN of the corticospinal tracts, inciting hyper-reflexia as an early clinical sign
how long should you give magnesium sulphate in someone having an eclampsia episode?
Magnesium treatment should continue for 24 hours after delivery or after last seizure
