Hypertensive disease in pregnancy (incl. pre-eclampsia and eclampsia) Flashcards
Define hypertension in pregnancy including the differences between the 3 types.
Hypertension in pregnancy in usually defined as:
- systolic > 140 mmHg or diastolic > 90 mmHg
- OR an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic
Types:
- Chronic = hx of HTN before pregnancy or BP >140/90mmHg at <20 weeks
- Gestational = HTN as above occurring at >20 weeks
- Pre-eclampsia = HTN at >20 weeks and proteinuria >0.3g/24hours
What is chronic hypertension?
Hypertension present before 20 weeks
How common is pre-existing hypertension in pregnancy?
3-5% affected, more common in older women
Why might chronic hypertension be masked in the first trimester?
There is a phsyiological decrease in BP here
What is the management of chronic (pre-existing) hypertension pre-conception?
Adjust medication:
Stop ACEi, ARBs, thiazides and thiazide-like diuretics
Arrange alternatives with GP within 2 days of +ve pregnancy test
- Labetalol (1st line)
- Nifedipine (2nd)
What is the antenatal management of chronic hypertension?
Conservative - give lifestyle advice on exercise, diet and salt intake
Monitoring -
- BP weekly if poorly controlled otherwise 2-4 weekly
- serial growth scans 4-weekly at 28-36 weeks
Medical -
- Low dose aspirin 75mg OD from 12 weeks gestation until birth
Which antihypertensives must be stopped before pregnancy or as soon as possible after and why?
ACE inhibitors, ARBs, thiazide or thiazide-like diuretics cause congenital malformations if taken early during the pregnancy
Other antihypertensives have shown no such association
What is the goal BP in HTN management in pregnancy?
135/85 mmHg
Why is aspirin given antenatally in chronic hypertension patients?
It is used as an anti-platelet medication as chronic hypertension is a “high risk” factor for pre-eclampsia
NB: 1 high risk factor or 2 or more moderate risk factors = give aspirin
How often should antenatal appointments be given to monitor HTN in pregnancy?
- weekly appointments if hypertension is poorly controlled
- appointments every 2 to 4 weeks if hypertension is well-controlled.
Should induction of labour be offered in chronic HTN?
If <160/110mmHg after 37 weeks then patient and senior obstetrician can decide on time of birth. These patients do not need to be induced at a specific time.
What is the postnatal management of chronic HTN post-partum?
BP monitoring - daily for first 2 days after birth, then at least once between day 3-5, as clinically indicated once medication is changed after birth.
Follow up at 2 weeks with GP or specialist for antihypertensive review to enzure BP <140/90mmHg
Offer women with chronic hypertension a medical review 6–8 weeks after the birth with their GP or specialist as appropriate.
What is gestational hypertension?
New HTN without proteinuria occurring after 20 weeks gestation
What proportion of women with gestational hypertension progress to pre-eclampsia?
a third
Are there any adverse outcomes associated with gestational hypertension?
Benign condition so no
But may progress to pre-eclamspia
What is the difference in management of a gestational HTN patient with BP:
- 140/90-159/109mmHg?
- >160/110mmHg?
NB: PLGF offerred at 20-35 weeks only
What is the management of gestational hypertension antenatally?
Antenatal - consider admission to antenatal ward if severe (>160/110 mmHg) until BP is controlled
Monitoring -
- BP and urinalysis 1-2x/week until BP is controlled, thereafter weekly
- Bloods (FBC, LFTs, U&Es) weekly
- US foetal surveillance (growth, liquor, UA blood flow) every 2-4 weeks
- PlGF-based testing on 1 occasion if suspicion of pre-eclampsia
Medical - antihypertensives
- 1st line = labetalol
- 2nd line = nifedipine
- 3rd line = methyldopa
Aim for BP <135/85 mmHg
What is the postnatal management of gestational hypertension?
Monitoring BP - daily for first 2 days, at least once between days 3-5 and then as clinically indicated if antihypertensive treatment is changed after birth
Medical - continue treatment if required (NB: stop methyldopa within 2 days postnatally and change to alternative agent). Reduce medication if BP falls to <130/80 mmHg.
Follow up -
- At 2 weeks at GP if still on antihypertensive treatment
- At 6-8 weeks i. with GP or specialist; if fails to resolve consider diagnosis of chronic hypertension
If a patient did not take anti-HTN treatment for gestational hypertension but postnatally has a BP of 155/100mmHg, should you start treatment then?
For women with gestational hypertension who did not take antihypertensive treatment and have given birth, start antihypertensive treatment if their BP is 150/100 mmHg or higher
How long is gestational hypertension expected to last postnatally?
When should you think about reducing the treatment?
Duration of postnatal anti-HTN treatment will usually be similar to duratio of antenatal treatment (but may be longer)
Reduce if BP <130/80mmHg
Define pre-eclampsia.
New HTN with proteinuria occurring after 20 weeks gestation
Apart from ‘new onset HTN after 20 weeks’ what are the other 3 major factors which are used in pre-eclampsia diagnosis?
New onset of hypertension (>140 mmHg systolic or >90 mmHg diastolic) >20 weeks pregnancy and the coexistence of 1 or more of the following new-onset conditions:
- proteinuria (urine protein:creatinine ratio of 30 mg/mmol or more or albumin:creatinine ratio of 8 mg/mmol or more, or at least 1 g/litre [2+] on dipstick testing) or
- other maternal organ dysfunction
- uteroplacental dysfunction such as fetal growth restriction, abnormal umbilical artery doppler waveform analysis, or stillbirth.
Give 4 examples of ‘maternal organ dysfunction’ which can be used in the diagnosis of pre-eclampsia.
- Renal insufficiency - Cr _>_90 micromol/L, _>_1.02 mg/100 ml
- Liver involvement - elevated transaminases [ALT or AST >40 IU/L] +/- RUQ or epigastric abdominal pain
- Neurological complications - such as eclampsia, altered mental status, blindness, stroke, clonus, severe headaches or persistent visual scotomata
- Haematological complications - such as thrombocytopenia (Plt <150,000/microlitre), DIC or haemolysis
Which test can be used to rule out pre-eclampsia early between 20-35 weeks of pregnancy?
If women with chronic hypertension are suspected of developing pre-eclampsia
offer placental growth factor (PlGF)-based testing
to help rule out pre-eclampsia between 20 weeks and up to 35 weeks
What are the moderate-risk RFs for pre-eclampsia?
Moderate-risk risk factors:
- First pregnancy
- Age >40 years
- Multiple pregnancy
- Interval of >10 years between pregnancy
- BMI >35 at booking visit
- FH of pre-eclampsia (x3-4 risk)
FAMI FH BMI
What are the high-risk RFs for pre-eclampsia?
- Hypertensive disease in a previous pregnancy
- Pre-existing maternal disease
- chronic hypertension,
- renal disease,
- diabetes,
- autoimmune disease
What are the signs and symptoms of pre-eclampsia?
- hypertension: typically > 160/110 mmHg and proteinuria as above
- proteinuria: dipstick ++/+++
- frontal headache
- visual disturbance
- papilloedema
- RUQ/epigastric pain
- hyperreflexia
- oedema of hands and fave (rapidly progressing)
- platelet count < 100 * 106/l, abnormal liver enzymes or HELLP syndrome
What are the complications of pre-eclampsia? Name 4.
- eclampsia or other neurological complications include altered mental status, blindness, stroke, clonus, severe headaches or persistent visual scotomata
- liver involvement (elevated transaminases)
- haemorrhage: placental abruption, intra-abdominal, intra-cerebral
- cardiac failure
- fetal complications
- intrauterine growth retardation
- prematurity
What risk prediction model can be used in pre-eclampsia?
These help predict adverce maternal (but not fetal) outcomes in women admitted with pre-eclampsia, using clinical findings in the first 48 hours after admission.
- fullPIERS - intended for use at any time during pregnancy
- PREP-S - intended for use <34 weeks of pregnancy
What measures can be taken to prevent pre-eclampsia?
Measure BP and test urine for proteinuria at each antenatal appointment
- If dipstick 1+ → use albumin:creatinine or protein:creatinine ratio (PCR) to quantify proteinuria
- 30mg/mol threshold for protein:creatinine
- 8mg/mol threshold albumin:creatinine
Offer aspirin 75-150mg OD from 12 weeks gestation until delivery in women with 1 high-risk right factor or ≥2 moderate-risk risk factors
What are the indications for admission to antenatal ward in pre-eclampsia?
- Severe HTN (BP >160/110mmHg)
- Symptoms of severe late-stage disease (headache, visual disturbance, epigastric pain, hyperreflexia, impending pulmonary oedema)
- Biochemical abnormalities (deranged LFTs, abnormal U&Es)
- Haematological abnormalities (low platelets, DIC)
- Suspected foetal compromise
- Adverse events suggested by the full PIERS or PREP-S risk prediction models
What are the late-stage symptoms of pre-eclampsia?
- headache,
- visual disturbance,
- epigastric pain,
- hyperreflexia,
- impending pulmonary oedema
What kind of monitoring is needed in pre-eclampsia antenatally?
Monitoring BP at least every 2 days, and more frequently if woman is admitted to hospital
Bloods (FBC, LFTs, U&Es) 2x/week
US foetal surveillance (growth, liquor, UA blood flow) every 2 weeks
What is the medical treatment of pre-eclampsia?
Antihypertensives
- 1st line = labetalol
- 2nd line = nifedipine
- 3rd line = methyldopa
Aim for BP <135/85 mmHg
Consider IV magnesium sulphate in women with features of severe pre-eclampsia if birth is planned within 24 hours (to prevent eclampsia)
Give 3 examples of scenarios inpre-eclampsia which may warrant elective delivery at less than 37 weeks.
- inability to control maternal BP despite using _>_3 antihypertensives
- maternal pulse oximetry less than 90%
- progressive deterioration in LFT, renal function, haemolysis, or platelet count
- ongoing neurological features, such as severe intractable headache, repeated visual scotomata, or eclampsia
- placental abruption
- reversed end-diastolic flow in the umbilical artery doppler velocimetry, a non-reassuring CTG, or stillbirth.
A patients is diagnosed with seevre pre-eclampsia at the following times… what should you do?
- <34 weeks
- 34-36+6 weeks
- _>_37 weeks
- <34 weeks - surveillance and treatment, unless indications*
- 34-36+6 weeks - suirveillance and treatment, unless indications*
- _>_37 weeks - initiate birth within 24-48 hours
*Indications for delivery at <37 weeks in pre-eclampsia are on previous slide
What mode of delivery can be used in pre-eclampsia? What should not be given?
Offer choice between elective C-section or induction of labour
If induction is preferred:
- Advise to deliver in labour ward, with continuous CTG monitoring
- Analgesia (encourage use of epidural anaesthesia which helps control BP)
- Avoid use of ergometrine
What is the postnatal management of pre-eclampsia?
Observation for at least 24 hours
Monitor BP:
- At least 4x/day as inpatient
- At least once between days 3-5
- If 3-5 days abnormal then alternate days until normal
Medical:
- Continue use of antihypertensives if required (NB: if taking methyldopa, stop within 2 days after birth and change to alternative)
- Reduce antihypertensive treatment if their BP falls <130/80 mmHg
- At 2 weeks follow up with GP if still on antihypertensive treatment for medication review
- At 6-8 weeks follow up to ensure resolution of hypertension
Note: here is no cure for pre-eclampsia other than to end the pregnancy by delivery the baby (and placenta).
When should you expect pre-eclampsia symptoms to resolve by?
Hypertension and proteinuria should resolve within 6 weeks → if this fails to resolve consider diagnosis of chronic hypertension or renal disease
What are the differences in management of pre-eclampsia with normal vs severe hypertension?
What is the cure for pre-eclampsia?
No cure other than to end the pregnancy by delivery the baby (and placenta)
Define eclampsia.
Eclampsia may be defined as the development of seizures in association pre-eclampsia.
What are the risk factors fro eclampsia?
- Uncontrolled HTN
- _<_2 antenatal visits
- Para 0
- Obesity
- Black ethnicity
- Diabetes hx
- <20 years
What % of eclamptic seizures occur post-partum?
40%
What is the management of eclampsia?
ABCDE approach
IV magnesium sulphate - 4g over 5-15min loading dose, followed by IV infusion of 1g/hour continued for 24 hours after last seizure or after delivery
- In recurrent seizures give second loading dose of 4g and involve anaesthetists
Antihypertensives - IV/oral labetalol, oral nifedipine, IV hydralazine
Expedite delivery
Other than treatment of seziures, what are the other indications for magnesium sulfate treatment in eclampsia?
Consider the need for magnesium sulfate treatment, if 1 or more of the following features of severe pre-eclampsia is present:
- ongoing or recurring severe headaches
- visual scotomata
- nausea or vomiting
- epigastric pain
- oliguria and severe hypertension
- progressive deterioration in laboratory blood tests (such as rising creatinine or liver transaminases, or falling platelet count)
NB: it is used for prevention and treatment of seizures
What is the ABCDE approach for eclampsia?
What are the signs of toxicity of magnesium sulfate?
- respiratory depression
- arrhythmias
Should monitor for signs of toxicity every 4 hours (HR, BP, RR, deep tendon reflexes)
What is the antidote for magnesium sulfate toxicity?
10ml 10% calcium gluconate over 10mins (and stop magnesium sulphate infusion)
What alternatives to magnesium sulfate can be used in eclampsia?
Do not use diazepam, phenytoin or other anticonvulsants as an alternative to magnesium sulfate in women with eclampsia
How common is eclampsia?
27.5 cases per 100,000 pregnancies, with a case fatality rate
estimated to be 3.1%.
What is the pathophysiology of pre-eclampsia?
Only occurs in pregnancy, but also reported where there is placenta but no fetus e.g. molar pregnancy - suggests that trophoblast tissue is a stimulus
Theory is that development of pre-eclamsia has 2 stages:
- Stage 1: Trophoblast invasion is patchy and spiral arteries retain their muscular walls. This prevents development of high-flow, low impedance uteroplacental ciruclation and leads to uteroplacental ischaemia. Why trophoblasts invade less effectively is unknown but may be to do with maternal immune system
- Stage 2: Uteroplacental ischaemia results in oxidative and inflammatory stress, with the invovlement of secondary mediators leading to endothelial dysfunction, vasospasm and activation of coagulation. The target cell (endothelial) is so ubiquitous that pre-eclampsia is truly a multisystem disorder affecting many organs concurrently.
Define HELLP syndrome.
Haemolysis
Elevation of liver enzymes
Low platelets
What is the pathophysiology of HELLP syndrome?
Subendothelial fibrin deposition (due to increased coagulation in pre-eclampsia) causes elevation of liver enzymes
This may also cause haemolysis and low platelets due to platelet consumption –> HELLP
How common is HELLP syndrome? How dangerous is it?
Only 2-4% of pre-eclampsia cases affected
BUT up to 60% mortality - other complications are acute renal failure, placental abruption, stillbirth
How does HELLP syndrome present clinically?
- Haemolysis, elevated LFTs, low Plt
- Epigastric pain
- Nausea
- Vomiting
- HTN may be mild or even absent
What is the management of HELLP syndrome?
- Stabilise mother
- Correct coagulation deficits
- Assess fetus for delivery
Presents with epigastric pain, nausea + vomiting.
What is the threshold for PCR/ACR in pre-eclampsia diagnosis?
Protein: creatinine ratio >30mg/mmol
Albumin: creatinine ratio >8mg/mmol
What level of proteinuria over 24 hours is significant enough for pre-eclampsia?
300mg/24 hours
Why is spinal anaesthesia useful in pre-eclampsia during labour and why is ergometrine contraindicated?
- Epidural anaesthesia - can help control BP
- Ergometrine - can cause significant rise in BP - agonist or partial agonist effects at myometrial 5-HT2 receptors and alpha-adrenergic receptors
What are the 3 most important bloods in pre-eclampsia?
- FBC - platelets
- LFTs - ALT
- U&E - creatinine
