Pre-eclampsia and Eclampsia

Quick Answer

One-liner: Pre-eclampsia is new-onset hypertension (≥140/90 mmHg) with proteinuria or end-organ dysfunction after 20 weeks gestation; eclampsia is the occurrence of seizures in this context.

Pre-eclampsia affects 2-8% of pregnancies globally and remains a leading cause of maternal mortality, accounting for 10-15% of maternal deaths worldwide [1]. Aboriginal and Torres Strait Islander women and Māori women experience 2-3x higher maternal mortality rates from hypertensive disorders [2]. Immediate priorities are blood pressure control (target below 160/110 mmHg), seizure prophylaxis with magnesium sulfate, and assessment for delivery. The definitive treatment is delivery of the placenta.

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ACEM Exam Focus

Primary Exam Relevance

• Anatomy: Spiral artery remodelling, uteroplacental circulation, glomerular endotheliosis
• Physiology: Angiogenic factor balance (sFlt-1, PlGF, VEGF), endothelial function, renin-angiotensin-aldosterone in pregnancy
• Pharmacology: Magnesium sulfate mechanism (NMDA antagonism, vasodilation), labetalol (α/β-blockade), hydralazine (direct vasodilation), nifedipine (calcium channel blockade)

Fellowship Exam Relevance

• Written: Diagnostic criteria, HELLP syndrome recognition, magnesium dosing, antihypertensive selection, delivery timing
• OSCE: Eclamptic seizure management, breaking bad news about emergency delivery, postpartum pre-eclampsia presentation
• Key domains tested: Medical Expert, Collaborator, Leader, Communicator

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Key Points

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Epidemiology

Australian/NZ Specific

Indigenous Health Disparities:

• Aboriginal and Torres Strait Islander maternal mortality ratio: 17.5 per 100,000 vs 5.5 per 100,000 for non-Indigenous women (2012-2021) [2]
• Māori women: 2x higher maternal mortality than NZ Europeans [6]
• Higher rates of chronic hypertension, earlier onset pre-eclampsia
• Delayed antenatal care access contributes to later diagnosis
• Higher rates of severe pre-eclampsia and eclampsia at presentation

Rural/Remote Variations:

• Late presentation more common due to distance from antenatal services
• Higher severity at diagnosis due to delayed detection
• RFDS retrieval for pre-term deliveries and maternal stabilisation [7]
• Limited access to CTG monitoring and specialist obstetric input

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Pathophysiology

Two-Stage Model

Stage 1: Abnormal Placentation (First Trimester)

• Failed remodelling of maternal spiral arteries by extravillous trophoblasts
• Spiral arteries retain high-resistance, muscular structure
• Results in placental hypoxia and oxidative stress [8]

Stage 2: Maternal Syndrome (Second/Third Trimester)

• Hypoxic placenta releases anti-angiogenic factors
• Systemic endothelial dysfunction develops
• Multi-organ involvement ensues

Angiogenic Factor Imbalance

Placental Hypoxia
       ↓
↑ sFlt-1 (soluble fms-like tyrosine kinase-1)
↑ Soluble Endoglin (sEng)
       ↓
Sequestration of VEGF and PlGF
       ↓
Endothelial Dysfunction
       ↓
Hypertension + Proteinuria + End-Organ Damage

Key Molecules:

• sFlt-1: Decoy receptor binding VEGF/PlGF (elevated in pre-eclampsia) [9]
• PlGF: Placental growth factor (reduced in pre-eclampsia) [10]
• sFlt-1/PlGF ratio greater than 38: Highly predictive of pre-eclampsia development (PROGNOSIS study) [11]

Why It Matters Clinically

• Endothelial damage explains proteinuria (glomerular endotheliosis), hypertension (vasoconstriction), and oedema
• Hepatic involvement causes HELLP and epigastric pain
• Cerebral endothelial dysfunction leads to eclampsia
• Placental dysfunction causes fetal growth restriction
• Delivery removes placenta = source of pathology = definitive treatment

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Definitions and Diagnostic Criteria

Classification (SOMANZ/ISSHP)

Diagnostic Criteria for Pre-eclampsia (SOMANZ 2023) [3]

Hypertension: BP ≥140/90 mmHg on two occasions ≥4 hours apart after 20 weeks gestation

PLUS one or more of:

Severe Features (Warrants Immediate Action) [12]

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HELLP Syndrome

Diagnostic Criteria (Tennessee Classification) [13]

Mississippi Classification (Severity)

HELLP Complications

• Placental abruption (7-20%)
• Acute renal failure
• DIC
• Subcapsular liver haematoma (rare but catastrophic)
• Hepatic rupture
• Maternal mortality 1-3% [14]

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Clinical Approach

Recognition

High-Risk Patients:

• Primigravida
• Age extremes (below 20 or greater than 40 years)
• Multiple gestation
• Pre-existing hypertension, renal disease, diabetes
• Previous pre-eclampsia (especially severe/early-onset)
• Antiphospholipid syndrome, SLE
• BMI greater than 35
• IVF pregnancy
• Indigenous women (Aboriginal, Torres Strait Islander, Māori)

Initial Assessment

Primary Survey

• A: Patent airway (eclamptic seizure may compromise)
• B: SpO2 (pulmonary oedema), RR
• C: BP (manual sphygmomanometer), HR, IV access, bloods
• D: GCS, hyperreflexia, clonus (greater than 3 beats = pathological)
• E: Epigastric tenderness, oedema, fundal height

History

Key Questions

Red Flag Symptoms

Examination

General Inspection

• Alert or confused? (cerebral involvement)
• Pallor (haemolysis)
• Facial/periorbital oedema (significant if new-onset)
• Respiratory distress (pulmonary oedema)

Specific Findings

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Investigations

Immediate (Resus Bay)

Standard ED Workup

Advanced/Specialist

Point-of-Care Ultrasound

• Lung: B-lines for pulmonary oedema
• IVC: Volume assessment
• Liver: Free fluid, capsular haematoma (rare)
• Fetal: Heart rate, presentation, AFI (if trained)

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Management

Immediate Management (First 10 Minutes)

1. Call for help (obstetric, anaesthetics, paediatrics on standby)
2. IV access x2, bloods (FBC, LFT, UEC, coag, G&H)
3. BP control if ≥160/110 (labetalol/hydralazine/nifedipine)
4. Magnesium sulfate if severe/eclampsia
5. Continuous CTG monitoring
6. Strict fluid balance (avoid overload)
7. Urinary catheter with hourly urine output

Eclamptic Seizure Management

During Seizure:

1. Call for help - note time
2. Position: Left lateral (prevents aspiration, optimises uterine blood flow)
3. Airway: Do NOT insert tongue blade, clear secretions, give O2
4. Protect from injury (side rails, soft surroundings)
5. Most seizures self-terminate within 60-90 seconds

Post-Seizure/Ongoing:

1. Magnesium sulfate (if not already given) - see below
2. If recurrent seizure: Additional MgSO4 2g bolus
3. If refractory (greater than 2 seizures despite Mg): Consider IV diazepam 5-10mg or IV midazolam 2-5mg [15]
4. Do NOT give phenytoin (inferior to MgSO4) [16]

Magnesium Sulfate Protocol

MAGPIE Trial Evidence [17]

• 58% reduction in eclampsia (RR 0.42, 95% CI 0.29-0.60)
• NNT = 63 for moderate pre-eclampsia
• NNT = 109 for mild pre-eclampsia
• Maternal mortality reduced (RR 0.55)

Dosing Regimen (SOMANZ 2023) [3]

Alternative IM Regimen (Resource-Limited Settings)

• Loading: 4g IV + 5g IM each buttock (10g IM total)
• Maintenance: 5g IM every 4 hours in alternating buttocks

Indications for Magnesium Sulfate

• Treatment: Eclamptic seizure
• Prophylaxis: Severe pre-eclampsia, especially with neurological symptoms
• Prophylaxis in labour/delivery: Severe pre-eclampsia

Monitoring for Magnesium Toxicity

Magnesium Toxicity Progression

Therapeutic: 2-3.5 mmol/L → Seizure prevention
Loss of reflexes: 3.5-5 mmol/L → STOP infusion
Respiratory depression: 5-6.5 mmol/L → Support ventilation
Cardiac arrest: greater than 6.5 mmol/L → CPR + calcium

Magnesium Toxicity Treatment

• STOP magnesium infusion immediately
• Calcium gluconate 1g (10 mL of 10%) IV over 10 minutes
• Supportive care (airway, breathing, consider intubation if apnoeic)

Antihypertensive Therapy

Indications

• BP ≥160/110 mmHg (treat within 30-60 minutes to prevent stroke)
• Target: 130-150 / 80-100 mmHg (avoid precipitous drops)

First-Line Options (All Equally Effective) [18]

Labetalol Escalating Regimen

1. 20mg IV bolus
2. If no response in 10 min: 40mg IV
3. If no response: 80mg IV
4. If no response: 80mg IV (max cumulative 300mg)
5. Then commence infusion 1-2 mg/min if needed

Important Considerations

• Avoid sublingual nifedipine (unpredictable, precipitous hypotension)
• Do NOT use ACE inhibitors/ARBs (teratogenic)
• Avoid atenolol (fetal growth restriction)
• Avoid diuretics unless pulmonary oedema

Fluid Management

Important Note: CRITICAL: Avoid fluid overload

• Pre-eclamptic patients have intravascular depletion but interstitial overload
• Pulmonary oedema is a leading cause of maternal death
• Restrict total IV fluid to 80-100 mL/hour (including drug infusions)
• Target urine output ≥25 mL/hour
• Avoid colloids
• Use Hartmann's or N/Saline

Fetal Considerations

Antenatal Corticosteroids

Administer if delivery anticipated below 34+6 weeks:

• Betamethasone 11.4mg IM x2 doses, 24 hours apart
• OR Dexamethasone 6mg IM x4 doses, 12 hours apart
• Single course; rescue course if greater than 14 days since first course [19]

Late Preterm (34+0 to 36+6 weeks):

• Consider single course if delivery likely within 7 days and no prior course (ALPS trial) [20]

Fetal Monitoring

• Continuous CTG if admitted
• Abnormalities: Late decelerations, reduced variability, sinusoidal pattern

Delivery Timing

Immediate Delivery Indications (Regardless of Gestation)

• Eclampsia
• Uncontrolled severe hypertension despite maximal therapy
• Abruption
• DIC
• Non-reassuring fetal status
• Pulmonary oedema not responsive to treatment
• Hepatic capsule haematoma/rupture

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Postpartum Pre-eclampsia

Key Points

• Can occur up to 6 weeks postpartum
• 63% of delayed postpartum pre-eclampsia have no antepartum hypertensive disease [22]
• Present with headache, visual changes, hypertension
• High index of suspicion needed

Management

• Same as antepartum (labetalol, hydralazine, nifedipine)
• Magnesium sulfate for severe features or seizures
• Consider NSAIDs cautiously (can worsen hypertension)
• Avoid ergometrine (causes vasoconstriction)
• Outpatient BP monitoring if mild, discharge with clear return advice

Long-Term Cardiovascular Risk

• 2x increased lifetime risk of cardiovascular disease
• 4x risk of chronic hypertension
• Counsel regarding lifestyle modification, BP monitoring [23]

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Disposition

Admission Criteria

• All patients with pre-eclampsia (mild may be managed outpatient at some centres)
• Any severe feature
• Gestational hypertension with new symptoms
• Postpartum hypertension with symptoms

ICU/HDU Criteria

• Eclampsia
• Severe hypertension requiring IV infusion
• Pulmonary oedema
• HELLP syndrome
• Magnesium infusion (may be managed on labour ward with 1:1 care)
• Impending delivery requiring multidisciplinary input

Discharge Criteria (Gestational Hypertension without Pre-eclampsia)

• BP below 160/100 on oral antihypertensive
• No proteinuria or symptoms
• Normal bloods
• Fetal assessment normal
• Clear follow-up arranged (below 48-72 hours)
• Written red flag advice given

Follow-up

• Obstetric review within 24-72 hours
• Postpartum BP monitoring (daily initially)
• GP letter with BP targets and medication plan
• 6-week postnatal cardiovascular review
• Consider aspirin prophylaxis counselling for future pregnancies

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Special Populations

Atypical Presentations

• Pre-eclampsia can occur without proteinuria if other end-organ dysfunction present
• HELLP may occur without hypertension (15-20% of cases) [13]
• Eclampsia may be first presentation (no preceding symptoms in 20%)

Postpartum Pre-eclampsia

• Up to 6 weeks after delivery
• Can occur de novo
• Highest risk 3-6 days postpartum
• Treat as per antepartum protocols [24]

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Indigenous Health

Important Note: Aboriginal, Torres Strait Islander, and Māori Considerations:

Health Disparities:

• Aboriginal/Torres Strait Islander maternal mortality: 17.5/100,000 vs 5.5/100,000 non-Indigenous [2]
• Māori maternal mortality: 2x higher than NZ Europeans [6]
• Higher rates of chronic hypertension, diabetes, renal disease
• Earlier onset and more severe pre-eclampsia
• Later presentation to antenatal care

Barriers to Care:

• Geographic isolation (remote communities)
• Transport challenges to tertiary maternity services
• Cultural safety concerns may delay presentation
• Language barriers
• Mistrust of health system

Cultural Safety Approaches:

• Involve Aboriginal Health Workers/Aboriginal Liaison Officers
• Māori Health Workers/Kaiāwhina for NZ patients
• Family-centred care (whānau involvement)
• Respect for cultural practices around birth
• Clear, jargon-free communication
• Consider cultural protocols around bad news
• Involve Elders if appropriate and requested
• Plan for "Birthing on Country" support where possible
• Ensure interpreter services if required

Clinical Implications:

• Lower threshold for investigation and admission
• Early involvement of multidisciplinary team
• Proactive transfer planning for remote patients
• Consider social supports for relocation
• Ensure culturally safe discharge planning

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Remote/Rural Considerations

Pre-Hospital

• Early activation of retrieval services (RFDS, state-based retrieval)
• Remote Area Nurses (RANs) and Rural GPs: Initial stabilisation
• Telemedicine consultation with tertiary obstetric service
• Have magnesium sulfate and antihypertensives available

Resource-Limited Setting

• Oral nifedipine if no IV access (equally effective) [25]
• IM magnesium protocol if IV infusion not possible
• Urinary catheter for output monitoring
• Manual BP monitoring (automated may be inaccurate in pre-eclampsia)
• Prepare for potential delivery during retrieval

RFDS/Retrieval Medicine

• Pre-eclampsia/eclampsia is common indication for maternal retrieval [7]
• Risk of "in-flight birth"
• ensure obstetric kit available
• Neonatal resuscitation capability required
• Consider flight physiology (mild hypoxia at altitude)
• Secure IV access and magnesium infusion before flight
• Continue CTG monitoring if possible

Retrieval Criteria

• Severe pre-eclampsia below 34 weeks
• Any eclampsia
• HELLP syndrome
• Need for delivery without local surgical/anaesthetic capability
• Preterm labour in context of pre-eclampsia

Telemedicine

• Real-time consultation with tertiary MFM specialists
• Photo of blood film (schistocytes)
• Shared CTG review
• Decision support for expectant management vs transfer

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Prevention

Aspirin Prophylaxis

Indication: High-risk women, commenced before 16 weeks gestation [26,27]

High-Risk Criteria (One or More):

• Previous pre-eclampsia
• Multiple pregnancy
• Chronic hypertension
• Pre-existing renal disease
• Diabetes (Type 1 or 2)
• Autoimmune disease (SLE, antiphospholipid syndrome)

Moderate-Risk Criteria (Two or More):

• First pregnancy
• Age ≥40
• Pregnancy interval greater than 10 years
• BMI ≥35
• Family history of pre-eclampsia

Dosing:

• 150mg nocte (ASPRE trial) [26]
• OR 100-150mg daily (SOMANZ) [3]
• Start before 16 weeks, continue until 36 weeks

Evidence:

• ASPRE trial: 62% reduction in preterm pre-eclampsia [26]
• Cochrane review: 18% reduction overall [27]

Calcium Supplementation

• 1.5-2g/day for women with low dietary calcium intake
• Reduces pre-eclampsia risk by 50% in high-risk women [28]

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Differential Diagnosis

Conditions Mimicking Pre-eclampsia

HELLP Mimics

When to Consider Alternative Diagnoses

• Onset before 20 weeks gestation
• ADAMTS13 below 10% (TTP)
• Hypoglycaemia or encephalopathy (AFLP)
• Severe AKI out of proportion to other features
• Thrombosis or recurrent pregnancy loss history
• Active SLE with complement consumption

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Complications

Maternal Complications

Fetal/Neonatal Complications

Long-Term Maternal Sequelae

Pre-eclampsia is associated with significant long-term cardiovascular risk:

Counselling Points:

• Lifestyle modification (weight, exercise, diet)
• Annual BP monitoring
• Cardiovascular risk factor screening
• Consider aspirin prophylaxis in future pregnancies
• Preconception counselling for future pregnancies [23]

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Prognosis

Maternal Outcomes

Factors Associated with Poor Maternal Outcome:

• Late presentation
• Delayed treatment of severe hypertension
• HELLP with hepatic complications
• Eclampsia (especially remote from medical care)
• Aboriginal, Torres Strait Islander, or Māori ethnicity (due to systemic barriers)
• Remote geographic location

Fetal/Neonatal Outcomes

Recurrence Risk

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Pharmacology Details

Magnesium Sulfate Pharmacology

Clinical Pearls:

• Does NOT lower blood pressure (separate antihypertensive needed)
• Continue for 24 hours after delivery OR last seizure
• Monitor closely if oliguria (accumulation risk)
• Fetal effects: transient hypotonia, decreased variability on CTG

Antihypertensive Pharmacology

Labetalol

Hydralazine

Nifedipine

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Patient Education

Red Flags for Patients

Return immediately if you experience:

• Severe headache not relieved by paracetamol
• Visual disturbances (flashing lights, spots, blurred vision)
• Upper abdominal or shoulder tip pain
• Sudden swelling of face, hands, or feet
• Difficulty breathing
• Reduced baby movements
• Seizure or loss of consciousness
• Nausea or vomiting (new onset in third trimester)

Discharge Advice (for Mild Gestational Hypertension)

1. Blood pressure monitoring: Daily home BP or GP check
2. Medications: Take antihypertensives as prescribed
3. Warning signs: Know the red flags above
4. Follow-up: Antenatal appointment within 48-72 hours
5. Fetal movements: Report any decrease immediately
6. Activity: Rest encouraged, avoid strenuous activity
7. Salt intake: Normal dietary salt (no restriction)
8. When to call: BP greater than 160/100 or any red flag symptoms

Postpartum Information

• BP may worsen in first week postpartum
• Continue BP medications as prescribed
• Avoid NSAIDs if possible (may worsen hypertension)
• Breastfeeding is safe with labetalol, nifedipine
• Long-term cardiovascular screening recommended
• Discuss aspirin for future pregnancies

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Quality Assurance Checklist

Pre-eclampsia Management Bundle

On Arrival:

• Manual BP confirmed ≥140/90
• IV access established
• Bloods sent: FBC, LFT, UEC, coagulation, G&H
• Urinalysis performed
• Fetal heart rate assessed

Severe Features (BP ≥160/110 or symptoms):

• Antihypertensive given within 30-60 minutes
• MgSO4 loading dose given
• MgSO4 infusion commenced
• Obstetric team notified
• Anaesthetic team alerted
• Paediatric team alerted (if preterm)
• CTG monitoring initiated
• Steroids given if below 34+6 weeks

Ongoing Monitoring:

• BP every 15 minutes until stable, then hourly
• Urine output hourly
• Patellar reflexes 4-hourly
• Respiratory rate monitored
• Repeat bloods 6-12 hourly

Documentation:

• Time of antihypertensive administration
• Time of MgSO4 loading and infusion start
• Delivery plan discussed with patient
• Red flag advice given

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Pitfalls & Pearls

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Viva Practice

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OSCE Scenarios

Station 1: Eclamptic Seizure Management

Format: Resuscitation Time: 11 minutes Setting: ED resuscitation bay

Candidate Instructions:

You are the senior ED registrar. A 29-year-old woman at 34 weeks gestation has just been brought in by ambulance after a witnessed seizure at home. She is currently having another generalised tonic-clonic seizure. Lead the resuscitation of this patient.

Examiner Instructions: Patient is actively seizing for the first 60 seconds. After the candidate initiates left lateral positioning and avoids harmful interventions, the seizure stops. Post-ictal GCS 10, BP 182/116 (when checked), HR 108, RR 24, SpO2 92% on room air. If magnesium given appropriately, no further seizures. If BP treatment delayed, she has another seizure at 8 minutes.

Actor/Patient Brief: Manikin with simulated seizure. Post-ictal, responds to painful stimuli, then gradually improves to GCS 14 by end of scenario.

Marking Criteria:

Expected Standard:

• Pass: ≥6/11
• Key discriminators: Avoiding harmful interventions during seizure, correct magnesium dosing, closed-loop communication

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Station 2: Breaking Bad News - Emergency Caesarean

Format: Communication Time: 11 minutes Setting: ED relatives room

Candidate Instructions:

Sarah, a 32-year-old primigravida at 31 weeks, has been diagnosed with severe pre-eclampsia with HELLP syndrome. She requires an emergency caesarean section within the next 2 hours. Her husband Michael is in the waiting room. He does not know why his wife was admitted. Please speak with him and explain the situation.

Examiner Instructions: Michael is anxious, asks about the baby's survival chances, asks if his wife could die. He may become upset. Assess candidate's ability to deliver difficult information with empathy while being honest about uncertainties.

Actor/Patient Brief: Michael, 34, works in finance. Wife Sarah had an uncomplicated pregnancy until this morning. He is anxious, pacing. When told about the need for caesarean, he asks: "But she's only 31 weeks - will the baby survive?" and "Could Sarah die from this?"

Marking Criteria:

Expected Standard:

• Pass: ≥6/11
• Key discriminators: Honest answers about risk without catastrophising, appropriate empathy, avoiding medical jargon

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Station 3: Postpartum Pre-eclampsia History

Format: History Time: 11 minutes Setting: ED cubicle

Candidate Instructions:

You are the ED registrar. A 28-year-old woman presents 6 days postpartum with a severe headache. Take a focused history and outline your initial management plan.

Examiner Instructions: Patient had normal antenatal care, uncomplicated vaginal delivery, discharged day 2. Headache started 2 days ago, now severe, frontal, constant, associated with "spots" in vision this morning. BP will be given as 168/108 when asked or measured. No fever. No previous migraines.

Actor/Patient Brief: 28-year-old new mother. Delivered healthy baby 6 days ago, everything was normal. Developed headache 2 days ago, took paracetamol with minimal relief. This morning noticed "flashing spots" in right eye. Husband insisted she come in. She is worried something is seriously wrong.

Marking Criteria:

Expected Standard:

• Pass: ≥6/11
• Key discriminators: Recognising postpartum pre-eclampsia despite no antenatal history, appropriate urgency

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SAQ Practice

Question 1 (6 marks)

Stem: A 32-year-old primigravida at 28 weeks gestation presents to the ED with BP 168/112 mmHg, headache, and right upper quadrant pain.

Question: List 6 investigations you would order and briefly state what abnormality you are looking for in each.

Model Answer:

1. FBC - thrombocytopenia (below 100 × 10⁹/L) indicating HELLP (1 mark)
2. LFT (AST/ALT) - elevated transaminases (≥2x ULN) indicating liver involvement (1 mark)
3. LDH - elevated (greater than 600 U/L) indicating haemolysis (1 mark)
4. UEC/Creatinine - elevated creatinine (greater than 90 μmol/L) indicating renal involvement (1 mark)
5. Coagulation profile - DIC (prolonged PT/APTT, low fibrinogen) (1 mark)
6. Urinalysis/PCR - proteinuria (≥2+ or PCR greater than 30 mg/mmol) (1 mark)

Examiner Notes:

• Accept: Blood film for schistocytes, uric acid, bilirubin
• Accept: CTG as an investigation for fetal assessment
• Do not accept: non-specific tests without reason stated

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Question 2 (8 marks)

Stem: A 26-year-old woman at 35 weeks gestation has a witnessed generalised tonic-clonic seizure in the ED waiting room. She has no previous seizure history.

Question: a) Describe your immediate management during the seizure (3 marks) b) Outline your management after the seizure has terminated (5 marks)

Model Answer:

a) During seizure (3 marks):

• Position left lateral/recovery position (1 mark)
• Protect from injury (side rails, move objects) (0.5 mark)
• Do NOT insert tongue blade/objects into mouth (0.5 mark)
• Call for help/activate resuscitation team (0.5 mark)
• Note time/duration of seizure (0.5 mark)

b) Post-seizure (5 marks):

• Airway management: suction, supplemental O2, SpO2 monitoring (1 mark)
• IV access, bloods: FBC, LFT, UEC, coagulation, glucose, G&H (1 mark)
• Magnesium sulfate 4g IV loading over 20 minutes, then 1g/hour infusion (1 mark)
• BP control if ≥160/110: IV labetalol 20mg or oral nifedipine 10mg (1 mark)
• CTG monitoring, obstetric consultation, plan for delivery after stabilisation (1 mark)

Examiner Notes:

• Do not accept: phenytoin (inferior to MgSO4)
• Accept: brief mention of CT head if focal signs or prolonged decreased consciousness

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Question 3 (6 marks)

Stem: You are working in a regional ED. A 30-year-old Aboriginal woman at 36 weeks gestation is brought in by ambulance from a remote community (4 hours away) with BP 172/108, severe headache, and blurred vision. She is reluctant to stay in hospital and wants to return home.

Question: Outline 6 key considerations in managing this patient, including cultural safety.

Model Answer:

1. Clinical urgency: This is severe pre-eclampsia requiring BP control and MgSO4 prophylaxis - medical emergency (1 mark)
2. Cultural safety: Involve Aboriginal Health Worker/Liaison Officer in all discussions (1 mark)
3. Family involvement: Ask if she wants family/Elder present for decision-making (1 mark)
4. Clear communication: Explain risks in plain language, avoid medical jargon, check understanding (1 mark)
5. Acknowledge barriers: Understand her reluctance (cultural connection to Country, previous negative healthcare experiences, family responsibilities) (1 mark)
6. Shared decision-making: If she declines admission, document capacity, provide clear return advice, arrange telemedicine follow-up, maintain non-judgemental relationship (1 mark)

Examiner Notes:

• Accept: Mention of higher maternal mortality in Indigenous women
• Accept: Practical considerations (transport for family, child care)
• Accept: Involving senior clinician/consultant in discussions

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Question 4 (8 marks)

Stem: A 35-year-old woman with pre-eclampsia is receiving magnesium sulfate infusion. The nurse reports her urine output has been 60mL over the past 3 hours and she appears drowsy.

Question: a) What is your immediate concern? (1 mark) b) What clinical signs would you assess? (3 marks) c) Describe your management if you confirm magnesium toxicity with respiratory rate of 8/min and absent reflexes (4 marks)

Model Answer:

a) Immediate concern (1 mark):

• Magnesium toxicity (accumulation due to reduced renal excretion) (1 mark)

b) Clinical signs to assess (3 marks):

• Respiratory rate and effort (depression at 5-6.5 mmol/L) (1 mark)
• Deep tendon reflexes (lost at 3.5-5 mmol/L) (1 mark)
• Level of consciousness/GCS (1 mark)
• Accept: ECG changes, BP, heart rate

c) Management of confirmed toxicity with RR 8 (4 marks):

• Stop magnesium infusion immediately (1 mark)
• Give Calcium gluconate 1g (10mL of 10%) IV over 10 minutes (1 mark)
• Prepare for/commence bag-mask ventilation, call for airway support (1 mark)
• Check serum magnesium level, continue monitoring, supportive care (1 mark)

Examiner Notes:

• Calcium is the antidote and first-line treatment
• Do not accept: dialysis as first-line management

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Australian Guidelines

SOMANZ (Society of Obstetric Medicine of Australia and New Zealand) [3]

SOMANZ 2023 Guidelines - Key Points:

• Hypertension definition: ≥140/90 mmHg
• Pre-eclampsia diagnosis: HTN + proteinuria OR end-organ dysfunction after 20 weeks
• Target BP in treatment: 130-150/80-100 mmHg
• Aspirin 150mg nocte for high-risk women (start below 16 weeks)
• Calcium 1.5-2g/day for women with low dietary calcium
• MgSO4 for eclampsia and severe pre-eclampsia

RANZCOG

C-Obs 06: Hypertension in Pregnancy:

• Endorses SOMANZ guidelines
• Emphasises multidisciplinary care
• Recommends tertiary referral for severe preterm disease

State-Specific

NSW Health Clinical Guidelines:

• PD2019_038: Maternity - Hypertensive Disorders of Pregnancy
• Specific protocols for escalation and transfer

Queensland Health:

• Statewide Maternity and Neonatal Clinical Guideline: Hypertension in pregnancy

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References

Guidelines

1. Mol BWJ, et al. Pre-eclampsia. Lancet. 2016;387:999-1011. PMID: 26342729
2. Australian Institute of Health and Welfare. Maternal deaths in Australia 2012-2021. AIHW. 2023.
3. Lowe SA, et al. SOMANZ guidelines for the management of hypertensive disorders of pregnancy 2023. ANZJOG. 2023;63:529-555. PMID: 37705353
4. Knight M. Eclampsia in the United Kingdom 2005-2014. BJOG. 2007;114:1072-8. PMID: 17617191
5. Barton JR, Sibai BM. Prediction and prevention of recurrent preeclampsia. Obstet Gynecol. 2008;112:359-372. PMID: 18669736

Indigenous Health

6. Perinatal and Maternal Mortality Review Committee. 14th Annual Report of the PMMRC. Wellington: Health Quality & Safety Commission. 2020.
7. Margolis SA, et al. Aeromedical retrieval for obstetric emergencies. Aust J Rural Health. 2011;19:77-83.

Pathophysiology

8. Phipps EA, et al. Pre-eclampsia: pathogenesis, novel diagnostics and therapies. Nat Rev Nephrol. 2019;15:275-289. PMID: 31273318
9. Maynard SE, et al. Excess placental sFlt1 may contribute to preeclampsia pathogenesis. J Clin Invest. 2003;111:649-658. PMID: 12618519
10. Levine RJ, et al. Circulating angiogenic factors and the risk of preeclampsia. N Engl J Med. 2004;350:672-683. PMID: 14764923
11. Zeisler H, et al. Predictive value of the sFlt-1:PlGF ratio in women with suspected preeclampsia. N Engl J Med. 2016;374:13-22. PMID: 26735993
12. ACOG Practice Bulletin No. 222: Gestational Hypertension and Preeclampsia. Obstet Gynecol. 2020;135:e237-e260. PMID: 32443079

HELLP Syndrome

13. Sibai BM. Diagnosis, controversies, and management of HELLP syndrome. Obstet Gynecol. 2004;103:981-991. PMID: 15121574
14. Martin JN Jr, et al. HELLP syndrome: The state of the art. Am J Obstet Gynecol. 2006;195:40-7. PMID: 16813742

Seizure Management

15. Sibai BM. Diagnosis, prevention, and management of eclampsia. Obstet Gynecol. 2005;105:402-410. PMID: 15684172
16. The Eclampsia Trial Collaborative Group. Which anticonvulsant for women with eclampsia? Lancet. 1995;345:1455-1463. PMID: 7769899

MAGPIE Trial

17. Altman D, et al. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial. Lancet. 2002;359:1877-1890. PMID: 12057549

Antihypertensives

18. Duley L, et al. Drugs for treatment of very high blood pressure during pregnancy. Cochrane Database Syst Rev. 2013;7:CD001449. PMID: 23897483
19. Roberts D, et al. Antenatal corticosteroids for accelerating fetal lung maturation. Cochrane Database Syst Rev. 2017;3:CD004454. PMID: 28321847
20. Gyamfi-Bannerman C, et al. Antenatal betamethasone for women at risk for late preterm delivery. N Engl J Med. 2016;374:1311-1320. PMID: 26842679

Delivery Timing

21. Koopmans CM, et al. Induction of labour versus expectant monitoring for gestational hypertension or mild pre-eclampsia after 36 weeks' gestation (HYPITAT). Lancet. 2009;374:979-988. PMID: 19632407

Postpartum Pre-eclampsia

22. Al-Safi Z, et al. Delayed postpartum preeclampsia and eclampsia: demographics, clinical course, and complications. Obstet Gynecol. 2011;118:1102-1107. PMID: 22015879
23. Bellamy L, et al. Pre-eclampsia and risk of cardiovascular disease and cancer in later life. BMJ. 2007;335:974. PMID: 17975258
24. ACOG Committee Opinion No. 767. Emergent Therapy for Acute-Onset, Severe Hypertension. Obstet Gynecol. 2019;133:e174-e180. PMID: 30801469

Remote/Rural

25. Shekhar S, et al. Oral nifedipine versus intravenous labetalol for severe hypertension in pregnancy: a randomised controlled trial. BJOG. 2013;120:1747-1752. PMID: 23906215

Prevention

26. Rolnik DL, et al. Aspirin versus placebo in pregnancies at high risk for preterm preeclampsia. N Engl J Med. 2017;377:613-622. PMID: 28657417
27. Duley L, et al. Antiplatelet agents for preventing pre-eclampsia and its complications. Cochrane Database Syst Rev. 2019;10:CD004659. PMID: 31684684
28. Hofmeyr GJ, et al. Calcium supplementation during pregnancy for preventing hypertensive disorders. Cochrane Database Syst Rev. 2018;10:CD001059. PMID: 30277579

Additional Evidence

29. Venkatesha S, et al. Soluble endoglin contributes to preeclampsia pathogenesis. Nat Med. 2006;12:642-649. PMID: 16751773
30. American College of Obstetricians and Gynecologists. Task Force on Hypertension in Pregnancy. Hypertension in pregnancy. Obstet Gynecol. 2013;122:1122-1131. PMID: 24150343
31. ACOG Practice Bulletin No. 203. Chronic Hypertension in Pregnancy. Obstet Gynecol. 2019;133:e26-e50. PMID: 30575676
32. Lowe SA, et al. SOMANZ guidelines for the management of hypertensive disorders of pregnancy 2014. ANZJOG. 2015;55:11-16. PMID: 25312330
33. Steegers EA, et al. Pre-eclampsia. Lancet. 2010;376:631-644. PMID: 20598363
34. Magee LA, et al. Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy. Pregnancy Hypertens. 2014;4:105-145. PMID: 26104418
35. Brown MA, et al. Hypertensive Disorders of Pregnancy: ISSHP Classification. Hypertension. 2018;72:24-43. PMID: 29899139
36. Abalos E, et al. Antihypertensive drug therapy for mild to moderate hypertension during pregnancy. Cochrane Database Syst Rev. 2018;10:CD002252. PMID: 30277556
37. Magee LA, et al. Less-tight versus tight control of hypertension in pregnancy. N Engl J Med. 2015;372:407-417. PMID: 25629739
38. Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol. 1998;92:883-889. PMID: 9794695
39. Sibai BM. Magnesium sulfate prophylaxis in preeclampsia: lessons learned from recent trials. Am J Obstet Gynecol. 2004;190:1520-1526. PMID: 15284724
40. Duley L, et al. Magnesium sulphate and other anticonvulsants for women with pre-eclampsia. Cochrane Database Syst Rev. 2010;11:CD000025. PMID: 21069663
41. Shear RM, et al. Postpartum hypertension and preeclampsia: incidence and associated complications. Obstet Gynecol Clin North Am. 2015;42:37-47.
42. Chames MC, et al. Late postpartum eclampsia: a preventable disease? Am J Obstet Gynecol. 2002;186:1174-1177. PMID: 12066094