Pre-eclampsia and eclampsia — branching viva

Reader-visible authorities for every branch: NICE NG133, ACOG Practice Bulletin 222, ISSHP 2021, the Queensland Clinical Guideline eclampsia flowchart, and Hypertensive Disorders in Pregnancy - SA Perinatal Practice Guidelines.^[1][3][7]

Node 1 — classify the disorder

Examiner: “A previously normotensive patient at 31 weeks has BP 146/94 mmHg. What must you establish before calling this pre-eclampsia?”^[1][3]

Candidate: “I confirm that either systolic is ≥140 or diastolic is ≥90 mmHg, repeat correctly according to urgency and the named guideline, then look for proteinuria and specified maternal or uteroplacental dysfunction. Hypertension alone after 20 weeks is gestational hypertension, not automatically pre-eclampsia.”^[1][3]

Branch 1A — if the candidate gives the core definition

Examiner: “Now separate ACOG from ISSHP.”^[3][7]

Candidate: “ACOG ordinarily uses two BP readings at least 4 hours apart, but confirms severe hypertension over a shorter interval so treatment is not delayed. It uses proteinuria ≥300 mg/24 h, PCR ≥0.3, or dipstick 2+ only if quantitative testing is unavailable; hypertension plus a named severe feature can diagnose pre-eclampsia without proteinuria. The laboratory boundaries are platelets <100 ×10⁹/L, creatinine >1.1 mg/dL or doubling without other renal disease, and transaminases ≥2 times normal. ISSHP also accepts uteroplacental dysfunction, such as fetal growth restriction or abnormal placental Doppler, in its definition.”^[3][7]

Branch 1B — rescue if the candidate says “hypertension plus proteinuria” only

Examiner: “Must proteinuria be present?”^[1][3]

Candidate: “No. Specified maternal end-organ dysfunction can establish pre-eclampsia without proteinuria, and ISSHP also accepts uteroplacental dysfunction. Oedema is not diagnostic, and protein quantity does not grade severity.”^[1][3]

Branch 1C — examiner tests a threshold trap

Examiner: “Is 160/110 a single combined number?”^[7]

Candidate: “No. Systolic ≥160 mmHg or diastolic ≥110 mmHg is severe hypertension; either component triggers prompt confirmation and urgent treatment.”^[7]

Node 2 — severe disease changes the path

Examiner: “The patient now has BP 168/112, headache unrelieved by analgesia and photopsia. What are the severe findings?”^[7]

Candidate: “Persistent severe systolic and diastolic hypertension, a new persistent cerebral symptom and a visual symptom. I do not score 3+ protein or clonus as separate severe-feature criteria, although clonus may reinforce neurological concern.”^[1][3][7]

Branch 2A — BP remains severe after prompt confirmation

Examiner: “She is alert, saturation 97% and chest clear. What do you do in the next hour?”^[1][7]

Candidate: “I call senior obstetric and anaesthetic help, admit to a monitored maternity area, obtain IV access, avoid unnecessary fluid, and begin the local acute severe-hypertension bundle urgently. ACOG examples are IV labetalol, IV hydralazine or oral immediate-release nifedipine, with treatment as soon as possible and within 30–60 minutes. I give magnesium because she has severe neurological features under the applicable protocol, obtain maternal bloods and quantify protein, assess the fetus, and plan birth after stabilization.”^[1][4][7]

Examiner probe: “Do you give 15 litres of oxygen?”^[2]

Candidate: “Not routinely with normal saturation and ventilation. Oxygen is for hypoxaemia or inadequate ventilation.”^[2]

Branch 2B — BP responds and symptoms completely resolve

Examiner: “BP is controlled and symptoms resolve. Does that guarantee discharge or waiting to 34 weeks?”^[1][7]

Candidate: “No. She still needs inpatient senior review, serial symptoms, BP, laboratory and fetal assessment. Before 34 weeks, selected expectant care requires continuing maternal and fetal stability and tertiary resources. Any recurrence or deterioration changes the branch to birth after stabilization.”^[1][7]

Branch 2C — laboratory deterioration

Examiner: “Platelets are falling and AST is rising with right-upper-quadrant pain. What syndrome must you consider?”^[6]

Candidate: “HELLP—haemolysis, elevated liver enzymes and low platelets. I add blood film, LDH, bilirubin, coagulation studies and group-and-screen, and assess for abruption, DIC, kidney injury and hepatic complications. Tennessee complete HELLP requires LDH ≥600 IU/L, AST ≥70 IU/L and platelets <100 ×10⁹/L; partial HELLP has one or two components. Mississippi class 1 is platelets ≤50 ×10⁹/L, AST or ALT ≥70 IU/L, LDH ≥600 IU/L; class 2 is platelets >50 to ≤100 ×10⁹/L with AST or ALT ≥70 IU/L and LDH ≥600 IU/L; class 3 is platelets >100 to ≤150 ×10⁹/L with AST or ALT ≥40 IU/L and LDH ≥600 IU/L. Classification must not delay stabilization and required birth.”^[6]

Node 3 — seizure branch

Examiner: “She has a generalized tonic-clonic seizure. Talk through the first minutes.”^[2]

Candidate: “Call the obstetric, anaesthetic and neonatal teams; place her left lateral; protect from injury; open the airway; assess breathing and circulation; check glucose; and give high-flow oxygen during the active generalized seizure while protecting the airway and assessing ventilation, under Hypertensive Disorders in Pregnancy - SA Perinatal Practice Guidelines. Obtain IV access and give magnesium using one complete local regimen; treat persistent severe BP, assess the fetus after maternal stabilization and plan birth. Once the convulsion ends, titrate oxygen to ventilation and saturation rather than continuing routine oxygen in stable normoxia. I also assess urgent mimics such as stroke, cerebral venous thrombosis, epilepsy, infection, hypoglycaemia and electrolyte disturbance.”^[2][7]

Branch 3A — examiner selects NICE magnesium

Examiner: “Give the NICE IV regimen.”^[4]

Candidate: “Magnesium sulphate 4 g IV over 5–15 minutes, then 1 g/hour for 24 hours. A recurrent seizure receives 2–4 g IV over 5–15 minutes under the protocol.”^[4]

Branch 3B — examiner selects ACOG magnesium

Examiner: “Give the common ACOG regimen.”^[7]

Candidate: “A loading dose 4–6 g IV over 20–30 minutes, then 1–2 g/hour, with duration and adjustment following the local protocol.”^[7]

Branch 3C — recurrent seizure despite the loading dose

Examiner: “She convulses again.”^[2][4]

Candidate: “I reassess airway, ventilation, glucose and whether the loading dose was delivered correctly, then give the protocol’s additional magnesium dose—NICE 2–4 g over 5–15 minutes. Persistent seizures require anaesthetic airway control, neurology input and urgent evaluation for stroke, CVT, infection or metabolic disease rather than repeated unbounded magnesium.”^[2][4]

Branch 3D — oliguria or renal impairment

Examiner: “Urine output falls and creatinine rises. What changes?”^[3][5]

Candidate: “Magnesium is renally cleared. I stop or reduce the maintenance infusion according to protocol, check serum magnesium, monitor reflexes, respiration and urine output closely, and treat the cause of renal deterioration. I do not repeat routine doses blindly.”^[3][5]

Branch 3E — toxicity

Examiner: “Reflexes disappear and respiration falls.”^[5]

Candidate: “Stop magnesium, call for help and support airway and ventilation. The Queensland Clinical Guideline eclampsia flowchart specifies 10% calcium gluconate 10 mL IV over 5 minutes—equivalent to 1 g—under the emergency medicine protocol. Recheck magnesium and renal function.”^[7]

Node 4 — the 33-week decision

Examiner: “At 33 weeks, when can you wait and when must you deliver?”^[1][7]

Branch 4A — stable after treatment, ACOG pathway

Candidate: “Before 34 weeks, ACOG permits expectant management only for a carefully selected stable patient in a centre with adequate maternal and neonatal resources. BP must remain controlled, severe symptoms must resolve, labs and fetal status must be stable, and predefined stop criteria must be documented. Give corticosteroids if preterm birth is expected, but never delay an indicated birth to finish them.”^[7]

Branch 4B — stable after treatment, NICE pathway

Candidate: “NICE NG133 generally continues surveillance before 34 weeks and at 34+0 to 36+6 unless a listed maternal or fetal threshold for planned early birth is met. From 37 weeks it initiates birth within 24–48 hours. The team records thresholds and does not use PlGF alone to decide birth.”^[1]

Branch 4C — deterioration

Examiner: “Headache persists, BP remains severe and CTG becomes non-reassuring.”^[1][7]

Candidate: “Expectant management has failed. Stabilize maternal airway, seizures and BP, then proceed to prompt birth with senior obstetric, anaesthetic and neonatal teams. Route is based on urgency, fetal status, cervix and standard obstetric indications; eclampsia itself does not mandate caesarean birth.”^[1][2][7]

Branch 4D — HELLP at 33 weeks

Examiner: “Does ‘HELLP’ mean automatic un-stabilized caesarean?”^[6]

Candidate: “No. Once HELLP is identified, birth is required after maternal stabilization regardless of gestation. Stabilize airway and breathing, control seizures and severe BP, correct life-threatening coagulopathy and arrange blood products as indicated; individualize only these immediate steps and the route according to urgency and obstetric factors. Do not postpone birth to complete corticosteroids. High-dose dexamethasone solely to improve maternal platelet count is not routine.”^[6]

Node 5 — postpartum branch

Examiner: “The baby is born. Is the danger over?”^[1][2]

Candidate: “No. Hypertension, pulmonary oedema, neurological symptoms and eclampsia can first occur or worsen postpartum. I continue the named magnesium plan when indicated, monitor symptoms, BP, fluid balance and urine output, and complete a formal VTE risk assessment.”^[1][2]

Branch 5A — breastfeeding and antihypertensives

Examiner: “She is breastfeeding and still needs treatment.”^[1]

Candidate: “Under NICE, enalapril is an option with renal-function and potassium monitoring; nifedipine or amlodipine are alternatives, and combination treatment may add labetalol or atenolol. Stop methyldopa within 2 days postpartum and avoid ARBs and diuretics where possible while breastfeeding. I check the current local formulary and infant factors.”^[1]

Branch 5B — follow-up schedule

Examiner: “Give one complete UK or US schedule.”^[1][7]

Candidate: “NICE: inpatient BP at least four times daily, once between day 3 and day 5, alternate days if abnormal, review at 2 weeks if still treated and all patients at 6–8 weeks; check urine at 6–8 weeks and review kidneys at 3 months if proteinuria persists. ACOG: BP evaluation within 72 hours after severe hypertension and no later than 7–10 days for any hypertensive disorder. I name the pathway rather than merging them.”^[1][7]

Branch 5C — VTE and long-term counselling

Examiner: “What do you counsel before discharge?”^[1][3]

Candidate: “Complete individualized postpartum VTE assessment; pre-eclampsia is one risk factor, not an automatic universal LMWH course. Explain recurrence—NICE uses roughly one in five for any hypertensive disorder and one in six for pre-eclampsia overall, higher after earlier birth—and increased future hypertension, cardiovascular disease and stroke risk. Arrange primary-care risk review; ISSHP supports annual blood-pressure and cardiovascular-risk follow-up.”^[1][3]

Examiner stop rules

• Stop and redirect if the candidate waits 4 hours to confirm severe hypertension.^[7]
• Stop and redirect if the candidate gives routine high-flow oxygen to a stable, normally oxygenated, non-seizing patient or withholds protocol oxygen during an active generalized eclamptic seizure.^[2]
• Stop and redirect if the candidate mixes NICE and ACOG magnesium loading and maintenance doses.^[4][7]
• Stop and redirect if the candidate says 3+ proteinuria alone makes disease severe.^[1][3]
• Stop and redirect if the candidate promises to wait until 34 weeks despite persistent neurological symptoms, uncontrolled severe BP or non-reassuring fetal status.^[1][7]
• Stop and redirect if the candidate offers expectant management after HELLP is identified; birth is required after maternal stabilization regardless of gestation, and steroids must not delay it.^[6]
• Stop and redirect if the candidate says delivery instantly cures all maternal risk or ends postpartum surveillance.^[1][2]

References7ShowHide

1. [1]Wu P, Green M, Myers JE. Hypertensive disorders of pregnancy BMJ, 2023.PMID 37391211
2. [2]Fishel Bartal M, Sibai BM. Eclampsia in the 21st century American Journal of Obstetrics and Gynecology, 2022.PMID 32980358
3. [3]Magee LA, Brown MA, Hall DR, et al. The 2021 International Society for the Study of Hypertension in Pregnancy classification, diagnosis & management recommendations for international practice Pregnancy Hypertension, 2022.PMID 35066406
4. [4]Altman D, Carroli G, Duley L, et al. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial Lancet, 2002.PMID 12057549
5. [5]Diaz V, Long Q, Oladapo OT. Alternative magnesium sulphate regimens for women with pre-eclampsia and eclampsia Cochrane Database of Systematic Reviews, 2023.PMID 37815037
6. [6]Jayawardena L, McNamara E. Diagnosis and management of pregnancies complicated by haemolysis, elevated liver enzymes and low platelets syndrome in the tertiary setting Internal Medicine Journal, 2020.PMID 31062430
7. [7]American College of Obstetricians and Gynecologists. Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222 Obstetrics & Gynecology, 2020.PMID 32443079