Pre-eclampsia

Pre-eclampsia is a multisystem hypertensive disorder of pregnancy, diagnosed after 20 weeks gestation by the presence of:

• Hypertension (SBP ≥140 mmHg or DBP ≥90 mmHg)
• Proteinuria (e.g. ≥300 mg/day or ≥1+ on dipstick)

It is the most common medical complication of pregnancy and poses risks to both mother and fetus. The condition may progress to eclampsia, defined by the occurrence of seizures.

The only definitive cure is delivery.

See also:

• Eclampsia
• HELLP syndrome

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Classification of Hypertensive Disorders of Pregnancy

1. Chronic Hypertension: Before 20 weeks gestation
2. Gestational Hypertension: After 20 weeks, no proteinuria, resolves postpartum
3. Pre-eclampsia/Eclampsia: After 20 weeks, with end-organ dysfunction
4. Pre-eclampsia Superimposed on Chronic Hypertension

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Pathophysiology

• Thought to be a placental disorder causing widespread endothelial dysfunction, vasospasm, and coagulopathy
• Vascular permeability increases, leading to third-space fluid loss and hypovolemia
• HELLP syndrome and DIC are advanced hematological complications

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Risk Factors

1. Age >40
2. History of pre-eclampsia, gestational hypertension, or multiple pregnancy
3. Chronic hypertension, renal disease, diabetes, thrombophilia
4. Obesity (BMI ≥35)
5. Family history

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Complications

• Neurological: Eclampsia, seizures, cerebral hemorrhage
• Renal: Acute kidney injury, oliguria
• Hepatic: Elevated enzymes, rupture
• Hematological: HELLP syndrome, DIC
• Respiratory: Pulmonary edema
• Fetal: IUGR, placental abruption, IUFD

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Clinical Features

• Diagnosis: Hypertension + Proteinuria after 20 weeks

Proteinuria definitions:

• ≥1+ on dipstick
• ≥300 mg/day
• Protein:Creatinine ratio >30 mg/mmol

Edema is not diagnostic but rapid development of facial/hand edema is suspicious.

Severity grading:

Severity	BP (mmHg)	Proteinuria	Symptoms	Biochemistry
Mild	≥140/90	None	None	Normal
Moderate	≥150/95	+1	None	Normal
Severe	≥160/110	+2	Maybe present	Abnormal
Imminent	≥160/110	+3	Present	Abnormal

Symptoms suggesting severe disease:

• Headache, visual disturbances, RUQ pain
• Clonus, hyperreflexia
• Drowsiness

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Differential Diagnoses

• Other hypertensive disorders of pregnancy (see classification above)

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Investigations

Bloods:

• FBE: Thrombocytopenia
• U&Es, Glucose: AKI
• LFTs: Elevated AST, bilirubin
• Coags: DIC indicators
• Uric acid: >0.35 mmol/L = abnormal

Urine:

• FWT
• MSU for M&C

CTG:

• Assess fetal wellbeing

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Management

General Nursing:

• Calm environment, left lateral position
• Monitor vitals closely
• Strict fluid balance

Monitoring:

• BP (non-invasive or arterial line)
• ECG, SpO2, CTG
• IDC (urine output ≥0.5 mL/kg/hr)

Antihypertensives:

• Indication: SBP ≥170 or DBP ≥110 mmHg
• Oral options:
  • Labetalol
  • Methyldopa
  • Nifedipine SR

Magnesium Sulphate:

• Prevents seizures in severe PET
• First-line treatment for eclampsia
• See Eclampsia document for dosing

Parenteral Antihypertensives:

• IV Labetalol (preferred)
• IV Hydralazine (for beta-blocker contraindication)

Delivery:

• Only definitive cure
• Indicated for severe PET or gestation >37 weeks
• Delivery mode and timing depend on maternal/fetal condition and patient preferences

Risks persist postpartum; complications may arise or worsen after delivery

Avoid Ergometrine. Syntocinon may be used.

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Disposition

• All cases must be discussed with Obstetrics
• Moderate/severe PET requires hospital admission
• Severe PET: Admit to HDU or Birthing Suite for close monitoring

Postpartum:

Assess for chronic hypertension and comorbidities

Counsel on recurrence risk

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References

FOAMed

• Nickson C. Pre-eclampsia and Eclampsia. CCC
• Nickson C. Eclampsia. CCC
• Hiller J, Yarwood L. Eclampsia. FFS
• Yarwood L, Hiller J. Pre-eclampsia. FFS
• Flower O. Emergency management of Pre-eclampsia. CODA

Publications

• Duley L, Meher S, Abalos E. Management of pre-eclampsia. BMJ. 2006 Feb 25;332(7539):463-8