🔑 Key Learning

  • Hypertension in pregnancy is defined as BP >140/90 mmHg, or a rise of 30 systolic / 15 diastolic.
  • Pre-eclampsia is diagnosed when hypertension is accompanied by proteinuria.
  • Aspirin 75–150 mg daily from 12 weeks is recommended in women with high or moderate risk factors for pre-eclampsia.
  • Labetalol is first-line treatment for BP >160/110 mmHg.
  • Magnesium sulfate is used in eclampsia and severe pre-eclampsia to prevent seizures.
  • The only definitive cure for pre-eclampsia is delivery.

🧬 Pathophysiology

  • Blood pressure usually decreases in early pregnancy, then rises again in the third trimester.
  • Pre-eclampsia involves abnormal placentation and systemic endothelial dysfunction.

📋 Diagnosis of Hypertension in Pregnancy

Hypertension is diagnosed if any of the following criteria are met:

  • BP ≥ 140/90 mmHg (either value)
  • Systolic BP rise ≥ 30 mmHg
  • Diastolic BP rise ≥ 15 mmHg

📂 Classification

1. Pre-existing Hypertension

  • Diagnosed prior to pregnancy or before 20 weeks gestation

2. Pregnancy-Induced Hypertension (PIH)

  • Diagnosed after 20 weeks gestation without proteinuria
  • Usually resolves post-partum

3. Pre-eclampsia

  • Hypertension after 20 weeks + Proteinuria (>0.3g/24h or ≥1+ on dipstick)
  • May be associated with oedema or systemic features

⚠️ Risk Factors for Pre-eclampsia

High Risk (any one = offer aspirin 75–150 mg from 12 weeks until delivery)

  • Hypertension in a previous pregnancy 
  • Chronic hypertension
  • Chronic kidney disease
  • Type 1 or 2 diabetes
  • Autoimmune disease (SLE or antiphospholipid syndrome)

Moderate Risk (2 or more = offer aspirin as above)

  • First pregnancy
  • Age ≥ 40 years
  • Pregnancy interval ≥ 10 years
  • BMI ≥ 35 kg/m²
  • Family history of pre-eclampsia
  • Multiple pregnancy

🧒 Complications

Foetal

  • Intrauterine growth restriction (IUGR)
  • Prematurity
  • Placental abruption

Maternal

  • Eclampsia (seizures)
  • Cerebral haemorrhage
  • HELLP syndrome
  • Heart failure
  • Multi-organ failure

🚨 Severe Pre-eclampsia

Pre-eclampsia is severe if any one of the following present:

  • BP > 170/110 mmHg
  • Significant proteinuria (++ or +++)
  • Headache
  • RUQ/epigastric pain
  • Visual disturbance
  • Hyperreflexia
  • Papilloedema
  • Blood markers
    • Platelets < 100 x10⁹/L
    • Elevated ALT/AST
    • Features of HELLP

💊 Management of Pre-eclampsia

  • Aspirin 75–150 mg from 12 weeks (if high/moderate risk)
  • Monitor BP and proteinuria
  • Delivery is the only cure

Antihypertensive therapy

If BP ≥ 160/110 mmHg:

  • 1st Line: Oral labetalol
  • Alternatives: Nifedipine or hydralazine

Severe pre-eclampsia

  • Start magnesium sulfate

⚡ Eclampsia

Defined as seizures in the setting of pre-eclampsia

Management

  • Magnesium sulfate 4 g IV bolus, followed by 1 g/hour infusion

🩸 HELLP Syndrome

A life-threatening complication defined by:

  • Haemolysis
  • Elevated Liver enzymes
  • Low Platelets

🔗 Useful Links and References