Hypertension in Pregnancy ✅

🌸 Introduction

• Hypertension in pregnancy is defined as BP ≥140/90 mmHg.
• Do not use a rise from booking BP alone (for example +30 systolic or +15 diastolic) to diagnose hypertension.

🗂️ Classification of Hypertension in Pregnancy

• 💙 Chronic (pre-existing) hypertension:
  • Present before pregnancy, or first identified before 20 weeks.
  • May be essential or secondary hypertension.
  • Increases the risk of superimposed pre-eclampsia, fetal growth restriction, and preterm birth.
• 💛 Gestational hypertension:
  • New hypertension after 20 weeks of pregnancy.
  • No significant proteinuria and no features of pre-eclampsia at diagnosis.
  • Can progress to pre-eclampsia, so requires ongoing maternal and fetal surveillance.
• ❤️ Pre-eclampsia:
  • New hypertension after 20 weeks with signs of maternal organ dysfunction and/or placental dysfunction.
  • Often associated with significant proteinuria, but proteinuria should be interpreted in the context of the full clinical picture.
  • Proteinuria should be quantified with protein:creatinine ratio (PCR) or albumin:creatinine ratio (ACR); PCR ≥30 mg/mmol is significant.
  • May involve renal impairment, raised liver enzymes, thrombocytopenia, neurological symptoms, and fetal growth restriction.

⚠️ Symptoms of possible pre-eclampsia

Pregnant women should seek urgent assessment if they develop:

• 💥 Severe or persistent headache.
• 👀 Visual disturbance (blurred vision, flashing lights).
• ⚡ Severe epigastric or right upper quadrant pain.
• 🤢 Vomiting.
• 🫁 Sudden breathlessness or chest symptoms.
• 👶 Reduced fetal movements.
• 💧 Sudden swelling may occur, but is not diagnostic of pre-eclampsia.

💊 Aspirin prophylaxis

Offer aspirin 75–150 mg daily from 12 weeks until birth to women at increased risk of pre-eclampsia, unless contraindicated.

🟥 High risk factors

• Previous hypertensive disease during pregnancy.
• Chronic kidney disease.
• Autoimmune disease such as SLE or antiphospholipid syndrome.
• Type 1 or type 2 diabetes.
• Chronic hypertension.

🟨 Moderate risk factors

Offer aspirin if a woman has 2 or more moderate risk factors.

• First pregnancy.
• Age 40 years or over.
• Pregnancy interval more than 10 years.
• BMI ≥35 kg/m² at first visit.
• Family history of pre-eclampsia.
• Multi-fetal pregnancy.

🩺 Key management points

• Offer antihypertensive treatment if BP remains above 140/90 mmHg.
• Aim for a target BP of 135/85 mmHg once on treatment.
• Labetalol is first-line in most cases; consider nifedipine if labetalol is not suitable, and methyldopa if both are unsuitable.
• In gestational hypertension, arrange ultrasound assessment of fetal growth, amniotic fluid volume, and umbilical artery Dopplers at diagnosis and repeat every 2–4 weeks if normal and clinically indicated.
• Pre-eclampsia is cured only by delivery of the placenta, but timing balances maternal risk against fetal maturity.

📚 References

• NICE NG133: Hypertension in pregnancy: diagnosis and management
• NICE NG133 Recommendations
• NICE visual summary: aspirin for moderate/high risk of pre-eclampsia

Clinical cases

• 🤰 Case 1 – Age 28 (Gestational hypertension): At 32 weeks, BP 148/95 mmHg with no significant proteinuria and normal bloods. Diagnosis: Gestational hypertension. Management: Antihypertensive treatment if BP remains above threshold, close BP/protein surveillance, and fetal growth scanning. Teaching point: Gestational hypertension can evolve into pre-eclampsia, so follow-up matters as much as the initial label.
• 🩺 Case 2 – Age 35 (Pre-eclampsia): At 30 weeks with headache, visual disturbance, BP 170/110 mmHg, and significant proteinuria with abnormal LFTs. Diagnosis: Pre-eclampsia. Management: Hospital admission, antihypertensive treatment, magnesium sulfate if indicated, fetal assessment, and planning for delivery based on maternal and fetal status. Teaching point: Pre-eclampsia is a multisystem endothelial/placental disorder, not just hypertension plus protein in urine.
• 💊 Case 3 – Age 39 (Chronic hypertension): Known hypertension at booking, BP 142/92 mmHg at 10 weeks, normal urine. Management: Continue pregnancy-safe antihypertensive therapy and start aspirin from 12 weeks because chronic hypertension is a high-risk factor for pre-eclampsia. Teaching point: Women with chronic hypertension need prepregnancy or early pregnancy medication review, especially avoiding ACE inhibitors and ARBs.