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Hypertensive Disorders of Pregnancy: MCCQE Notes

Preeclampsia no longer requires proteinuria, magnesium is for seizures rather than blood pressure, and delivery is the only cure.

MCCQEObstetrics & Gynaecology6 min read

The four categories

  • Chronic hypertension — present before pregnancy or before 20 weeks
  • Gestational hypertension — new after 20 weeks, no proteinuria or end-organ features
  • Preeclampsia — new hypertension after 20 weeks plus proteinuria or end-organ dysfunction
  • Chronic hypertension with superimposed preeclampsia

Preeclampsia does not need proteinuria

The modern definition accepts hypertension after 20 weeks with any of:

  • Proteinuria (≥ 0.3 g/24 h, or urine protein-to-creatinine ratio ≥ 30 mg/mmol)
  • Platelets < 100
  • Creatinine rising, or > 90–100 µmol/L
  • Transaminases twice normal
  • Pulmonary oedema
  • New cerebral or visual symptoms — headache, scotomata, blurred vision
  • Severe persistent right upper quadrant or epigastric pain

Severe features: systolic ≥ 160 or diastolic ≥ 110, plus any of the above.

Treatment of the blood pressure

Antihypertensives prevent maternal stroke; they do not treat preeclampsia.

  • Acute severe hypertension: IV labetalol, oral or IV hydralazine, or oral nifedipine
  • Maintenance: labetalol, nifedipine, methyldopa
  • Contraindicated: ACE inhibitors, ARBs, and direct renin inhibitors — fetal renal damage and oligohydramnios

Magnesium sulphate

For seizure prophylaxis and treatment, not for blood pressure. Give it in preeclampsia with severe features and in eclampsia.

Monitor for toxicity by clinical examination: loss of deep tendon reflexes first, then respiratory depression, then cardiac arrest. Treat with calcium gluconate. Magnesium is renally cleared, so reduce the dose in renal impairment.

Magnesium also provides fetal neuroprotection when given before preterm delivery.

Delivery is the only cure

  • ≥ 37 weeks with preeclampsia → deliver
  • Severe features at ≥ 34 weeks → deliver
  • < 34 weeks, stable → expectant management in a tertiary centre with corticosteroids for fetal lung maturity
  • Deliver regardless of gestation for: eclampsia, pulmonary oedema, uncontrollable hypertension, placental abruption, DIC, non-reassuring fetal status, HELLP with deterioration

Preeclampsia can present or worsen postpartum, usually within 48 hours but up to 6 weeks. Do not discount it because the baby has been delivered.

HELLP

Haemolysis, Elevated Liver enzymes, Low Platelets. May occur without marked hypertension. Complications include hepatic haematoma and rupture, DIC and abruption. Management is delivery, magnesium and supportive care.

Prevention

Low-dose aspirin from 12–16 weeks for women at high risk: previous preeclampsia, chronic hypertension, pregestational diabetes, chronic kidney disease, autoimmune disease, multiple pregnancy. Calcium supplementation where dietary intake is low.

Preeclampsia is a lifelong cardiovascular risk marker — long-term follow-up belongs in the answer.

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