What are the clinical features and management of preeclampsia?

Clinical Features and Management of Preeclampsia

Preeclampsia is a life-threatening hypertensive disorder of pregnancy requiring prompt diagnosis and management to reduce maternal and fetal morbidity and mortality. 1

Definition and Epidemiology

• Preeclampsia is diagnosed by new-onset hypertension (>20 weeks of gestation) with at least one other associated complication, including proteinuria, maternal organ dysfunction, or uteroplacental dysfunction 1
• It affects 2-8% of pregnancies globally, with incidence increasing by approximately 25% between 1987 and 2004 2, 3
• Hypertensive disorders are responsible for 14% of maternal deaths worldwide, representing the second most common cause of direct maternal deaths 2
• In the United States, hypertensive disorders of pregnancy account for 7.8% of maternal deaths 2

Risk Factors

• Prepregnancy overweight and obesity 2
• Diabetes mellitus 2
• Multiple births 2
• Advanced maternal age 2
• Prior preeclampsia 2
• Chronic hypertension 2
• Mental health disorders 2
• Sleep-disordered breathing 2
• Black women are at increased risk of hypertensive disorders of pregnancy with higher associated morbidity and mortality 2

Clinical Features

Maternal Manifestations

• Hypertension (BP ≥140/90 mmHg) 2
• Proteinuria (protein/creatinine ratio ≥30 mg/mmol or 0.3 mg/mg) 2
• Neurological symptoms:
  • Severe headache 4
  • Visual disturbances/scotomata 4
  • Hyperreflexia with clonus 2
  • Seizures (eclampsia) 2
• Hepatic involvement:
  • Elevated liver enzymes 2
  • Epigastric/right upper quadrant pain 4
• Renal dysfunction:
  • Elevated creatinine 2
  • Elevated uric acid 2
• Hematological abnormalities:
  • Thrombocytopenia 2
  • Hemolysis 2
• Pulmonary edema 2

Fetal Manifestations

• Fetal growth restriction 2
• Abnormal amniotic fluid volume 2
• Abnormal umbilical artery Doppler findings 2
• Increased risk of preterm birth 1

Management

Prevention

• Low-dose aspirin (75-162 mg/day) is recommended for women with strong clinical risk factors for preeclampsia 2
• Treatment should ideally begin before 16 weeks but definitely before 20 weeks gestation 2

Monitoring in Preeclampsia

Maternal Monitoring

• Blood pressure monitoring at regular intervals 2
• Clinical assessment including testing for clonus 2
• Laboratory tests at least twice weekly:
  • Hemoglobin 2
  • Platelet count 2
  • Liver transaminases 2
  • Creatinine 2
  • Uric acid 2
• Repeated assessments for proteinuria if not already present 2

Fetal Monitoring

• Initial assessment of fetal well-being 2
• Ultrasound assessment of fetal biometry 2
• Amniotic fluid assessment 2
• Umbilical artery Doppler studies 2
• Follow-up ultrasounds every 2 weeks if initial assessment normal 2
• More frequent monitoring in the presence of fetal growth restriction 2

Antihypertensive Management

• Urgent treatment is required for severe hypertension (>160/110 mmHg) in a monitored setting 2
• First-line agents for severe hypertension:
  • Oral nifedipine 2
  • Intravenous labetalol 2
  • Intravenous hydralazine 2
• For non-severe hypertension (≥140/90 mmHg):
  • Target diastolic BP of 85 mmHg and systolic BP of 110-140 mmHg 2
  • First-line agents: oral methyldopa, labetalol, oxprenolol, nifedipine 2
  • Second/third-line agents: hydralazine, prazosin 2
• Reduce or discontinue antihypertensive drugs if diastolic BP falls <80 mmHg 2

Seizure Prophylaxis

• Magnesium sulfate is indicated for women with preeclampsia who have:
  • Proteinuria and severe hypertension 2
  • Hypertension with neurological signs or symptoms 2
• Monitoring during magnesium sulfate administration:
  • Presence of patellar reflexes 5
  • Respiratory rate (should be ≥16 breaths/min) 5
  • Urine output (maintain at ≥100 mL over 4 hours preceding each dose) 5
  • Serum magnesium levels (therapeutic range: 3-6 mg/100 mL or 2.5-5 mEq/L) 5
• Injectable calcium should be immediately available to counteract magnesium toxicity 5

Delivery Considerations

• Delivery is the only definitive treatment for preeclampsia 3
• Indications for delivery include:
  • Gestational age ≥37 weeks 2
  • Uncontrollable severe hypertension despite treatment with 3 classes of antihypertensives 2
  • Progressive thrombocytopenia 2
  • Progressive abnormal renal or liver function tests 2
  • Pulmonary edema 2
  • Abnormal neurological features (severe headache, visual scotomata, seizures) 2
  • Placental abruption 2
  • Non-reassuring fetal status 2
  • Reversed end-diastolic flow in umbilical artery Doppler 2
• For preeclampsia diagnosed at <34 weeks, conservative management at a center with maternal-fetal medicine expertise is recommended 2
• For preeclampsia at the limits of viability (generally <24 weeks), termination of pregnancy may be required 2

Postpartum Management

• Blood pressure monitoring at least 4-6 hourly during the day for at least 3 days postpartum 4
• Women should not be discharged early (before 24 hours) 4
• Women requiring antihypertensive medications at discharge should be reviewed within 1 week 4
• Antihypertensive medications should be continued after delivery and tapered slowly only after days 3-6 postpartum 4
• Follow-up visits at 7-14 days and 6 weeks postpartum 4
• All women should be reviewed at 3 months postpartum 4
• Persistent abnormalities at 3 months require further investigation 4

Long-term Considerations

• Women with a history of preeclampsia have increased risks of:
  • Cardiovascular disease 1
  • Stroke 1
  • Diabetes 1
  • Reduced life expectancy 1
• All women with preeclampsia require lifelong follow-up due to increased cardiovascular risk 4
• Regular monitoring of blood pressure, fasting lipids, and blood sugar is recommended 4
• Risk of recurrence in future pregnancies: approximately 4% risk for developing preeclampsia and 25% risk for gestational hypertension 4