What is the management of preterm pre eclampsia?

Management of Preterm Preeclampsia

For women with preterm preeclampsia before 37 weeks' gestation, expectant management with intensive maternal-fetal surveillance is recommended until 34 weeks or until maternal/fetal complications develop, at which point immediate delivery is indicated. 1

Patient Selection for Expectant Management

Expectant management is appropriate for carefully selected patients between 24-34 weeks' gestation who meet specific criteria:

• Blood pressure must be controllable with antihypertensive medications (not requiring 3 or more drug classes) 1
• Maternal laboratory values (platelets, liver enzymes, creatinine) must remain stable 1, 2
• Fetal biophysical profiles must remain reassuring 2
• No evidence of severe maternal complications (see absolute delivery indications below) 1

For gestations <24 weeks, expectant management carries high maternal morbidity with limited perinatal benefit and should generally be avoided. 3

Maternal Monitoring Protocol

Blood pressure monitoring and clinical assessments should follow this intensive schedule:

• Blood pressure checks at regular intervals with target to maintain systolic <160 mmHg and diastolic <110 mmHg 1
• Assessment for clonus and neurological symptoms (headache, visual scotomata) at each evaluation 1
• Laboratory testing at minimum twice weekly including: hemoglobin, platelet count, liver transaminases (AST/ALT), creatinine, and uric acid 1
• Repeated proteinuria assessments if not already documented 1

The uric acid level is particularly important as elevated levels are associated with worse maternal and fetal outcomes. 1

Fetal Surveillance

Serial fetal monitoring must include:

• Ultrasound assessment of fetal biometry, amniotic fluid volume, and umbilical artery Doppler studies 1
• Regular fetal biophysical profiles to assess fetal well-being 2
• Continuous or intermittent fetal heart rate monitoring as clinically indicated 1

Antihypertensive Management

For severe hypertension (≥160/110 mmHg), immediate treatment is required with first-line agents:

• Intravenous labetalol: 10-20 mg IV bolus, then 20-80 mg every 10 minutes to maximum 300 mg 1
• Intravenous hydralazine: 5 mg IV, then 5-10 mg every 20-30 minutes to maximum 30 mg (though associated with more maternal hypotension and requires closer monitoring) 1
• Oral nifedipine (immediate-release): 10-20 mg orally, repeat in 30 minutes if needed, though this carries risk of uncontrolled hypotension especially when combined with magnesium sulfate 1

For non-severe hypertension requiring maintenance therapy, use oral agents:

• Labetalol, nifedipine (long-acting), or methyldopa as first-line options 1

Seizure Prophylaxis

Magnesium sulfate should be administered for seizure prophylaxis in women with severe features or when delivery is planned: 1

• Loading dose: 4-5 g IV over 5-10 minutes, or combined regimen of 4 g IV plus 10 g IM (5 g in each buttock) 4
• Maintenance: 1-2 g/hour continuous IV infusion 4
• Monitoring: Assess deep tendon reflexes, respiratory rate (must be >12/min), and urine output (>100 mL over 4 hours) before each dose 4
• Therapeutic level: Target serum magnesium 4-7 mEq/L for seizure control 4

Critical warning: Continuous magnesium sulfate administration beyond 5-7 days causes fetal skeletal demineralization, osteopenia, and neonatal fractures. 4

Corticosteroids for Fetal Lung Maturity

Administer betamethasone or dexamethasone for fetal lung maturation if delivery is anticipated before 35 weeks' gestation. 1

• This improves neonatal respiratory outcomes in preterm delivery 1
• Multiple courses are not recommended 5

Absolute Indications for Delivery

Delivery must proceed immediately when any of the following develop, regardless of gestational age:

• Uncontrollable severe hypertension despite 3 classes of antihypertensive agents 1
• Progressive thrombocytopenia or HELLP syndrome 1
• Progressively abnormal liver enzymes or renal function tests 1
• Pulmonary edema 1
• Severe persistent headache, visual scotomata, or eclamptic seizures 1
• Placental abruption 1
• Nonreassuring fetal status 1
• Gestational age ≥37 weeks 1

At 34 weeks' gestation, delivery should be initiated as neonatal outcomes are favorable and maternal risks of expectant management increase. 1, 3

Expected Outcomes with Expectant Management

When properly selected, approximately two-thirds of women with severe preeclampsia before 34 weeks are candidates for expectant management. 2

• Mean pregnancy prolongation is typically 5-6 days 6
• Gestational age <30 weeks is the strongest predictor of adverse perinatal outcome 6
• Perinatal mortality with expectant management in selected cases is approximately 3-4% 6

Critical Pitfalls to Avoid

Do not use NSAIDs for analgesia in women with preeclampsia, especially those with renal dysfunction, placental abruption, or acute kidney injury, as they worsen renal function 1

Avoid combining magnesium sulfate with calcium channel blockers due to severe hypotension risk 5

Do not use diuretics as plasma volume is already reduced in preeclampsia 5

Sodium nitroprusside should only be used as last resort for extreme hypertensive emergencies due to fetal cyanide toxicity risk 1, 5

Setting Requirements

Expectant management of severe preeclampsia should only be performed at tertiary perinatal centers with 24-hour availability of maternal-fetal medicine specialists, neonatal intensive care, and immediate cesarean delivery capability. 2