What are the guidelines for delivery in preeclampsia?

Guidelines for Delivery in Preeclampsia

Delivery timing in preeclampsia should be based primarily on gestational age and the presence of maternal or fetal complications, with immediate delivery indicated at ≥37 weeks' gestation and for any severe features regardless of gestational age. 1

Gestational Age-Based Delivery Guidelines

• ≥37 weeks' gestation: Immediate delivery is recommended for all women with preeclampsia 1
• 34-37 weeks' gestation: Expectant management with close monitoring is appropriate in the absence of severe features 1
• <34 weeks' gestation: Conservative (expectant) management at a center with Maternal and Fetal Medicine expertise is recommended when maternal and fetal conditions are stable 1
• <24 weeks' gestation (limits of viability): Counseling about possible pregnancy termination should be provided due to high maternal risks and poor fetal outcomes 1

Indications for Immediate Delivery Regardless of Gestational Age

Delivery is necessary when any of the following conditions develop 1:

• Uncontrolled severe hypertension despite using ≥3 classes of antihypertensives in appropriate doses 1
• Maternal pulse oximetry <90% 1
• Progressive deterioration in liver function, creatinine, hemolysis, or platelet count 1
• Ongoing neurological features (severe intractable headache, repeated visual scotomata, eclampsia) 1
• Pulmonary edema 1
• Placental abruption 1
• Non-reassuring fetal status or reversed end-diastolic flow in umbilical artery Doppler 1

Management During Expectant Approach

Maternal Monitoring

• Blood pressure monitoring 1
• Repeated assessments for proteinuria if not already present 1
• Clinical assessment including clonus 1
• Twice weekly blood tests for hemoglobin, platelet count, liver enzymes, creatinine, and uric acid 1
• MgSO₄ for seizure prophylaxis in women with severe hypertension or neurological symptoms 1, 2

Fetal Monitoring

• Initial assessment of fetal biometry, amniotic fluid, and umbilical artery Doppler 1
• Follow-up ultrasound every 2 weeks if initial assessment was normal 1
• More frequent monitoring in the presence of fetal growth restriction 1

Special Considerations

Preeclampsia with Severe Features at 34-37 Weeks

• The American Association for the Study of Liver Diseases recommends delivery at 34 weeks for preeclampsia with severe features 1
• This differs slightly from ISSHP guidelines which allow for individualized assessment between 34-37 weeks 1

HELLP Syndrome

• Expeditious delivery after maternal stabilization is recommended when HELLP syndrome develops 1
• Abdominal imaging should be performed to rule out hepatic complications 1

Magnesium Sulfate Administration

• For severe preeclampsia or eclampsia, the total initial dose is 10-14g of magnesium sulfate 2
• Intravenously, 4-5g in 250mL of appropriate solution may be infused 2
• Therapy should continue until paroxysms cease, with a serum magnesium level of 6 mg/100mL considered optimal for seizure control 2
• Total daily dose should not exceed 30-40g 2

Important Caveats

• Do not attempt to classify preeclampsia as mild versus severe clinically, as all cases may rapidly progress to emergencies 1
• Neither serum uric acid nor the level of proteinuria should be used as an indication for delivery 1
• The level of blood pressure alone is not a reliable way to stratify immediate risk, as serious organ dysfunction can develop at relatively mild levels of hypertension 1
• Plasma volume expansion is not recommended routinely in women with preeclampsia 1
• Between 24-34 weeks, antenatal corticosteroids should be administered to promote fetal lung maturity before delivery 3