Timing of Delivery in Preeclampsia
Women with preeclampsia at ≥37 weeks' gestation should be delivered immediately, while those between 34-37 weeks can be managed expectantly unless severe features develop, and those <34 weeks require conservative management at a maternal-fetal medicine center with delivery indicated only for specific maternal or fetal complications. 1
Delivery Timing by Gestational Age
At or After 37 Weeks
- Deliver all women with preeclampsia at ≥37 weeks' gestation regardless of severity. 1, 2, 1
- This recommendation applies even without severe features, as maternal benefits outweigh risks of continued pregnancy at term. 2
Between 34-37 Weeks
- Manage with expectant conservative approach unless severe features or complications develop. 1
- For preeclampsia with severe features at ≥34 weeks, delivery is recommended. 2
- Recent meta-analysis data (1,790 participants) shows planned delivery from 34 weeks reduces maternal morbidity (2.6% vs 4.4%; adjusted RR 0.59) with acceptable neonatal outcomes. 3
Less Than 34 Weeks
- Conservative (expectant) management at a center with Maternal-Fetal Medicine expertise is recommended. 1
- Median pregnancy prolongation is typically 2-3 days even with expectant management. 4, 5
- This approach improves neonatal outcomes in carefully selected patients. 6
At Limits of Viability (<24 Weeks)
- Counsel patients that termination of pregnancy may be required. 1
- Expectant treatment at <24 weeks is associated with high maternal morbidity with limited perinatal benefit. 6
Immediate Delivery Indications (Any Gestational Age)
Deliver immediately when any of the following develop, regardless of gestational age: 1
Maternal Indications
- Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses 1
- Maternal pulse oximetry <90% 1
- Progressive deterioration in liver function, creatinine, hemolysis, or platelet count 1
- Progressive thrombocytopenia 1
- Ongoing neurological features: severe intractable headache, repeated visual scotomata, or eclampsia 1
- Pulmonary edema 1
Fetal Indications
- Placental abruption 1
- Reversed end-diastolic flow in umbilical artery Doppler velocimetry 1
- Nonreassuring cardiotocograph 1
- Stillbirth 1
Critical Management Principles
Severity Assessment
- Do not attempt to diagnose "mild" versus "severe" preeclampsia clinically, as all cases may become emergencies rapidly. 1
- BP level alone is not a reliable way to stratify immediate risk—some women develop serious organ dysfunction at relatively mild BP levels. 1
- Women ineligible for expectant management have a 5-fold increased risk of maternal morbidity, confirming the need for delivery without delay. 7
What NOT to Use for Delivery Decisions
- Neither serum uric acid nor level of proteinuria should be used as indications for delivery. 1
Special Considerations for HELLP Syndrome and Eclampsia
- When HELLP syndrome or eclampsia are suspected, expeditious delivery is recommended after maternal stabilization. 2
- Delivery for eclampsia should occur as soon as possible after maternal stabilization, regardless of gestational age. 2
Monitoring During Expectant Management
- Maternal monitoring should include BP monitoring, repeated proteinuria assessments, clinical assessment including clonus, and twice-weekly blood tests (hemoglobin, platelets, liver transaminases, creatinine, uric acid). 1
- Fetal monitoring should include biometry, amniotic fluid, and umbilical artery Doppler at diagnosis, then every 2 weeks if normal (more frequently with growth restriction). 1
Common Pitfalls
Avoid these errors:
- Waiting for "severe" features to develop before planning delivery at ≥37 weeks—all preeclampsia warrants delivery at term. 1
- Using proteinuria levels or uric acid to time delivery—these do not predict outcomes. 1
- Assuming stable BP means stable disease—organ dysfunction can occur at relatively mild hypertension levels. 1
- Attempting prolonged expectant management <34 weeks outside a maternal-fetal medicine center. 1