Do all women with preeclampsia at 30 weeks gestation require dexamethasone for fetal lung development?

Antenatal Corticosteroids for Women with Preeclampsia at 30 Weeks Gestation

All women with preeclampsia at 30 weeks gestation should receive dexamethasone for fetal lung maturation, as this significantly reduces neonatal respiratory distress syndrome and improves survival in very preterm infants. 1

Rationale for Corticosteroid Administration

Preeclampsia at 30 weeks represents a high-risk scenario that often necessitates preterm delivery due to maternal and/or fetal complications. The ISSHP guidelines clearly recommend antenatal corticosteroids for fetal lung maturation in preeclampsia cases where delivery before 34 weeks is anticipated 1.

Key considerations:

• At 30 weeks gestation, the fetus is at significant risk for respiratory distress syndrome
• Preeclampsia may require urgent delivery if maternal condition deteriorates
• Corticosteroids significantly reduce neonatal respiratory morbidity and mortality

Timing and Administration Protocol

Antenatal corticosteroids should be administered as soon as preeclampsia is diagnosed at 30 weeks, as the maternal condition may deteriorate rapidly, necessitating emergency delivery. The recommended regimen is:

• Dexamethasone 12 mg intramuscularly every 24 hours for 2 doses 2
• Maximum benefit occurs when delivery occurs between 24 hours and 7 days after administration

Maternal Safety Considerations

There is no evidence that corticosteroid administration worsens maternal outcomes in preeclampsia. A study specifically examining dexamethasone use in severe pregnancy-induced hypertension found no aggravation of hypertension in the treated patients 3.

Evidence of Benefit in Very Preterm Infants

Meta-analysis of controlled trials has demonstrated that maternal corticosteroid treatment significantly decreases respiratory distress syndrome incidence in infants born before 30 weeks gestation 4. Additionally:

• Corticosteroid exposure is associated with mature L/S ratios (≥2.7) in tracheal aspirates
• Prenatal glucocorticoid treatment markedly increases survival rates (odds ratio 2.4) 4
• The greatest benefit is seen in infants delivered between 31-34 weeks gestation 2

Management Algorithm for Preeclampsia at 30 Weeks

1. Confirm preeclampsia diagnosis - Hypertension with proteinuria or evidence of maternal organ dysfunction 1
2. Administer dexamethasone - 12 mg IM every 24 hours for 2 doses
3. Monitor maternal condition - BP monitoring, clinical assessment, and laboratory tests (hemoglobin, platelets, liver and renal function) at least twice weekly 1
4. Fetal assessment - Initial ultrasound for fetal biometry, amniotic fluid volume, and umbilical artery Doppler 1
5. Plan for delivery if any of the following develop:
   • Severe uncontrolled hypertension despite treatment
   • Progressive thrombocytopenia
   • Worsening liver or renal function
   • Pulmonary edema
   • Neurological complications
   • Non-reassuring fetal status 1

Additional Considerations

• Magnesium sulfate should be administered for seizure prophylaxis in women with preeclampsia who have proteinuria and severe hypertension or neurological symptoms 1
• Magnesium sulfate also provides fetal neuroprotection when administered before 32 weeks gestation 1
• Expectant management should be considered in stable preeclampsia between 30-34 weeks in facilities with appropriate maternal and neonatal care capabilities 1

Potential Pitfalls to Avoid

1. Delaying corticosteroid administration - Given the unpredictable course of preeclampsia, waiting could result in emergency delivery without the benefit of completed steroid therapy
2. Administering multiple courses - Repeated courses of antenatal corticosteroids are not recommended 1, 5
3. Failing to monitor for maternal complications - Close maternal surveillance is essential during corticosteroid administration
4. Overlooking fetal assessment - Regular fetal monitoring is crucial in preeclampsia management

In conclusion, dexamethasone administration for fetal lung maturation is a crucial intervention for all women with preeclampsia at 30 weeks gestation, as it significantly improves neonatal outcomes without increasing maternal risks.