What is the recommended treatment for a pregnant primigravida (first-time mother) at 31 weeks gestation with mild preeclampsia to promote fetal lung maturity?

Antenatal Corticosteroid Therapy for Pregnant Primigravida at 31 Weeks with Mild Preeclampsia

Antenatal corticosteroids are strongly recommended for your pregnancy at 31 weeks with mild preeclampsia to reduce neonatal respiratory morbidity and mortality. 1, 2

Benefits of Antenatal Corticosteroids

• Reduces risk of neonatal respiratory distress syndrome by approximately 29% 3
• Decreases neonatal death risk by 22% 3
• Reduces perinatal death risk by 15% 3
• Lowers risk of intraventricular hemorrhage by 42% 3
• May reduce developmental delay in childhood by 49% 3

Recommended Regimen

The recommended dosing regimens are:

• Betamethasone: 12 mg intramuscular, two doses separated by 24 hours (total dose: 24 mg)
• OR
• Dexamethasone: 6 mg administered intramuscularly every 12 hours for a total of 4 doses (24 mg total) 1

Timing and Effectiveness

• Benefits begin to appear within the first 24 hours after administration
• Maximum benefit occurs between 48 hours to 7 days after administration
• Reduces severe respiratory morbidity by 33% 1
• Benefits diminish but remain present beyond 7 days 1

Special Considerations for Preeclampsia

• In cases of preeclampsia, corticosteroids are particularly important if delivery is expected before 35 weeks 1
• The Society for Maternal-Fetal Medicine and American College of Obstetricians and Gynecologists support administration of antenatal corticosteroids for pregnancies at risk of preterm delivery 1
• Delivery decisions should be based on maternal and fetal status, not delayed solely to complete steroid course 2

Potential Side Effects

• Maternal: Transient hyperglycemia, increased risk of infection
• Neonatal: Mild and self-limited hypoglycemia (more significant in diabetic pregnancies) 1

Important Monitoring Considerations

• Fetal monitoring should include assessment of fetal biometry, amniotic fluid, and umbilical artery Doppler 2
• Maternal monitoring should include blood pressure monitoring, clinical assessment, and blood tests for hemoglobin, platelet count, liver enzymes, creatinine, and uric acid 2
• If delivery is planned before 32 weeks, magnesium sulfate for fetal neuroprotection should also be administered 2

Decision Algorithm

1. Confirm gestational age is 31 weeks
2. Verify diagnosis of mild preeclampsia
3. Assess likelihood of preterm delivery within 7 days
4. Administer full course of antenatal corticosteroids if delivery is anticipated
5. Do not delay medically indicated delivery to complete steroid course
6. Monitor maternal and fetal status closely during and after administration

By consenting to antenatal corticosteroid therapy, you are providing your baby with the best chance of reduced respiratory complications and improved survival if preterm delivery occurs.