Dexamethasone is given to a pregnant woman at 28–34 weeks gestation for threatened preterm labor. The purpose is:

• A To suppress uterine contractions by reducing prostaglandin synthesis
• B To prevent neonatal hypoglycemia by stimulating hepatic glycogen synthesis
• C To accelerate fetal lung maturity by stimulating surfactant synthesis in type II pneumocytes, reducing risk of neonatal RDS ✓
• D To reduce fetal brain inflammation associated with preterm delivery

Explanation

Antenatal glucocorticoids (betamethasone or dexamethasone) are given between 24–34 weeks of gestation when preterm birth is expected within 7 days. They induce expression of surfactant proteins A, B, C, and D and phospholipids in fetal type II pneumocytes via glucocorticoid receptor-mediated transcription, accelerating lung maturation and dramatically reducing neonatal respiratory distress syndrome (RDS) incidence, as well as intraventricular hemorrhage and necrotizing enterocolitis. Betamethasone is preferred for antenatal use as it does not contain sulfite preservative.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.