A 32-year-old primigravida at 28 weeks gestation presents with vaginal bleeding and uterine contractions. Fetal heart rate is 140 bpm. She is counselled about preterm labor and the role of antenatal corticosteroids. Which of the following statements about antenatal corticosteroids in preterm labor is NOT true?

Explanation

## Antenatal Corticosteroids in Preterm Labor ### Mechanism & Efficacy **Key Point:** Antenatal corticosteroids (betamethasone 12 mg IM × 2 doses 24 hours apart, or dexamethasone 6 mg IM × 4 doses 12 hours apart) are the standard of care for threatened preterm delivery between 24 and 34 weeks gestation. **High-Yield:** Corticosteroids reduce: - Neonatal respiratory distress syndrome (RDS) by ~30–40% - Intraventricular hemorrhage (IVH) by ~50% - Neonatal mortality by ~30% ### Timing & Dosing **Clinical Pearl:** Maximum neuroprotective and respiratory benefit occurs when delivery happens **within 7 days** of the first dose. Efficacy wanes after 7 days, but some benefit persists up to 14 days. **Mnemonic:** **BEST** = **B**etamethasone, **E**fficacy within **S**even days, **T**wo doses 24 hours apart. ### Maternal Infection: NOT a Contraindication **Key Point:** Maternal infection (including chorioamnionitis, UTI, or suspected infection) is **NOT** a contraindication to antenatal corticosteroids. In fact, corticosteroids may be given even when infection is present, as the fetal benefit outweighs maternal risk in preterm labor. **Warning:** This is a common exam trap — students often confuse "immunosuppression" with absolute contraindication. Corticosteroids are safe and indicated in preterm labor regardless of maternal infection status. ### Repeat Courses **High-Yield:** A single course is recommended. Repeat courses ("rescue" corticosteroids) are associated with: - Reduced birth weight - Smaller head circumference - Increased neonatal morbidity - No additional benefit over single course **Current guideline:** Single course is standard; repeat dosing is NOT recommended. ### Summary Table | Aspect | Correct Statement | |--------|-------------------| | Efficacy | Reduces RDS by 30–40%, IVH by 50% | | Timing | Maximum benefit within 7 days | | Infection | NOT a contraindication | | Repeat courses | Not recommended; single course only | | Gestational age | 24–34 weeks (some benefit up to 36+6 weeks) | **The incorrect statement:** "Antenatal corticosteroids are contraindicated if maternal infection is suspected" — this is FALSE. Corticosteroids are indicated even with infection.