Antenatal corticosteroids

Overview

Given to the mother in anticipated preterm birth to mature the fetal lungs — one of the highest-impact obstetric interventions (cross-references the corticosteroid class).

Mechanism

Maternally-administered betamethasone/dexamethasone cross the placenta and accelerate fetal type-II pneumocyte maturation and surfactant production → markedly reduced neonatal respiratory distress syndrome, intraventricular haemorrhage, necrotising enterocolitis and mortality. Two doses 12–24 h apart.

Indications

• Anticipated preterm birth 24⁺⁰–33⁺⁶ weeks (offer)
• Consider 34⁺⁰–35⁺⁶ weeks (and before elective caesarean <38⁺⁶)

Adverse effects

Cautions & contraindications

Interactions

• Steroid effect on glucose — coordinate diabetic control

Monitoring & kinetics

Maternal capillary glucose (esp. diabetes),Co-administer magnesium sulfate for neuroprotection if <30–34 weeks

IM, 2 doses 24 h apart; benefit greatest 24 h–7 days after the course.