In a lady of 32 weeks pregnancy injection dexa- methasone is to given to prevent:
Administration of dexamethasone before delivery:

– Reduces the incidence and severity of intraventricular hemorrhage
– Accelerates fetal lung maturation in preterm labour and prevents hyaline membrane disease.

It should be given atleast 24 hours before delivery.
Its effect lasts for 7 days therefore earlier it was said that repeat injections of betamethasone should be given weekly. Recent trials have shown that repeated injection lead to an increase in incidence of cerebral palsy therefore repeated injections are not given.
Steroid of choice for lung maturity is Betamethasone.
Dose = 2 doses of 12 mg of steroid (i.e., 3 ampules) are given i/m - 24 hours apart.

Adverse effects of Dexamethasone:
Respiratory distress syndrome
Neonatal convulsions
Neonatal jaundice
Cerebral palsy