The dose of betamethasone in prenatal to prevent respiratory distress syndrome is –
**Core Concept**
Betamethasone is a corticosteroid used to accelerate fetal lung maturation and prevent respiratory distress syndrome (RDS) in preterm infants. It acts by stimulating the production of surfactant in the fetal lungs.
**Why the Correct Answer is Right**
Betamethasone is administered to pregnant women at risk of preterm delivery to enhance fetal lung maturation. The recommended dose is 12 mg intramuscularly, given as two 6 mg injections 24 hours apart. This dose stimulates the production of surfactant, reducing the risk of RDS and improving neonatal outcomes. The exact mechanism involves the activation of the glucocorticoid receptor, which upregulates the expression of surfactant protein genes.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as the dose is too low to effectively stimulate fetal lung maturation.
**Option B:** This option is incorrect as the dose is too high, increasing the risk of maternal side effects without providing additional benefit.
**Option C:** This option is incorrect as it does not specify the correct dose or administration schedule.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that betamethasone should be administered 24 hours apart to maximize its effectiveness in preventing RDS.
**Correct Answer: D. 12 mg, given as two 6 mg injections 24 hours apart.**