**Core Concept**
Betamethasone, a synthetic corticosteroid, is administered to pregnant women at risk of preterm delivery to promote fetal lung maturation, reducing the risk of respiratory distress syndrome (RDS) in the newborn.

**Why the Correct Answer is Right**
Antenatal corticosteroids, such as betamethasone, stimulate the production of surfactant in the fetal lungs, a crucial component for reducing surface tension and preventing alveolar collapse. This effect is mediated through the induction of surfactant protein-A (SP-A) and the activation of the enzyme phospholipid transfer protein. The administration of betamethasone is most effective when given between 24 and 34 weeks of gestation.

**Why Each Wrong Option is Incorrect**
**Option A:** Not a contraindication for antenatal corticosteroids. In fact, women with a history of preterm labor are ideal candidates for antenatal corticosteroid therapy to promote fetal lung maturation.
**Option B:** Not a contraindication for antenatal corticosteroids. These steroids are often administered to women with multiple gestations to reduce the risk of RDS in both fetuses.
**Option C:** This option is correct. Antenatal corticosteroids should not be administered in cases of intrauterine growth restriction (IUGR) due to the potential for fetal compromise and the risk of exacerbating fetal growth restriction.

**Clinical Pearl / High-Yield Fact**
It's essential to note that antenatal corticosteroids should not be administered more than twice to the same patient, as the benefits of repeated courses are unclear and potential risks may outweigh the benefits.

**Correct Answer: C. Intrauterine growth restriction (IUGR)**