**Question:** Which can be used in pregnancy -

A. Aspirin
B. Insulin
C. Metformin
D. Glucocorticoids

**Core Concept:** Medications used during pregnancy should be carefully chosen due to the potential risks to the fetus.

**Why the Correct Answer is Right:** Glucocorticoids are used in pregnancy to prevent preterm labor. They work by reducing inflammation and stimulating lung maturation in the fetus, reducing the risk of respiratory distress syndrome.

**Why Each Wrong Option is Incorrect:**

A. Aspirin: Although used for secondary prevention of cardiovascular events, it can increase the risk of bleeding and is contraindicated in pregnancy due to potential harm to the fetus.
B. Insulin: Used for diabetes mellitus management, insulin is essential in pregnancy to control blood glucose levels; however, it is not a medication specifically indicated for pregnancy.
C. Metformin: Used in gestational diabetes management, metformin carries a higher risk for birth defects compared to insulin. Therefore, insulin is preferred in pregnancy.

**Clinical Pearl:** When choosing medications in pregnancy, consider the specific indication, potential risks, and benefits to both the mother and the fetus. Insulin is preferred over metformin due to the lower risk of birth defects.

**Correct Answer:** D. Glucocorticoids