What is the primary pathophysiologic driver of gestational diabetes?

• A. Genetic variants that have been identified as causes of diabetes in the general population
• B. Antibodies directed against specific beta cell antigens
• C. Increased insulin resistance in late gestation
• D. Significant decreases in insulin sensitivity with advancing gestation

Answer: (D)

The main idea is that gestational diabetes is driven by rising insulin resistance as pregnancy advances. Placental hormones (like early placental lactogen and others) make maternal tissues less responsive to insulin, and the pancreas must compensate by secreting more insulin. In those who develop gestational diabetes, the beta cells can’t increase insulin enough to overcome this resistance, so blood glucose becomes elevated. That progressive drop in insulin sensitivity with advancing gestation is the core pathophysiologic driver.

Autoimmune destruction of beta cells (antibodies) describes type 1 diabetes, not gestational diabetes. While genetic factors can influence overall diabetes risk, they don’t explain the pregnancy-specific insulin resistance that drives gestational diabetes.