What is gestational diabetes mellitus (GDM)?

• A. A form of glucose intolerance first recognized during pregnancy arising from pregnancy-related insulin resistance.
• B. A chronic condition unrelated to pregnancy.
• C. Diabetes caused by autoimmune destruction of beta cells during pregnancy.
• D. A temporary condition that resolves before delivery without any monitoring.

Answer: (A)

Gestational diabetes mellitus is a form of glucose intolerance first recognized during pregnancy, arising from pregnancy-related insulin resistance. During pregnancy, hormones such as human placental lactogen, estrogen, progesterone, and cortisol increase insulin resistance to support fetal growth. If the pancreas cannot produce enough insulin to overcome this resistance, blood glucose rises and gestational diabetes develops.

This definition distinguishes it from chronic diabetes that exists outside pregnancy, from autoimmune destruction of beta cells (as seen in type 1 diabetes), and from a condition that would simply resolve without any need for monitoring. Even though GDM often improves after delivery, it requires appropriate management during pregnancy and postpartum glucose testing because it signals an elevated risk of diabetes in the future and needs careful follow-up.