Gestational diabetes is most commonly diagnosed in which period of pregnancy?

Gestational diabetes is most commonly diagnosed in which period of pregnancy?

• A. First trimester
• B. Second trimester
• C. Third trimester
• D. Postpartum

Answer: (C)

Gestational diabetes arises when insulin resistance, driven by placental hormones, increases as pregnancy progresses and the pancreas can’t keep up with the higher glucose demands. This resistance grows throughout the second and into the third trimester, peaking late in pregnancy. As glucose intolerance crosses diagnostic thresholds with that peak, most cases are identified in the third trimester. While screening is often done around 24–28 weeks (in the second trimester) to catch cases earlier, the condition is most commonly diagnosed later when insulin resistance is greatest. After delivery, the placental hormones vanish and glucose tolerance usually returns to normal, which is why postpartum testing is used separately. A diagnosis in the first trimester would more likely indicate preexisting diabetes.

Gestational diabetes arises when insulin resistance, driven by placental hormones, increases as pregnancy progresses and the pancreas can’t keep up with the higher glucose demands. This resistance grows throughout the second and into the third trimester, peaking late in pregnancy. As glucose intolerance crosses diagnostic thresholds with that peak, most cases are identified in the third trimester. While screening is often done around 24–28 weeks (in the second trimester) to catch cases earlier, the condition is most commonly diagnosed later when insulin resistance is greatest. After delivery, the placental hormones vanish and glucose tolerance usually returns to normal, which is why postpartum testing is used separately. A diagnosis in the first trimester would more likely indicate preexisting diabetes.