If early screening in pregnancy is negative for GDM, when is glucose testing repeated?

• A. 12-16 weeks
• B. 24-28 weeks
• C. 32-36 weeks
• D. At delivery

Answer: (B)

Glucose intolerance from gestational diabetes tends to emerge as pregnancy progresses because placental hormones increase insulin resistance. If an early screen is negative, that doesn’t guarantee everything stays normal, since insulin resistance ramps up later in pregnancy. Testing around mid-pregnancy, roughly 24 to 28 weeks, catches those cases as they first become evident. If the test is positive, further diagnostic testing confirms the diagnosis and guides management. Testing earlier in the first trimester or right at delivery isn’t the standard window for detecting GDM.