GDM is screened during which gestational window?

• A. 8-12 weeks
• B. 16-20 weeks
• C. 24-28 weeks
• D. 32-36 weeks

Answer: (C)

Insulin resistance in pregnancy climbs as the placenta releases hormones, so glucose intolerance from gestational diabetes most often becomes detectable in the mid-second trimester. Screening around 24–28 weeks catches the majority of cases while still leaving time to start management that can reduce risks to both mother and baby. Testing earlier than this usually wouldn’t reveal GDM yet, and testing later wouldn’t give enough time to intervene and help prevent complications such as larger baby size, delivery difficulties, or neonatal issues. In practice, a screening test is done around this window, with a follow-up diagnostic test if the initial screen is abnormal.