Gestational diabetes screening test during pregnancy is best done at:

الشرح

Core Concept: Gestational Diabetes Mellitus (GDM) typically develops in the second or third trimester due to the diabetogenic effects of placental hormones (e.g., human placental lactogen) which peak and cause maximal insulin resistance between 24 and 28 weeks of gestation. Therefore, universal screening is optimally performed during this window.

Clinical Presentation:

• Often asymptomatic.
• Potential for polyuria, polydipsia, or macrosomia (large for gestational age fetus).

Diagnosis:

• First-line diagnostic plan: 1-hour 50g oral glucose challenge test (non-fasting) at 24-28 weeks.
• Most accurate (gold standard) test: If the screening test is abnormal, a 3-hour 100g oral glucose tolerance test (OGTT) or a 2-hour 75g OGTT to confirm the diagnosis.

Management:

• Acute management: Initiate medical nutrition therapy (dietary modifications) and blood glucose monitoring.
• Gold standard long-term management: If diet fails, start insulin or oral hypoglycemics. Monitor fetal growth via ultrasound to prevent macrosomia and shoulder dystocia. Postpartum follow-up with a 75g OGTT at 6-12 weeks.