Epidemiology
- A 2024 systematic review of 36 U.S. samples (≈ 1.55 million pregnancies) estimated a pooled GDM prevalence of ≈ 8 %‑10 % .
- Recent CDC data show the rate rising from 6.0 % in 2016 to 7.8 % in 2021 , reflecting a clear upward trend.
Screening & diagnostic criteria
| Timing | Test | Positive threshold (IADPSG) |
|---|---|---|
| 24‑28 weeks (earlier for high‑risk) | 75 g OGTT (fasting, 1 h, 2 h) | Fasting ≥ 5.1 mmol/L; 1 h ≥ 10 mmol/L; 2 h ≥ 8.5 mmol/L |
| High‑risk (BMI ≥ 30, prior GDM, PCOS, family diabetes) | Same OGTT at 12‑16 weeks | Same thresholds |
First‑line lifestyle therapy
- Medical nutrition therapy – 30‑45 g carbohydrate per meal, distributed over 3‑5 meals, emphasizing low‑glycemic‑index foods, lean protein and healthy fats.
- Physical activity – 150 min/week of moderate‑intensity aerobic exercise (e.g., walking, stationary cycling) unless obstetric contraindications exist. Exercise improves insulin sensitivity and helps maintain gestational weight gain within guidelines .
- Self‑monitoring – Check fasting and 1‑hour post‑meal glucose 4‑6 times daily; target fasting 4.4‑5.5 mmol/L, post‑prandial < 7.8 mmol/L .
Pharmacologic escalation
- If diet + exercise fail to achieve targets after 1‑2 weeks, initiate insulin (short‑acting or basal‑bolus) – the only medication with unequivocal safety data in pregnancy .
- Oral agents (metformin, glyburide) may be considered when insulin is refused, but guidelines still recommend insulin as first line .
Monitoring & complication surveillance
- Fetal growth ultrasounds every 4‑6 weeks; watch for macrosomia (> 4 kg) and polyhydramnios.
- Maternal blood pressure & urine protein at each prenatal visit to detect pre‑eclampsia.
- Post‑delivery – Perform a 75 g OGTT at 6‑12 weeks postpartum to assess for persistent dysglycemia; ~50 % of women with GDM develop type 2 diabetes within 5 years .
Long‑term health promotion
- Enroll in a structured postpartum diabetes‑prevention program (dietary counseling, regular physical activity, weight‑loss support).
- Annual fasting glucose or HbA1c screening thereafter.
System‑level support
- The CDC’s “Gestational Diabetes” toolkit provides clinician checklists, patient handouts and culturally adapted educational videos .
- Insurance coverage for nutrition counseling and glucose monitoring devices is mandated under the Affordable Care Act’s preventive‑services provisions.
Take‑away – Early universal screening, intensive lifestyle modification, timely insulin therapy and coordinated obstetric‑endocrine follow‑up are essential to mitigate maternal and neonatal complications and to reduce the long‑term risk of type 2 diabetes.
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