Gestational Diabetes — Clinical Management Protocol
Diagnosis
Source: OGSB, ACOG, NICE
GDM: Fasting plasma glucose: 5.1–6.9 mmol/L (92–125 mg/dL), 1-hour plasma glucose: ≥10.0 mmol/L (180 mg/dL), 2-hour plasma glucose: 8.5–11.0 mmol/L (153–199 mg/dL)
Diabetes in Pregnancy (DIP): Fasting plasma glucose: ≥7.0 mmol/L (126 mg/dL), 2-hour plasma glucose: ≥11.1 mmol/L (200 mg/dL), Random plasma glucose: ≥11.1 mmol/L (200 mg/dL) + symptoms
Screening
All pregnant women at booking; rescreen at 24–28 weeks if normal initially. High-risk women: rescreen at 34–36 weeks. Risk factors: previous GDM, prediabetes, age ≥35, BMI ≥23, PCOS, steroid use, macrosomia, family history, acanthosis nigricans.
Management
Lifestyle Management: Moderate aerobic exercise: 30 min/day, 3–4 times/week.
Medical Nutrition Therapy (MNT): 3 meals + 3 snacks daily. Caloric needs: Normal BMI: 30–38 kcal/kg/day; Overweight: 25–30 kcal/kg/day; Obese: 30–33% calorie restriction; Underweight: 35–40 kcal/kg/day. Calorie distribution: Breakfast 10–15%, Lunch 20–30%, Dinner 30–40%, Snacks 0–10%. Macronutrients: Carbohydrates 40–50% (complex), Protein 20%, Fat 30–40%.
Pharmacologic Therapy: If uncontrolled after 1–2 weeks of MNT → Insulin. Insulin dosing: 1st trimester: 0.8 U/kg/day; 2nd trimester: 1.0 U/kg/day; 3rd trimester: 1.2 U/kg/day. Regimens: Regular insulin before meals; or Mixtard 70/30. Metformin may be considered per local guidance if insulin is not acceptable. Glyburide is not preferred.
Glycemic Targets: Preprandial: <5.3 mmol/L, 1-hour postprandial: <7.8 mmol/L, 2-hour postprandial: <6.7 mmol/L, Self-monitoring: at least 4 times/day (fasting + 2h after meals).
Antenatal Care
Well-controlled GDM: routine ANC. Uncontrolled/complicated: 2-weekly in 2nd trimester, weekly in 3rd trimester. Fetal scans: anomaly scan 18–22 wks, fetal echocardiogram 24–26 wks. Fetal movement count monitoring for risk of IUD. Delivery planning: Well-controlled on MNT → term delivery; On insulin → refer to higher centre for monitoring during labour, insulin therapy, and neonatal management.
Care During Labour
Induction in early morning. Blood glucose monitoring: On MNT: every 4–6 hrs; On insulin: hourly. Target glycemia: 4–7 mmol/L. May need insulin + 5% dextrose infusion. Analgesia: epidural if available.
Care During Caesarean Section
Plan elective CS in morning. Continue night insulin; withhold morning dose. Hourly BG monitoring. Avoid hyperglycemia to reduce neonatal hypoglycemia risk. Optimize glycemic control perioperatively.
Neonatal Care
Ensure neonatologist/pediatrician presence if available. Start feeds within 30 min of birth; continue every 2–3 hrs. Maintain pre-feed glucose ≥2.0 mmol/L. If <2.0 mmol/L twice, or feeding issues → tube feeds/IV dextrose.
Postnatal Care
Women with GDM: Test for persistent diabetes at 4–12 weeks postpartum with OGTT. Lifestyle advice: diet, exercise, weight management. Annual diabetes screening if normal. Early screening/self-monitoring in future pregnancies. Safe medicines during breastfeeding: continue metformin or insulin, avoid statins, ACEi/ARBs.
International Guideline Highlights
NICE: Screen women with risk factors. Target glucose: fasting ≤5.3 mmol/L; 1h post-meal ≤7.8 mmol/L; 2h post-meal ≤6.4 mmol/L. Management: diet + exercise; if uncontrolled → Metformin or insulin. Antenatal care: joint diabetes + ANC clinic, fetal scans 20, 28, 32, 36 weeks. Delivery: GDM no later than 40+6 weeks; type 1/2 diabetes 37–38+6 weeks. Neonatal care: early feeding, monitor glucose, watch for macrosomia & RDS.
ACOG: Classification: A1 (diet only), A2 (requires medication). Screening: 2-step approach at 24–28 weeks. Early screening for high-risk women (BMI ≥25, prior GDM, strong family history, prediabetes). Glucose targets: Fasting <5.3 mmol/L; 1h <7.8 mmol/L; 2h <6.7 mmol/L. Diet: 3 meals + 2 snacks; exercise 150 min/week. Pharmacologic: Insulin preferred; short-acting analogues recommended. Fetal monitoring: start 32 weeks if A2 GDM or poor control. Timing of delivery: controlled on diet 39–40+6 weeks; controlled on meds 39–39+6 weeks; poorly controlled 37–38+6 weeks; consider CS if EFW ≥4500 g.
References
- Standard clinical management protocols and flowcharts on emergency obstetric and neonatal care 2019, OGSB
- Diabetes in pregnancy: management from preconception to the postnatal period
- ACOG Guidance: Gestational Diabetes Mellitus (GDM) Management
Compiled By:
Dr. Taslima Akter
Contributors
- Prof Fawzia Hossain
- Prof Tabassum Parveen
- Dr Rashida Begum
- Dr Umme Rumman
- Dr Fahmida Rashid Swati
- Dr Farhana Kalam
- Dr Afsana Akter
- Dr Wahida Zannat
- Dr Zakia Yashmin
- Dr Abir Anwarul Hoque
- Dr Rafaa Islam
- Dr Kaniz Fatema Bristy
- Dr Asma Akter Sonia
- Dr Shroddha Nivedita Paul
- Dr Shanjida Kabir