Blog Post

Gestational Diabetes Mellitus (GDM) is diabetes that develops during pregnancy in women who did not have diabetes before. It affects approximately 10–15% of pregnancies in India — one of the highest rates globally. While it typically resolves after delivery, it requires careful management to prevent complications for both mother and baby.

Why Does Gestational Diabetes Develop?

During pregnancy, the placenta produces hormones that help the baby develop. These hormones also make the mother’s cells more resistant to insulin. In most women, the pancreas compensates by producing more insulin. When it cannot keep up, blood sugar levels rise, resulting in gestational diabetes.

Risk Factors

• Age over 25 years
• BMI over 25 kg/m² (overweight or obese)
• Family history of type 2 diabetes
• Previous GDM or large baby (over 4 kg)
• PCOS
• South Asian ethnicity (inherently higher risk)

Screening and Diagnosis

The Diabetes in Pregnancy Study Group India (DIPSI) recommends universal screening for all pregnant women using a 75g oral glucose tolerance test (OGTT). This is typically performed between 24–28 weeks of gestation, though women with risk factors may be tested earlier.

Diagnostic criteria: A 2-hour plasma glucose value of 140 mg/dL or above after a 75g glucose load (DIPSI criteria) confirms the diagnosis.

Potential Complications If Uncontrolled

For the baby:

• Macrosomia (large baby) — increasing risk of birth injuries and cesarean delivery
• Neonatal hypoglycemia (low blood sugar after birth)
• Respiratory distress syndrome
• Jaundice
• Higher risk of obesity and type 2 diabetes later in life

For the mother:

• Pre-eclampsia
• Increased likelihood of cesarean delivery
• Polyhydramnios (excess amniotic fluid)
• 50% risk of developing type 2 diabetes within 5–10 years postpartum

Management

Medical Nutrition Therapy (MNT): The cornerstone of GDM management. Key principles include distributing carbohydrates evenly across 3 meals and 2–3 snacks, choosing complex carbohydrates with low glycemic index, adequate protein intake, and avoiding sugary drinks and refined foods.

Physical Activity: Moderate exercise such as brisk walking for 30 minutes after meals significantly improves glucose control. Swimming and prenatal yoga are also excellent options.

Blood Sugar Monitoring: Self-monitoring of blood glucose (SMBG) — typically fasting and 2-hour post-meal values. Targets are fasting below 95 mg/dL and 2-hour postprandial below 120 mg/dL.

Insulin Therapy: If blood sugar targets are not met with diet and exercise within 1–2 weeks, insulin is the preferred pharmacological treatment during pregnancy. Metformin may be used as an alternative in selected cases.

After Delivery

Blood sugar typically normalizes after delivery, but a repeat OGTT at 6–12 weeks postpartum is essential to rule out persistent diabetes. Annual screening is recommended thereafter, along with lifestyle modifications to reduce the risk of developing type 2 diabetes.

With proper monitoring and management, women with gestational diabetes can have healthy pregnancies and healthy babies.