Gestational Diabetes Mellitus: Indian (GOI) Guidelines
Screening Approach for Indian Population
The Diabetes In Pregnancy Study group India (DIPSI) recommends a single-step, non-fasting 75g oral glucose tolerance test (OGTT) for all pregnant women, with diagnosis made when the 2-hour plasma glucose is ≥140 mg/dL. 1
DIPSI Protocol (India-Specific)
Universal screening is essential for all Indian pregnant women due to the high prevalence of GDM in the Indian population, which reaches 23.3% in some studies. 1, 2
Perform a 75g OGTT as soon as the pregnant woman arrives at the antenatal clinic – even if she is in a fasting state – and measure venous plasma glucose at 2 hours. 1
Diagnosis is made when the 2-hour plasma glucose value is ≥140 mg/dL (7.8 mmol/L). 1
Screening is recommended between 24 and 28 weeks of gestation, though evidence shows that 38.7% of Indian women develop GDM before 24 weeks, supporting earlier screening. 1, 3
Rationale for DIPSI Approach
This one-step procedure is simple, economical, and feasible for the Indian healthcare environment, avoiding the complexity and cost of multi-step protocols. 1
The DIPSI method does not require fasting, making it more practical and patient-friendly in busy antenatal clinics. 1
Women who have normal OGTT at the first visit require repeat OGTT at subsequent visits, as 28.9% of GDM cases are diagnosed on repeat testing. 3
Timing Considerations for Indian Women
GDM manifests across all trimesters in Indian women: 16.3% are diagnosed within 16 weeks, 22.4% between 17-23 weeks, and 61.3% after 24 weeks of gestation. 3
Early universal screening at the first prenatal visit is recommended for the Indian population, particularly given the high prevalence and early onset of glucose intolerance. 2
Do not postpone screening beyond 28 weeks, as this misses the optimal window for intervention and increases adverse maternal-fetal outcomes. 4
Management Framework
Team-Based Approach
- A multidisciplinary team is ideal for managing GDM, comprising an obstetrician, diabetes physician, diabetes educator, dietitian, midwife, and pediatrician. 1
Treatment Cornerstones
Intensive monitoring, medical nutrition therapy, and insulin therapy form the foundation of GDM management in India. 1
Achieve and maintain normoglycemia in every pregnancy complicated by GDM, as maternal hyperglycemia is associated with adverse outcomes even when fetal growth appears normal on ultrasound. 1
Oral hypoglycemic agents and insulin analogues, though used in practice, remain controversial and lack definitive evidence for safety in pregnancy. 1
Postpartum Follow-Up
All women with GDM should undergo a 75g OGTT at 4-12 weeks postpartum using non-pregnancy diagnostic criteria to detect persistent diabetes or prediabetes. 5
Lifelong diabetes screening at least every 3 years is mandatory, as women with prior GDM have a 3.4-fold increased risk of developing type 2 diabetes. 4, 5
Women identified with prediabetes should receive intensive lifestyle interventions or metformin therapy to prevent progression to overt diabetes. 4, 5
Comparison with International Guidelines
DIPSI vs. IADPSG/ADA Criteria
IADPSG/ADA recommends fasting 75g OGTT at 24-28 weeks with diagnosis requiring any one abnormal value: fasting ≥92 mg/dL (5.1 mmol/L), 1-hour ≥180 mg/dL (10.0 mmol/L), or 2-hour ≥153 mg/dL (8.5 mmol/L). 4, 6
DIPSI uses a simpler non-fasting approach with only a 2-hour value ≥140 mg/dL, making it more practical for resource-limited settings. 1
Critics argue that IADPSG criteria cause over-diagnosis and unnecessary interventions, though these are the only outcome-based criteria derived from the HAPO study. 6
ACOG Two-Step Approach
ACOG recommends a 50g non-fasting glucose challenge test followed by a 100g OGTT if the 1-hour value is ≥140 mg/dL, requiring at least two abnormal values for diagnosis. 4, 6
This approach identifies only 5-6% of pregnancies with GDM compared to 15-20% with the one-step method. 4
Critical Pitfalls to Avoid
Do not rely on single fasting glucose measurements alone, as they miss a substantial proportion of women with elevated postprandial glucose who have normal fasting values. 4
Do not use urine glucose testing for GDM detection or management, as it is not validated or useful. 4
Do not apply gestational diabetes thresholds before 24 weeks, as they were derived from data collected in the later half of pregnancy; use non-pregnancy criteria (fasting ≥126 mg/dL) for early screening. 4
Failing to repeat screening at 24-28 weeks in women with negative early tests is the most common error, leading to missed diagnoses as insulin resistance peaks in the second and third trimesters. 4, 7
Long-Term Prevention Strategy
Short-term intensive care during pregnancy provides long-term benefits in primary prevention of obesity, impaired glucose tolerance, and diabetes in offspring, as preventive medicine starts before birth. 1
The maternal and fetal outcome depends on committed care by diabetologists, obstetricians, and neonatologists working collaboratively. 1