A 32-year-old multigravida with a BMI of 29 kg/m² presents for antenatal care at 12 weeks of gestation. She has a family history of type 2 diabetes mellitus in her mother and sister. Which of the following is the most common risk factor for the development of gestational diabetes mellitus in Indian pregnant women?

## Risk Factors for Gestational Diabetes in Indian Populations **Key Point:** **Obesity and overweight (BMI ≥25 kg/m²)** is the single most common modifiable risk factor for GDM in Indian pregnant women, driven by high baseline prevalence of metabolic syndrome and insulin resistance. ### Epidemiology in Indian Context India has one of the highest GDM prevalence rates globally (15–20% in urban populations). The primary driver is **metabolic phenotype**, not age: - **Obesity prevalence:** 20–30% in urban Indian pregnant women - **Insulin resistance:** Intrinsic to South Asian populations (genetic predisposition to metabolic syndrome at lower BMI thresholds) - **WHO BMI cutoff for Asian populations:** Overweight ≥23 kg/m², Obese ≥25 kg/m² (lower than Caucasian cutoffs) ### Risk Factor Hierarchy in Indian GDM | Risk Factor | Prevalence in GDM | Relative Risk | Modifiable? | |---|---|---|---| | **Obesity/Overweight (BMI ≥25)** | 60–70% | 2.5–3.5× | Yes | | **Family history of T2DM** | 40–50% | 2.0–2.5× | No | | **Previous GDM** | 15–20% | 5.0–7.0× | No | | **Advanced age (>35 yr)** | 25–30% | 1.5–2.0× | No | | **PCOS** | 10–15% | 2.0–3.0× | Partially | | **Multiparity** | 35–45% | 1.5–2.0× | No | **High-Yield:** The **IADPSG (International Association of Diabetes and Pregnancy Study Groups)** recommends universal screening for GDM at 24–28 weeks in all pregnant women, with **no risk stratification**, because obesity is so prevalent that risk-based screening misses 20–30% of cases. ### Why Obesity Is "Most Common" 1. **Highest attributable risk:** Obesity accounts for ~40% of all GDM cases in Indian populations 2. **Biological mechanism:** Adipose tissue insulin resistance → compensatory hyperinsulinemia → pancreatic β-cell exhaustion during pregnancy 3. **Modifiable:** Weight loss and lifestyle intervention reduce GDM risk by 30–50% (DPP, LIFE-Moms trials) **Clinical Pearl:** Indian women have **lower BMI thresholds for metabolic dysfunction** compared to Caucasians. A BMI of 25–27 kg/m² in an Indian woman carries similar metabolic risk as BMI 30 in a Caucasian — this is why the WHO recommends lower cutoffs for Asian populations.