A 32-year-old multiparous woman at 20 weeks of gestation presents for her routine antenatal checkup in a primary health center in rural India. According to the standard antenatal care package, which is the most common obstetric complication for which she should be screened during the second trimester?

Explanation

## Most Common Screened Obstetric Complication in Second Trimester **Key Point:** Gestational diabetes mellitus (GDM) is the most common metabolic complication of pregnancy, with a prevalence of 15–20% in Indian pregnant women. Second-trimester screening (75-g oral glucose tolerance test at 24–28 weeks) is a universal component of the antenatal care package. ### Epidemiology of GDM in India - **Prevalence:** 15–20% of pregnant women (significantly higher than in Western populations due to genetic predisposition and lifestyle factors). - **Risk factors:** Maternal age > 25 years, obesity (BMI > 25), family history of diabetes, multiparity, previous GDM. - **Impact:** Increases risk of preeclampsia, cesarean delivery, neonatal hypoglycemia, and long-term type 2 diabetes in mother and offspring. ### Screening Protocol (NRHM / ICMR Guidelines) | Timing | Test | Criteria | Action | |--------|------|----------|--------| | 24–28 weeks | 75-g OGTT (fasting, 2-hour) | Fasting ≥ 92 mg/dL OR 2-hr ≥ 180 mg/dL | Diagnose GDM | | All pregnant women | Universal screening | No risk stratification | Mandatory in India | | High-risk (if available) | Early screening at 16–18 weeks | Fasting ≥ 110 mg/dL | Repeat at 24–28 weeks | **High-Yield:** The 75-g OGTT (single-step approach) is recommended in India; the 2-hour value ≥ 180 mg/dL or fasting ≥ 92 mg/dL confirms GDM. Even one abnormal value warrants dietary counseling and monitoring. ### Why GDM is the Most Common Screened Complication 1. **High prevalence:** 15–20% of Indian pregnancies (vs. 5–10% in Western countries). 2. **Preventable morbidity:** Tight glycemic control reduces adverse outcomes by 50%. 3. **Universal screening:** Recommended for all pregnant women, not just high-risk groups. 4. **Timing:** Second trimester is optimal for detection and intervention. **Clinical Pearl:** GDM often resolves postpartum but confers lifelong risk of type 2 diabetes (30–50% within 10 years); postpartum glucose tolerance testing and lifestyle modification are essential. ### Differentiation from Other Complications | Complication | Prevalence | Screening Timing | Why Not Most Common | |--------------|-----------|-----------------|---------------------| | **Gestational diabetes** | 15–20% | 24–28 weeks | **MOST COMMON** | | Placenta previa | 0.5–1% | Ultrasound at 18–20 weeks | Rare; most resolve by term | | IUGR | 5–10% | Serial ultrasound from 28 weeks | Detected later; not 2nd trimester focus | | Preeclampsia | 5–10% | BP monitoring throughout; labs at 28 weeks | Develops mainly in 3rd trimester | **Mnemonic:** **GLUCOSE GATEWAY** — GDM is the Gateway complication screened universally in the second trimester, affects 15–20% of Indian pregnancies, and requires early dietary and medical intervention. ### Management Approach 1. **Diagnosis:** 75-g OGTT at 24–28 weeks (fasting ≥ 92 mg/dL OR 2-hr ≥ 180 mg/dL). 2. **First-line:** Dietary modification (low glycemic index, 6 small meals/day), exercise (30 min/day). 3. **Pharmacotherapy:** Insulin (preferred in pregnancy) if diet fails; metformin is increasingly used in India. 4. **Monitoring:** Fetal biometry every 4 weeks, NST from 32 weeks, delivery at 38–39 weeks if well-controlled.