Among pregnant women diagnosed with gestational diabetes mellitus, which of the following is the most common maternal complication during pregnancy and labour?

Explanation

## Maternal Complications of Gestational Diabetes **Key Point:** Preeclampsia is the **most common maternal complication** of GDM, occurring in 15–25% of women with GDM compared to 5–10% in non-diabetic pregnancies. ### Why Preeclampsia Is Most Common in GDM **High-Yield:** The link between GDM and preeclampsia is multifactorial: 1. **Endothelial dysfunction** — Hyperglycemia and hyperinsulinemia impair endothelial nitric oxide production 2. **Oxidative stress** — Increased reactive oxygen species in GDM 3. **Inflammatory state** — Elevated inflammatory cytokines (TNF-α, IL-6) 4. **Shared risk factors** — Obesity, insulin resistance, and metabolic syndrome predispose to both GDM and preeclampsia 5. **Placental insufficiency** — Abnormal placentation in GDM increases preeclampsia risk ### Frequency of Maternal Complications in GDM | Complication | Incidence in GDM | Incidence in Non-GDM | Comment | |---|---|---|---| | **Preeclampsia** | **15–25%** | **5–10%** | **Most common maternal complication** | | Polyhydramnios | 5–10% | 1–2% | Associated with fetal hyperglycemia and osmotic diuresis | | Intrauterine fetal death | 1–2% | 0.3–0.5% | Rare with modern management; more common in undiagnosed/uncontrolled GDM | | Maternal hypoglycemia | <1% | N/A | Only if insulin overdosed; not a natural GDM complication | | Cesarean delivery | 30–50% | 15–20% | Due to macrosomia, cephalopelvic disproportion | **Clinical Pearl:** Women with GDM have a **3-fold increased risk** of preeclampsia compared to non-diabetic pregnancies. This is one of the strongest independent associations and should prompt close monitoring of blood pressure and proteinuria from diagnosis onwards. **Mnemonic for GDM maternal complications: PREP** - **P**reeclampsia (most common) - **R**enal complications (diabetic nephropathy if pre-existing diabetes) - **E**ye complications (diabetic retinopathy if pre-existing diabetes) - **P**olyhyramios (fetal hyperglycemia → osmotic diuresis)