A 38-year-old primigravida at 41 weeks + 3 days of gestation presents to the labour ward for induction of labour. She has an uncomplicated pregnancy with a singleton vertex presentation. Cervical examination reveals: cervix 2 cm dilated, 50% effaced, firm consistency, and posterior position (Bishop score 6). She has no contraindications to vaginal delivery. What is the most appropriate next step in management?

Explanation

## Clinical Assessment This patient has a **Bishop score of 6**, which falls in the **unfavorable cervix category** (Bishop score ≤ 6). With an unfavorable cervix, cervical ripening is mandatory before attempting labor induction with oxytocin. ## Cervical Ripening Agents | Agent | Route | Dosing | Advantages | Disadvantages | |-------|-------|--------|------------|----------------| | Misoprostol | Vaginal/Buccal | 25 mcg q3–6h | Cost-effective, stable storage | Risk of uterine tachysystole, hyperstimulation | | Dinoprostone | Intracervical | 0.5 mg q6h (max 3 doses) | Reversible (removal if hyperstimulation) | Expensive, requires refrigeration | | Mifepristone | Oral | 200 mg single dose | Single dose, no systemic effects | Not widely available in India | | Mechanical (Foley balloon) | Transcervical | 30 mL saline | No systemic effects, no hyperstimulation | Slower ripening, requires removal | **Key Point:** A Bishop score ≤ 6 mandates cervical ripening before oxytocin. Misoprostol (25 mcg vaginally q3–6h) or dinoprostone (0.5 mg intracervically q6h) are first-line agents. Once cervix becomes favorable (Bishop ≥ 8), oxytocin infusion can begin. ## Why Cervical Ripening First? 1. **Reduces failed induction**: Unfavorable cervix + direct oxytocin = high cesarean delivery rate (>50%). 2. **Decreases hyperstimulation**: Ripening agents soften cervix, reducing uterine irritability. 3. **Improves vaginal delivery rates**: Favorable cervix before oxytocin increases success to >80%. **High-Yield:** In India, misoprostol is preferred due to cost and availability. Dinoprostone is reserved for cases where misoprostol is contraindicated (e.g., prior uterine scar with relative contraindication to misoprostol). **Clinical Pearl:** Reassess cervix 12–24 hours after ripening. If cervix becomes favorable, proceed to oxytocin. If still unfavorable, repeat ripening or consider cesarean delivery depending on indication for induction. ## Why Not Immediate Oxytocin? Starting oxytocin on an unfavorable cervix results in: - Prolonged, ineffective contractions - Increased uterine hyperstimulation - Higher cesarean delivery rate - Maternal and fetal morbidity [cite:ACOG Practice Bulletin 107 on Induction of Labor; Williams Obstetrics 26e Ch 21]