A 32-year-old multigravida (G3P2) at 40 weeks gestation is admitted to the labour ward in active labour. After 8 hours of labour, her cervical dilation is plotted on the partograph and crosses the action line. She has had 3–4 contractions per 10 minutes, each lasting 40 seconds. Vital signs are stable, and the fetus is in cephalic presentation at −2 station. What is the most appropriate next step in management?

Explanation

## Management When Partograph Crosses the Action Line **Key Point:** When cervical dilation crosses the **action line** on the partograph, the standard management is **labour augmentation with oxytocin** (after excluding cephalopelvic disproportion), NOT immediate operative delivery. ### Partograph Interpretation Algorithm ```mermaid flowchart TD A[Cervical dilation plotted on partograph]:::outcome A --> B{Crosses alert line?}:::decision B -->|No| C[Continue labour, reassess]:::action B -->|Yes| D{Crosses action line?}:::decision D -->|No| E[Observe for progress, consider augmentation]:::action D -->|Yes| F[Assess for CPD and obstruction]:::decision F -->|CPD excluded| G[Augment with oxytocin]:::action F -->|CPD present| H[Operative delivery]:::urgent G --> I[Reassess progress]:::action I --> J{Labour progresses?}:::decision J -->|Yes| K[Vaginal delivery]:::outcome J -->|No| L[Operative delivery]:::urgent ``` ### When Action Line is Crossed: Management Steps 1. **Exclude cephalopelvic disproportion (CPD)** — clinical assessment of: - Pelvic adequacy (obstetric history, pelvic examination) - Fetal size (ultrasound if available) - Degree of caput succedaneum and molding 2. **If CPD is excluded:** - Start **intravenous oxytocin** at 2–4 mIU/min, increase by 2–4 mIU/min every 15–30 minutes - Target: 3–4 contractions per 10 minutes, each lasting 40–60 seconds - Replot cervical dilation on partograph 3. **Reassess after augmentation:** - If cervical dilation progresses and crosses back toward the alert line → continue labour - If dilation remains on or crosses the action line despite adequate contractions → operative delivery ### Why Oxytocin Augmentation is Preferred Over Immediate Surgery **High-Yield:** The partograph is designed to **reduce unnecessary cesarean sections** while maintaining maternal and fetal safety. Most cases of slow labour respond to oxytocin augmentation. **Clinical Pearl:** In this multigravida: - Contractions are **suboptimal** (3–4 per 10 min; optimal is 4–5 per 10 min) - Fetal station is **−2** (not deeply engaged), suggesting room for descent - Vital signs and fetal heart rate are **normal**, indicating no acute fetal compromise - These factors make labour augmentation the **first-line intervention** ### Contraindications to Oxytocin Augmentation - Cephalopelvic disproportion - Placenta previa - Vasa previa - Transverse lie - Previous classical cesarean section - Fetal distress [cite:Park 26e Ch 15; Obstetric Care Consensus (ACOG)]