Key Facts

Caesarean section is the most commonly performed major abdominal surgery worldwide. In the UK, approximately one-third of all deliveries are by CS, divided roughly equally between elective (planned) and emergency procedures.

Epidemiology

• UK CS rate: approximately 30-35% (has risen from 12% in 1990)
• Elective (Category 4): approximately 15%
• Emergency (Categories 1-3): approximately 15-20%
• Variation between hospitals (25-40%)
• England CS rate higher than Scotland/Wales

Aetiology (Indications)

• Elective: previous CS (most common), breech presentation, placenta praevia, maternal request, multiple pregnancy (certain presentations), HIV with high viral load
• Emergency: failure to progress in labour, fetal compromise, cord prolapse, placental abruption, uterine rupture, failed instrumental delivery

Pathophysiology

• Surgical delivery through lower uterine segment transverse incision (most common)
• Classical (vertical) incision: used for very preterm, transverse lie, anterior placenta praevia
• Lower segment incision preferred: less blood loss, less adhesion formation, lower rupture risk in subsequent pregnancy

Pre-operative Assessment

• Confirm indication and urgency category
• Consent (including risks of haemorrhage, infection, thromboembolism, injury to bladder/bowel/ureter, future pregnancy implications)
• Blood group and antibody screen
• FBC
• Assessment of anaesthetic suitability

Urgency Classification (NICE CG132)

• Category 1: Immediate threat to life of woman or fetus (decision to delivery within 30 minutes)
• Category 2: Maternal or fetal compromise not immediately life-threatening (within 75 minutes)
• Category 3: No maternal or fetal compromise but early delivery needed
• Category 4: Delivery timed to suit woman and staff (elective)

Red Flags Post-operatively

• Excessive bleeding (PPH >1000 mL)
• Signs of wound infection (erythema, discharge, dehiscence)
• DVT symptoms (unilateral leg swelling, pain)
• PE symptoms (chest pain, dyspnoea)
• Urinary retention or haematuria (bladder injury)
• Abdominal distension (ileus or internal bleeding)

Bedside

• CTG (if in labour or fetal concern)
• Blood pressure, pulse, temperature
• Urinary catheter

Bloods

• FBC
• Group and save / crossmatch (crossmatch for placenta praevia/accreta)
• Coagulation screen if indicated (pre-eclampsia, abruption)

Imaging

• Ultrasound: fetal presentation, placental localisation (if not confirmed)
• MRI: if placenta accreta suspected

Special Tests

• Anaesthetic assessment (airway evaluation, allergies, fasting status)
• VTE risk assessment (all patients)

Non-pharmacological

• WHO surgical safety checklist
• Skin preparation with chlorhexidine
• Urinary catheterisation
• Informed consent (verbal for Cat 1 if written not feasible)
• Partner/support person present (if safe under GA, they should leave)
• Skin-to-skin contact as soon as possible
• Delayed cord clamping (≥1 minute) unless compromised neonate

Pharmacological

• Anaesthesia: spinal (first-line for elective and most emergency), epidural top-up, or general anaesthesia (Cat 1 if no regional in situ)
• Prophylactic antibiotics: IV cefuroxime 1.5g + metronidazole 500mg at induction of anaesthesia (reduces surgical site infection by 65%)
• Oxytocin: 5 IU slow IV at delivery of baby (reduces PPH)
• Thromboprophylaxis: LMWH (e.g., enoxaparin 40mg SC OD) for minimum 10 days post-CS (RCOG GTG 37a); TED stockings
• Analgesia: regular paracetamol 1g QDS + ibuprofen 400mg TDS + rescue opioids (morphine PCA or oral codeine/dihydrocodeine)

Surgical/Interventional

• Skin incision: Joel-Cohen (straight transverse) or Pfannenstiel (curved)
• Uterine incision: lower segment transverse
• Closure: uterus in two layers, peritoneum not closed (CAESAR/CORONIS trials)
• Placenta accreta: may require planned hysterectomy, uterine artery embolisation

Referral Criteria

• Post-CS wound infection: GP review, antibiotics
• Persistent pain or abnormal bleeding: urgent obstetric review
• Subsequent pregnancy: early booking for VBAC counselling
• Mental health support if traumatic delivery experience

• Maternal mortality from CS: approximately 13 per 100,000 (higher than vaginal delivery at 3 per 100,000)
• Surgical site infection: 8-10% (reduced to 3-4% with prophylactic antibiotics)
• PPH (>1000 mL): 4-8%
• VTE: 1-2% without prophylaxis; 0.1% with LMWH
• Bladder injury: 0.1-0.3%
• Uterine rupture in subsequent pregnancy (VBAC): 0.5% with one previous lower segment CS
• VBAC success rate: 72-75%
• Each additional CS increases surgical complexity and risk of placenta accreta

CS Category Classification

VBAC Counselling