Summary

Caesarean section (CS) is the surgical delivery of a baby through incisions in the abdominal wall and uterus. It is one of the most commonly performed major surgical procedures worldwide, accounting for approximately 25-35% of all deliveries in developed countries. The lower segment caesarean section (LSCS) is the standard technique, involving a transverse incision in the lower uterine segment. Indications are classified as elective (planned) or emergency, and emergency cases are further categorised by urgency (Categories 1-4). While CS is a life-saving procedure, it carries maternal risks (haemorrhage, infection, thromboembolism) and has implications for future pregnancies (placenta accreta spectrum, uterine rupture).

Key Facts

• CS rate: UK ~27%; varies globally from 5% to >50%
• Category classification: 1 (immediate threat to life) to 4 (elective)
• Category 1 target: Decision-to-delivery interval <30 minutes
• Standard incision: Pfannenstiel (skin) + transverse lower segment (uterus)
• Anaesthesia: Spinal (preferred) > Epidural > General (for Cat 1/emergencies)
• Maternal mortality: Very rare (~1:12,000 in UK)
• Major risks: Haemorrhage, infection, VTE, bladder/bowel injury
• Future pregnancy risks: Uterine rupture (VBAC), placenta accreta spectrum
• Recovery: Hospital stay 2-4 days; full recovery 6-8 weeks
• VBAC success rate: 72-75% with appropriate selection

Clinical Pearls

"Category 1 = Everyone Runs": A Category 1 CS means immediate threat to life of mother or baby. The team must aim for delivery within 30 minutes — this is "crash CS" territory requiring full team mobilisation.

"Know Your Pfannenstiel": The Pfannenstiel incision (transverse, curved, along skin creases) heals well cosmetically. Joel-Cohen is a straight transverse alternative. Both are in the "bikini line" area.

"Accreta Risk Escalates": The risk of placenta accreta spectrum increases with each repeat CS: 3% after 1 CS, 11% after 2, 40% after 3, 60% after 4+. Always counsel women about future pregnancy implications.

"Spinal Over General": Regional anaesthesia (spinal) is preferred whenever time permits. It allows maternal bonding at delivery, has fewer respiratory complications, and reduces anaesthetic-related mortality.

"Double-Layer Closure": Closing the uterus in two layers is associated with reduced risk of uterine rupture in subsequent pregnancies compared to single-layer closure.

Why This Matters Clinically

Caesarean section is a fundamental obstetric procedure that every obstetrician and many other clinicians must understand. Knowing when CS is indicated, the urgency categories, and the risks allows proper counselling of women and timely decision-making in emergencies. The rising CS rate worldwide has implications for maternal morbidity in future pregnancies, making informed consent and appropriate indication essential.[1,2]

Pre-Operative Checklist

Maternal Assessment:

• Vital signs (BP, pulse, temperature, SpO2)
• Airway assessment (for anaesthesia)
• Abdominal examination (fundal height, presentation, engagement)
• Vaginal examination (cervical dilatation, station, presenting part)
• Check for urinary catheter
• Fasting status documented

Fetal Assessment:

• CTG interpretation
• Presentation confirmation (ultrasound if uncertain)
• Exclude cord prolapse if membranes ruptured

Documentation:

• Indication for CS clearly documented
• Category assigned and justified
• Consent obtained (or documented reason if not possible)
• WHO surgical safety checklist completed

Theatre Setup

Maternal Outcomes

Neonatal Outcomes

VBAC (Vaginal Birth After Caesarean)

Key Guidelines

Landmark Trials

Term Breech Trial (Hannah et al. 2000)

• RCT comparing planned CS vs vaginal birth for breech
• CS reduced perinatal mortality/morbidity
• Changed practice: CS now recommended for term breech
• PMID: 11052579

CAESAR Trial (2010)

• Single vs double-layer uterine closure
• No significant difference in short-term outcomes
• Long-term follow-up suggested double-layer may reduce rupture risk
• PMID: 20598272

CORONIS Trial (2013)

• Large factorial RCT of CS techniques
• Blunt vs sharp entry, single vs double-layer closure, etc.
• Informed current practice guidelines
• PMID: 23953766

Evidence Strength

What is a Caesarean Section?

A caesarean section (also called C-section or CS) is an operation to deliver your baby through a cut in your tummy and womb. It's a very common procedure — in the UK, about 1 in 4 babies are born this way.

Why might I need one?

Some C-sections are planned in advance (elective), and others happen during labour (emergency).

Planned reasons include:

• Your baby is in a bottom-first position (breech)
• You've had C-sections before
• Your placenta is covering your cervix
• Personal preference after counselling

Emergency reasons include:

• Labour isn't progressing
• Your baby shows signs of distress
• The umbilical cord comes out first (cord prolapse)

What happens during the operation?

• You'll usually have a spinal anaesthetic, meaning you're awake but can't feel from the waist down
• A cut is made across your lower tummy (along the "bikini line")
• Your baby is lifted out of your womb
• The whole surgery takes about 45-60 minutes
• You can usually hold your baby within minutes of delivery

What about recovery?

• You'll stay in hospital for 2-4 days
• The cut usually heals well but takes 6-8 weeks to fully recover
• Avoid driving for 4-6 weeks
• You can breastfeed normally
• Tell your doctor in future pregnancies that you've had a C-section

What are the risks?

Like any operation, there are some risks:

• Infection
• Bleeding (rarely needing transfusion)
• Blood clots (prevented with injections and compression stockings)
• Injury to bladder or bowel (rare)
• Risks in future pregnancies (placenta problems, uterine rupture)

Most C-sections go smoothly, and serious complications are rare.

High-Yield Exam Topics

Sample Viva Questions

Q1: A primigravida at 38 weeks in labour for 18 hours is 5 cm dilated and has been that way for 4 hours. CTG shows recurrent late decelerations. What is your management?

Model Answer: This presentation suggests failure to progress in the first stage of labour with non-reassuring fetal status. The recurrent late decelerations indicate fetal compromise. I would classify this as a Category 2 CS (maternal/fetal compromise but not immediately life-threatening). Management: Inform the consultant and anaesthetist. Prepare for CS within 60 minutes. Spinal anaesthesia if feasible (time permits). If CTG deteriorates to prolonged bradycardia, I would escalate to Category 1 requiring delivery within 30 minutes, potentially under GA.

Q2: What are the long-term risks of caesarean section for future pregnancies?

Model Answer: Key long-term risks include:

1. Uterine rupture: 0.5-1% risk with VBAC/TOLAC; higher if classical incision
2. Placenta accreta spectrum: Risk increases with each CS (3% after 1, 11% after 2, 40% after 3+)
3. Placenta praevia: Increased risk due to uterine scarring
4. Adhesions: May complicate future surgery
5. Increased repeat CS rate: Many women require repeat CS
6. Ectopic pregnancy in scar: Rare but recognised

Counselling women about these risks is essential, especially those desiring large families.

Q3: What are the anaesthetic options for caesarean section and when would you choose general anaesthesia?

Model Answer: Options include:

1. Spinal anaesthesia: Single injection; rapid onset; preferred for most CS
2. Epidural anaesthesia: If already sited for labour; top-up for CS
3. Combined spinal-epidural (CSE): Flexibility of both
4. General anaesthesia: Fastest; patient asleep

I would choose GA for:

• Category 1 CS without epidural in situ (fastest)
• Maternal refusal of regional
• Contraindications to regional (coagulopathy, infection, raised ICP)
• Failed regional technique
• Maternal preference

However, GA carries higher risks (aspiration, failed intubation) and precludes maternal bonding at delivery.

Common Exam Errors

Last Reviewed: 2025-12-24 | MedVellum Editorial Team

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