Summary

Exomphalos (also known as omphalocele) is a congenital anterior abdominal wall defect in which abdominal contents (bowel and/or liver) herniate through the umbilical ring and are covered by a translucent membrane composed of peritoneum and amnion. Unlike gastroschisis, the hernia is covered by a protective sac and is located centrally at the umbilicus. Exomphalos is strongly associated with chromosomal abnormalities (trisomies 13, 18, 21) and syndromes (especially Beckwith-Wiedemann syndrome), with up to 50% having significant associated anomalies. Management depends on defect size: small defects (exomphalos minor) undergo primary surgical closure, while large/giant defects (containing liver) may require staged closure or "paint and wait" conservative management with topical agents to promote escharification.

Key Facts

• Definition: Midline abdominal wall defect at umbilicus with herniation of viscera into a membrane-covered sac
• Incidence: 1 in 4000-7000 live births
• Key differentiator: Covered by membrane (vs gastroschisis which is uncovered and lateral to umbilicus)
• Associated anomalies: 50-70% (chromosomal, cardiac, Beckwith-Wiedemann)
• Classification: Minor (less than 5cm, bowel only) vs Major/Giant (greater than 5cm, contains liver)
• Antenatal detection: Usually detected on anomaly scan (18-20 weeks)

Clinical Pearls

"Exomphalos = Anomalies": Up to 50-70% of exomphalos cases have associated chromosomal or structural anomalies. Always perform karyotyping and detailed cardiac echo. Contrast with gastroschisis which is usually isolated.

"In the Cord vs Beside the Cord": Exomphalos is IN the umbilical cord (central, covered). Gastroschisis is BESIDE the cord (lateral, right side, uncovered). This distinction is critical for prognosis and management.

"Paint and Wait": For giant exomphalos where primary closure is impossible, topical silver sulfadiazine or other desiccating agents promote eschar formation over the sac, allowing gradual epithelialisation before delayed surgical repair.

Why This Matters Clinically

Antenatal diagnosis allows planning of delivery at a tertiary centre with neonatal surgical facilities. The key clinical challenge is identifying and managing associated anomalies, particularly cardiac defects and chromosomal abnormalities, which drive prognosis more than the abdominal wall defect itself.

Structured Approach

General:

• Gestational age assessment
• Overall appearance (dysmorphic features suggest chromosomal abnormality)
• Vital signs (especially oxygen saturations for cardiac anomalies)

Abdominal:

• Inspect sac: intact or ruptured? size? contents (bowel, liver)?
• Do NOT attempt to reduce

Look for Associations:

• Head: Macroglossia (Beckwith-Wiedemann)
• Cardiac: Murmur, cyanosis
• Growth: Large for gestational age (BWS)
• Digits: Polydactyly (trisomy 13)

Special Examinations

Natural History

• Prognosis primarily determined by associated anomalies, NOT the abdominal wall defect
• Isolated exomphalos minor has excellent prognosis (greater than 95% survival)
• Giant exomphalos with major chromosomal or cardiac anomalies has poorer prognosis

Outcomes

Prognostic Factors

Good Prognosis:

• Isolated defect (no chromosomal or major organ anomaly)
• Small defect (exomphalos minor)
• Intact sac at delivery
• Antenatal detection with planned delivery

Poor Prognosis:

• Associated chromosomal abnormality (especially trisomy 18)
• Major cardiac defect
• Giant exomphalos with liver herniation
• Pulmonary hypoplasia
• Rupture of sac

Key Guidelines

1. BAPS/RCPCH Best Practice Guidelines — Management of anterior abdominal wall defects. BAPS
2. NICE Antenatal Care Guidelines — Referral pathways for fetal anomalies. NICE
3. EUROCAT Surveillance — Congenital anomaly registry and data. EUROCAT

Key Literature

van Eijck et al. (2008) — Outcome of exomphalos

• Systematic review of outcomes
• Key finding: Survival 70-90% overall; primarily determined by associated anomalies
• Clinical Impact: Emphasises importance of anomaly screening

Danzer et al. (2018) — Giant exomphalos management

• Compared primary repair vs staged approaches
• Key finding: "Paint and Wait" safe and effective for giant exomphalos with acceptable long-term outcomes
• Clinical Impact: Established conservative management as valid option

Evidence Strength

What is Exomphalos?

Exomphalos (also called omphalocele) is a condition where a baby is born with part of their bowel or liver outside their tummy, covered by a thin protective membrane. The umbilical cord attaches to this membrane rather than directly to the tummy. It happens because the tummy wall doesn't close properly before birth.

Is it serious?

Exomphalos can range from small to very large. The seriousness depends mainly on whether there are other problems with the baby's heart, kidneys, or chromosomes. About half of babies with exomphalos have other conditions that need treatment. That's why many tests are done before and after birth to check for these.

How is it treated?

1. Before birth: Once exomphalos is found on a scan, you will be referred to a specialist centre. Tests will check for other problems. Your baby should be delivered at a hospital with paediatric surgeons.
2. After birth: The sac covering the bowel is protected with special wrappings. Your baby will be kept warm and given fluids through a drip.
3. Surgery: For small defects, surgery to close the tummy can be done within a day or two. For larger defects, a staged approach or special ointments to let the skin grow over the sac may be used before surgery later.

What to expect

• Your baby will need time in the neonatal unit
• Feeding may need to wait until the bowels start working
• Most babies with isolated exomphalos do very well after surgery
• Long-term follow-up with the surgical team is important

When to seek help

Contact the medical team immediately if:

• The membrane covering the bowel looks broken or damaged
• Your baby's skin colour changes (blue, pale, or mottled)
• Your baby seems very unsettled or in pain
• There are problems with feeding or the baby is vomiting green fluid