Omphalocele – Causes, Diagnosis and Treatment

What is an Omphalocele?

An omphalocele (also spelled omphalocoele) is a congenital birth defect of the abdominal wall in which abdominal organs – such as the intestines, stomach, or liver – protrude through an opening at the navel (umbilicus). Unlike the related condition gastroschisis, the protruding organs in an omphalocele are covered by a thin protective sac made of peritoneum and amniotic membrane.

Omphalocele occurs in approximately 1 in 4,000 to 7,000 births and is classified as a congenital abdominal wall defect. It may occur in isolation or as part of chromosomal abnormalities or other congenital syndromes.

Causes and Development

An omphalocele develops early in pregnancy when the abdominal wall of the embryo fails to close completely. Under normal circumstances, the developing abdominal organs temporarily migrate into the umbilical cord region and then return to the abdominal cavity. In omphalocele, this return process is incomplete or does not occur.

Known risk factors and associated causes include:

• Chromosomal abnormalities: Present in approximately 30–50% of cases, including Trisomy 13, Trisomy 18, and Trisomy 21.
• Genetic syndromes: Beckwith-Wiedemann syndrome, Pentalogy of Cantrell, and other malformation syndromes.
• Environmental factors: Certain medications, alcohol consumption, and smoking during pregnancy have been discussed as possible risk factors.
• Idiopathic: In many cases, no specific cause can be identified.

Symptoms and Clinical Presentation

Omphalocele is typically detected prenatally via ultrasound, often in the first or second trimester. After birth, the clinical picture includes:

• Visibly protruding abdominal organs (intestines, and sometimes the stomach or liver) at the navel
• The organs are enclosed in a transparent membranous sac
• The defect varies in size: from small (only intestinal loops) to large (involving the liver and other organs)
• Possible associated malformations of the heart, kidneys, or skeletal system

Diagnosis

Diagnosis is primarily made prenatally through the following methods:

• Ultrasound examination: Detection of the protruding organs and the surrounding membrane is possible from approximately 12 weeks of gestation
• Fetal MRI: For more detailed assessment of the defect and involved organs
• Amniocentesis or chorionic villus sampling: To evaluate for chromosomal abnormalities
• Fetal echocardiography: To rule out associated cardiac defects

After birth, clinical examination of the newborn and further imaging studies are performed to plan surgical intervention.

Treatment

Treatment of omphalocele is always surgical and requires a multidisciplinary team including pediatric surgeons, neonatologists, and other specialists.

Surgical Repair

The goal of surgery is to return the organs to the abdominal cavity and close the abdominal wall. The approach depends on the size of the defect:

• Small defect: Primary single-stage closure shortly after birth
• Large defect: Staged approach – initial protection of the organs using a plastic pouch (silo), gradual reduction over several days, followed by final abdominal wall closure

Postoperative Care

After surgery, newborns are monitored in an intensive care unit. Common postoperative measures include:

• Ventilatory support, as increased abdominal pressure may follow organ reduction
• Parenteral nutrition until bowel function is restored
• Close monitoring for associated malformations and potential complications

Long-Term Outlook

The prognosis of omphalocele depends largely on the size of the defect and the presence of associated malformations or chromosomal abnormalities. Isolated omphaloceles without additional anomalies generally carry a good long-term prognosis. When severe associated conditions are present, the overall prognosis may be significantly less favorable.

References

1. Stoll C et al. - Epidemiology of omphalocele: Genetic Counseling and Prenatal Diagnosis - European Journal of Medical Genetics (2008)
2. Ledbetter DJ - Gastroschisis and omphalocele - Surgical Clinics of North America (2006)
3. World Health Organization (WHO) - Congenital Anomalies Fact Sheet - who.int (2023)