In brief — the direct answer
Abdominal wall defects are conditions where there is an opening in the baby's abdomen, causing some of the internal organs (like the bowel or liver) to develop outside the body. The two most common types are Gastroschisis and Omphalocele. While they may look similar on a standard ultrasound, they are very different in terms of their causes and associated risks. Both conditions require a planned delivery at a tertiary hospital with immediate access to pediatric surgery, but the long-term outlook for these babies is generally excellent.
What is Gastroschisis & Omphalocele?
It is essential to understand the differences between the two:
- Gastroschisis: A small opening (usually to the right of the umbilical cord) through which the bowel floats freely in the amniotic fluid. There is no sac covering the bowel. It is rarely associated with other genetic issues but can lead to bowel irritation or 'kinking' during pregnancy.
- Omphalocele: An opening where the organs (bowel, liver, stomach) protrude into a protective sac (the base of the umbilical cord). This condition is more complex because it is associated with chromosomal variations (like Trisomy 18) or heart defects in about 50% of cases.
Who is at risk?
- Gastroschisis: More common in younger mothers (under age 20-25). The reason for this is not fully understood, but it is not typically genetic.
- Omphalocele: Does not have a strong link to maternal age but requires an immediate genetic assessment due to the high association with other syndromes.
Both conditions are usually caught during the first-trimester screening (12 weeks) or the 20-week anomaly scan.
How we diagnose it
At the MFM Unit, our diagnosis focuses on three priorities:
- Defect Characterization: Distinguishing between Gastroschisis and Omphalocele and measuring the size of the opening.
- Bowel Health: In Gastroschisis, we look for signs of 'dilation' or thickening of the bowel, which could indicate a blockage.
- Associated Issues: For Omphalocele, we perform a detailed Fetal Echocardiogram and discuss Amniocentesis to check the baby's chromosomes.
What does management involve?
During pregnancy, management includes regular scans to monitor the baby's growth and the condition of the exposed organs.
- In-Utero: There is currently no surgical fix inside the womb for these conditions.
- Delivery Planning: We aim for a delivery between 37 and 38 weeks. In Gastroschisis, many babies can be delivered vaginally, while for larger Omphaloceles, a Caesarean section may be safer to protect the organs.
- Postnatal Repair: Immediately after birth, the organs are protected (often with a sterile 'silo' bag) and gradually or immediately returned to the abdomen by a pediatric surgeon.
What are the outcomes?
The survival rate for isolated Gastroschisis and isolated Omphalocele is over 90-95%.
- Gastroschisis: The main challenge is the time it takes for the bowel to 'wake up' and start working correctly after birth. These babies may need help with feeding through a vein (TPN) for several weeks.
- Omphalocele: The long-term outcome depends largely on whether there are associated heart or genetic issues. If isolated, the outlook is excellent.
Most children grow up to have a completely normal life, with only a small scar and a 'different' belly button as a reminder of their surgery.
When to see a subspecialist
If an abdominal opening is detected, you should be referred to the MFM Unit for a subspecialty scan and a consultation with a Pediatric Surgeon.
We provide a unified care approach, ensuring that your delivery is perfectly timed and that the surgical team is standing by to care for your baby from the first minute of life. Our lead, Dr. Ali Al-Ibrahim, manages the coordination between the MFM and the Pediatric Surgery teams at Mediclinic partner hospitals.
Questions to ask your doctor
References & Clinical Guidelines
- ISUOG Practice Guidelines: performance of the routine mid-trimester fetal ultrasound scan
- Gastroschisis: prenatal diagnosis and management (Scientific Impact Paper)
- Management of gastroschisis and omphalocele: consensus guidance