What Is Omphalocele? Causes, Types, and Treatment

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026

Quick Answer: What Is Omphalocele?

Omphalocele, also known as exomphalos, is a condition present at birth where organs like the intestines, liver, or spleen protrude through the belly button area. These organs are protected by a transparent membrane. Treatment involves surgery—either immediately for small cases or in stages for larger ones—to move the organs back inside and close the abdominal wall. [1]

What the research says

• Omphalocele often comes with other abnormalities, including chromosomal changes. In a retrospective study of 81 prenatally diagnosed cases, 71.6% of fetuses had other ultrasound anomalies and 29.6% (24 of 81) had chromosomal abnormalities, most often trisomy 18 (11 of 24) and trisomy 13 (7 of 24). Chromosomal abnormalities were far more common when the omphalocele was non-isolated (39.7%, 23 of 58) than when it was isolated (4.3%, 1 of 23) (Shi et al., Ann Med, 2021). [2]

• In giant omphalocele, pulmonary hypertension is linked to worse outcomes. A meta-analysis of five retrospective cohorts (258 newborns, 112 of them [43%] with pulmonary hypertension) found that pulmonary hypertension was associated with higher mortality (OR 6.78, 95% CI 2.72–16.88) and about 21 more days of mechanical ventilation (mean difference 21.25 days, 95% CI 13.19–29.31) (Isaac Maximo et al., Neonatology, 2026). [3]

• Staged closure of giant omphalocele has been studied mostly in small series. A systematic review of 94 neonates (9 in case reports and 85 in cross-sectional studies) reported mortality of 11.1% in the case reports and 18.8% in the cross-sectional studies, with deaths attributed to causes such as heart, kidney, intestinal, or respiratory failure, prematurity, pulmonary hypoplasia, and trisomy 13. Wound infection was the main complication, in 5.4% of patients (Barrios Sanjuanelo et al., J Pediatr Surg, 2021). [4]

Key Takeaways: Omphalocele at a Glance

What is an omphalocele?

An omphalocele (pronounced uhm-FA-lo-seal) is a congenital condition where a baby's abdominal organs stick out through an opening at their belly button. Unlike other abdominal wall defects, these organs are encased in a see-through membrane made of peritoneum, which offers some protection against infection and damage.

This condition develops early in pregnancy. Between the 6th and 10th weeks, it is normal for a fetus's intestines to grow into the umbilical cord. By the 11th week, they should naturally return to the abdomen. When this process fails to occur, an omphalocele is formed. [1]

What are the types of omphalocele?

An omphalocele is classified as small or large (giant) based on the size of the abdominal opening and which organs are involved. [1]

• Small Omphalocele: Only a portion of the intestine protrudes. The opening is less than 5 centimeters (about 2 inches) in diameter. [1]

• Large (Giant) Omphalocele: Most abdominal organs, including the liver and spleen, are outside the body. The opening is larger than 5 centimeters, and the abdomen may be underdeveloped because it hasn't grown to hold the organs. [1]

What causes an omphalocele, and who is at risk?

The exact cause of an omphalocele is often unknown, but researchers have identified certain factors that may increase a baby's risk. [1]

How is an omphalocele diagnosed and monitored?

Most cases of omphalocele are detected before birth through routine prenatal care. [1]

1. Prenatal Ultrasound: Providers can often see the organs developing outside the abdominal wall as early as the second trimester. [1]

2. Amniocentesis: A test where fluid is removed from the uterus to check for chromosomal abnormalities. [1]

3. Fetal Echocardiogram: Because heart issues are common in babies with omphalocele, this specialized ultrasound checks the baby's heart function. [1]

4. Blood Tests: Screening for high levels of alpha-fetoprotein, which can indicate the need for further testing. [1]

How is an omphalocele treated and surgically repaired?

The goal of treatment is to safely return the organs to the abdomen and close the opening. The approach depends on the size of the omphalocele and the baby's overall health. [1]

Small Omphalocele Repair

For smaller defects, surgeons typically perform an operation shortly after birth. They gently place the intestines back into the belly and close the hole in the abdominal wall. [1]

Giant Omphalocele Repair

For large cases, a “staged” approach is often used. Because the baby's abdomen is too small to hold all the organs at once, surgeons move them back gradually over several days or weeks. During this time, the organs are protected by a sterile sheet. Some babies may also need a ventilator to help them breathe while their abdomen adjusts to the new pressure. [1]

What is the outlook and recovery for an omphalocele?

The long-term outlook for a baby with an omphalocele is generally very good, especially if the condition is the only health issue present. If the baby has other complications, such as heart or lung problems, recovery may take longer and require more specialized support. Most babies are able to eat normally and participate in regular activities by the time they are ready to go home.

Conclusion

A diagnosis of omphalocele can be overwhelming for parents, but modern surgical techniques have made it a highly manageable condition. With early detection and a specialized care team, most babies go on to live healthy, active lives. Staying informed and working closely with your healthcare providers are the best ways to support your baby's journey to recovery.

Frequently Asked Questions

What is an omphalocele?

It is a birth abnormality where abdominal organs protrude through the belly button area.

Is it the same as an umbilical hernia?

No, an omphalocele is a more serious defect where organs are outside the body in a protective sac.

What is another name for it?

It is also known as exomphalos.

How common is it?

About 1 in every 4,200 babies in the U.S. is born with it.

What organs can be involved?

Intestines, liver, and sometimes the spleen.

Is the sac see-through?

Yes, it is a transparent membrane called the peritoneum.

When does it develop?

It happens before birth, usually if the intestines don't return to the belly by week 11.

How is it diagnosed?

Usually by a prenatal ultrasound during the second or third trimester.

Can it be seen at birth?

Yes, if not found during pregnancy, it is immediately obvious at birth.

What is a “small” omphalocele?

A defect less than 5 centimeters in diameter involving only the intestines.

What is a “giant” omphalocele?

A defect larger than 5 centimeters involving multiple organs.

Are there other health risks?

Over two-thirds of babies with omphalocele have other abnormalities in the heart, spine, or limbs.

What is Beckwith-Wiedemann syndrome?

A condition sometimes linked to omphalocele that causes high insulin and low blood sugar.

Does maternal age matter?

Women over 35 may have a slightly higher risk.

Can smoking cause it?

Smoking is a known risk factor for developing an omphalocele.

Is alcohol a risk?

Yes, drinking alcohol during pregnancy can increase the risk.

What about medications?

Certain SSRIs or fertility drugs have been linked to a higher risk.

Can genetics play a role?

Yes, it can sometimes run in families or be linked to chromosomal issues like Down syndrome.

What is Trisomy 18?

A chromosomal abnormality often associated with omphalocele.

What is an amniocentesis?

A test that checks the fluid around the baby for genetic issues.

Why is a heart ultrasound needed?

To check for heart malformations, which are common in these cases.

What is alpha-fetoprotein?

A protein produced by the fetus that can be measured in the mother's blood.

How is a small omphalocele treated?

With a single surgery shortly after birth.

How is a giant omphalocele treated?

Usually in stages over several days or weeks.

Why do it in stages?

To allow the baby's abdomen to grow and avoid cutting off blood flow to the organs.

What is a sterile sheet?

A protective covering used to keep the organs safe during staged surgery.

Will the baby need a ventilator?

Some babies with large omphaloceles need help breathing after surgery.

What is a skin flap?

A surgical technique used to cover the opening if there isn't enough skin.

Can the baby eat after surgery?

Most babies eat normally by the time they go home.

What if they have trouble eating?

A feeding tube may be used if the baby has other complications.

Is there a recovery period?

Yes, the baby will spend time in the NICU (Neonatal Intensive Care Unit).

Can the baby be active?

Once recovered, the baby can participate in age-appropriate activities.

What is the long-term outlook?

Most babies make a full recovery if there are no other major health issues.

Does it affect future pregnancies?

Discuss your specific case with a genetic counselor or doctor.

Are there activity restrictions?

Usually none once the surgical site has fully healed.

Can it be prevented?

There is no guaranteed way to prevent it, but avoiding tobacco and alcohol helps.

What is the peritoneum?

The thin membrane that lines the abdominal cavity and covers the organs.

How do I pronounce it?

It is pronounced uhm-FA-lo-seal.

Is fetal surgery an option?

In some specialized centers, fetal evaluation and planning are key.

What is a NICU?

A specialized hospital unit for newborns who need intensive medical care.

Can it cause lung problems?

Large omphaloceles can sometimes lead to poor lung development.

What is an MRI used for?

To get detailed images of the fetus's organs before birth.

Is it the same as gastroschisis?

No, gastroschisis is a different abdominal wall defect where there is no protective sac.

What is Trisomy 13?

Another chromosomal abnormality that can be associated with omphalocele.

Can nutrition affect risk?

Poor maternal nutrition or vitamin deficiencies may increase the risk.

How often are ultrasounds needed?

Frequent ultrasounds are used to monitor fetal growth.

What is a fetal echocardiogram?

A specialized ultrasound of the fetus's heart.

Will my baby have a scar?

Yes, there will be a scar from the surgical repair.

Can the belly button be reconstructed?

Surgeons often try to create a natural-looking belly button during repair.

Where can I find more info?

Consult your pediatric surgeon and visit Rinnit.com for health resources.

Related Reading

20-Week Ultrasound (Anatomy Scan): What It Checks, How to Prepare and What Results Mean explains the mid-pregnancy scan that can detect signs of this condition before birth.

References

1. Cleveland Clinic. Omphalocele. Cleveland Clinic. Last updated July 11, 2024. https://my.clevelandclinic.org/health/diseases/10030-omphalocele

2. Shi X, Tang H, Lu J, et al. Prenatal genetic diagnosis of omphalocele by karyotyping, chromosomal microarray analysis and exome sequencing. Ann Med. 2021;53(1):1285-1291. PMID 34374610. https://doi.org/10.1080/07853890.2021.1962966

3. Isaac Maximo LM, De Carlos GA, Messias Hirano Padrao E, et al. Pulmonary hypertension association with mortality in newborns with giant omphalocele: a systematic review and meta-analysis. Neonatology. 2026;123(5):641-650. PMID 41911150. https://doi.org/10.1159/000551723

4. Barrios Sanjuanelo A, Abelló Munarriz C, Cardona-Arias JA. Systematic review of mortality associated with neonatal primary staged closure of giant omphalocele. J Pediatr Surg. 2021;56(4):678-685. PMID 32981659. https://doi.org/10.1016/j.jpedsurg.2020.08.019

Disclaimer

This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional regarding any pregnancy concerns or medical conditions.