What is omphalocele?
Omphalocele is a rare birth defect that occurs in 1 in 4,000 — 7,000 live births. It is a type of abdominal wall defect in which the bowel, liver and other abdominal organs protrude out of the abdomen and into the base of the umbilical cord. Surgical repair is performed primarily in stages, or after a period of waiting which can last several months.
Omphalocele occurs very early in pregnancy when the abdominal cavity fails to form normally. The abdominal cavity is normally formed at three to four weeks gestation when the disk-like embryo undergoes infolding. A large or “giant” omphalocele forms when there is a failure of lateral infolding of the embryo, resulting in an inadequate abdominal cavity with containment of the abdominal organs only by a thin clear membrane called the omphalocele sac.
Smaller omphaloceles, also referred to as “hernia of the cord,” form later (eight to 11 weeks gestation) after normal infolding of the embryo occurs (resulting in a formed abdominal cavity), when the umbilical ring fails to close around the umbilical cord resulting in a small defect that usually contains only intestine. Small omphaloceles are more likely to be associated with chromosomal defects or syndromes.
Omphalocele differs from gastroschisis in that the protruding organs are covered by the omphalocele sac. Gastroschisis has no sac and is likely caused by a rupture of a hernia of the cord, resulting in extrusion of intestine through the small umbilical defect. In contrast to gastroschisis, a ruptured giant omphalocele has all of the organs, including liver, outside the abdomen without a covering membrane.
In addition, compared to gastroschisis, giant omphaloceles are frequently associated with small lung size. Finally, whereas gastroschisis often develops in the first pregnancy of young mothers, omphaloceles typically develop in the pregnancies of older women.
The Center for Fetal Diagnosis and Treatment sees between 30 and 50 cases of omphalocele each year, making us one of the most experienced teams in the world when it comes to diagnosing and treating this rare condition.
For more information about the diagnosis, delivery and treatment of babies with omphalocele, watch our educational video series about abdominal wall defects.
Evaluation and diagnosis of omphalocele
The diagnosis of omphalocele is usually made by ultrasound in the middle or second trimester of pregnancy (about 20 weeks). An amniocentesis is recommended to evaluate for chromosomal abnormalities or genetic syndromes. Families referred to the Center for Fetal Diagnosis and Treatment at The Children’s Hospital of Philadelphia undergo a comprehensive evaluation that includes:
- Detailed level II fetal ultrasound — a noninvasive, high-resolution imaging study used to determine the amount and type of abdominal organs within the umbilical sac and possible rupture of the sac, as evidenced by free floating bowel or the liver outside of the abdomen. The possibility of other anatomic abnormalities is evaluated. Lung size can also be estimated.
- Ultrafast fetal MRI — an additional imaging technique advanced at CHOP that shows the omphalocele and the entire fetus. The MRI is used to confirm ultrasound findings and evaluate for the presence of any other anatomic abnormalities, especially central nervous system anomalies. Lung volumes are determined and compared to normal values at that gestational age (this comparison is called the observed-to-expected lung volume ratio, or O/E ratio).
- Fetal echocardiogram — an ultrasound of the fetal heart to look for heart defects. A unique collaboration with our specialized Fetal Heart Program, staffed by pediatric cardiologists with fetal expertise, ensures early diagnosis of heart defects.
For proper counseling and management of pregnancies diagnosed with omphalocele, it is important to distinguish fetal omphalocele from other abdominal wall defects and check for associated birth defects.
What are the risks to my baby?
The prognosis for a baby with an omphalocele largely depends upon the size of the herniation and the presence or absence of other birth defects. More than half of all babies born with omphalocele have other birth defects, including brain, spine, heart, gastrointestinal issues, genitourinary problems or Pentalogy of Cantrell. Other syndromes more commonly seen with small omphaloceles include chromosomal abnormalities such as trisomy 18, or genetic syndromes such as Beckwith-Wiedemann syndrome.
One-third of all babies with omphalocele have liver herniation, which is often associated with a small belly size and small lungs (known as pulmonary hypoplasia), two factors that can affect treatment and long-term outcomes. Up to one-third can also have a heart defect which can also affect long-term outcome.
After a comprehensive diagnostic evaluation, CHOP’s multidisciplinary team (pediatric surgeon, high-risk obstetrician/reproductive geneticist, nurse coordinator and genetic counselor) meets with your family to review test results, confirm the diagnosis, explain options and potential outcomes, and answer questions.
Our team works with you to develop a treatment plan tailored to the specific needs of you and your baby. Your family will also receive educational information about omphalocele and can tour CHOP’s Garbose Family Special Delivery Unit (SDU) and the Harriet and Ronald Lassin Newborn/Infant Intensive Care Unit (N/IICU).
Monitoring and delivery of babies with omphalocele
Your pregnancy will be closely monitored, particularly in the third trimester. Regularly scheduled ultrasounds help us detect developing issues throughout the pregnancy. If monitoring indicates fetal distress, our team, with over 100 years combined experience, is prepared to move quickly and ensure the best outcome for both mother and baby.
Delivery of babies with omphalocele may be vaginal or cesarean (C-section) depending on the size and contents of the omphalocele. For a small omphalocele that does not involve the liver, vaginal delivery is possible, provided there are no obstetrical contraindications. Babies with liver in the omphalocele are delivered by C-section to protect the omphalocele and prevent organs from rupturing or bleeding, which can be life-threatening.
Planning for Jackson's Arrival
At CHOP, babies with omphaloceles are born in the SDU, allowing for the highest level of immediate care for the newborn, as well as expert obstetric services for the mother — all within the same pediatric hospital. The world’s first birth facility designed exclusively for pregnancies complicated by birth defects, the SDU is a vital part of our team’s ability to provide comprehensive care.
Your baby is stabilized by a highly specialized team of pediatric surgeons, neonatologists, specially trained nurses and respiratory therapists, all with extensive experience in treating neonates with omphalocele. The omphalocele sac is wrapped with a sterile dressing and particular attention is paid to breathing assistance, as babies with giant omphaloceles typically have small lungs and often require a breathing tube and ventilator.
Once your baby is stabilized, you will have a chance to meet him before he is brought to the N/IICU.
Surgical repair of the omphalocele takes place after birth. The overall health of your baby, especially his respiratory status, the size of the omphalocele and the degree of liver involvement, determine the type of omphalocele treatment. Babies with small omphaloceles are monitored closely until they are ready to undergo primary repair. This means the herniated organs are placed back into the abdominal cavity and the defect is completely closed in one operation.
For babies with giant omphalocele that contain the liver and other organs, a staged repair (involving several steps, also called the Schuster procedure) is needed to gradually return the abdominal contents to the belly. This gradual process provides time for the abdominal wall to stretch to accommodate the viscera, and ensures that the lungs can continue to grow and expand without immediate pressure of surgical closure.
In a staged repair, a mesh fabric is sewn to the fascia (connective tissue) and muscle on each side of the omphalocele defect. The two pieces of fabric are then sewn together over the defect, and the omphalocele sac remains intact. Your baby returns to the N/IICU, where his organs are gradually returned to the abdominal cavity and the mesh is continuously tightened over the course of days or weeks. Once all of his organs are back in his belly, your child's surgeons can remove the mesh and safely perform the final closure. Babies are monitored very closely throughout this process.
In some cases of babies with giant omphaloceles, the amount of organs protruding may be so large that there isn’t enough room in your baby’s body to fit them all inside, preventing omphalocele closure in the neonatal period. Small lung size may also delay closure. If this is the case, surgery may be postponed for months to allow the lungs and body to grow. During this time, a technique called “paint and wait” is used. The sac covering the omphalocele is painted with an antibiotic cream and covered with elastic gauze. Your baby’s skin will grow over the sac with time.
Some babies do not need to remain hospitalized during the paint and wait treatment. We will teach you how to do this technique so that you can bring your baby home. When all of the contents of the omphalocele are covered with skin and the lungs have had a chance to grow, your child's surgeon will talk with you about options for surgically closing the remaining hole.
N/IICU stays for babies with omphalocele can range from several days to several months, depending on your baby’s lung function, the size of the defect and timing of surgical repair. Infants are monitored for common complications of omphalocele, such as feeding difficulties, bowel obstruction and gastroesophageal reflux. Babies with omphalocele also frequently have inguinal hernias, another condition that requires surgical repair.
Before your baby is ready to go home, he will need to gradually meet certain milestones, including:
- breathing on his own (may need supplemental oxygen)
- full enteral feedings (by mouth or feeding tube)
- maintaining his own temperature
- gaining weight
Another important milestone is making sure you and any other caretakers are ready to take care of your child at home. Our team is here to support you throughout that learning process.
Parents are an integral part of the team and play an important role in caring for their baby from the start. During the stay in the N/IICU, a specialized team of surgeons, nurses, speech therapists (for feeding therapy), lactation consultants, respiratory therapists and social workers are available as needed to help educate your family about what you can do during the hospital stay, as well as caring for your baby after discharge. The nursing staff teaches you special feeding techniques and other specialized care that your child might need.
Families also have access to the Connelly Resource Center and CHOP’s Child Life department. These programs provide resources and support to make the hospital experience easier on the entire family. From sleeping rooms and laundry facilities to programs that help siblings adjust to having a new baby in the family that requires special medical care, the team can help every family make use of all resources available to them.
Babies who have had small omphaloceles receive follow-up through their pediatrician and the pediatric surgeon. Those without associated defects generally have good long-term outcomes. Babies with giant omphaloceles typically need to be followed more closely by a multidisciplinary team as part of ongoing omphalocele treatment. The pulmonary hypoplasia (small lungs) associated with giant omphalocele can affect not only breathing, but also heart function, ability to feed, and overall development. This represents a significant long-term health issue.
The Children’s Hospital of Philadelphia has created a unique Pulmonary Hypoplasia Program (PHP) that provides comprehensive, interdisciplinary care specifically focused on this challenging condition. The multidisciplinary team that follows children throughout infancy and well into school age includes:
- Pediatric surgeons
- Pediatric pulmonologists
- Pediatric cardiologists
- Developmental pediatricians
- Developmental psychologists
- Social workers
- Other specialties as needed, including gastroenterology, orthopedics, urology, physical therapy and occupational therapy.
The PHP team collaborates with each family to improve your child’s health and development, monitor growth, monitor for surgical issues that may develop, and help locate resources and support near the home.
Updated: March 2013