Inside Out: Understanding Abdominal Wall Defects (AWD)

Learning Your Baby Has a Problem

Kate Distasio, Parent: Entenzo is our first child. I found out I was pregnant the end of November last year. I went for genetic testing initially and that's when they first saw something.

Dom Distasio, Parent: They just gave us a hint that here might be something wrong, which was at 12 weeks.

Kate Distasio, Parent: At 15 weeks they confirmed that he had gastroschisis.

Dom Distasio, Parent: Not knowing what it was, we were very scared at that point.

Stefanie B. Kasperski, MS: Getting the diagnosis of a fetal anomaly is devastating to a family. They go from the joy of being pregnant, the joy of having a baby, to my baby has a problem. My baby might not survive. Where do I turn?

Gayle Hughes, Parent: We were told that my son had a congenital defect called an omphalocele.

Charles Hughes, Parent: It was a difficult diagnosis to accept.

Gayle Hughes, Parent: They looked at all of our tests that we had had done up to that point and basically told us that they thought that they could fix Charlie's problem.

Charles Hughes, Parent: They thought they could help us and that it would be probably the most challenging thing we'd take on in our lives.

Stefanie B. Kasperski, MS: They want the best care for their baby. They want the best place, the best team to care for their child. And The Children's Hospital of Philadelphia's Center for Fetal Diagnosis and Treatment has a multidisciplinary team in place that will help the family and that will guide the family to try and achieve the best possible outcome for their child.

Understanding Abdominal Wall Defects (AWD)

Natalie E. Rintoul, MD: Abdominal wall defects occur very early in gestation.

Tracy M. Widmer, MS: The abdominal wall doesn't form exactly as it should. And as a result, abdominal contents can protrude out of the abdomen.

Lori J. Howell, RN: The two types of major abdominal wall defects that we deal with are generally grouped into omphaloceles or into gastroschisis.

N. Scott Adzick, MD: The differences between a gastroschisis and omphalocele, the major difference is that an omphalocele is usually midline, right in the middle, it is covered with a membrane and it may or may not contain the liver.

Gayle Hughes, Parent: If you can imagine a balloon full of abdominal organs on top of his stomach born outside of the body, that's what he looked like when he was born.

Natalie E. Rintoul, MD: Babies with omphaloceles fall into a wide spectrum.

N. Scott Adzick, MD: Then we can divide them up into small, which is bowel only; large which is some liver; and giant, which is the majority of the liver. A gastroschisis is to the side of the umbilical cord, usually on the right side. There's no membrane so the small and large intestine can protrude through this hole in the abdomen and go out into the amniotic fluid. The causes of these two major abdominal wall defects are unknown.

Mark P. Johnson, MD: One thing that we know is that very early in embryologic development, the bowel actually migrates out into the umbilical cord. And usually about 12 weeks or so it's already migrating back into the abdomen where it kind of rotates and assumes its final position.

N. Scott Adzick, MD: So we've all had an omphalocele at some point in time. But then the abdomen properly closed, whereas the way I explain it to parents is that with omphalocele the abdominal wall defect forgot to close.

Natalie E. Rintoul, MD: Abdominal wall defects are by themselves relatively rare problems in the newborn period.

N. Scott Adzick, MD: We think for omphalocele it's probably 1 in every 4,000 to 7,000 births, which is just an estimate. For gastroschisis, about 1 in every 5,000 births. But it's interesting that gastroschisis worldwide is becoming more and more frequent.

Diagnosis and Treatment Options

Stefanie B. Kasperski, MS: For most families this is an overwhelming situation because they typically go in for an ultrasound wanting to know the gender of their baby, not expecting that they are being given a diagnosis of a serious birth defect.

Natalie E. Rintoul, MD: The two types of abdominal wall defect are very different.

N. Scott Adzick, MD: They're usually diagnosed in one of two ways: either the maternal alpha-fetoprotein screening because that fetoprotein goes into the amniotic fluid, leaks across to the mother's circulation and she has this elevated fetoprotein.

Mark P. Johnson, MD: So the simple blood test for mother will detect these increased levels of protein and tell the obstetrician that there's something going on here that needs to be looked at further.

Lori J. Howell, RN: From there, they go on to a screening ultrasound. And that screening ultrasound detects the actual anatomic problem of either a gastroschisis or an omphalocele.

N. Scott Adzick, MD: The diagnosis is made by seeing bowel, small and large bowel, floating in the amniotic fluid.

Mark P. Johnson, MD: There's a membrane covering it and holding it in so that would be an omphalocele versus these free-floating loops of bowel that would suggest that it was a gastroschisis.

Lori J. Howell, RN: Just like with all birth defects that we deal with, our job is to confirm the diagnosis and then to talk to the families about what their options are for the pregnancy.

Stefanie B. Kasperski, MS: We provide a comprehensive one-day evaluation which consists of an ultrasound, a fetal ultrafast MRI as well as a fetal heart study to evaluate the fetus completely and ensure that there are no other abnormalities present.

N. Scott Adzick, MD: With omphalocele, it's also very important to get a karyotype, usually by amniocentesis.

Stefanie B. Kasperski, MS: Following the comprehensive evaluation, the family meets with the multidisciplinary team of specialists that typically includes a high-risk obstetrician, a pediatric surgeon, as well as a coordinator to discuss all of the findings and to discuss all of the options that are available to that particular family.

N. Scott Adzick, MD: We try very hard to counsel the families with regard to what some of the issues and obstacles may be not only before birth and during birth but after birth.

Lori J. Howell, RN: Finding out that your baby has a birth defect is devastating in and of itself. Getting a plan through the team at our center makes it almost bearable.

Stefanie B. Kasperski, MS: So it's important for us to be able to provide that family from the first moment that they contact us with the sense of, "We're here to help you in any way that we can."

Other Issues Related to AWD

N. Scott Adzick, MD: Gastroschisis is much more common in young mothers. So it's not unusual for mothers to be less than 20 years of age carrying a fetus with a gastroschisis.

Lori J. Howell, RN: There is no known cause for gastroschisis and it tends to be an isolated problem.

Stefanie B. Kasperski, MS: Meaning that there are more often than not no other birth defects that are present in that particular fetus. As opposed to an omphalocele where there is an increased risk of other fetal abnormalities.

N. Scott Adzick, MD: Such as central nervous system problems, cardiac problems, gastrointestinal problems, even problems such as diaphragmatic hernia, genital urinary problems, problems with the kidneys.

Gayle Hughes, Parent: We went essentially through a checklist of all of the things that could be wrong with him aside from this congenital defect.

Stefanie B. Kasperski, MS: Paradoxically, it is the smaller omphaloceles, the ones that might have just bowel involvement, that are actually at increased risk to be associated with chromosomal abnormalities or potentially a genetic syndrome such as Beckwith-Wiedemann syndrome, or other conditions that might be present might include Pentalogy of Cantrell.

N. Scott Adzick, MD: Prognosis, outcomes — things of that sort are really pegged in those cases, not so much to the omphalocele but to the other associated abnormalities.

Lori J. Howell, RN: Once families are educated about outcomes and the types of children these babies can be, then they can make the decisions that are best for their family.

Monitoring Your Baby before Birth

Lori J. Howell, RN: Monitoring babies with abdominal wall defects is crucial to making sure that you get the best outcome.

N. Scott Adzick, MD: For surveillance of gastroschisis, there are several important things to follow. There's about a 5 percent rate of intrauterine fetal demise during the third trimester. So the protocol that we institute here is routinely beyond 30 to 32 weeks' gestation. We do twice weekly sonographic surveillance, we are doing bio-physical profiles and non-stress testing because we want to make certain the fetus is not getting into trouble or it's not at risk to die before birth. It's important to follow fetal growth because these fetuses, for whatever reason, tend to be small and may be due in part to loss of protein from the extruded bowel into the amniotic fluid.

Kate Distasio, Parent: At 32 weeks we were coming in twice a week. And that's when it really kind of hit us that, at least hit me that, it was getting closer and closer.

N. Scott Adzick, MD: The other things to follow with gastroschisis are the appearance of the bowel. Because the bowel, due to the amniotic fluid exposure or due to constriction at the abdominal wall defect, can cause bowel damage.

Mark P. Johnson, MD: And as the baby grows and that defect becomes more restrictive or constricting, it can actually interfere with blood flow out to the bowel or it can interfere with blood flow back from the bowel.

N. Scott Adzick, MD: And that can cause a piece of the intestine to die leading to what's called intestinal atresia. So the consequences of a defect in the abdominal wall, if it's too small, can be fairly devastating.

Kate Distasio, Parent: Entenzo had about, I think, it was five different things that he had to accomplish during the ultrasound and then a non-stress test. They would just hook me up to a monitor that would check his heart rate and would also see if I was having contractions. His heart rate had to increase when he moved. And what gave it away the day that I had him was his heart rate was elevated and it didn't change.

Dom Distasio, Parent: Within a few minutes they basically came back in and said, "You're delivering a baby today."

Lori J. Howell, RN: So things can change quite rapidly. And it's important to have the team that can mobilize quickly again to get the best outcome for mother and baby.

N. Scott Adzick, MD: For omphalocele, once the workup is done including karyotyping, it's important to do serial sonographic surveillance, particularly following for fetal growth.

Gayle Hughes, Parent: We went through five months of continual testing.

Mark P. Johnson, MD: One of the things that we look for prenatally with giant omphaloceles is how is the chest growing.

N. Scott Adzick, MD: Because giant omphaloceles are associated with relative pulmonary hypoplasia, small lungs which obviously can affect prognosis.

Mark P. Johnson, MD: If the chest is way behind in size, then we know that these are babies that are going to have big, big trouble breathing.

N. Scott Adzick, MD: So we're working hard these days by ultrasound and by MRI to try to judge fetal lung size. And one advantage that newborns and fetuses have is that they can have remarkable compensatory lung growth, particularly after birth once the omphalocele is closed, so that they can eventually lead normal lives.

Lori J. Howell, RN: It's one of the hallmarks of our center that we follow mothers and their babies so closely to ensure the best outcome.

Gastroschisis: Delivery and Care

N. Scott Adzick, MD: For babies with gastroschisis, the average gestational age at the time of birth is between 35 and 37 weeks' gestation, where term, of course, is 40 weeks. So as a rule these babies come early. For gastroschisis, there is no advantage to a caesarean section delivery over a vaginal delivery in most cases.

Mark P. Johnson, MD: There are some physiologic benefits to being delivered vaginally. It helps to squeeze some of the fluid out of the lungs. It triggers reabsorption of fluid within the lungs. It's less risk to the mother. The recovery time is certainly much more rapid after a vaginal delivery and allows the mom to be down at the bedside within hours.

N. Scott Adzick, MD: Of course, if there's a maternal indication for a caesarean section or if a stress-gastroschisis fetus is having difficulty before birth, then a caesarean section might be mandatory.

Mark P. Johnson, MD: It's critically important to watch these babies carefully during the labor process because they are kind of at the fringe. And some of them may not tolerate labor, and failure to recognize that they're not tolerating that labor can result in a much, much more compromised child.

N. Scott Adzick, MD: When a baby with a gastroschisis is born and has been moved from the delivery room immediately to the resuscitation room, we need to assess the baby's breathing status, place an IV or two, place a nasogastric tube to decompress the intestine.

Natalie E. Rintoul, MD: It's really important to keep the bowel decompressed so that you don't have reflux of gastric contents. There's a risk that they could then aspirate or breathe that into their lungs. So that's a really critical step.

N. Scott Adzick, MD: The thing we worry about is the constrictive effect of the abdominal wall defect, which can cause damage to the blood supply or blood drainage from the bowel that can lead to loss of bowel, which can be difficult to repair.

Natalie E. Rintoul, MD: So we have to have very careful positioning of the infant, usually on their right side, to take the pressure off that area and very close surveillance of the bowel and whatever else is out to make sure that it looks well perfused and healthy.

Dom Distasio, Parent: By the time I got in there, the baby was already, I guess, what we call prepped. They basically put plastic over his body because of infection and to keep everything moist.

N. Scott Adzick, MD: The baby is started on antibiotics. And our protocol at the current time for the most part for uncomplicated gastroschisis is to immediately place a spring-loaded silo. The concept is like a silo on a farm that contains grain. There's a long sheet that's clear silastic so you can see the intestine. And the intestine is placed sterilely into the sheet. And then the spring-loaded base is manipulated to go inside the abdomen. And since the spring is larger, the circular spring is larger than the defect, that stays in place.

Natalie E. Rintoul, MD: And it's suspended from the top of the baby's bed. With gravity, the bowel can then move from the silo into the abdomen. After a day or two, we begin the process of daily reductions where they gently squeeze on the silo and tie a piece of umbilical tape to hold the bowel down. So that you're creating a little bit of pressure on the intestines that are going into the abdomen.

N. Scott Adzick, MD: And the baby's abdominal wall and abdominal capacity will increase dramatically from day to day such that in the usual circumstance, within a week or sometimes substantially less than that, we can reduce the intestine into the abdomen, bring the baby to the operating room, remove the spring-loaded silo, close the fascia, the strength layer, and then close the skin around the belly button, around the umbilical cord, such that a fairly normal-appearing umbilicus is maintained.

Omphalocele: Delivery and Care

Mark P. Johnson, MD: For small- to moderate-size omphaloceles, as long as the baby's testing is reassuring and there are no obstetrical contraindications, those are babies that actually do better with a vaginal delivery. Babies with giant omphaloceles or omphaloceles that contain liver are a whole different issue.

N. Scott Adzick, MD: It is important in our view for fetuses that have a large or giant omphalocele in which there is a portion or majority of the liver in the omphalocele sac to have a planned delivery by cesarean section because of the risk of dystocia or difficulty in the delivery with a giant omphalocele, or because the risk of damage to the liver during the vaginal delivery.

Gayle Hughes, Parent: Charlie was delivered by C-section and immediately rushed over here to Children's Hospital and put in the Neonatal ICU.

Natalie E. Rintoul, MD: In babies with omphaloceles, their bowel and liver are covered with a sac. And that sac is critical.

N. Scott Adzick, MD: If the omphalocele sac ruptures, then the complication risk and the risk of death skyrockets.

Tracy M. Widmer, MS: So it's one of our top concerns when the baby is born that someone's sole responsibility is management of that omphalocele sac while someone else's responsibility is management of the airway.

Natalie E. Rintoul, MD: A lot of times infants with a giant omphalocele will have small lungs and require assistance right from the moment they're delivered.

Gayle Hughes, Parent: Charlie was put immediately on a ventilator and was on a ventilator for almost two months.

N. Scott Adzick, MD: For an omphalocele we usually wrap with a sterile dressing the entire omphalocele and then bring the baby to the intensive care nursery.

Gayle Hughes, Parent: Just going to the NICU for the first time was very scary because you saw all these very, very sick babies and realized that that would be you.

N. Scott Adzick, MD: Once the baby is stabilized, the issue is how is the omphalocele going to be closed.

Tracy M. Widmer, MS: Babies with small omphaloceles often are able to go to the OR and have what's known as a primary repair, which means they go to the OR one time and are able to have it closed right then and there.

Natalie E. Rintoul, MD: Then there are infants with giant omphaloceles that contain different components of bowel and liver. And those infants are a little more complicated.

N. Scott Adzick, MD: There's not much abdominal capacity because virtually everything is out, particularly the liver. The majority of the liver is in the omphalocele sac. So the issue there is how you can gradually reduce the contents of the omphalocele sac back into the abdomen and eventually close it without causing harm to the baby.

Mark P. Johnson, MD: You could imagine trying to slowly reduce all of those organs back in. Well, as you do that what does it do? It pushes the diaphragm up. If you have a small chest cavity and small lungs, any kind of disturbance can just push the kid over the edge and to a major respiratory crisis.

N. Scott Adzick, MD: We use a technique which involves bringing the baby to the operating room, finding the fascia or the strength layer, two bands of muscle along each side of the omphalocele defect, then sewing a teflon-coated mesh sheet on each side to the fascia so you have two sheets coming up. And then you sew the sheets together and you leave the omphalocele sac intact. Then usually on an every-other-day basis, you can then crimp down on these two sheets and sew them back together so you eventually close the baby all the way.

Natalie E. Rintoul, MD: During that time we have to follow them very closely to make sure that with the challenges of closing the abdominal wall defect, we don't interfere or have any setbacks with their pulmonary performance.

Tracy M. Widmer, MS: We watch the pressures that it takes to fill their lungs with air. We expect that those pressures will be high initially postop. And once they begin to come down, then that tells us that the baby's ready to go back to the OR.

Gayle Hughes, Parent: He went through seven different surgeries in the course of three weeks. It seemed like it was every other day.

Tracy M. Widmer, MS: And so this can take place over a period of a week or longer where they go to the OR every other day, every third day until final closure.

After AWD Surgery: Your Baby's Feeding and Growth

Natalie E. Rintoul, MD: Once an infant has an abdominal wall closure, the next challenge is to initiate feeds. And that's a challenge.

Kate Distasio, Parent: It took them a week to do the closure surgery. It took another week at least, if not a little longer, for him to poop. And then they started feeding him 5 milliliters at a time.

Natalie E. Rintoul, MD: The feeds are very small initially, oftentimes not more than a teaspoon. And we wait and watch.

Tracy M. Widmer, MS: And try to work them up to where they're taking enough calories and enough volume to be able to gain and grow to get off their IV fluids.

Kate Distasio, Parent: We definitely had our patience tested with trying to get him to full feeds especially, I think, it was even harder that he wanted to eat.

Natalie E. Rintoul, MD: So it's a delicate balance. You want to advance the feeds as fast as you can to get them off, but yet you don't want to go too quickly and have a setback. Infants with abdominal wall defects are at risk of having a lot of trouble with reflux. And we try to do every thing possible to treat them medically.

N. Scott Adzick, MD: The need for therapy for gastroesophageal reflux is quite common with giant omphalocele. And those babies who don't respond to medical therapy, they may require an operation called a fundoplication, which creates a one-way valve to prevent gastroesophageal reflux.

Natalie E. Rintoul, MD: To make it more difficult anatomically for reflux to occur. But we really try everything else before we get there. Babies with gastroschisis are at risk of something called late necrotizing enterocolitis.

N. Scott Adzick, MD: That's a serious infection of the bowel that we'd like to minimize the risk thereof. And if it occurs, it usually responds to bowel rest and intravenous antibiotics.

AWD Recovery Time and Going Home

N. Scott Adzick, MD: Every parent, particularly every mother, wants to know how long is my baby going to be in the NICU?

Tracy M. Widmer, MS: For a baby with gastroschisis, in the best-case scenario, maybe a month.

N. Scott Adzick, MD: If a baby has a small omphalocele that's straightforward to close, they'll be in the hospital for less than a week if there is nothing else wrong, if it's an isolated omphalocele. Babies with a large omphalocele will be here for a longer period of time.

Charles Hughes, Parent: They took us down to see the intensive care unit that day and said, "Get used to this place because you'll be living here for a while."

N. Scott Adzick, MD: Babies with a giant omphalocele, the family has to be prepared for at least a month or more stay and maybe even significantly longer than that because there are other issues.

Tracy M. Widmer, MS: They have to successfully breathe off the ventilator. They need to be able to tolerate feeds, and they need to be able to gain weight and grow.

N. Scott Adzick, MD: But basically the baby's progress is going to inform us about how long he or she is going to be in the hospital.

Natalie E. Rintoul, MD: A lot of babies go home still needing care.

Lori J. Howell, RN: So the ability to help them parent, both when the child is more seriously ill to the point where they're going home, requires a lot of education, a lot of support, a lot of continuity of care.

Dom Distasio, Parent: They allowed us to really do everything just like if we took the baby home.

Natalie E. Rintoul, MD: They're a part of the team right from the beginning, and we teach them a lot of what we do.

Dom Distasio, Parent: It really helped out a lot. I think, it made us feel much more comfortable, too, especially when we got home, that we could handle everything.

Charles Hughes, Parent: One nurse was primary in training us. I said, "Do you think that we're really ready to do something on this?" And she said, "I'm not going to let you take my little Charlie home unless you know how to take care of him." And when the time came we took him home.

Follow-up Care for AWD

Kate Distasio, Parent: Entenzo is a very happy 4-and-a-half month old baby.

Dom Distasio, Parent: He's a very normal baby. He acts like any other baby. He has his moments. But he's a very happy baby, smiles a lot, drools a lot.

Gayle Hughes, Parent: Charlie is a sixth grader. He's a straight-A student. He is in the band. He plays for the middle school soccer team. He's on a swim team.

Stefanie B. Kasperski, MS: A couple of years down the road these babies do not act different. These babies are — you would not know that these babies ever had to go through what they had gone through.

N. Scott Adzick, MD: The follow-up with a gastroschisis will be with the pediatrician and the pediatric surgeon basically. It's all referable to the intestine.

Natalie E. Rintoul, MD: Families have to pay really close attention to their growth. The pediatrician needs to be really involved with that as well.

N. Scott Adzick, MD: But all those issues, for the most part, are completely surmountable.

Natalie E. Rintoul, MD: In an infant with an omphalocele, really the big challenge is the pulmonary status.

N. Scott Adzick, MD: So babies with a small omphalocele, they just need follow-up with their pediatrician and with their pediatric surgeon and that's about it. And the long-term outcomes are great. Babies with giant omphaloceles are those that need to be followed closely. And it's best to be followed by a multidisciplinary team.

Natalie E. Rintoul, MD: At The Children's Hospital of Philadelphia, we have a Pulmonary Hypoplasia Program that follows infants with small lungs.

N. Scott Adzick, MD: There is a pediatric surgeon there, a neonatologist there, developmental follow-up, gastroenterology, pulmonology, nutrition. All those things for the family's convenience and for optimal care are brought to the child, as opposed to the child being brought to each of those separate providers. So, I think, that's the way of the future for long-term follow-up.

Will My Baby Have a Belly Button?

N. Scott Adzick, MD: In the short-term, I don't think families worry about the appearance because they just want the baby to survive and do well. Well, long-term I think it's important to do a cosmetically-pleasing operation. And so if you did the operation and didn't create a belly button, that'd be an issue. It would be an issue on the beach. I mean, that would be an issue.

Natalie E. Rintoul, MD: They often do come back from the operating room with a belly button. I don't know how they do it, but it's amazing. And they really do look really good.

N. Scott Adzick, MD: For a giant omphalocele you have a long midline wound. So there's a long scar and then there's the belly button that we correct, so it actually looked pretty good. For babies with a small omphalocele closure, you don't actually see a scar because all the work's done through the belly button.

Natalie E. Rintoul, MD: Babies with a gastroschisis after their closure, they often — you'd never know.

N. Scott Adzick, MD: So it's important to have a belly button.