Children's Hospital Colorado

Gastroschisis

Gastroschisis (Greek for belly cleft) is a full-thickness defect in the abdominal wall almost always located immediately to the right of the insertion of the umbilical cord. The defect often measures 2 to 3 cm in diameter. In addition to the small abdominal wall defect, there is a variable amount of bowel protruding through the defect. The bowel is floating freely in the amniotic fluid. Young maternal age (less than 20 years old) is associated with an increased risk of gastroschisis along with cigarette smoking and recreational drug usage (methamphetamines, ecstasy and cocaine) around the time of conception. Mostly, however, the condition randomly occurs due to multiple factors rather than a single identifiable cause.

Second-trimester maternal serum-α –fetoprotein (MSAFP) screening has demonstrated an association between elevated MSAFP levels and gastroschisis. The diagnosis of abdominal wall defects during the first trimester is difficult because it is normal for the bowel to protrude or push into the base of the umbilical cord. Some have suggested that ultrasound examination should be performed at 14 weeks of pregnancy because the bowel should be entirely back in the abdomen by 11 weeks. By waiting until 14 weeks, this allows for any errors in estimating gestational age and decreases the chances for an incorrect diagnosis.

Abdominal wall defect comparisons

The conventional wisdom regarding abdominal wall defects is that gastroschisis, unlike omphalocele (a larger abdominal wall defect usually covered by a membrane) is not associated with chromosomal abnormalities (chromosomes are the “blueprint” for the baby). In contrast to omphalocele, gastroschisis associated abnormalities, if present, are confined to the GI tract.

Even in rare cases in which other abnormalities are present, they are not usually life-threatening. There is an increased risk for intrauterine growth restriction (poor growth of the baby while in the uterus) and stillbirth (where the baby dies inside the mother’s uterus). The rate of stillbirth may be as high as 10% of cases.

For Patients

Babies with gastroschisis are born with their intestines outside of their bodies, protruding through a hole in the abdomen that’s usually to the right of the umbilical cord. In some cases, the hole is large enough for additional organs to lie exposed. This abnormality begins in early pregnancy, when the abdominal wall muscles form incorrectly. Because the intestines are not encased in a protective sac, they can become irritated, twisted or swollen.

For parents, the prospect of having a child with gastroschisis can be scary. But the good news is that while babies born with the defect require surgery, the vast majority of patients achieve positive outcomes.

The Colorado Fetal Care Center (CFCC) is a national leader in diagnosing and treating gastroschisis. 

Gastroschisis is often detected through a routine prenatal ultrasound. It can also trigger abnormal results on a blood screening test. If not diagnosed during pregnancy, the condition is obvious once a baby is born.

Treatment of Gastroschisis is through surgery after birth where the intestines are placed back into the baby's belly. 

Role of fetal intervention

There are currently no fetal interventions for gastroschisis, though several researchers are using animal models to develop treatments.

Treatment Options for Gastroschisis

Modern medicine has advanced gastroschisis treatment in recent years, and surgeons at the Colorado Fetal Care Center are leading experts in diagnosing and treating the condition.

The extent of surgery required for your baby depends on how much of the intestines or additional organs lie outside of his or her body at birth and if there is an associated atresia or blockage in the intestine. Soon after the baby is born, surgeons place the organs inside of the abdominal cavity and close the opening in the abdominal wall. In more severe cases, where the opening is large and multiple organs are exposed, surgeons may cover them and return them to the abdomen one by one over a period of time.

Babies with gastroschisis often need additional treatment during this process, including intravenous nutritional supplementation, antibiotics to prevent infection and careful body temperature monitoring. Intravenous support is particularly important as it often takes days to weeks for the GI tract to function well enough for feedings to fully support the body.

Throughout treatment, our staff helps prepare families to care for their baby at home. We also connect loved ones with support groups and other resources to help them maintain their emotional and physical health.

What causes gastroschisis?

In most babies, the cause of gastroschisis is unknown. However, recent research has indicated that certain factors can increase a mother’s likelihood of having a baby with the condition. Those factors include having a baby as a teenager and smoking tobacco or drinking alcohol during pregnancy.

What are the most common gastroschisis symptoms?

In addition to the obvious location of the organs outside of the body and potential damage to those organs due to exposure, infants with this condition can experience problems with feeding, digestion and absorption of nutrients.

What is the impact of this diagnosis on my pregnancy?

Obstetric complications associated with gastroschisis include intrauterine growth restriction (IUGR), a condition in which the baby does not grow appropriately while inside the uterus.  This can affect up to 77% of fetuses with gastroschisis. Excess amniotic fluid (called polyhydramnios) or too little amniotic fluid (oligohydramnios) is also commonly seen with gastroschisis. There is also an increased risk for preterm labor due to the increased amount of amniotic fluid stretching the uterus more than usual. There will be many more ultrasounds performed in a pregnancy complicated by gastroschisis to assess growth and the amount of amniotic fluid. In addition, because of the increased risk for stillbirth, fetal testing involving monitoring the fetal heart rate twice per week usually begins between 30 to 32 weeks of pregnancy.

Will I need to have a cesarean section?

The recommended method of delivery for fetuses with abdominal wall defects is controversial. Part of the difficulty in comparing a normal vaginal delivery versus a cesarean section is the multiple factors that confuse the issue. It is difficult to determine if cesarean section provides any advantages. Most experts feel that a vaginal delivery avoids the risks of a cesarean section without negatively affecting the baby’s outcome in gastroschisis. Often, delivery is recommended around 37 weeks of pregnancy (approximately 3 weeks prior to the date when the pregnancy is full term) to avoid the chance of stillbirth. It is generally recommended to transfer the mother before delivery to a medical center that can better coordinate the obstetric, neonatal, and pediatric surgical teams. This is preferred over transferring the baby after birth.

What is the long-term outcome for babies with gastroschisis?

Surgical techniques to treat this condition have improved dramatically in recent years. While decades ago many babies with gastroschisis died at birth or shortly thereafter, today’s modern procedures enable the vast majority to live healthy lives. Their degree of need for ongoing care varies depending on the severity of their condition and associated symptoms.

Will this happen in future pregnancies?

Gastroschisis has been generally considered to be a somewhat random event caused by multiple factors that might not be able to be identified. There have been reports of it happening again in some families. Some estimate that the risk of this to happen again (referred to as recurrence risk) is approximately 4%. Meaning, if you took 100 families who had a baby with gastroschisis, four of those families would have another baby with gastroschisis, but 96 of those families would not experience this condition again.

For Healthcare Professionals

Gastroschisis is an abdominal wall defect that causes the abdominal organs – which can include the intestines, stomach, and bladder – to protrude without protection into the amniotic sac. This can lead to swelling or damage to those organs if blood flow is blocked or the intestines become twisted.

Gastroschisis is diagnosed via maternal serum screening and subsequent ultrasound during pregnancy. In a majority of cases, staged intervention and surgery is required immediately after birth to enclose and return the organs into the abdominal cavity. The multi-pronged process is gradual, with monitoring and an extended stay in the NICU required during this process.

Gastroschisis is a congenital abdominal wall defect that is characterized by a full thickness defect to the right of the umbilical cord. The defect is present as early as the 6th week of gestation. There are several theories as to what causes gastroschisis, such as a discrete teratogenic insult to the somatopleural mesenchyme resulting in an isolated defect in differentiation. Another theory is that the physiologic hernia of the cord ruptures in utero, before closure of the umbilical ring. Others have suggested that in-utero regression of the right umbilical vein leaves a weakness on right side of the abdominal cord insertion,or that there is a disruption of the right omphalomesenteric artery again leading to a weakness predisposing to what we clinically recognize as gastroschisis.

At birth, the bowel may have a typical inflammatory matted abnormal appearance which is referred to as an intestinal “peel”. The peel is a layer of fibrin and collagen on the serosal surface of the bowel, which likely is caused by the combination of inflammatory reaction to constituents in the amniotic fluid and constriction at the bowel as it herniates through the abdominal wall defect. In addition, the bowel in fetuses with gastroschisis is often foreshortened.

Most cases of gastroschisis are being detected prenatally. Ultrasound will often detect an abdominal wall defect at the time of the “dating” ultrasound, which is usually done around 20 weeks of gestation. Occasionally the abdominal wall defect is seen before 20 weeks gestation, if an ultrasound is obtained late in the first trimester. In the second trimester, maternal serum alpha-fetoprotein (MSAFP) screening will be elevated in most mothers pregnant with a fetus with gastroschisis, but the test is not specific for gastroschisis. MSAFP is also elevated in twin pregnancies, in neural tube defects, in omphalocele and in autosomal chromosomal anomalies.

Incidence

The number of babies born with gastroschisis has increased over the last 2 decades. The reason for the increase is not known. Epidemiologic data have shown that young maternal age is associated with an increased risk of gastroschisis. Goldbaum et al (1990) studied infants with gastroschisis in the state of Washington and found a 4 fold increased risk in mothers less than 20 years of age.

Cigarette smoking has been associated with gastroschisis. Medication and recreational drugs that can cause vascular constriction has been linked to an increased risk of gastroschisis.

It is difficult to diagnose gastroschisis in the first trimester because of the normal herniation into the umbilical cord (Cyr et al., 1986). The intestine returns to the abdomen by 11 weeks gestation. The earliest reported diagnosis is 13 weeks 3 days gestation (Guzman, 1990).

Ultrasound will typically demonstrate a full thickness abdominal wall defect, almost always, to the right of the umbilical cord. There is bowel floating freely in the amniotic fluid without a limiting membrane as seen in omphalocele. In omphalocele the bowel is contained within the omphalocele sac, which is comprised of the parietal peritoneum and the amnion with hyaluronic acid in between. Omphalocele can be confused with gastroschisis if the omphalocele sac ruptures which is a relatively rare event. The prenatal detection rate for gastroschisis is over 80% (Barisic et al., 2001). Gastroschisis and omphalocele was shown to be accurately distinguished in 79.3% of cases on initial diagnosis and in 84.5% of cases after referral for further evaluation (Walkinshaw et al., 1992).

A ruptured hernia of the cord can present as gastroschisis. In these cases gastroschisis develops late in pregnancy and will not be detected on ultrasound early in pregnancy (Knott and Colley, 1987).

Differential Diagnosis

The differential diagnosis of gastroschisis should include omphalocele, ruptured omphalocele, hernia of the cord and limb-body wall complex. Omphalocele and gastroschisis are differentiated by the presence of a sac in omphalocele with cord insertion at the tip of the sac. In contrast, in gastroschisis there is no sac and the intestines are floating freely in the amniotic cavity. In addition, the abdominal wall defect is small usually less than 2.5 cm in diameter even at term. In contrast, the abdominal wall defect in omphalocele is quite large often with herniated liver and stomach which is not the case with gastroschisis.

Ruptured omphalocele may be mistaken for gastroschisis, however if the abdominal wall defect is sufficiently large that it allows the liver to herniated into through the abdominal wall defect it is likely to be a ruptured omphalocele and not gastroschisis. Ruptured hernia of the cord will present late in pregnancy and may be difficult to differentiate from gastroschisis. Limb body wall complex is characterized by very severe limb defects and anterior wall defects, these can be of head, chest or abdomen usually not in the midline and with spinal abnormalities which together are rarely mistaken for gastroschisis.

Amnioexchange has been proposed as a possible fetal treatment for gastroschisis. The rationale is that there are two mechanisms that cause bowel damage: constriction of the abdominal wall defect with resultant hypo-perfusion of the bowel and various irritants in the amniotic fluid (Langer et al., 1989, 1990). In France Luton et al. (2003) performed a trial of amnioexchange, there was no significant improvement in outcomes with this intervention.

Most stillbirths in pregnancies with gastroschisis occur late in the third trimester. Crawford et al. (1992) recommended weekly biophysical profile testing starting at 30-32 weeks gestation and weekly ultrasounds to assess the bowel.  Sonographic changes to the bowel can be difficult to interpret but this can be a sign of a temporary change or development of atresia or necrosis. Since prematurity is associated with multiple problems, it is recommended to prolong pregnancy until the fetus is as close to term as possible.  Most pregnancies are electively induced at 37 weeks gestation if spontaneous delivery has not taken place yet.

Gastroschisis is not an indication for cesarean section (C-section) outcomes are similar for babies delivered via vaginal birth (Boutros et al., 2009). In a contemporary study from Canada 62% of babies with gastroschisis were delivered vaginally (Boutros et al., 2009). Studies from New Zealand (Abdel-Latif et al., 2008) and from Missouri (Snyder and StPeter, 2005) show a trend towards an increase in cesarean sections in pregnancies with gastroschisis.  Since there is no evidence that cesarean sections improve outcomes in neonates with gastroschisis it is unclear why there is a trend towards more cesarean sections.

Treatment for gastroschisis for newborns is a staged process. Immediately after delivery, the newborn with gastroschisis is placed in a plastic “bowel” bag. This is done to reduce evaporative fluid losses and to help keep the baby warm. The baby should be placed on the right side and the bowel should be supported to prevent kinking of the mesenteric vessels.

An orogastric or nasogastric tube is placed into the stomach to decompress it. Intravenous (IV) access is important and necessary immediately after birth for the administration of crystalloid intravenous fluids and antibiotics. Newborn babies with gastroschisis are at risk for large evaporative fluid losses and may need in excess of 10-30 ml/kg in IV fluid boluses. Depending on the maturity of the newborn and the complexity of the defect, endotracheal intubation and mechanical ventilation may be necessary.

A surgeon soon after birth assesses the bowel for any abnormalities and decides on the next steps in the surgical gastroschisis treatment.

Surgical Treatment

Either a peripherally inserted central venous catheter (PICC) is placed in the NICU prior to surgery or a tunneled central venous catheter (broviac) is placed by the surgeon. The central line is critical for the newborn with gastroschisis, to allow for administration of IV nutrition and medications.

There are essentially three approaches to closing the gastroschisis abdominal wall defect. The surgeon’s preference, the appearance of the bowel and how the newborn is doing clinically are some of the factors that will determine the surgical treatment.

Primary closure can be achieved in a minority of the patients. It is important that the baby is doing well and that the bowel is not very dilated and there is minimal visceral-abdominal disproportion to be able to close the defect primarily.

The operation takes place in the operating room under general anesthesia. In brief, the bowel is pushed in to the abdomen and the muscle fascia around the abdominal wall defect is closed with sutures. A patch is usually not required to close the defect.

An alternative technique does not require operative primary closure. This technique also requires a clinically well neonate and that the bowel is not very dilated, the difference is that the bowel is reduced and the defect covered with the umbilical stump and a Duoderm dressing. No general anesthesia is usually necessary. The sutureless closure avoids an operation, but it may increase the risk for an umbilical hernia which will require closure later in life.

The most common approach and the safest approach for those babies who are in distress, have dilated bowel, or complex gastroschisis is to place the bowel in a preformed silo bag and then sequentially reduce it. When all of the bowel has been reduced into the abdominal cavity, the fascia is closed with sutures or closed with a Duoderm dressing as described above.

Even in an infant with gastroschisis is known to have an associated bowel atresia the primary goal in gastroschisis is closure of the abdominal wall defect. Any attempt at resection of the bowel atresia at the time of delivery should be avoided as the bowel wall is edematous and inflamed and resection and primary anastomosis may result in anastomotic leak and sepsis. Once the bowel has been reduced into the abdomen the inflammatory peel begins to regress and by two weeks post-operatively the bowel is back to normal. At this point the atresia can be safely resected and a primary anastomosis safely performed.

Postnatal Management

Postnatally the most common and problem affecting babies with gastroschisis is intestinal dysmotility and inability to absorb nutrients. In the first few weeks of life, all babies with gastroschisis will require total parenteral nutrition (TPN) as they slowly adjust to enteral feeds. During this time a nasogastric (or orogastric) tube will drain the secretions from the stomach until the baby has bowel function. The mean time to first enteral feed was 16 days in a Canadian study (Boutros et al., 2009) and the median time to full enteral feeds in babies with simple gastroschisis was 24 days and 81 days in complex gastroschisis in a cohort study from England and Ireland (Bradnock et al., 2011).

Bradnock et al. (2011) identified 11% with complex gastroschisis: atresia, necrosis or bowel perforation in their cohort study. Emil et al. (2011) identified 23% with complex gastroschisis in a smaller cohort. Boutros et al., found that 22% of the patients in the Canadian study required multiple operations, likely related to complex gastroschisis. This group of patients with gastroschisis has a significantly longer NICU stay, ranging from 84 days (Bradnock et al., 2011) to 104 days (Emil et al., 2011) and is more at risk to develop short bowel syndrome and TPN induced liver failure.

Associated Conditions

Intestinal failure may result from gastroschisis. It can either be secondary to short bowel syndrome as a result of loss of bowel length, or it can be a result of severe dysmotility and chronic intestinal pseudo-obstruction. Both conditions will require long-term TPN dependency, which can result in liver failure, sepsis and may require bowel and liver transplantation. Fortunately it is rare that patients born with gastroschisis end up needing bowel and liver transplantation.

Cryptorchidism is common in baby boys with gastroschisis, about a third of baby boys with gastroschisis will have cryptorchidism at birth and a third of these babies will need to undergo orchidopexy (Hill and Durham, 2011).  Hernias, both inguinal and incisional are common in infants with gastroschisis which may not present for several months after discharge from the NICU.

Infants born with gastroschisis are often small typically < 5% for body weight at delivery and their small size tends to persists through the end of the first year of life. Most children will begin catching up in somatic growth after their first year of life.

Chromosomal anomalies are rare in gastroschisis (Mayer et al., 1980; Mann and Ferguson-Smith, 1984; Sermer et al., 1987; Romero et al., 1988; Lewinsky et al., 1990; Sipes et al., 1990). Only in cases where sonographic abnormalities in addition to gastrointestinal abnormalities are seen, is chromosomal evaluation recommended. Chromosomal anomalies are rare in gastroschisis (Mayer et al., 1980; Mann and Ferguson-Smith, 1984; Sermer et al., 1987; Romero et al., 1988; Lewinsky et al., 1990; Sipes et al., 1990). Only in cases where sonographic abnormalities in addition to gastrointestinal abnormalities are seen, is chromosomal evaluation recommended.

In utero bowel dilatation is one of the most commonly noted abnormalities on fetal ultrasound. Its significance for outcome has not been established. A large study from Canada including a 100 patients diagnosed prenatally with gastroschisis did not find that prenatal bowel dilatation over 18 mm was associated with a worse outcome (Skarsgaard et al., 2007). Piper and Jaksic (2006) reviewed the experience at Boston Children’s Hospital and found no difference in length of stay, time on TPN, mortality, or time in the NICU for babies who had bowel dilatation over 6 mm prenatally.

Intra uterine growth retardation (IUGR) is common and may affect as many as 77% of babies (Carpenter et al., 1984; Molenaar and Tibboel, 1993). A study by Royner and Richards (1977) found a large difference between predicted IUGR (43%) and actual IUGR at birth (23%).  The weight of the fetus is often under estimated because the abdominal circumference is taken into account. In babies with gastroschisis the abdominal circumference is small because most of the bowel is outside the abdomen.

A few studies (Crawford et al.,1992; Burge and Ade-Ajayi, 1997) have reported up to a 10% rate of stillbirth in the third trimester in babies with gastroschisis. The cause of death is thought to be mid-gut volvulus or cord compression. More recently, the CAPSNET data from Canada  reported 1 stillbirth out of 106 (0.9%) prenatally diagnosed babies with gastroschisis (Skarsgaard et al. 2008).

Premature birth is common in pregnancies with gastroschisis. At least one third of babies are born prematurely, possibly the most important reason for premature labor is polyhydramnios (Mayer et al., 1980; Kirk and Wah, 1983; Carpenter et al., 1984; Caplan and McGregor, 1989; Molenaar and Tibboel, 1993).  Also oligohydramnios is seen in gastroschisis (Bair et al., 1986; Crawford et al., 1992).  Mercer et al. (1988) reported amniotic fluid staining in 73% of their series of 22 babies with gastroschisis. The significance of this is unclear but it may indicate fetal distress.


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