Children's Hospital Colorado

Gastroschisis

Gastroschisis, which is Greek for "belly cleft," is an opening in a baby's abdominal wall. In addition to the small abdominal wall defect, there may be some of the baby's bowels (intestines) protruding through the opening.

For parents, the prospect of having a child with gastroschisis can, naturally, be very scary. But the good news is that most babies born with this defect achieve positive outcomes. At the Colorado Fetal Care Center, we work with families to diagnose gastroschisis early, as well as develop a treatment plan after birth.

For patients

Gastroschisis is a hole in the abdominal wall, which allows a baby's intestines to fall outside of the abdominal cavity. Gastroschisis is almost always located immediately to the right of the insertion of the umbilical cord, measuring about 2 to 3 cm in diameter. The hole can also be much larger, which may also cause the stomach, liver or other organs to be exposed.

What causes gastroschisis?

In most babies, the cause of gastroschisis is unknown. However, recent research has indicated that certain factors can increase the likelihood of having a baby with the condition. Those factors include young mothers (under 20 years of age) and smoking tobacco, drinking alcohol or using recreational drugs during pregnancy.

There are also reports that gastroschisis can occur again within the same family. Some research estimates that gastroschisis can recur in future pregnancies about 4 percent of the time.

Complications associated with gastroschisis

Gastroschisis, unlike other abdominal wall defects, is not associated with chromosomal abnormalities (chromosomes are the "blueprint" for the baby). In contrast to other anomalies, gastroschisis-associated abnormalities, if present, are confined to the GI tract.

Even when other abnormalities are present, they are not usually life-threatening. There is, however, an increased risk for intrauterine growth restriction (poor growth of the baby while in the uterus) and stillbirth in 10 percent of cases.

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.

Most cases of gastroschisis are diagnosed during routine ultrasounds. In addition, second trimester maternal serum alpha–fetoprotein (MSAFP) screening has shown a connection 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. This is why the most reliable ultrasounds occur after 14 weeks of pregnancy, when the bowel should be entirely enclosed in the abdomen.

If gastroschisis is not diagnosed before birth, it will be evident upon delivery.

How will gastroschisis affect 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 may affect up to 77 percent of fetuses with gastroschisis. Excess amniotic fluid (called polyhydramnios) or too little amniotic fluid (oligohydramnios) are 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 to assess the baby's growth as well as the amount of amniotic fluid surrounding him or her. In addition, fetal testing to check the baby's heart rate twice per week will begin between 30 to 32 weeks of pregnancy.

Often, delivery is recommended around 37 weeks of pregnancy (approximately 3 weeks early) to avoid the risk of stillbirth. It is generally recommended that you deliver in our state-of-the-art fetal center so we can better coordinate the obstetric, neonatal and pediatric surgical teams. There is no indication that a C-section is necessary in most cases, but you will discuss your delivery options with your team.

Gastroschisis is treated with surgery after birth, at which time the intestines are placed back in the baby's belly. There are no fetal interventions available at this time.

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
  • Careful body temperature monitoring

Intravenous nutritional support is particularly important as it often takes days or even weeks for the GI tract to function well enough for feedings to fully support the baby.

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 is the long-term outcome for babies with gastroschisis?

Surgical techniques to treat this condition have improved dramatically in recent years. Today’s modern procedures enable the vast majority of babies diagnosed with gastroschisis to live healthy lives. Their degree of need for ongoing care varies depending on the severity of their condition and associated symptoms.

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 sixth 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 two 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 four-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 have also 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 percent (Barisic et al., 2001). Gastroschisis and omphalocele was shown to be accurately distinguished in 79.3 percent of cases on initial diagnosis and in 84.5 percent 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 that is not the case with gastroschisis.

Ruptured omphalocele may be mistaken for gastroschisis, however, if the abdominal wall defect is large enough that it allows the liver to herniate through the abdominal wall. 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, which can be in the head, chest or abdomen but usually not in the midline. There are also spinal abnormalities which, along with the other defects, 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 and 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) because outcomes are similar for babies delivered via vaginal birth (Boutros et al., 2009). In a contemporary study from Canada, 62 percent 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 St. Peter, 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 as it allows 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 a dilated bowel or are diagnosed with 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 if 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 percent with complex gastroschisis: atresia, necrosis or bowel perforation in their cohort study. Emil et al. (2011) identified 23 percent with complex gastroschisis in a smaller cohort. Boutros et al. found that 22 percent 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 but may not present for several months after discharge from the NICU.

Infants born with gastroschisis are often small, typically < 5 percent 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 and 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).

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 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.

Intrauterine growth restriction (IUGR) is common and may affect as many as 77 percent of babies with gastroschisis (Carpenter et al., 1984; Molenaar and Tibboel, 1993). A study by Royner and Richards (1977) found a large difference between predicted IUGR (43 percent) and actual IUGR at birth (23 percent). The weight of the fetus is often underestimated 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 percent 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 percent) 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 percent of their series of 22 babies with gastroschisis. The significance of this is unclear but it may indicate fetal distress.


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