Information on the following diseases can be found in the Related Disorders section of this report:

• omphalocele
• prune belly syndrome
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Gastroschisis is apparent at birth and can also be detected prenatally with ultrasound. Patients with this disorder have a 2-5 cm opening in the front (anterior) abdominal wall in which herniated abdominal organs appear on the outer surface of the abdomen. The abdominal cavity is smaller than normal and has no membranous sac covering it. This defect is typically found on the right side of the umbilical cord. Stomach, small intestine and large intestine are the most common organs to herniate. Herniation of gallbladder, uterus, fallopian tubes, ovaries, urinary bladder and testes may be apparent.

The intestines may look swollen, inflamed, thickened, short and covered with a thick fibrous peel due to exposure to the liquid that surrounds the fetus during pregnancy (amniotic fluid). Malrotation of the bowel is present and the exposed bowel is at risk for obstruction leading to decay and interruption of the blood supply due to the small size of the abdominal wall defect.

Bowel function is delayed in most infants due to malabsorption and deficient movement (hypomotility). Absence or closure (atresia) of intestines and other gastrointestinal tract abnormalities occur in as many as 10% of infants with gastroschisis.

Other symptoms of this disorder may be low birth weight, small size for gestational age, infection, dehydration, and dangerously low body temperature (hypothermia).
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The exact cause of Gastroschisis is not known. Several theories have been suggested. One theory is that there is a rupture of an Omphalocele during fetal development. An Omphalocele is similar to Gastroschisis except that there is a membranous sac covering the herniated material at birth. It is thought that the sac may be reabsorbed before birth in the case of Gastroschisis.

Another theory is that while the fetus is in the uterus there is some type of accident or dysfunction in the system of tubes that transport body fluid to the region where the umbilical chord enters the fetus (the omphalomesenteric artery).

Several cases of Gastroschisis have occurred in siblings which suggests that it may be caused by an autosomal recessive genetic trait in a few cases. Human traits, including the The exact cause of Gastroschisis is not known. Several theories have been suggested. One theory is that there is a rupture of an Omphalocele during fetal development. An Omphalocele is similar to Gastroschisis except that there is a membranous sac covering the herniated material at birth. It is thought that the sac may be reabsorbed before birth in the case of Gastroschisis.

Another theory is that while the fetus is in the uterus there is some type of accident or dysfunction in the system of tubes that transport body fluid to the region where the umbilical chord enters the fetus (the omphalomesenteric artery).

Several cases of Gastroschisis have occurred in siblings which suggests that it may be caused by an autosomal recessive genetic trait in a few cases. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In recessive disorders, the condition does not appear The exact cause of gastroschisis is not known. Several theories have been suggested. One theory is that a defect occurs in the lateral folds of the abdominal wall during fetal development. Another theory is that while the fetus is in the uterus, an accident or dysfunction occurs in the system of tubes that transport body fluid to the region where the umbilical cord enters the fetus (the omphalomesenteric artery).

Consistent chromosomal or genetic abnormalities have not been defined but reports have been made of multiple affected family members. The most likely explanation is that isolated gastroschisis follows multifactorial inheritance, such that multiple genes and environmental factors acting together cause the abnormality.
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Gastroschisis is a rare disorder that affects males and females in equal numbers. Estimates of birth prevalence for this disorder are approximately one in 1,500 to 1 in 13,000. It is more common in births to women who are younger than 30 years and have not had many pregnancies (low gravidity).
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Symptoms of the following disorders can be similar to those of gastroschisis. Comparisons may be useful for a differential diagnosis:

Omphalocele is a protrusion of internal abdominal organs from a defect in the abdominal wall. The protrusion may be very small with just a few loops of bowel protruding or may contain all of the intestines, the liver and the stomach. Unlike gastroschisis the organs that are protruding are covered with a membranous sac. It has been suggested that omphalocele and gastroschisis may be the same disorder but that the omphalocele may rupture during fetal growth thus absorbing the membranous sac. This theory has not been proven to date.

Prune belly syndrome is a rare disorder characterized by underdevelopment of the abdominal muscles associated with intestinal and urogenital abnormalities. The abdomen appears large and lax, the abdominal wall is thin and the intestinal loops can be seen through the thin abdominal wall. This condition is present at birth. (For more information on this disorder, choose "Prune Belly Syndrome " as your search term in the Rare Disease Database.)
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Diagnosis
Gastroschisis can be diagnosed by prenatal ultrasound and is differentiated from omphalocele by the presence of freely floating abdominal organs in the amniotic cavity. The finding of herniated bowel after delivery confirms the diagnosis.

Treatment
Women with pregnancies in which gastroschisis has been prenatally diagnosed should be delivered at a tertiary care center where neonatal and pediatric surgical care is available. Consultation with specialists prior to delivery is advisable. Outcomes after cesarean section and vaginal delivery are similar. Planned induction of delivery at 37-40 weeks gestation may prevent the bowel from becoming constricted and receiving insufficient blood supply.

Surgery is needed to close the abdominal wall defect. Techniques that allow gentle reduction of the herniated bowel followed by closure of the defect on an elective basis are being advocated by many centers. One such technique uses a spring-loaded silo that is placed at the bedside without anesthesia or suturing and is associated with fewer complications and a shorter hospital stay.
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McLean SE and Minkes RK. Gastroschisis. In: The NORD Guide to Rare Disorders, Philadelphia: Lippincott, Williams and Wilkins, 2003:197-198.

McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore, MD: The Johns Hopkins University; Entry No. 230750; Last Update:7/16/97.

Cooney DR, Defects of the abdominal wall. In: O'Neill JA, Rowe MI, Grosfeld JL. Et al., eds. Pediatric surgery, 5th ed. St. Louis: CV Mosby, 1998:1045-1069.

Dykes EH. Prenatal diagnosis and management of abdominal wall defects. Semin Pediatr Surg 1996;5:90-94.

Fonkalsrud EW, Smith MD, Shaw KS, et al. Selective management of gastroschisis according to the degree of visceroabdominal disproportion. Ann Surg 1993;218: 742-747.

Langer JC. Gastroschisis and omphalocele. Semin Pediar Surg 1996;5:124-128.

Minkes RK, Langer JC, Mazziotti MV, et al. Routine insertion of a silastic spring-loaded silo for infants with gastroschisis. J Pediatr Surg 2000;35:843-846.

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eMedicine - Gastroschisis -Author: Ali Nawaz Khan, MBBS, LRCP, FRCS, FRCP, FRCR,
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