Gastroschisis

What gastroschisis is

Early in pregnancy, the abdominal wall forms by folding together. In gastroschisis, a small defect, usually 2 to 4 cm, forms to the right of where the umbilical cord enters. The intestines push through it and float freely in the amniotic fluid. Exposure to amniotic fluid can make the bowel thickened, matted and inflamed, and the bowel can be damaged if the opening narrows.

It is classified as:

• simple gastroschisis: the bowel is intact, about 80 to 90% of cases
• complex gastroschisis: with bowel atresia (intestinal atresia, a blocked or missing segment), perforation, twisting or bowel loss

Gastroschisis vs omphalocele

Causes and risk factors

The cause is not fully understood. It may involve disrupted blood flow to the developing abdominal wall. Risk factors include:

• young maternal age, under 20 especially
• smoking, alcohol and recreational drugs in pregnancy
• some medicines, such as decongestants and aspirin, have been linked in some studies
• low body weight and poor nutrition before pregnancy
• genitourinary infections early in pregnancy

It is rarely genetic, and the chance of recurrence in a future pregnancy is low.

Prenatal diagnosis and pregnancy care

Gastroschisis is usually detected by:

• maternal serum alpha-fetoprotein (AFP), which is raised
• ultrasound, showing loops of free-floating bowel

After diagnosis, pregnancy is monitored with regular scans to check the baby's growth, the bowel's appearance and amniotic fluid. Babies with gastroschisis are often small and at higher risk of premature birth and stillbirth. Delivery is usually planned at around 37 weeks in a hospital with a neonatal intensive care unit (NICU) and pediatric surgeons. Vaginal birth is usually possible.

Treatment after birth

Immediate care

• covering the bowel in a sterile bag or wrap to prevent heat and fluid loss and infection
• IV fluids and antibiotics
• a tube through the nose to empty the stomach
• careful positioning to protect blood flow to the bowel

Surgical repair

• Primary closure: if the bowel fits, the surgeon returns it to the abdomen and closes the defect within hours of birth. Sometimes the umbilical cord is used to cover the defect without stitches (sutureless closure).
• Staged closure with a silo: if the bowel is swollen or the abdomen is too small, the bowel is placed in a clear plastic pouch (silo) hanging above the baby. Gravity gradually moves the bowel inside over several days, then the defect is closed.
• Complex cases: atresia may be repaired at the same time or weeks later.

Feeding and recovery

The bowel often works slowly at first. Babies receive IV nutrition (total parenteral nutrition) until they can tolerate milk, introduced gradually. Breast milk is encouraged. Simple gastroschisis typically needs a hospital stay of about 4 to 6 weeks. Complex cases can take months.

Complications

• slow bowel function and feeding problems
• infections, including central line infections
• necrotizing enterocolitis
• bowel obstruction from adhesions later in life
• short bowel syndrome if a large length of bowel is lost or damaged, needing long-term nutrition support
• liver problems from prolonged IV nutrition
• an umbilical hernia at the repair site
• undescended testicles in boys

Outlook

Survival is over 90%, and higher for simple gastroschisis. Most children grow and develop normally and live healthy lives. Those with complex gastroschisis or short bowel syndrome face more challenges and need follow-up with specialist intestinal rehabilitation teams.

Frequently asked questions

What causes gastroschisis?

The exact cause is unknown. It is thought to result from a disruption in blood supply to the developing abdominal wall early in pregnancy. It is much more common in babies of young mothers and is associated with smoking and recreational drug use, but most cases have no identifiable cause.

What is the difference between gastroschisis and omphalocele?

In gastroschisis, the intestines come out through a hole beside the belly button with no covering. In omphalocele, organs protrude through the belly button itself and are covered by a sac. Omphalocele is more often linked to other genetic or heart conditions.

What is the survival rate for gastroschisis?

More than 90% of babies with gastroschisis survive. Babies with simple gastroschisis generally do very well. Survival and long-term health are lower when the bowel is badly damaged or there is bowel atresia.

How long do babies with gastroschisis stay in the hospital?

Babies with simple gastroschisis usually stay about 4 to 6 weeks, mostly waiting for the bowel to start working and for feeding to be established. Babies with complex gastroschisis may stay several months.

Can gastroschisis happen again in another pregnancy?

The recurrence risk is low, slightly higher than in the general population. Most families have no further affected pregnancies. Avoiding smoking, alcohol and drugs, and good nutrition before and during pregnancy, may help lower risk.