Abdominal birth defects

Three types of birth defect (congenital anomaly) that affect the abdomen are:

• diaphragmatic hernia – organs protrude into the chest cavity
• exomphalos – organs protrude through the navel
• gastroschisis – organs protrude through the abdominal wall

These conditions can often be picked up during pregnancy with ultrasound scans. Too much amniotic fluid around the baby (polyhydramnios) may also be a sign of these defects. The causes are unknown, so prevention is not possible.

How the abdomen and diaphragm normally develop#

The organs of the digestive system, including the intestines, stomach, pancreas and liver, sit in the abdomen, separated from the chest cavity by the diaphragm. The diaphragm is a sheet of muscle slung beneath the lungs.

When we breathe, the diaphragm contracts and relaxes. This changes the air pressure in the chest, drawing air into the lungs on inhalation and pushing it out on exhalation. Normally, the abdominal organs sit below the diaphragm.

During fetal development, the diaphragm or the abdominal wall can fail to fuse properly, which allows the abdominal organs to protrude.

Diaphragmatic hernia#

A diaphragmatic hernia is an abnormal hole in the diaphragm that lets the abdominal organs develop inside the ribcage. The lack of space in the chest cavity and the defect in the diaphragm can make breathing difficult, and the crowded lung may have failed to develop properly.

At birth, the baby may look blue (cyanotic) because of a lack of oxygen, and may breathe erratically or not at all. The abdomen may also feel flatter than usual. The incidence of diaphragmatic hernia is around one in every 2,500 births.

Treatment for diaphragmatic hernia#

Diaphragmatic hernia is diagnosed by physical examination and chest x-rays. This defect is potentially fatal, and the baby needs immediate surgery to move the abdominal organs back into place and repair the diaphragm. In most cases, the baby needs respiratory support and a prolonged hospital stay after surgery.

The outlook depends on how severely the lungs were affected by the overcrowding, and the child may be prone to lung infections.

Exomphalos#

Exomphalos (omphalocele) is an abnormal hole in the abdominal wall that allows the intestines and other organs to protrude. The organs are covered by the abdominal membrane (peritoneum) rather than by skin.

In most cases the hernia occurs at the navel (umbilicus). In severe cases, the navel of the newborn may be up to 10 cm across, and the organs may have herniated into the umbilical cord. Estimates vary, but around one third to one half of babies born with exomphalos have other birth defects as well, including congenital heart disorders. The incidence of exomphalos is around one in every 2,500 births.

Treatment for exomphalos#

Physical examination alone is usually enough to diagnose exomphalos. After delivery, the baby needs surgery in the first days of life. If there is not enough room to repair the hernia straight away, a special sack is stitched around it. This sack shrinks over time, gently easing the intestines back into the abdomen, and the hole can then be sutured closed. The baby may need a prolonged hospital stay.

Gastroschisis#

Gastroschisis also involves herniated abdominal organs, but it differs from exomphalos in several ways:

• there is less likely to be other organ problems
• the hernia is through the abdominal wall rather than the navel
• the protruding organs are not covered by the protective peritoneum

Because the organs are exposed, they can dry out or become infected, so they are covered with moist, sterile dressings as soon as possible after birth. In severe cases, the entire contents of the abdomen are outside the body. The incidence of gastroschisis is around one in every 4,000 births.

Treatment for gastroschisis#

Physical examination alone is usually enough to diagnose gastroschisis. After delivery, the baby needs surgery in the first days of life. Treatment depends on the size of the hernia and whether there is enough room inside the abdominal cavity to take the herniated organs.

If the baby’s abdomen is large enough, the organs are returned to the body and the hernia sewn shut. In severe cases, a mesh sack is sewn around the hernia and the repair carried out at a later stage. If the intestines are damaged, the child may have digestion problems.

Key points#

• Too much amniotic fluid around the baby (polyhydramnios) may also be a sign of these defects.
• The causes are unknown, so prevention is not possible.
• At birth, a baby with a diaphragmatic hernia may look blue (cyanotic) from a lack of oxygen and may breathe erratically or not at all.

Where to get help#