Duodenal atresia is a condition in which the first part of the small bowel (the duodenum) has not developed properly. It is not open and cannot allow the passage of stomach contents.

The cause of duodenal atresia is unknown, but it is thought to result from problems during an embryo's development in which the duodenum does not normally change from a solid to a tube-like structure.

Duodenal atresia is seen in more than 1 in 10,000 live births. Approximately 20-30% of infants with duodenal atresia have Down syndrome. Duodenal atresia is often associated with other birth defects.

• Upper abdominal swelling may or may not be present
• Early vomiting of large amounts, which may be greenish (containing bile)
• Continued vomiting even when infant has not been fed for several hours
• Absent urination after first few voidings
• Absent bowel movements after first few meconium stools

A fetal ultrasound may show excessive amounts of amniotic fluid in the womb, a condition called polyhydramnios. It may also show swelling of the baby's stomach and part of the duodenum.

An abdominal x-ray may show air in the stomach and first part of duodenum, with no air beyond that. This is known as the double-bubble sign.

A tube is placed to decompress the stomach. Dehydration and electrolyte abnormalities are corrected by providing fluids through an intravenous tube. An evaluation for other congenital anomalies should be performed.

Surgery to correct the duodenal blockage is necessary, but is not an emergency. The surgical approach will depend on the nature of the abnormality. Associated problems (such as those related to Down syndrome) must be treated as appropriate.

Recovery from the duodenal atresia is expected after treatment. Untreated, the condition is deadly.

• Other birth defects
• Dehydration

After surgery, there may be late complications such as:

• Swelling of the first part of the small bowel (megaduodenum)
• Problems with movement through the intestines
• Gastroesophageal reflux

Call your health care provider if your newborn is feeding poorly or not at all, vomiting (not simply spitting up), not urinating or stooling, or if the vomit is green.

There is no known prevention.

Wyllie R. Intestinal atresia, stenosis, and malrotation. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 327.