Duodenal Atresia in Down Syndrome

Diagnosis and Treatment of Duodenal Atresia

Pregnant woman getting ultrasound
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Duodenal atresia is a birth defect of the digestive or gastrointestinal (GI) system that occurs more frequently in infants with Down syndrome. Somewhere between 5 percent and 7 percent of infants with Down syndrome will be born with duodenal atresia, as compared to only 1 in 10,000 infants who do not have Down syndrome.

No one knows exactly why this happens, but it is known that it occurs early in the prenatal development of a fetus, prior to eleven weeks gestation.

Rest assured that if your baby has duodenal atresia, there is nothing that you did to cause it or could have done to prevent it. Most infants with this problem do well after surgery.

What Is Duodenal Atresia?

Duodenal atresia is a condition in which part of the small bowel (the duodenum) does not form properly. The duodenum is a small tube-like structure that lets digested material from the stomach pass into the small bowel. Occasionally, the duodenum does not form correctly and is either closed (duodenal atresia) or much smaller than normal (duodenal stenosis).

Prenatal Diagnosis of Duodenal Atresia

Duodenal atresia is often diagnosed during pregnancy during an ultrasound. If it is, there is a 30% chance that the baby will have Down syndrome. Incidentally, the only ways to diagnose Down syndrome in the second or third trimester is an amniocentesis test or PUBS testing (percutaneous umbilical blood sampling).

The ultrasound will show what is called a “double bubble” sign. The double bubble sign is caused by extra fluid in the duodenum and stomach, which causes them to swell up. Since they are located next to each other and separated by a small circular opening, these two structures resemble a “double bubble” or two bubbles side by side, when viewed with an ultrasound.

Duodenal atresia may be detected by ultrasound as early as 18 to 20 weeks of pregnancy, but is usually seen after 24 weeks. Another sign of duodenal atresia in pregnancy is excessive amniotic fluid. The mother’s abdominal circumference measurement may also be increased due to the excess fluid in the stomach. This generally does not occur until after 24 weeks.

Diagnosis of Duodenal Atresia at Birth

Most cases of duodenal atresia are diagnosed during pregnancy or shortly after birth.

If your baby is diagnosed during your pregnancy, you will be referred to a perinatologist (an obstetrician who deals with high-risk pregnancies) to discuss managing the rest of your pregnancy. You may also be referred to a genetic counselor, to discuss the option of prenatal testing, and a pediatric surgeon, to discuss the surgical correction of this problem after birth.

Newborns with duodenal atresia may have any of the following symptoms, which can lead to diagnosis:

  • swollen upper abdomen
  • excessive vomiting, even without feeding or green vomit (bile)
  • a lack of urination
  • absent bowel movements after the first few meconium stools

Once the diagnosis of duodenal atresia is suspected, the doctor will order an x-ray of the abdomen. If the diagnosis is duodenal atresia, the x-ray will show air in the stomach and the first part of the duodenum, but no air after that indicating a blockage.

Treatment of Duodenal Atresia

The only treatment for duodenal atresia is surgery, which is usually done shortly after birth. Prior to surgery, a nasogastric (NG) tube will be placed in the baby’s stomach to drain the excess fluid and air that have accumulated, and the baby will get an IV so that he can receive fluids that will prevent dehydration. Your pediatrician and surgeon will discuss your baby’s prognosis and care plan with you prior to surgery.

Infants with other birth defects or other underlying conditions may not do as well as infants that only have duodenal atresia. Most infants do extremely well after surgery and completely recover from this birth defect.

Sources:

Cassidy, Suzanne B. , Allanson, Judith E., (2001) Management of Genetic Syndromes. 1st ed. New York, NY; 2001.

Karrer, F., Duodenal Atresia, Emedicine, 2009

Newberger, D., Down Syndrome: Prenatal Chance Assessment and Diagnosis. American Family Physician. 2001.

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