An Overview of Duodenal Atresia

Duodenal atresia is a rare condition that's present at birth. It is a malformation of the duodenum, which is the section of the small intestine that receives food directly from the stomach. The condition can cause severe vomiting in newborns, and it can also cause some signs during pregnancy, including large amounts of fluid surrounding the growing baby.

Symptoms

Prenatal (Before Birth) Symptoms

Duodenal atresia often results in polyhydramnios, an abnormal accumulation of amniotic fluid (the fluid that surrounds the fetus during pregnancy). Under normal circumstances, the fetus swallows amniotic fluid, but when duodenal atresia is present, swallowing is difficult for the fetus, resulting in a buildup of extra amniotic fluid.

Polyhydramnios presents a higher risk of complications during pregnancy, such as premature delivery.

Prenatal symptoms of duodenal atresia include:

• Polyhydramnios: This can cause the mother's abdomen to appear unusually large. A prenatal ultrasound can detect excess amniotic fluid, sometimes tipping off the healthcare provider that duodenal atresia may be present.
• Double bubble: This is a classic sign of duodenal atresia seen on ultrasound. One bubble is an image of the fetus's fluid-filled stomach and the other is a fluid-filled duodenum. These occur when there is fluid in the stomach and part of the duodenum, but there is no fluid further down the intestinal tract.

Symptoms After Birth

After birth, infants may exhibit other symptoms of duodenal atresia, such as:

• Swelling of the upper abdomen
• Large amounts of vomiting (which may include greenish colored bile)
• Vomiting that continues even if formula or breast milk is withheld for several hours
• Absence of bowel movements after the first few meconium stools. Meconium stools are normal stools that are dark-colored and contain the contents that line the intestines during a fetus’s development in utero.

Causes

Normally, the lumen (opening) of the duodenum leads to the rest of the digestive tract. It should be open during fetal development to allow food and fluids to flow freely through the digestive tract while the fetus is developing. Duodenal atresia is an obstruction (blockage) of the duodenum due to a developmental malformation. It involves either an absence of or complete closure of the duodenal lumen.

With duodenal atresia, liquids can't move through the digestive tract, and the baby vomits all of the material that's swallowed.

Duodenal atresia is a congenital condition that develops before birth. The cause is unknown, and genetics may play a role. Duodenal atresia can be an isolated condition, or it may occur along with other congenital birth defects. 

Other associated congenital abnormalities include esophageal atresia (an abnormality of the esophagus that impacts its motility), renal problems, defects of the limbs, cardiac (heart) defects, premature birth, and other intestinal abnormalities.

Down Syndrome (Trisomy 21)

Down syndrome is a genetic disorder that occurs when a child has three, instead of two, copies of chromosome 21. Down’s syndrome is referred to as “trisomy 21.” The extra chromosome results in physical and intellectual disabilities. Various other abnormalities, such as duodenal atresia, can be present, as well as heart problems, vision problems, and hearing problems.

Diagnosis

A 20-week prenatal ultrasound checkup is often recommended during pregnancy. Duodenal atresia may not be visible on ultrasound until the last trimester of the pregnancy.

An additional ultrasound may be performed after the 20-week prenatal check-up—during the third trimester of pregnancy—for several reasons, including:

• Genetic screening that has indicated Down syndrome is present
• An abnormally large measurement of the uterus during a routine prenatal exam.
• Polyhydramnios or a double bubble noted on an early ultrasound.

If duodenal atresia is suspected, further diagnostic tests may be conducted, including:

• Genetic testing to evaluate the parents for possible hereditary conditions
• High-resolution fetal ultrasonography, a non-invasive diagnostic test, can visualize the fetus’s intestinal tract and other organs
• Fetal echocardiography, an ultrasound to evaluate the heart's structure and motion
• Amniocentesis, a procedure in which a sample of amniotic fluid is taken from the amniotic sac with a long needle that is inserted into the mother’s abdomen to analyze the fetus’s chromosomes for genetic disorders

The definitive diagnosis of duodenal atresia cannot be undertaken until after the baby is born—when an X-ray can verify the diagnosis. If duodenal atresia is detected, an echocardiogram test will be done to evaluate the heart.

Treatment

Duodenal Atresia Treatment Before Birth

Duodenal atresia can only be treated after an infant is born, but there are some prenatal interventions that can reduce the risk of complications at birth. 

Close observation is needed so the fetus and mother can be monitored for urgent problems. This includes sequential measurements of the uterus and evaluation of internal uterine pressure. Sometimes an amnioreduction procedure is done to remove some of the amniotic fluid during pregnancy.

Duodenal Atresia Treatment After Birth

Babies diagnosed with duodenal atresia can be delivered normally, without the necessity of a surgical C-section procedure. The overall goal is for the mother to have a vaginal delivery as close as possible to the baby's due date. Although the delivery may be normal, specialized medical interventions will be needed after the baby is born and the infant will be taken to the newborn intensive care unit after birth.

An infant with duodenal atresia has to be fed with intravenous nutrients and fluids. In addition, a very thin flexible tube called a nasogastric (NG) tube will be inserted into the infant’s stomach via the nose or mouth. This will remove air since trapped air and gases will not be able to move through the digestive tract normally. The tube will also allow the delivery of fluids to help prevent dehydration as well as provide nutrition.

An infant diagnosed with duodenal atresia will not be able to take milk from a bottle or breastfeed until surgery is done to correct the obstruction.

Surgical Treatment

Under most circumstances, the surgical procedure is done around day two or three after birth. Although there are several different types of malformations of the duodenum that are considered subtypes of duodenal atresia, the procedure is similar for each subtype. The steps in the procedure include:

1. Administration of general anesthesia
2. Opening the blocked end of the duodenum
3. Connecting the remainder of the small intestine to the end that was blocked

After Surgery

After the procedure, the baby will be returned to the neonatal intensive care unit; it may be necessary for the newborn to be put on a ventilator (a machine that helps the baby breathe) for a few days.

Under normal circumstances, the baby will be in the hospital approximately three weeks after having surgery for duodenal atresia. After the surgical site heals, the baby can begin taking a bottle or breastfeeding right away. Once the baby is taking food by mouth, without any complications, the baby can go home with the parents.

Prognosis

When duodenal atresia is promptly diagnosed and treated, the prognosis is excellent, according to the National Institutes of Health.

Post-operative complications are rare and can include dehydration, swelling of the small bowel, intestinal motility problems, or gastroesophageal reflux.

Study of Minimally-Invasive Surgery vs. Conventional Surgery

A 2017 study examined the outcome of infants with duodenal atresia who were treated between 2004 and 2016 with minimally invasive surgery (MIS) or traditional open surgery.

The results of the study were measured to evaluate the overall healing time of the infants:

Coping

Infants with duodenal atresia and without co-occurring congenital disorders have a very good prognosis. The baby will more than likely be able to live a completely normal life after surgery. However, if you are a parent of a baby that has been diagnosed with other congenital defects (such as a heart condition or Down syndrome) the duodenal atresia repair procedure may be just the beginning of a long road to your baby’s stability. 

Keep in mind that in the modern world, children born with Down syndrome often grow up to live long, happy, healthy, and productive lives. What may initially seem overwhelming often turns out to be one of the biggest blessings in life, according to many parents of children born with Down’s syndrome.

The first step is to reach out and explore the plethora of resources available for parents, such as the National Down Syndrome Congress, which offers a wealth of resources. They offer advice for new and expectant parents, adult siblings, education, speech and language tools, health and medical information, and research opportunities. They also have a quick directory of local and national support networks.

A Word From Verywell

Most babies who have surgery for duodenal atresia will not need any type of long-term treatment or ongoing follow-up care for the condition once they are discharged from the hospital.