What Is Atresia?

Learning that your baby may have a congenital condition can be overwhelming. One condition that may be detected during pregnancy is called atresia, a developmental abnormality that affects the digestive tract.

Atresia occurs when part of the digestive system does not form properly during fetal development. This can create a narrowing or complete blockage that prevents food and fluids from moving normally through the digestive tract after birth.

While a diagnosis of atresia can be frightening, advances in prenatal imaging, neonatal care, and pediatric surgery have significantly improved outcomes for affected babies.

Dr. Suwan Mehra, MD, is a leading Maternal Fetal Medicine specialist and fetal surgeon in Chicago who helps families navigate complex fetal diagnoses with expert guidance, advanced diagnostics, and compassionate care.

What Causes Atresia?

During fetal development, the digestive tract forms through a complex process of growth and connection between different structures.

In babies with atresia, a portion of the digestive tract does not develop normally. As a result, part of the passage may be narrowed, blocked, or completely absent.

Atresia is considered a congenital condition, meaning it develops before birth.

Importantly, nothing a mother did or did not do during pregnancy causes atresia.

Types of Atresia

Several forms of atresia can affect the digestive system.

Esophageal Atresia

Esophageal atresia occurs when the esophagus does not form as a continuous tube connecting the mouth to the stomach.

Instead, the upper portion of the esophagus ends in a pouch and does not connect properly to the lower esophagus.

Many babies with esophageal atresia also have:

Tracheoesophageal Fistula (TEF)

A tracheoesophageal fistula is an abnormal connection between the esophagus and the windpipe (trachea).

This condition can create feeding and breathing difficulties after birth and often requires surgical repair.

Duodenal Atresia

Duodenal atresia affects the duodenum, which is the first section of the small intestine located just beyond the stomach.

The duodenum may be narrowed or completely blocked, preventing food and fluid from passing normally.

Duodenal atresia is one of the most commonly diagnosed forms of intestinal blockage during pregnancy.

It is also associated with certain genetic conditions, particularly Down syndrome, making additional evaluation important after diagnosis.

Intestinal Atresia

Intestinal atresia occurs when a section of the small intestine or large intestine is narrowed or blocked.

The condition can affect:

• Jejunum
• Ileum
• Colon

The severity varies depending on the location and extent of the blockage.

What Are the Signs of Atresia During Pregnancy?

Many cases of atresia are first suspected during routine prenatal ultrasound examinations.

Common findings may include:

• Enlarged stomach
• Dilated bowel loops
• Excess amniotic fluid (polyhydramnios)
• Distended intestines
• Abnormal fluid accumulation

These findings do not always confirm atresia, but they often prompt referral to a Maternal Fetal Medicine specialist for further evaluation.

How Is Atresia Diagnosed Before Birth?

When atresia is suspected, additional testing is often recommended to better understand the diagnosis and prepare for delivery.

Diagnostic tools may include:

High-Resolution Ultrasound

Detailed ultrasound imaging allows specialists to evaluate the digestive tract, fetal growth, and associated findings.

Fetal MRI

Ultrafast fetal MRI can provide additional anatomical detail and help confirm the location and severity of the blockage.

Genetic Evaluation

Because some forms of atresia are associated with chromosomal abnormalities, additional testing may be recommended, including:

• Amniocentesis
• Chorionic Villus Sampling (CVS)
• Genetic counseling

Fetal Echocardiography

Some babies diagnosed with atresia may also have congenital heart abnormalities. A fetal echocardiogram allows specialists to carefully evaluate the baby’s heart before birth.

How Is Atresia Managed During Pregnancy?

The primary goal during pregnancy is careful monitoring and preparation.

Dr. Mehra and his team work closely with families to:

• Monitor fetal growth
• Assess amniotic fluid levels
• Watch for signs of preterm labor
• Coordinate neonatal and surgical care
• Develop a delivery plan

In some cases, excessive amniotic fluid may create discomfort for the mother or increase the risk of premature labor.

When necessary, a procedure called amnioreduction may be performed to remove excess fluid and reduce pressure within the uterus.

What Happens After Birth?

Following delivery, neonatologists and pediatric surgeons evaluate the baby and determine the most appropriate treatment plan.

Most forms of atresia require surgical correction after birth.

Fortunately, pediatric surgical techniques have advanced significantly, and many babies go on to thrive following successful repair.

The timing and type of surgery depend on:

• The location of the blockage
• The severity of the condition
• The baby’s overall health
• Whether other congenital conditions are present

Why Early Diagnosis Matters

Prenatal diagnosis provides significant advantages for both parents and medical teams.

When atresia is identified before birth, specialists can:

• Monitor the pregnancy more closely
• Coordinate delivery at an appropriate hospital
• Assemble neonatal and surgical teams in advance
• Reduce delays in treatment after birth
• Improve overall outcomes

For families, early diagnosis also provides valuable time to understand the condition and prepare for the journey ahead.

Expert Fetal Care for Atresia in Chicago

A diagnosis of atresia can feel overwhelming, but you do not have to face it alone.

Dr. Suwan Mehra provides comprehensive Maternal Fetal Medicine services for families throughout Chicago, Illinois, and the surrounding Tri-State area. From advanced prenatal diagnosis to delivery planning and coordination of neonatal care, Dr. Mehra is committed to supporting families every step of the way.

If your baby has been diagnosed with duodenal atresia, esophageal atresia, intestinal atresia, or another fetal condition, contact Dr. Mehra’s office today to schedule a consultation and learn more about your care options.