Although the small intestine is a continuous portion of bowel, segments are named differently. The duodenum is the first portion after the stomach. This is followed by the longest portion known as the jejunum.
The ileum is the last portion before the small intestine connects with the colon or large intestine. When part of the bowel fails to develop normally in the fetus, a blockage of the intestinal tract can occur. This is called an intestinal atresia or bowel obstruction. Intestinal atresias can occur at any portion of the intestinal tract and are named for the location of the blockage. In general, 'intestinal atresia' refers to atresias of the small intestine (jejunum and ileum). Most blockages occur in the small intestine (known as jejunal atresia, or ileal atresia) but may also occur in the large intestine (colonic atresia). These blockages can be complete or partial but all require the same treatment, surgery. Duodenal atresias present differently and are discussed separately.
Intestinal atresia occurs between 1 in 1,000 and 1 in 5,000 live births. There are several variants of intestinal atresia which can be located at any portion of the bowel but all of them cause a bowel obstruction which needs an operation to repair.
What will happen during pregnancy?
In general, intestinal atresias are difficult to diagnose with routine prenatal ultrasound. Although the ultrasound may be suggestive that there is an abnormality, it cannot determine with 100% certainty that there is an intestinal atresia.
A prenatal ultrasound may show bowel that is dilated or larger than normal.
There may also be an increase in fluid around the baby, called hydramnios. Although there are many other causes of hydramnios, this may be a first sign of a bowel obstruction. It is important to have a thorough evaluation of the fetus for associated anomalies if there is hydramnios and/or suggestion of an intestinal atresia. The obstetrician may order a special ultrasound that will examine the baby's heart, known as a fetal echocardiogram. In addition, an amniocentesis may be performed because some babies with bowel obstructions may have abnormal chromosomes or other genetic conditions. The mother's amniotic fluid level and the growth of the baby will be monitored closely with ultrasound. Severe hydramnios may increase the risk of premature delivery.
The fetal team will evaluate the severity of the intestinal atresia and help determine the best course of treatment. Your pregnancy will be closely monitored for complications. The Center coordinator will keep you in contact with the appropriate physicians and specialists as well as coordinating the care for you and your baby after delivery.
Will a fetal treatment be required?
Although there are no prenatal treatment options for a baby with intestinal atresia, careful planning of delivery and care of the baby after birth can make a smooth transition for mother and child.
What special considerations should be made for delivery?
Type of delivery - Babies with intestinal atresia usually do not need a cesarean delivery. The delivery plan will be discussed with you and your obstetrician.
Place of delivery - As long the baby does not demonstrate signs of distress, he or she should be cared for and delivered with the ordinary obstetrical precautions. After birth, the baby can be safely transported to a treatment center with doctors and services such as a neonatal intensive care unit and pediatric surgery. A child diagnosed with intestinal atresia will require an operation to address the problem and may stay in the hospital for several weeks.
Time of delivery - Intentional early delivery does not improve outcome. However, increasing amniotic fluid levels (hydramnios) does raise the chance for preterm delivery. If complications arise, the obstetrician may decide to induce delivery earlier than the expected due date.
What will happen at birth?
In most cases, a child with intestinal atresia will be born without any immediate problems. Afterwards, he or she will be taken to the neonatal intensive care unit. The neonatologists, specialized doctors for high-risk babies, will immediately assess your baby and begin appropriate treatment, if necessary. In most cases, you and your family will be able to see and hold your newborn.
What will happen after delivery?
Once the baby has been fully assessed, a pediatric surgeon will perform an operation in order to fix the intestinal atresia. The goal of this surgery is to remove the bowel obstruction and allow the digestive tract to be functional. However, depending on the location of the obstruction and the condition of the intestine, different types of operations may be necessary with the potential of having more than one surgery. This can only be determined by the pediatric surgeon during the operation.
Your surgeon will wait until there are signs of good bowel function before starting to feed the baby. Depending on the type of intestinal atresia and the operation performed, bowel function may occur in days to weeks. On average, it takes approximately two to three weeks before the intestinal tract functions fully.
Meanwhile, nutrition through a vein will be provided to the baby. The baby will receive all of the calories necessary to grow until he or she can be fed by mouth. Once bowel function returns, it will take a while before he or she can handle enough formula or breast milk to provide full nutrition. Your baby will likely be in the hospital for several weeks. Sometimes this can be much longer, depending on the degree of prematurity and the condition of the bowel.
What are the long-term outcomes and considerations?
The potential immediate complications after surgery include leaking from the repaired bowel connections, bleeding, and infection inside the abdomen and wound. The severity and treatment of these complications should be discussed with your pediatric surgeon if they occur.
The overall outcomes for most intestinal atresias are excellent depending on the type of atresia. Most infants may have minor intestinal problems in the first few weeks, but will recover and lead completely normal lives. If a baby is missing a large amount of small intestine, either because not enough intestine developed during pregnancy or if a large portion had to be removed during surgery, he or she may not be able to absorb the required amount of nutrients. As a result, the child may be dependent on nutrition through a vein for a longer period of time. This condition is called Short Bowel Syndrome. Your doctors will discuss this in detail with you if this occurs.
The Center team will help care for you and your infant with intestinal atresia. The Center will develop a comprehensive plan with all of the physicians and specialists involved in the care of you and your newborn before, during, and after delivery.
Contact The Fetal Center to make an appointment with a high-risk pregnancy doctor.
Note: This information regarding your condition is meant to be a helpful, informative introduction. Because every pregnancy is different, this may not be applicable to all cases, especially if there are additional defects. Your team of experts at the Center will provide you with information specific to your pregnancy.