When babies are born prematurely, many of their organs are not fully developed. This puts them at risk for a number of diseases within the first weeks of life.
One of these diseases is necrotizing enterocolitis (nek-roh-TIE-zing en-ter-oh-coh-LIE-tis), the most common and serious intestinal disease among preemies. Necrotizing enterocolitis (NEC) happens when tissue in the small or large intestine is injured or begins to die off. This causes the intestine to become inflamed or, in rare cases, develop a hole (perforation).
When this happens, the intestine can no longer hold waste, so bacteria and other waste products pass through the intestine and enter the baby's bloodstream or abdominal cavity. This can make a baby very sick, possibly causing a life-threatening infection.
NEC typically affects babies born before 32 weeks gestation, but it can occur in full-term infants who have health problems, like a heart defect. Babies with NEC usually develop it within the first 2 to 4 weeks of life.
What Causes NEC?
The exact cause of NEC is unknown, but experts believe that different factors might play a role. These include:
an underdeveloped intestine
too little oxygen or blood flow to the intestine at birth (usually the result of a difficult delivery)
injury to the intestinal lining
heavy growth of bacteria in the intestine that erodes the intestinal wall
formula feeding (babies who are breastfed have a lower risk of developing NEC)
NEC sometimes seems to occur in "epidemics," affecting several infants in the same nursery. Although this might be coincidental, it suggests that the disease could sometimes spread from one baby to another, despite the fact that all nurseries have very strict precautions to prevent the spread of infection.
Other signs of NEC can include apnea (periodic stops in breathing), bradycardia (slowed heart rate), and hypotension (low blood pressure). More severe cases may have fluid in the abdominal cavity that shows up on X-ray, peritonitis (infection of the membrane lining the abdomen), or shock.
In babies with symptoms of NEC, a diagnosis can be confirmed if an abnormal gas pattern shows up on an X-ray. This looks like a bubbly or streaky appearance of gas in the walls of the intestine.
In severe cases, air escapes from the intestine and shows up in the large veins of the liver or the abdominal cavity. A doctor may insert a needle into the abdominal cavity to withdraw fluid to determine whether there is a hole in the intestines.
All infants with NEC need to be treated with medicines and therapy. About one third may need surgery to repair the intestine.
After diagnosis, treatment begins immediately and includes:
temporarily stopping all feedings
nasogastric drainage (inserting a tube through the nose into the stomach to remove air and fluid from the stomach and intestine)
intravenous (IV) fluids for fluid replacement and nutrition
antibiotics to treat or prevent infection
frequent examinations and X-rays of the abdomen
a consultation with a pediatric surgeon to discuss surgery, if needed
The baby's poop also will be watched for blood and the baby's abdominal girth (belly size) will be checked regularly. If the intestine perforates or there is an infection in the abdominal cavity, the belly will swell. If a baby's belly is so swollen that it interferes with breathing, extra oxygen or a breathing machine (ventilator) will help the baby breathe. Also, blood samples are taken to look for bacteria and to make sure the baby has not developed anemia (a decrease in red blood cells).
After responding to treatment, a baby can be back on regular feedings after a week. Sometimes feedings are withheld a bit longer and antibiotics continue for another 10-14 days. When feedings start again, breast milk is recommended. Breast milk is beneficial for babies with NEC because it is easily digested, supports the growth of healthy bacteria in the intestinal tract, and boosts a baby's immunity — which is especially important for a preemie with an immature immune system.
For women who can't breastfeed or provide enough breast milk, doctors may recommend giving the baby pasteurized human breast milk from a milk bank, which is considered a safe alternative.
Some babies whose condition worsens or who have a perforation in the intestine, will need exploratory surgery. During this procedure, doctors examine the abdominal cavity to look for a hole in the intestine or to remove any dead or dying intestinal tissue. If needed, doctors will schedule a second surgery to remove a diseased section of the intestine. In some cases after this removal, the healthy intestine can be sewn back together. Other times, especially if the baby is very ill or a large section of the intestine was removed, an ostomy will be done. During an ostomy, surgeons bring an area of the intestine to an opening on the abdomen (stoma) so that stool can safely exit the body.
Most babies who develop NEC recover fully and do not have further feeding problems. In some cases, the bowel may be scarred or narrowed, or intestinal blockage may happen. If so, more surgery is needed.
Malabsorption (when the bowel can't absorb nutrients normally) can be a lasting problem from NEC. It's more common in babies who had part of their intestine removed. A baby with malabsorption may need nutrition delivered directly into a vein until the intestine heals well enough to tolerate normal feeding.
If your baby has NEC, it's normal to feel frightened or worried. And not being able to feed your baby can be frustrating — infants are so small, it just doesn't feel right to stop feedings or take away that precious bonding time. But that might be the best thing for your baby during treatment. And remember, there's a good chance that your baby will be back on regular feedings soon.
In the meantime, ask a member of your care team what you can do to care for and bond with your baby. There are ways you can help. Members of your care team are eager to support parents of preemies, as well as the preemies themselves, on the path to recovery.