Premature infants (born before 37 weeks of pregnancy) are likely to be admitted to a NICU (Neonatal Intensive Care Unit) for specialized medical treatment and support.
Premature babies are also likely to face a number of additional health challenges, both in the short and long term, compared with babies born after 37 weeks.
One hurdle they might face is a condition known as neonatal necrotizing enterocolitis.
For more on premature babies and what to expect read our articles:
Here’s what you need to know about the condition.
What is necrotizing enterocolitis (NEC)?
Necrotizing enterocolitis (NEC) is a serious condition that mainly affects premature babies, causing severe inflammation of the intestinal tract.
Inflammation of the intestinal wall causes damage and intestinal injury and can lead to the death of large areas of intestinal tissue.
Small or large sections of the bowel can also be affected.
Is necrotizing enterocolitis dangerous?
Necrotizing enterocolitis can be extremely dangerous, leading to life-threatening infection.
Damage caused by inflammation of the intestinal wall can lead to spontaneous intestinal perforation (a hole). This can cause ‘leaking’ of bacteria that usually live in the gut to spill out into the abdominal cavity or into the bloodstream, leading to a dangerous bacterial infection and sepsis.
Intestinal inflammation or damaged tissue will affect the body’s ability to absorb nutrients in the digestive system, affecting your baby’s growth and development.
In severe cases, sections of the necrotic bowel (dead tissue) might need to be removed in surgery.
Survivors of NEC could be left with life-long complications caused by the condition.
What is the survival rate for necrotizing enterocolitis?
Necrotizing enterocolitis is a devastating disease which affects many premature infants.
Despite significant advances in neonatal care, necrotizing enterocolitis remains a leading cause of neonatal morbidity and mortality in neonatal intensive care units.
Sadly, some babies will not survive necrotizing enterocolitis.
It affects approximately 1 in every 1,000 births, but rates are significantly higher in premature infants.
The estimated mortality rate is between 20 and 30% and is higher in infants who require surgery.
This means that approximately 8 out of 10 babies with NEC will survive; however, some will be left with life-long complications.
Types of necrotizing enterocolitis
There are different types of necrotizing enterocolitis, based on when symptoms occur and what causes the condition:
- Classic. This is the most common type, mainly affecting very premature infants under 28 weeks. Symptoms typically present 3-6 weeks after birth and can occur suddenly, without warning
- Transfusion associated. 1 in 3 premature newborns who require a blood transfusion for severe anemia will develop NEC 1-3 days after the transfusion
- Atypical. This type occurs within the first week of life or before the infant’s first feed
- In full term babies, symptoms usually begin sooner – often in the first week of life. This could be because they are more likely to start feeding earlier.
All types of necrotizing enterocolitis can range from mild to severe and can be life-threatening.
Can full term infants get necrotizing enterocolitis?
Necrotizing enterocolitis is mainly seen in extremely premature infants; however, full term babies are not completely in the clear.
It’s thought around 1 in 10,000 full term babies will develop necrotizing enterocolitis.
It appears full term infants with other health concerns are more susceptible to developing NEC than those without any underlying conditions.
NEC is seen more commonly in full term infants with conditions such as congenital heart disease, gastroschisis or those who were born with low oxygen levels at birth.
How is necrotizing enterocolitis diagnosed?
Diagnosing necrotizing enterocolitis based on physical examination alone can be difficult. This is because the symptoms of NEC can be quite generalized and might be similar to symptoms caused by other illnesses.
If NEC is suspected, your child’s doctor will probably suggest a number of tests to confirm the diagnosis:
- Blood tests and blood gases. Blood samples from your baby will detect signs of infection and confirm how your baby’s body is fighting the infection
- Fecal tests. A sample of your baby’s poop will be tested to look for signs of blood in the stool. This type of test will detect blood not visible to the eye
- Abdominal x-ray. Air bubbles in the abdominal cavity can be a sign of bowel damage or bowel perforation.
Stages of necrotizing enterocolitis
The stages of NEC are classified based on the severity of symptoms and the degree of damage to the bowel.
Stage 1. A baby might show generalised clinical signs of being unwell, including changes in temperature, heart rate, irregular breathing patterns or poor feeding. Other signs might be bloody stools or blood seen in vomit.
Stage 2. A baby will be moderately unwell. Diagnosis will be confirmed by x-ray findings and abnormal blood results. You baby is likely to show many of the above signs plus abdominal tenderness or absence of bowel sounds.
Stage 3. A baby will be severely unwell. Signs will include all of the above, plus abnormal blood clotting, abdominal distention (your baby’s belly will be swollen) and even respiratory arrest.
Classification of Stage 3 is split further, depending on whether the bowel remains intact or has become perforated.
Symptoms of necrotizing enterocolitis
Some babies with necrotizing enterocolitis will present with general signs of being unwell:
- Signs of infection, including raised heart rate, low blood pressure, irregular breathing and changes in body temperature
- Feeding intolerance or poor weight gain
Some symptoms might point more towards a bowel complication:
- Changes in bowel movements – bloody stool, constipation or diarrhoea
- Vomiting – bilious (green/yellow) or bloody vomit
- Abdominal distention – swollen belly
- Abdominal tenderness
- Large volumes of green fluid or blood in NG tube (if being tube fed).
How quickly does necrotizing enterocolitis develop?
Symptoms of NEC can develop slowly over a period of a few days or they can appear suddenly without warning.
NEC typically occurs about 3-6 weeks following birth. However, some types of NEC might present more quickly, especially in babies who are full term.
What causes necrotizing enterocolitis?
The causes of necrotizing enterocolitis are not well understood but the condition is likely to be due to a number of risk factors.
Who is at risk of necrotizing enterocolitis?
NEC is a condition that mainly affects babies who are born early.
It’s thought that 9 out of 10 babies with necrotizing enterocolitis are premature.
A premature infant is more likely to require a stay in the neonatal unit and require additional support and medical treatment. Babies born before they are ready will have greater health challenges, due to all of their systems being underdeveloped or immature.
These babies will find it harder to fight bacterial infections due to an underdeveloped immune system and fewer opportunities for skin to skin contact and breastfeeding. A premature baby is likely to have feeding and growth problems, due to an undeveloped suck reflex and a lack of brown adipose fat, which is usually laid down in the later weeks of pregnancy.
Related reading: Preterm Birth | Ways To Reduce Preterm Birth.
Risk factors for necrotizing enterocolitis
Prematurity is a big risk factor for the condition but babies with other health conditions can also develop NEC.
Here is a list of risk factors for necrotizing enterocolitis:
- Premature babies (particularly babies born before 32 weeks gestation). The incidence of NEC increases with decreasing gestational age
- Very low birthweight infants. The greatest risk occurs in babies under 2 pounds (907 gms) at birth
- IUGR (Intrauterine Growth Restriction)
- Tube fed babies. This refers to babies who receive feed through a naso-gastric (NG) tube. Many babies who are either too poorly or too young to take feeds from the breast or a bottle are fed in this way
- Underlying conditions. Birth defects, such as congenital heart disease, cardiovascular or lung disease, might affect blood flow to the gut, causing too little oxygen to the tissues of the intestinal cells. This can also cause damage to the intestines, increasing the chances of a baby developing NEC.
What is the treatment for necrotizing enterocolitis?
Mild to moderate necrotizing enterocolitis is likely to be managed and treated by temporarily stopping milk feeds; this allows the bowel time to recover.
There’s no need to worry; if this happens, your baby will still receive all of the nutrients she needs, by being fed in an alternative way.
IV antibiotics may also be given to prevent or fight infection.
For some babies, this could be all that’s needed to recover from the initial acute illness.
If, however, the bowel is found to be perforated, as in the most serious cases, those babies will require immediate pediatric surgery to repair the damage. Some babies might also require surgery to remove sections of the bowel where the tissue has died; this known as bowel necrosis.
It is thought that 1 in 4 babies with NEC will require surgery.
Sometimes it might be necessary for your baby’s healthcare provider to perform a procedure which involves removing parts of the affected bowel and joining the two healthy ends together again.
Sometimes, however, this is not possible. In that case the bowel will be brought to the surface and a stoma bag will be connected. This might be a temporary measure to allow your baby’s intestines to heal, following the surgery. Once healing has occurred and your baby is stronger, the bag can be removed and the bowel can be joined together again.
Complications caused by necrotizing enterocolitis
Recovery from the acute illness will take time; however, some infants will be left with life-long complications from the condition.
Common complications include:
- Reocurrence. It’s possible NEC might occur again; if so, your baby might require more surgery
- Developmental delays – neurological and/or physical
- Growth delays
- Gastro-intestinal problems, including intestinal stricture (narrowing of the bowel) and bowel obstruction caused by scar tissue
- Infections following surgery, which will require antibiotics
- Short bowel syndrome, where large sections of the bowel have been removed. This restricts the body’s ability to absorb nutrients from foods. People with short bowel syndrome will require additional nutritional supplementation in the form of enteral feeds
- Cholestasis. This is very common in infants following surgery
If your child has been diagnosed and treated for necrotizing enterocolitis, she will be followed up and monitored closely, to ensure she’s recovering well and thriving.
Is necrotizing enterocolitis contagious?
Necrotizing enterocolitis is not contagious, meaning it cannot be caught by being in close proximity to someone with the condition. However, viruses and bacteria such as e-coli, which might cause the condition, can be passed on.
Occasionally there might be multiple cases of necrotizing enterocolitis in a neonatal unit; it is possible it might have been passed on in this way.
How do I prevent necrotizing enterocolitis in my baby?
Research into preventing necrotizing enterocolitis is key. Some theories suggest that one cause of the condition may be related to an imbalance of unhealthy and healthy bacteria and microorganisms in the gut.
Due to the high levels of healing properties and antibodies present in human milk, it’s been proved that babies who are fed breast milk or receive human milk have a greater variation of healthy bacteria in their gut than those who are fed formula. This could be the reason why babies who are fed breast milk are less likely to develop NEC compared with babies who are formula feeding.
The very nature of antibiotics will disrupt the natural balance of organisms in the gut system. Therefore, reducing the use and duration of antibiotics, unless absolutely necessary, might reduce the chances of your baby developing necrotizing enterocolitis.
Research into the use of probiotic supplementation is still ongoing but some studies have suggested that it might reduce the incidence of the condition.
Discuss this with your child’s healthcare provider to find out whether it is an option for your baby.