What Is Necrotizing Enterocolitis (NEC)?

Necrotizing enterocolitis (neck-ro-tie-zing-en-tear-oh-ko-lie-tis), or NEC, describes an infection that inflames part of a baby’s intestines. This disease, which can often require surgery to remove damaged sections of intestine, often develops two to three weeks after birth but can occur much later. “Necrotizing” means damage and/or death of cells, “entero” refers to the intestine, and “colitis” means inflammation of the colon (lower part of the intestine). NEC can lead to intolerance of feedings, abdominal swelling, and other serious complications. This occurs predominantly in premature infants. Babies who have NEC are treated with antibiotics and fed intravenously (through a vein) while the intestine heals.

What causes NEC?

The cause of NEC is unknown. NEC is most common in extremely premature babies and/or babies who are already ill. Other possible risk factors may include:

  • Low birth weight (babies who weigh less than 2500 grams)
  • An underdeveloped intestine
  • Too little oxygen or blood flow to the intestine at birth (usually the result of a difficult delivery)
  • Congenital heart disease (“congenital” means existing at birth)
  • Blood transfusion
  • Formula feeding (babies who are fed breast milk have a lower risk of developing NEC)

What are some symptoms of NEC?

Onset of symptoms can occur slowly or quickly. Some of them include:

  • Vomiting
  • Diarrhea
  • Bloating of stomach
  • Low activity level
  • Blood in stool
  • Poor feeding tolerance
  • Abnormal body temperature (either too low or too high)

How does NEC impact health?

Premature babies who require surgery for NEC have a high risk for developing future health problems. A health economic study published in BMC Pediatrics demonstrated that within the group of preemies observed at ages 6 to 12 months who survived surgery for NEC, those infants were:

  • Four times more likely to develop chronic lung disease, or bronchopulmonary dysplasia1
  • Forty-seven times more likely to develop malabsorption syndrome, which is the inability to absorb nutrients, vitamins, and minerals from the intestinal tract into the bloodstream1

Can you prevent NEC from occurring?

According to the March of Dimes, when a healthcare provider suspects that a woman may deliver before 34 weeks of pregnancy, he/she may suggest treating her with a one of several drugs called tocolytics, which often delays preterm labor for few days. This buys them time to treat the pregnant woman with a medicine called corticosteroids.

Corticosteroids speed maturation of the fetal lungs and significantly reduce the risk of serious complications, such as respiratory distress syndrome, or RDS (breathing problems), intraventricular hemorrhage, or IVH (bleeding in the brain), and NEC.2 For those babies who are still born early, despite the use of the medicines listed above, there is still hope.

  • Several studies have reported that premature infants, specifically those born weighing between 500 and 1250 g (1 lb 1 oz to 2 lb 12 oz), who received an exclusive human milk diet (EHMD), as opposed to cow milk-based preterm formula or cow milk-based fortifier, have a reduced risk of developing medical NEC or surgical NEC.3,4,5
  • Humavant HMF, when used as part of an EHMD, is the first and only clinically proven human milk fortifier to reduce NEC, surgical NEC, sepsis, and mortality in premature infants weighing between 500 and 1250 g (1 lb 1 oz to 2 lb 12 oz) at birth, compared to cow milk-based preterm formula or cow milk-based fortifier.4,5,6,7

Is NEC life-threatening?

Yes. NEC is a dangerous and severe complication that often affects extremely preterm infants, in which the intestinal tissue disintegrates. NEC requires surgical intervention to remove the dead portions of the intestines or to insert a drain in 20% to 40% of the cases. The fatality rate for NEC surgery can be high as 50%.8 Early, aggressive treatment helps improve the chances of survival.

How is NEC treated?

When a baby is diagnosed with NEC:

  • They are no longer fed through their mouths.
  • A tube is inserted into the baby’s stomach to relieve gas pressure.
  • They are given antibiotics.
  • Fluids are given through an IV.

How do you know if a baby with NEC is making progress?

The NICU team will keep parents up to date on their baby’s progress. At first, babies with NEC receive X-rays and blood tests several times a day. As the baby gets better, these tests may get less frequent.

When would surgery be required to treat NEC?

  • If there is a lot of damage to the intestine
  • If there are perforations (holes or tears) in the wall of the intestine
  • If the baby has inflammation of the inner wall of the abdomen (peritonitis)
  • If the baby is not getting better with nonsurgical treatment

The fatality rate of NEC surgery is as high as 50%.8

The number of cases of NEC requiring surgery was significantly lower in infants* fed an exclusively human milk-based diet, which included Humavant™ HMF. 4

*Those born weighing between 500 and 1250 grams.

  1. Ganapathy V, et al. Long term healthcare costs of infants who survived neonatal necrotizing enterocolitis: a retrospective longitudinal study among infants enrolled in Texas Medicaid. BMC Pediatr. 2013;13(127):1-11.
  2. Treatments for preterm labor. March of Dimes. https://www.marchofdimes.org/complications/treatments-for-preterm-labor.aspx. Accessed January 12, 2019.
  3. Huston RK, et al. Decreasing necrotizing enterocolitis and gastrointestinal bleeding in the neonatal intensive care unit: the role of donor human milk and exclusive human milk diets in infants <1,500 g birth weight. Infant Child Adolesc Nutr. 2014;6(2):86-93.
  4. Sullivan S, et al. An exclusively human milk-based diet is associated with a lower rate of necrotizing enterocolitis than a diet of human milk and bovine milk-based products. J Pediatr. 2010;156(4):562-567.
  5. Cristofalo EA, et al. Randomized trial of exclusive human milk versus preterm formula diets in extremely premature infants. J Pediatr. 2013;163(6):1592-1595.
  6. Abrams SA, et al. Greater mortality and morbidity in extremely preterm infants fed a diet containing cow milk protein products. Breastfeed Med. 2014;9(6):281-285.
  7. Hair A, et al. Beyond necrotizing enterocolitis prevention: improving outcomes with an exclusive human milk-based diet. Breastfeed Med. 2016;11(2):70-74.
  8. Dominguez KM, et al. Necrotizing enterocolitis. Clin Perinatol. 2012;39(2):387-401.

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