Baby Formula NEC

Parents of premature babies in the NICU already have enough to worry about without also having to worry that formula being fed to their newborn might cause necrotizing enterocolitis. Necrotizing enterocolitis is an intestinal disease that most commonly affects premature infants or other at-risk newborns who were fed formula. Necrotizing enterocolitis is a serious condition that carries the risk of death. Doctors don’t know what causes it, but it’s associated with cow’s milk-based formula products fed to premature or at-risk newborns. Parents of newborns who have developed necrotizing enterocolitis after consuming formula in the hospital are suing Mead Johnson and Abbott Laboratories, the manufacturers of Enfamil and Similac, the two most popular brands of infant formula, for not adequately warning parents and medical providers of the risk of necrotizing enterocolitis.

Sign up for our newsletter to get updates on drugs & medical devices

If you would like to sign up for our newsletter click the button below.

Free Case Evaluation

What Is Premature Birth?

Childbirth is considered premature when it takes place three weeks or more prior to the estimated due date. Premature birth can often be dangerous for babies because they haven’t had as long to develop within the womb and are therefore more at risk for health complications. In fact, the earlier the baby is born, the more at risk they are.

What Are the Classifications of Premature Birth?

There are four different categories of premature birth:

  • Extremely preterm
  • Very preterm
  • Moderately preterm
  • Late preterm

An extremely preterm baby was born at or before 25 weeks of gestation, very preterm between 26 and 32 weeks, moderately preterm between 32 and 34 weeks, and late preterm between 34 and 36 weeks. Most of the time, a premature baby is born during the late preterm stage.

Which Premature Babies Spend Time in the NICU?

All preterm babies typically require some amount of special care and a longer stay in the hospital. Many spend some time in the Neonatal Intensive Care Unit (NICU), no matter how premature they were because all premature births carry some amount of risk. How long the baby spends in the NICU may depend on how preterm they were, however. The more preterm an infant was when born, the longer they generally stay in the NCIU due to the risks to their health.

What Are the Signs a Baby Is Premature?

Babies that are born prematurely typically display certain characteristics:

  • Small body size
  • Large head
  • Fine hair that covers the body
  • Respiratory distress
  • Feeding difficulties
  • Low body temperature

Many of these symptoms of premature birth occur because the baby hasn’t had time to develop fully. For example, the difficulties in feeding may occur because premature infants haven’t completely developed the reflexes to suck and swallow that they would need to properly feed.

Premature babies usually have lower birth weights and smaller physical sizes than babies born at full term. The earlier the preterm baby was born, the lower the birth weight and the smaller the physical size.

What Can Increase the Risk of a Premature Birth?

While it’s often difficult to determine exactly what caused a baby’s birth to be premature, there are some factors that can increase the risk of premature birth, including:

  • Conception through in vitro fertilization
  • Prior premature birth
  • A multiple birth (twins, triplets, etc.)
  • Fewer than six months in between pregnancies
  • Uterus problems
  • Cervix problems
  • Placenta problems
  • Smoking
  • Using illegal drugs
  • Being underweight pre-pregnancy
  • Being overweight pre-pregnancy
  • Diabetes
  • High blood pressure
  • Other chronic conditions
  • Amniotic fluid infection
  • Lower genital tract infection
  • Other infections
  • Physical injury
  • Trauma
  • Multiple miscarriages
  • Multiple abortions
  • Stressful life events
  • Death of a loved one
  • Domestic violence

Although these risk factors may increase the chances of a premature birth, premature birth can happen to anyone, even those who haven’t experienced any of the risk factors on the list above.

What Complications Can Result From Premature Birth?

A baby born prematurely may be at risk for health complications, both short-term and long-term. In the short-term, a premature infant may be at risk of having problems with the following:

  • Temperature control
  • Brain
  • Breathing
  • Heart
  • Metabolism
  • Gastrointestinal system
  • Blood
  • Immune system

In the long-term, premature infants may be more at risk for the following health complications:

  • Cerebral palsy
  • Dental issues
  • Hearing issues
  • Vision issues
  • Learning disability
  • Chronic health problems
  • Behavioral issues
  • Psychological issues

Can Premature Birth Be Prevented?

As the cause of premature birth may not be entirely known, it may be impossible to prevent. However, anyone who knows ahead of time that they have a greater risk of premature birth may be given progesterone supplements. Additionally, a surgical option in which, during pregnancy, a surgeon stitches the cervix closed may be available. This option may be used for women with short cervixes or cervical shortening, and may help to support the uterus. The stitches are removed when it’s time to give birth.

What Is Infant Formula?

Infant formula, or baby formula, is a type of milk manufactured for consumption by infants as either a replacement for or supplement to breast milk. While there is a debate surrounding the use of formula, with many insisting that breast milk is best, there are times when infant formula may be helpful, or even necessary. For example, if a premature baby is in the NICU and the parents may not be able stay at the hospital all the time. The infant will require feeding but mother’s breast milk may not be available for feeding. Even outside of the hospital, not all mothers are able to produce enough breast milk to keep their baby fed, making formula a necessary supplement or even replacement for breast milk.

What Kinds of Infant Formula Are There?

There are three different types of infant formula:

  • Cow’s milk-based formula
  • Soy formula
  • Protein hydrolysate

How Is Infant Formula Prepared?

Infant formula can come in several different forms, each of which requires a different method of preparation:

  • Ready-to-use formula
  • Powdered formula
  • Concentrated formula

Ready-to-use formula is the only type of formula that is ready to feed as-is. Both the powdered formula and the formula concentrate need to be mixed with water per the instructions on the packaging before being given to an infant.

Is Name-Brand Formula Better Than Generic Formula?

While there may be a difference in the ingredients from one brand to another, all infant formula companies are required by the FDA to meet certain nutritional requirements. It’s more important to look at what extra nutrients an infant may need instead of the brand of the formula. For example, babies need iron, so iron-fortified infant formula may be recommended for those who aren’t breastfeeding. Other recipes may be enhanced with other types of vitamins and nutrients. People purchasing formula should consult with their doctor beforehand to determine whether additional nutrients are needed for the baby.

Is Enhanced Formula Better Than Regular Formula?

Enhanced formula usually aims to mimic the nutrients found in breastmilk by including things like probiotics to help encourage the growth of healthy intestinal bacteria. In the short term, these formulas have appeared promising, but more research is needed to know if they’re beneficial in the long term.

How Long Does a Baby Need Formula?

Typically, babies consume infant formula until about a year old. After one year of age, they can usually drink regular milk (whole, not skim). The fat and calories from whole milk are needed for toddlers’ brain development.

What Is Necrotizing Enterocolitis?

Necrotizing enterocolitis, often abbreviated as NEC, is a disease that impacts the intestines. It most commonly affects premature infants or other at-risk newborn babies who were fed cow’s milk-based baby formula and usually occurs during the first two weeks of the baby’s life. In infants who develop NEC, bacteria get into their intestinal walls and cause inflammation. This inflammation may then cause a gap or a fissure to form in the wall of the intestine, through which the bacteria can travel into the abdomen.

Necrotizing enterocolitis can be very serious and, if it’s not promptly treated, may even lead to the death of the infant.

What Causes Necrotizing Enterocolitis?

Doctors don’t know exactly what causes necrotizing enterocolitis. However, it’s thought that it occurs predominantly in premature babies because their bodies may be weaker than those of full-term babies. Premature babies just aren’t as mature and their circulatory systems may not be able to move blood and oxygen around their bodies as well as full-term infants. Premature babies also may not be process food as well as full-term babies and they may be more at risk of infection. For these reasons, premature infants or babies that are otherwise at risk may be more likely to develop necrotizing enterocolitis.

Who Is Most at Risk of Developing Necrotizing Enterocolitis?

Fortunately, necrotizing enterocolitis is very rare and affects only about one in every two to four thousand babies. Babies that are at higher risk for developing necrotizing enterocolitis may have any of the following characteristics:

  • Under 3.25 pounds in weight
  • High-risk
  • Premature
  • Difficult delivery
  • Low oxygen levels
  • High red blood cell count
  • Seriously ill
  • Received a blood transfusion
  • Existing gastrointestinal infection

Premature or otherwise high-risk babies are at higher risk for necrotizing enterocolitis when fed cow’s milk-based formula either via the mouth or by tube. NEC also usually develops within an infant’s first two weeks of life.

What Are the Symptoms of Necrotizing Enterocolitis?

The symptoms of necrotizing enterocolitis may include:

  • Swollen belly
  • Bloated belly
  • Bloody poop
  • Sluggishness
  • Low heart rate
  • Difficulty breathing
  • Green fluid located in the stomach
  • Feedings that don’t move through the intestines, staying in the stomach instead

Necrotizing enterocolitis isn’t the only digestive problem that can present these symptoms. However, because NEC can be fatal, if you notice any of the above symptoms in your infant, it’s essential to contact a doctor immediately.

How Do Doctors Diagnose Necrotizing Enterocolitis?

Doctors diagnose necrotizing enterocolitis by taking x-rays of the baby’s belly. An x-ray can show if there are air bubbles within the intestinal walls. Air bubbles shown on an x-ray are a sign of necrotizing enterocolitis. Doctors may also test for NEC by inserting a needle into the baby’s belly where the intestines are. If any fluid comes out, that may be a sign that the baby has NEC. Fluid in the belly may be a symptom of a hole in the intestines which may occur with NEC.

Doctors may also do blood testing. A blood test may determine how many white blood cells a baby has. If there are too few white blood cells, then the infant may have a difficult time fighting off an infection like NEC.

Can NEC Be Prevented?

Unfortunately, there is currently no way to prevent NEC. Many hospitals are encouraging breastfeeding or the use of donor breast milk for occasions when the mother isn’t available to breastfeed. Another alternative may be baby formula that isn’t made from cow’s milk. There may be baby formulas that are made with soy or protein hydrolysate instead of cow’s milk which can be used.

How Is NEC Treated?

Once an infant has been diagnosed with NEC, treatment may depend on the following:

  • How premature the infant is
  • The infant’s overall health
  • Medical history
  • Spread of the infection

Necrotizing enterocolitis may be treated by:

  • Ceasing feedings
  • Antibiotics
  • Removing fluid from the stomach and intestines via tube
  • IV fluids
  • X-rays
  • Oxygen machine
  • Isolation from other infants

It usually takes about five to seven days to treat necrotizing enterocolitis infection. At that point, feedings via mouth can resume.

Do Babies With NEC Require Surgery?

If the baby’s condition doesn’t improve and the infection doesn’t go away after five to seven days, then surgery may be necessary. Surgery may also be necessary if there is a hole in the infant’s intestine. Surgery to treat NEC typically involves removing:

  • Dead tissue
  • Ruptured intestinal tissue
  • Intestinal tissue about to rupture

Sometimes, the surgeon connects the intestines or bowels to an opening in the abdomen, a surgery known as an ostomy. This type of surgery is often only performed in the most serious of NEC cases.

What Are the Chances of Recovery From NEC?

Fortunately, most infants who develop NEC are able to recover. In cases where surgery was necessary, however, there may be intestinal or bowel issues in the future due to narrowed intestinal tract or removal of a portion of the intestines which requires treatment. Future complications may include blockages or the inability to properly absorb nutrients. In the most severe cases, a baby may need a bowel transplant.

If necrotizing enterocolitis isn’t treated, it may be deadly.

Does Infant Formula Cause NEC?

While infant formula itself doesn’t necessarily cause NEC to occur in premature or at-risk infants, it may be a factor that increases the risk, particularly with cow’s milk-based baby formula. Studies comparing the rates of NEC in premature and at-risk infants that were fed cow’s milk-based formula to those that were fed breast milk found that the risk of developing NEC was higher in those that drank cow’s milk-based formula. One study showed that 8.9 percent of the babies studied who drank cow’s milk-based formula needed additional care in the NICU, while only 3.1 percent of babies that drank breast milk did.

How Does Infant Formula Increase the Risk of NEC in Premature Infants?

Scientists and doctors aren’t sure exactly why consuming cow’s milk-based formula increases the risk of developing NEC. However, it’s thought that cow’s milk could be encouraging the growth and spread of harmful bacteria. Full-term, healthy infants have more developed immune systems which may better protect from bacteria, but premature or at-risk infants may have been born before those systems fully developed. This means that their underdeveloped intestines may not be able to provide the same protection from infection. Additionally, a premature or at-risk infant’s immune system may not be as well-developed as full-term infants, so they may not fight off an infection as easily.

Notwithstanding claims relating to this product, the drug/medical device remains approved by the U.S. FDA. 


  1. Luhana, R. (2021, December 10). New study confirms link between infant formula and increased risk of NEC. New York Injury Law News. Retrieved April 29, 2022, from 
  2. Mayo Foundation for Medical Education and Research. (2021, April 14). Premature birth. Mayo Clinic. Retrieved April 27, 2022, from 
  3. Mayo Foundation for Medical Education and Research. (2022, February 25). Infrant formula: Your questions answered. Mayo Clinic. Retrieved April 27, 2022, from 
  4. Stoltz, T., Jones, A., Rogers, L., Sidhu, H., Patel, R., Shamsuddin, A., Lee, C., Graham, C., Costa, A., & Rosner, J. (n.d.). 51 Donor Milk in the NICU: A Community Pediatrics Perspective. Retrieved April 29, 2022, from 
  5. WebMD. (n.d.). Necrotizing enterocolitis: Symptoms, causes, treatment. WebMD. Retrieved April 27, 2022, from

Have you been affected by a drug or device listed?