NEC in premature babies

NEC is a disease that harms a baby’s bowel. It mostly strikes babies born too early. Here is how it is found and what the baby formula lawsuits claim.

What is necrotizing enterocolitis (NEC)?

NEC is a disease of the gut. The lining of the bowel swells, and parts of it die. It happens most often in babies born too early or babies who are sick.

In babies born early, it usually starts in the first two or three weeks after birth, often when the baby seems to be getting better.

NIH says the cause is not well known. A preterm baby’s gut is not fully grown, and a drop in blood flow to the bowel can harm it. The smaller or earlier the baby, the higher the risk. About 7% of babies with very low birth weight get NEC.

NEC is serious. MedlinePlus says up to 40% of babies with NEC die from it. A baby who loses a large part of the bowel can be left with short bowel syndrome.

What are the signs of NEC, and when should I see a doctor?

Signs include a swollen belly, trouble with feeds, blood in the stool and green or yellow vomit. The baby may also be very sleepy. If any of these signs develop, get emergency medical care.

Signs can build over a few days or come on all at once. A slow heart rate, pauses in breathing and a body temperature that will not stay steady can also be signs.

MedlinePlus says to get emergency medical care if any symptoms of NEC develop. If a hole forms in the bowel wall, the baby may need surgery right away.

How do doctors diagnose NEC?

Doctors look at the baby’s signs and take an X-ray of the belly. The X-ray usually confirms NEC. It may show bubbles of gas in the bowel wall or air outside the bowel.

Blood and stool tests, along with the X-ray, help doctors judge how serious it is. A stool test can find blood that the eye cannot see.

Doctors often sort NEC into three Bell stages. Stage 1 means NEC is suspected, stage 2 means it is definite and stage 3 means it is advanced. Care ranges from resting the bowel and feeding by vein to antibiotics and, in stage 3, sometimes surgery.

An NIH report says doctors can be fully sure only during bowel surgery or an autopsy, when the tissue itself is seen.

Which records show an NEC diagnosis?

NEC usually starts while the baby is still in the hospital. So the hospital chart holds most of the records. X-ray reports show what the scans found. Care team notes may give the stage. Lab reports show the blood and stool tests.

If the baby had surgery, the surgeon’s notes can confirm NEC, because doctors can see the bowel itself during the operation. In one formula case, an expert was asked to review the baby’s medical records to judge what caused the illness.

A parent can ask for copies of the baby’s records, including the X-rays. HHS says the hospital normally has up to 30 days to provide a copy. It cannot refuse because a bill is unpaid.

What does research say about baby formula and NEC?

In 2024, FDA, CDC and NIH said there is no clear proof that formula for preterm babies causes NEC. They also said there is strong proof that human milk helps protect babies from it.

The agencies said evidence so far suggests that being born too early is the main risk. They called preterm formula a critically important option for these babies.

An NIH working group said the evidence supports the idea that the lack of human milk, not formula itself, is linked to a higher risk. It also said the link between feeding and NEC is unclear, and that babies fed only human milk can still get NEC.

In May 2025, the judge who handles the federal formula cases let the families’ experts testify that cow’s milk formula can raise the risk of NEC. The judge called the ruling provisional and did not decide whether formula causes NEC. In the federal court papers we read, no judge has ruled that formula causes NEC.

On July 24, 2026, a federal appeals court upheld Abbott’s win in one family’s case. The court said the family had not shown that the different warning they wanted would have prevented their baby’s death. It said it did not need to decide whether the formula was a cause of the baby’s NEC.

Who brings NEC claims in the baby formula cases?

Families of babies born too early bring these claims. They say formula made from cow’s milk, sold as Similac or Enfamil, caused their baby’s NEC. Whether a family has a claim depends on its own records and facts.

In 2022, the federal cases were grouped before one judge in the Northern District of Illinois, Judge Rebecca R. Pallmeyer.

Test cases have gone different ways. In the first three, the judge ruled for Abbott without a trial. In the fourth, in May 2026, the judge let a family’s case against Mead Johnson go to trial. Mead Johnson denies that its products cause NEC.

Can a parent get a baby’s NEC records?

Yes, in most cases. HHS says a parent is usually the personal representative of a minor child. That lets the parent get the child’s records. HHS lists a few exceptions to this rule.

If a baby has died, the executor or administrator of the estate can get the records needed for that role. A hospital may also share limited facts with a family member who was involved in the baby’s care or in paying for it. Each state’s law decides who holds these roles.

If a baby has died, the wrongful death case page explains in general how those claims work.