When a family sues a baby formula manufacturer over necrotizing enterocolitis, or NEC, the entire case often comes down to one question: did the product cause the injury? You cannot answer that question with a receipt or a phone call. You need hard medical evidence, presented by people who know the science cold. That is why expert witnesses are the backbone of every NEC claim. They translate years of clinical research and complex neonatal medicine into words a jury can follow. Without them, even the most sympathetic fact pattern collapses.
NEC is a catastrophic intestinal disease that mostly strikes premature infants. The condition destroys bowel tissue, often leading to surgery, permanent disability, or death. For decades, doctors have known that premature babies fed with cow’s milk-based formula face a higher risk of NEC than those fed with human milk or fortified breast milk. The link is not subtle. It is backed by numerous peer-reviewed studies and clinical guidelines. But knowing that the risk is higher does not automatically prove that a specific baby’s NEC came from a specific bottle of formula. That leap requires causation, and causation requires experts.
Say the plaintiff’s family has a medical record showing their baby was born at 28 weeks, spent weeks in the NICU, and received a particular brand of liquid formula. The defense will argue that prematurity itself is the main risk factor for NEC. They will point out that even breastfed preemies develop NEC, though at lower rates. They will note that the baby had other conditions, maybe sepsis or a low birth weight, which could have triggered the disease. To counter that, the plaintiff needs a neonatologist who can testify about the standard of care, how formula is metabolized in an immature gut, and why the product’s effect went beyond mere chance. That expert must walk through the biology in a way that feels concrete, not abstract.
The reverse also happens. The manufacturer will hire its own experts. These are often highly respected physicians who will testify that the formula was safe and that no single cause can be pinpointed. They may cite industry-funded studies or reinterpret existing data. This is not fraud. It is how the adversarial system works. Each side gets to put its best science forward, and the jury has to decide who is more credible. But credibility is not just about diplomas. It is about clarity, consistency, and whether the expert can handle tough cross-examination without contradicting themselves.
Before a jury ever hears an expert, a judge must decide if the testimony is reliable. This is called a Daubert hearing, though lawyers use that term among themselves. In plain language, the judge asks three things. Is the expert actually qualified in the relevant field? Is the methodology used to reach their conclusion a legitimate scientific approach? And does that methodology actually apply to the facts of this case? For NEC claims, this often means scrutinizing how the expert measured “causation.” Animal studies, epidemiological data, and biochemical mechanisms all come into play. If the expert’s reasoning is based on guesswork or cherry-picked numbers, the judge will shut them down. If both sides survive that hurdle, the case moves to a trial where the real battle happens.
What makes NEC cases especially tricky is that there is no blood test that says, “This formula caused this disease.” The evidence is probabilistic. That is hard for people to swallow. We want certainty. We want a definitive answer. But the legal system does not require certainty. It requires proof that the formula was more likely than not the cause. That is a 51 percent threshold. Expert witnesses are the ones who push the number over that line. They do it by explaining risk ratios, confidence intervals, and biological plausibility in everyday language. A good expert can take a relative risk of two or three and make it feel real. A bad expert can take the same data and put the jury to sleep.
Because these claims are consolidated into mass torts, the role of experts becomes even more critical. When thousands of families sue the same manufacturers, courts will often choose a few “bellwether” cases to test the evidence. The expert testimony in those trials sets the tone for everything else. If plaintiffs’ experts are convincing, the manufacturer may start settling. If defense experts prevail, the backlog of cases gets harder to resolve. So the selection of experts is a strategic decision made early, often with huge financial stakes.
Families should understand that their own testimony matters, but it is not enough. You can describe how sick your baby was, how you fed them in the hospital, how you watched them suffer. That is powerful. But a jury needs more than emotion. They need to know why a product that is sold in every supermarket could cause such harm. That knowledge comes from experts, and it is the difference between a story and a winning case. If you are considering a claim, your lawyer will spend significant time finding the right experts. That process is not just paperwork. It is the beating heart of your lawsuit.
