CHICAGO — Four Illinois mothers would never have allowed their prematurely born babies to be fed a specialized formula made by Abbott Laboratories had they known about the risks, an attorney for the parents argued in court Monday, while a lawyer for the company countered that the formula is not dangerous and that additional warnings about it would not have prevented the infants from getting sick.

Attorneys for the parents and north suburban-based Abbott Laboratories faced off during opening arguments Monday in the first trial to hit Cook County Circuit Court over the issue of whether specialized, cow’s milk-based formula made by Abbott for babies born prematurely causes a serious intestinal disease called necrotizing enterocolitis (NEC).

The trial is part of a much larger legal tussle over the matter, with potential implications for Abbott and for families of babies born prematurely nationwide. The cases now at trial in Chicago are among more than 1,700 over the issue Abbott is facing across the country.

This is only the third time cases against Abbott over the issue have gone to trial. The other two trials — in Missouri state court — had opposite results, with one ending in a$495 million verdict against Abbott and the jury finding the company not liable in the other.

The trial now in Cook County Circuit Court involves four lawsuits against Abbott, all filed in 2022 by Illinois parents whose babies were born prematurely at Chicago area hospitals between 2012 and 2019.

Each of the babies was born before 32 weeks gestation, weighing no more than about 3 pounds. Two of the babies were born at University of Illinois Hospital, one was born at University of Chicago Medical Center and one was born at what is now Ascension Saint Alexius in Hoffman Estates.

The parents — Antonia Mendez, Casie Thompson, Kara Sharpe and Eboni Williams — allege that their babies consumed Abbott’s cow’s milk-based products, became ill and are now suffering from long-term health problems. The parents allege that Abbott failed to provide warnings about the risks of its products, was negligent and misrepresented the safety of the products — all of which Abbott has denied in court documents.

The formula at issue is a special product offered in hospitals for premature babies called Similac Special Care.

At the heart of the dispute is the question of what exactly causes NEC — a devastating disease in which tissue lining the intestine becomes inflamed and dies. Preterm and low-birth-weight babies are at higher risk than full-term babies of developing NEC, potentially because of their immature digestive systems, according to the National Institutes of Health. Research indicates 15% to 40% of infants with the disease die.

An attorney for the parents emphasized Monday that research shows a clear association between the use of cow’s milk-based formula in prematurely born babies and the risk of developing NEC.

“If (the parents) knew that formula increased the risk of getting NEC by double, triple, quadruple, they never would have agreed to that, but the moms didn’t know,” said Kenzo Kawanabe, a partner at Olson Grimsley, representing the mothers. “The doctors didn’t understand … but you know who knew? The defendant, Abbott Laboratories.”

He said that Abbott should have done more to warn parents of the risk associated with formula feeding for premature infants.

“When you look at their labels and their packaging, they don’t mention it. They don’t even use the words necrotizing enterocolitis,” Kawanabe said. “Their product is a risk factor for NEC and they don’t tell anyone.”

But Hariklia Karis, a partner with Kirkland & Ellis representing Abbott, argued that no study has shown that cow’s milk-based formula actually causes NEC in preterm babies. To the contrary, Harris pointed out a statement released in 2024 by the U.S. Food and Drug Administration, the Centers for Disease Control and Prevention and the National Institutes of Health, based on a working group report, that said, “Available evidence supports the hypothesis that it is the absence of human milk — rather than the exposure to formula — that is associated with an increase in the risk of NEC.”

Karis argued that there are multiple other risk factors for NEC, including being born prematurely, prolonged antibiotic use and infections as a premature infant.

“That boat, respectfully and candidly, was tipping regardless of what these kids got fed,” Karis said. “They were so premature, they were at such great risk, it didn’t matter.”

She also contended that doctors are well aware that breast milk is more protective against NEC for premature infants. Abbott agrees with doctors and the plaintiffs that a mother’s breast milk is the best choice for prematurely born babies, she said. But mother’s milk and donated breast milk are not always available.

“Different wording on these packages and bottles wouldn’t have made a difference,” Karis said. “Nobody … consumed this product because they didn’t know about the risk of NEC. None of these doctors ordered these products because they didn’t know about the risk of NEC. Donor milk was not available. They needed this last line of defense. These kids needed to eat.”

Experts are closely watching the four cases now at trial, wondering whether their outcomes might influence the many other, similar cases against Abbott that have also been filed in Cook County Circuit Court. The case is also being closely watched because the CEO of Abbott has suggested in the past that the company could pull the product altogether if Abbott continues to face litigation — a move that doctors worry would mean fewer nutritional options for preterm babies. Other plaintiffs’ attorneys, however, have called the CEO’s threat of yanking the product a scare tactic.

In addition to the two other cases against Abbott that already went to trial in Missouri, and in addition to the four now at trial in Cook County Circuit Court, hundreds of similar cases have also been filed in federal court in Chicago. Four of those federal cases were chosen as bellwether cases, meaning their outcomes are meant to help guide how all the other cases in federal court in Chicago might proceed, and/or how to settle those cases. So far, three of those federal bellwether cases were thrown out before they went to trial. The fourth bellwether case is scheduled to go to trial in July.

Abbott is appealing the $495 million verdict reached against it in Missouri state court in 2024. In the other Missouri state court case, in which a jury found Abbott and another manufacturer of preterm infant formula, Mead Johnson Nutrition, not liable, a St. Louis judge later granted a motion for a new trial citing “errors and misconduct.” Abbott is also appealing that decision.

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