In September 2016, a mother emailed Mead Johnson to report that her son died from necrotizing enterocolitis (NEC) after consuming the company's pre-term infant formula. Mead Johnson issued an internal memo concluding there was "not a reasonable possibility" that its formula caused the baby's death and stated, "No further investigation is needed. This file can be closed."

Federal regulations require infant formula manufacturers to investigate complaints showing a possible health hazard. These regulations also require manufacturers to notify the FDA within 15 days only if an investigation finds a reasonable possibility of a causal relationship between the formula and an infant's death. The FDA reported it did not receive any notifications from infant formula manufacturers regarding deaths between January 1, 2020, and March 2026, and found no records of such notifications between January 1, 2000, and May 5, 2026.

In a 2024 deposition, Christina Valentine, former medical director for North America for Mead Johnson, testified that she never sent the FDA a report of death from NEC during her seven years in that role. Valentine also testified that she never concluded there was a reasonable possibility that an infant's death from NEC might have been related to a Mead Johnson product.

Mead Johnson spokesperson Jen O'Neill stated that the company submits adverse event reports to the FDA when a physician report includes an opinion that a product caused NEC in a preterm infant. O'Neill added that physician reports triggering FDA submissions were generally made by plaintiffs' paid experts, with whom the company disagrees. She also stated that prior to current litigation, Mead Johnson received very few reports related to its products and NEC and even fewer for which investigation uncovered evidence supporting a reasonable possibility of a causal relationship.

Abbott Laboratories and Mead Johnson have denied fault in ongoing lawsuits alleging their formulas harmed or killed preterm babies. Approximately 2,300 newborns died of necrotizing enterocolitis in the United States from 2017 through 2023. A jury awarded a $60 million judgment against Mead Johnson in the case of Watson v. Mead Johnson.