Six weeks after Jack Mahoney was born prematurely on Feb. 3, 2011, the neonatal staff at WakeMed Hospital in Raleigh, N.C., noticed that his heart rate slowed slightly when he ate. They figured he was having difficulty feeding, and they added a thickener to help.
When Jack was discharged, his parents were given the thickener, SimplyThick, to mix into his formula. Two weeks later, Jack was back in the hospital, with a swollen belly and in inconsolable pain. By then, most of his small intestine had stopped working. He died soon after, at 66 days old.
A month later, the Food and Drug Administration issued a caution that SimplyThick should not be fed to premature infants because it may cause necrotizing enterocolitis, or NEC, a life-threatening condition that damages intestinal tissue.
Experts do not know how the product may be linked to the condition, but Jack is not the only child to die after receiving SimplyThick. An F.D.A. investigation of 84 cases, published in The Journal of Pediatrics in 2012, found a “distinct illness pattern” in 22 instances that suggested a possible link between SimplyThick and NEC. Seven deaths were cited; 14 infants required surgery.
Last September, after more adverse events were reported, the F.D.A. warned that the thickener should not be given to any infants. But the fact that SimplyThick was widely used at all in neonatal intensive care units has spawned a spate of lawsuits and raised questions about regulatory oversight of food additives for infants.
SimplyThick is made from xanthan gum, a widely-used food additive on the F.D.A.’s list of substances “generally recognized as safe.” SimplyThick is classified as a food and the F.D.A. did not assess it for safety.
John Holahan, president of SimplyThick, which is based in St. Louis, acknowledged that the company marketed the product to speech language pathologists who in turn recommended it to infants. The patent touted its effectiveness in breast milk.
However, Mr. Holahan said, “There was no need to conduct studies, as the use of thickeners overall was already well established. In addition, the safety of xanthan gum was already well established.”
Since 2001, SimplyThick has been widely used by adults with swallowing difficulties. A liquid thickened to about the consistency of honey allows the drinker more time to close his airway and prevent aspiration.
Doctors in newborn intensive care units often ask non-physician colleagues like speech pathologists to determine whether an infant has a swallowing problem. And those auxiliary feeding specialists often recommended SimplyThick for neonates with swallowing troubles or acid reflux.
The thickener became popular because it was easy to mix, could be used with breast milk, and maintained its consistency, unlike alternatives like rice cereal.
“It was word of mouth, then neonatologists got used to using it. It became adopted,” said Dr. Steven Abrams, a neonatologist at Texas Children’s Hospital in Houston. “At any given time, several babies in our nursery — and in any neonatal unit — would be on it.”
But in early 2011, Dr. Benson Silverman, the director of the F.D.A.’s infant formula section, was alerted to an online forum where doctors had reported 15 cases of NEC among infants given SimplyThick. The agency issued its first warning about its use in babies that May. “We can only do something with the information we are provided with,” he said. “If information is not provided, how would we know?”
Most infants who took SimplyThick did not fall ill, and NEC is not uncommon in premature infants. But most who develop NEC do so while still in the hospital. Some premature infants given SimplyThick developed NEC later than usual, a few after they went home, a pattern the F.D.A. found unusually worrisome.
Even now it is not known how the thickener might have contributed to the infant deaths. One possibility is that xanthan gum itself is not suitable for the fragile digestive systems of newborns. The intestines of premature babies are “much more likely to have bacterial overgrowth” than adults’, said Dr. Jeffrey Pietz, the chief of newborn medicine at Children’s Hospital Central California in Madera.
“You try not to put anything in a baby’s intestine that’s not natural.” If you do, he added, “you’ve got to have a good reason.”
A second possibility is that batches of the thickener were contaminated with harmful bacteria. In late May 2011, the F.D.A. inspected the plants that make SimplyThick and found violations at one in Stone Mountain, Ga., including a failure to “thermally process” the product to destroy bacteria of a “public health significance.”
The company, Thermo Pac, voluntarily withdrew certain batches. But it appears some children may have ingested potentially contaminated batches.
The parents of Jaden Santos, a preemie who died of NEC while on SimplyThick, still have unused packets of recalled lots, according to their lawyer, Joe Taraska.
The authors of the F.D.A. report theorized that the infants’ intestinal membranes could have been damaged by bacteria breaking down the xanthan gum into too many toxic byproducts.
Dr. Qing Yang, a neonatologist at Wake Forest University, is a co-author of a case series in the Journal of Perinatology about three premature infants who took SimplyThick, developed NEC and were treated. The paper speculates that NEC was “most likely caused by the stimulation of the immature gut by xanthan gum.”
Dr. Yang said she only belatedly realized “there’s a lack of data” on xanthan gum’s use in preemies. “The lesson I learned is not to be totally dependent on the speech pathologist.”
Julie Mueller’s daughter Addison was born full-term and given SimplyThick after a swallow test showed she was at risk of choking. It was recommended by a speech pathologist at the hospital.
Less than a month later, Addison was dead with multiple holes in her small intestine. “It was a nightmare,” said Ms. Mueller, who has filed a lawsuit against SimplyThick. “I was astounded how a hospital and manufacturer was gearing this toward newborns when they never had to prove it would be safe for them. Basically we just did a research trial for the manufacturer.”
