NEW YORK - Preemie parents may be left with lingering anxiety when newborn screening tests sound a false alarm, possibly driving them to take their baby to the doctor more often, a new study hints.

 

False alarms -- also called false positives -- are a cause for concern with all kinds of medical tests, but experts say their effects warrant extra scrutiny when it comes to newborn screening.

 

"The reason newborn screening is unique is because it's mandatory," said Dr. Beth Tarini, a pediatrician at the University of Michigan in Ann Arbor, who led the new work.

 

"There have been studies with parents who have been interviewed and have said they have lingering doubts about their child's health, even though they were told it was a false positive."

 

The mandatory newborn screening program was first proposed by the American College of Medical Genetics in 2005. It includes 29 "core" conditions, such as cystic fibrosis and phenylketonuria, a metabolic disorder that leaves kids severely mentally retarded if they don't get treatment.

 

The screens are done on samples of the infant's blood, urine and other fluids, and often look for telltale imbalances.

 

According to Susan Waisbren of Children's Hospital Boston, who studies parents' reaction to newborn screening results, the program identifies about 1,240 children with metabolic conditions every year in the U.S. At the same time, however, there are about 8,850 false positives.

 

"Expanded newborn screening continues to offer tremendous positive contributions to the prevention of death and brain damage in infants with these rare disorders," Waisbren told Reuters Health. "But we need to pay attention to its unintended consequences of potential increased use of healthcare services and the psychological impacts still need to be studied."

 

The new study, which is published in the journal Pediatrics, used data on nearly 50,000 Medicaid-enrolled babies born in 2006 in Michigan. About one in 10 was born prematurely.

 

Six percent of the preemies had false-positive screening results, compared to just one percent of the term babies.

 

Over ten months, preemie parents took their baby to the doctor nearly six times if they had a false-positive but only about four times if they didn't.

 

"It's possible that these kids are very sick, they get a false-positive and that makes the parents even more worried about their kids," said Tarini.

 

But she added that the study doesn't prove that. It might be, for example, that those who had false-positive tests really were sicker, even though the researchers tried to rule out that possibility.

 

Tarini also cautioned that things might look different for parents who are privately insured.

 

On the other hand, there was no difference in healthcare use for full-term infants with false alarms.

 

"The issue of false positives is far more nuanced and complex than most people realize," said Tarini. "It is not a foregone conclusion that parents of children who have false-positives are going to have lingering anxiety and use more health care. At the same time there might be a subset of parents who have lingering effects."

 

Waisbren echoed her sentiment, noting that just because parents don't go to the doctors more often they may still be unnecessarily concerned about their child's health.

 

"It does have an impact," she said. "If the person providing the newborn screening information and the results addresses the psychological concerns they might be able to alleviate the extra stress."

 

SOURCE: Pediatrics, online September 19, 2011.

 

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