Pros, Cons of Newborn Genetic Screening

In nearly all states, screening newborn babies for genetic diseases is mandatory. The tests allow parents to intervene early if their child has one of nearly 30 chronic illnesses, and, sometimes, the interventions can be life saving.

In other cases, though, the tests identify a genetic abnormality that is ambiguous. The child may simply carry a mutation that never leads to symptoms of a disease or the abnormality found may not point to a specific, treatable condition.

“We don’t always get a definitive answer” from newborn screening, said Dr. William Wilcox, the director of the Metabolic Disorders Clinic at Cedars-Sinai. “Even if we are able to make a diagnosis of what the child has, it doesn’t mean it has any consequences — it may imply a risk for something that is fairly low.”

For families who receive such uncertain results, newborn screening can set in motion a state of limbo that can last for weeks, months or even years, as they wait and watch to see whether their child will become ill.

In a recent study, published in December in the Journal of Health and Social Behavior, researchers Stefan Timmermans and Mara Buchbinder from UCLA’s department of sociology, examined the emotional effects of these unclear outcomes, and ultimately dubbed the families and babies “patients-in-waiting.”

The study states that “the major issue facing a newborn patient-in-waiting is not only whether he or she will develop a disease but also what the condition actually is.” 

Although requirements for newborn screening vary from state to state, most mandate that newborns be tested for between 20 and 30 diseases, including congenital phenylketonuria, or PKU, congenital hypothyroidism, sickle cell disease and cystic fibrosis. While still voluntary, testing for Jewish genetic diseases includes Tay-Sachs, Gaucher, Niemann-Pick and familial dysautonomia.

Babies are generally tested within 48 hours of being born, using a blood sample taken from the heel. In California, the sample is then sent to a laboratory that is contracted with the state.

The tests screen for abnormal levels of biochemicals in the infant’s body, and, in the event of a positive test result, the child is sent to a clinic or private physician for follow-up testing.

Nearly 90 percent of families who get a positive test result from newborn screening find out that they had a false positive, according to the study.

For the remaining 10 percent, a long road of medical visits and worrying may lie ahead.

For the study, Timmermans and Buchbinder followed 55 families that received positive test results from newborn screening for two years.

Most families were shocked by the results — some didn’t even know that screening was being conducted on their infants. 

“I think there is a lot of misinformation about the whole hospital experience,” said Gabrielle Kaufman, who runs a program for new mothers at Jewish Family Service of Los Angeles, “and the [newborn] screening is part of that.”

This lack of knowledge contributed to the surprise and devastation those families felt upon getting positive test results. Compounding that reaction was the fact that many had received normal test results throughout their pregnancy.

One study participant is quoted as saying that “all of our ultrasounds were really, really good … and so we were unconcerned about any of the genetic stuff.”

The stress caused by finding out that a child is at risk for what could be a major disorder can wreak havoc on parents’ emotional health, Kaufman says.

“People will find out that there’s something possibly wrong with their baby,” she said, “and just the anxiety of feeling like they’re constantly waiting for the other shoe to drop is a lot to sustain.”

She cites women who have been thrown into depression, and couples whose marriages have been strained by the news.

With an uncertain diagnosis, doctors will often instruct parents to treat the child as if they already have the condition for which they’re at risk, making specific diets, sleep schedules and lifestyle changes as precautionary measures while confirmative tests are being run.

According to the study, though, the messages received by parents from medical providers regarding how long they will have to wait to find out what’s wrong with their child, and what they should be doing in the meantime, can be ambiguous.

They may be told to watch for the child to meet certain developmental milestones, but those are often vague. Or, they may be told not to worry, while simultaneously being told to be vigilant in taking precautions.

For many parents, the ambiguity can mean that their hypervigilance is almost impossible to give up, should they ultimately find that their child is healthy or at a low risk for developing serious symptoms of disease.

“Some people are reluctant to give up their precautions,” Wilcox said. But, he adds, “The older the kids get and the more normal they are, the less the parents worry.”

And indeed, if children continue to develop without showing signs of illness, it’s often a sign to medical providers that their initial test results were nothing to worry about. Plus, the older children get without any symptoms, the less likely it is that they will develop severe symptoms that will inhibit their daily life.

Still, many parents may never hear the one answer that they’re looking for: that their child is completely out of the woods. Or, according to the study, “The geneticist does not unequivocally state that the child is ‘disease free.’ ”

Nevertheless, Wilcox says, the benefits of newborn screening far outweigh the risks or the discomfort that parents may feel.

“Overall,” he said, “the successes of newborn screening are enormous. It’s saved a lot of kids’ lives.”