Newborn Screening: Current Status

Pamela H. Arn


Health Affairs. 2007;26(2):559-566. 

In This Article

Abstract and Introduction

Newborn screening, which represents one of the major advances in child health of the past century, has been carried out in all fifty U.S. states since the 1970s. New-born screening programs are state-run, and decisions are left to the individual states re-garding the conditions to be screened for, the mechanism for confirmatory testing, follow-up care, and financing of the programs. Laboratory advances in tandem mass spectrome-try make it possible to screen newborns for many rare inborn errors of metabolism. This raises many policy issues including screening's cost-effectiveness, ethics, quality, and over-sight.

An estimated 4.1 million infants are screened annually in the United States for genetic metabolic disorders. U.S. newborn screening programs began in the early 1960s with phenylketonuria (PKU), a disorder of protein metabolism that causes mental retardation when untreated. Babies with PKU appear normal at birth, but the severe developmental disabilities associated with the condition can be avoided with early dietary treatment. Screening for PKU was followed by screening for congenital hypothyroidism in the early 1970s, based on the success of PKU screening and treatment and on the ability to prevent severe disability in another group of children.

Evolving screening capabilities. Each state is now responsible for its own newborn screening program. State legislatures play a key role in the newborn screening system, since they are (at a minimum) responsible for appropriating funds or authorizing fees to make the screening program possible. In all cases, the primary responsibility for newborn screening resides in the public health system, which faces many challenges as newborn screening capabilities evolve.[1]

Until the past few years, there was little controversy regarding state-run new-born screening programs. All fifty states screened for PKU and hypothyroidism; some states included galactosemia (a disorder of lactose metabolism that can cause liver failure and death if untreated) and hemoglobinopathies (such as sickle cell anemia), and a few screened for other rare disorders. Historically, for each disorder screened, a separate test was required, each with its associated costs and the need for a portion of the blood specimen, thus limiting the number of tests that could be done.[2]

In the early 1980s, with the advent of the technique of tandem mass spectroscopy (MS/MS), it became possible to screen for a sizable number of conditions on a single blood specimen in a timely fashion. In 1990, David Millington proposed using MS/MS analysis of dried blood spots for newborn screening.[3]With this technique, a profile of as many as fifteen different markers and ratios of metabolites (known as an acylcarnitine profile) can be determined using a very small amount of blood. This allows a single procedure to screen for thirty or more inherited disorders.[4]By the mid1990s it was possible to screen for amino acid, organic acid, and fatty acid disorders in the same procedure. The increase in the number of inheritedmetabolic disordersdetectableinthe newbornperiodextendedthe possibilities of early, generally presymptomatic, diagnosis and treatment. This mini-mized morbidity and mortality for many affected children but also raised questions of cost-effectiveness, treatment efficacy, ethics, and lack of data regarding the natural history of some of the disorders.[5]As a result of funding problems and lack of data regarding outcomes, not every state incorporated the new technolo-gies into their screening programs.

Growing disparities in screening programs. Private laboratories began offering newborn screening tests either by contracting with individual hospitals or states, or both, or by offering tests directly to the community as public awareness of these conditions grew. All of these factors contributed to growing disparities in screening programs across states. Pressure to adopt expanded screening has come from physicians, patient advocacy groups, and legal actions brought by the parents of children with genetic disorders that were not detected by screening. By as early as 2003, almost half of the states had implemented MS/MS screening, but the number and types of conditions for which they were screening still varied.


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