CDC Commentary: The Critical Importance of Newborn Screening and Follow-up

Stuart K. Shapira, MD, PhD


August 31, 2010

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Hello, I am Dr. Stuart Shapira.

I am a clinical geneticist with the Centers for Disease Control and Prevention (CDC) and I'm here to speak with you about the importance of newborn screening as part of the CDC Expert Video Commentary Series on Medscape.

Soon after birth, all babies born in the United States require assessment for certain disorders through newborn screening. A few drops of blood are taken from the newborn's heel, placed on filter paper, and sent to a newborn screening laboratory for testing. Finding newborn screening conditions soon after birth can help prevent serious problems, such as intellectual disability, organ damage, and even death.

Each state runs its own newborn screening program. Most states screen for a standard number of conditions, but some states may screen for more. All states screen for sickle cell disease, metabolic conditions (such as phenylketonuria), and endocrine disorders (such as hypothyroidism), and nearly all include cystic fibrosis.

Some states are piloting projects to standardize data collection on long-term follow-up of children with confirmed newborn screening conditions. Long-term follow-up benefits children by ensuring that they receive the full benefits of early identification through newborn screening. Tracking these children is also important for public health to assess disease trends and monitor health outcomes associated with newborn screening conditions.

For example, congenital hypothyroidism rates have almost doubled in the past 2 decades. The reasons for this increase are unclear, in part due to the lack of follow-up data on children diagnosed with the disorder. There are several issues that need to be addressed before we can understand the reasons for this increase.

  • First, there is significant variation among clinicians regarding testing to confirm a diagnosis after an initial abnormal screening test has occurred;

  • Second, part of the increase may be due to transient hypothyroidism, which can be difficult to differentiate from true, permanent congenital hypothyroidism;

  • Third, screening laboratory methods have changed over time, causing some changes in the rate of hypothyroidism cases identified by some laboratories; and

  • Fourth, epidemiologic studies have identified a higher rate of congenital hypothyroidism among infants of Hispanic ethnicity or infants who were born preterm or with low birthweight.

Increases in these demographic and birth characteristics of infants in the United States have also contributed somewhat to the increased rate of hypothyroidism.

Newborn screening programs have been established in all US states and territories to ensure that infants and children with newborn conditions are identified and receive treatment as soon as possible. Some states are beginning to track long-term follow-up of children with confirmed newborn screening conditions, but we need your help. Specifically, here is what you can do as a healthcare provider:

  • You can follow management guidelines for children who screen positive for newborn screening conditions;

  • You can be confident in your state laboratory's screening practices, but you should remember that any screening test may yield a false-negative result. Therefore, continued vigilance is necessary to recognize the clinical symptoms of a missed diagnosis, such as those for hypothyroidism, including poor feeding, failure to thrive, growth retardation, hypotonia, decreased activity, and constipation;

  • You should use published guidelines to distinguish transient hypothyroidism from true permanent congenital hypothyroidism and perform recommended follow-up testing; and

  • You should be sure that all newborn screening-related paperwork is filled out and returned to the state newborn screening follow-up programs.

Please visit for more information about newborn screening, including information on a May 2010 supplement in the journal Pediatrics about congenital hypothyroidism and newborn screening.[1]

Newborn screening is important for preventing morbidity and mortality in children. Long-term follow-up of children with confirmed newborn screening conditions, such as congenital hypothyroidism, is crucial for maintaining optimal health of these children. Tracking this follow-up is important for public health and is essential for understanding the natural history, prevalence, and management best practices for newborn screening conditions.

Thank you for working with public health programs to make newborn screening a success.

Web Resources

The Increasing Incidence of Congenital Hypothyroidism in the United States: Current Trends and Future Directions

Newborn Screening and Related Conditions

Newborn Screening

American College of Medical Genetics Action (ACT) sheets

Stuart K. Shapira, MD, PhD, is a Medical Officer on the Pediatric Genetics Team in the Division of Birth Defects and Developmental Disabilities at the CDC in Atlanta, Georgia. Dr. Shapira received his PhD degree in genetics and his MD degree, both from the University of Chicago. He completed a residency in pediatrics and a clinical fellowship in genetics and metabolism at Boston Childrens Hospital. He also completed dual research fellowships in genetics and metabolism, and in allergy and immunology at Harvard Medical School. Dr. Shapira is board-certified in pediatrics, as well as in clinical genetics, biochemical genetics, and molecular genetics.

Dr. Shapira practiced clinical genetics and metabolic genetics at Baylor College of Medicine in Houston and at the University of Texas Health Science Center in San Antonio, before joining the National Center on Birth Defects and Developmental Disabilities (NCBDDD) at the CDC in 2005. He serves as chairman of the Clinicians Committee for the National Birth Defects Prevention Study and chairman of the Dysmorphology Workgroup for the Centers for Autism and Developmental Disabilities Research and Epidemiology. He also serves as a metabolic disorders/mitochondrial disease expert for the Clinical Immunization Safety Assessment Network, NCBDDD liaison to the Committee on Obstetric Practice for the American College of Obstetricians and Gynecologists, and member of the Editorial Board for the American Journal of Medical Genetics. His current interests and activities include birth defects epidemiologic research, dysmorphology of autism, gene and nutritional interactions for adverse reproductive outcomes, and newborn screening.


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