Estimated Number of Infants Detected and Missed by Critical Congenital Heart Defect Screening

Infant wrapped in a blanket wearing a hat

In 2015, the journal Pediatrics published a study estimating the number of infants with critical congenital heart defects (critical CHDs) potentially detected or missed through universal screening for critical CHDs using pulse oximetry. CDC researchers estimated that about 1,755 infants with critical CHDs would be diagnosed late (meaning on or after the third day after birth). Of these, about half (875 infants) with a critical CHD would be detected through newborn screening using pulse oximetry, but an equal number (880 infants) might still be missed each year in the United States. These findings might be useful for states and hospitals that are using pulse oximetry screening to help detect infants with undiagnosed critical CHDs. You can read the abstract here.

Main Findings

  • About 5,965 infants were estimated to be born each year with a critical CHD in the United States. Of those, about:
    • 1,800 infants would be diagnosed with a critical CHD before they were born (prenatally diagnosed);
    • 2,410 infants would have a timely postnatal diagnosis (within 3 days of birth) of a critical CHD, likely due to the onset of symptoms before undergoing newborn screening by pulse oximetry; and
    • 1,755 infants would have a “late” diagnosis (diagnosed on or after the third day after birth) of a critical CHD.
  • About 875 of the 1,755 infants with a critical CHD that are estimated to be at risk of late detection would be identified through critical CHD screening using pulse oximetry, including about:
  • Screening would not detect all infants with a critical CHD at risk for late detection. About 880 of the 1,755 infants with a late diagnosed critical CHD were estimated to be missed through critical CHD screening using pulse oximetry, including about:
    • 245 infants with tetralogy of Fallot; and
    • 560 infants with coarctation of the aorta or interrupted aortic arch.
  • The effectiveness of critical CHD screening using pulse oximetry depends on several factors, including:
    • the number of babies born each year with a specific critical CHD type,
    • how many babies are diagnosed before birth, and
    • how well the screening technology can detect a specific type of critical CHD.
  • Because of this, the majority of infants who can benefit from critical CHD screening using pulse oximetry are those infants with coarctation of the aorta or interrupted aortic arch, tetralogy of Fallot, and transposition of the great arteries.
  • However, these are the same critical CHD types that might not be detected with pulse oximetry screening.
Basics about Critical Congenital Heart Defects

What are critical congenital heart defects?
Congenital heart defects are the most common type of birth defect in the United States, affecting nearly 1% of―or about 40,000―births per year.  About 1 in 4 babies born with a heart defect has a critical congenital heart defect (critical CHD, also known as critical congenital heart disease).1 Babies with a critical CHD need surgery or other procedures within the first year of life.

How can newborn screening help babies with critical CHD?
Some babies born with a critical CHD appear healthy at first and can be sent home before their heart defect is detected. These babies are at risk of having serious complications within the first few days or weeks of life and often require emergency care. Newborn screening can identify some of these babies so they can receive care and treatment that can help prevent disability or early death.

Newborn screening for critical CHD involves a simple bedside test to determine the amount of oxygen in a baby’s blood. Low levels of oxygen in the blood can be a sign of critical CHD. Critical CHD screening has begun in most states, where laws requiring this screening have been proposed or passed.

About this study

  • The aim of this study was to estimate how many infants with critical CHDs were likely to be detected or missed through critical CHD screening using pulse oximetry.
  • Researchers developed a mathematical model based on the number of cases of critical CHDs occurring each year in the United States, how many cases of critical CHDs are diagnosed before a baby is born (prenatally), how many cases of critical CHDs are diagnosed late (diagnosed on or after the third day after birth), and how accurate critical CHD screening using pulse oximetry is to detect each type of critical CHD.
  • This study used methods that included some levels of uncertainty, meaning that the results should not be interpreted as absolute numbers, but are likely included in a range of possible estimates. For example, 875 infants with critical CHD were estimated to be identified through screening using pulse oximetry, but when accounting for uncertainty, the actual estimate may be between 705 and 1,060 infants.

Heart Defects: CDC’s Activities

The Centers for Disease Control and Prevention (CDC) works to identify causes of CHDs and ways to prevent them. We do this through:

  1. Surveillance and Disease Tracking:
    1. CDC funds and coordinates the Metropolitan Atlanta Congenital Defects Program (MACDP).  CDC also funds population-based state tracking programs. Birth defects tracking systems are vital to help us find out where and when birth defects occur and whom they affect.
    2. CDC funds projects to track CHDs across the lifespan in order to learn about health issues and needs among all age groups.
    3. CDC, in partnership with March of Dimes, surveyed adults with CHDs to assess their health, social and educational status, and quality of life. The survey is called CH STRONG, Congenital Heart Survey To Recognize Outcomes, Needs, and well-beinG. Read project updates from CH STRONG.
  2. Research: CDC funds the Centers for Birth Defects Research and Prevention, which collaborate on large studies such as the National Birth Defects Prevention Study (NBDPS) (births 1997-2011) and the Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS) (began with births in 2014). These studies are working to identify factors that put babies at risk for birth defects, including heart defects.
  3. Collaboration:
    1. CDC is assessing states’ needs for help with CCHD screening and reporting of screening results. CDC helps states and hospitals better understand the cost and impact of CCHD screening.   CDC also promotes collaboration between birth defects tracking programs and newborn screening programs to improve understanding of the effectiveness of CCHD screening.
    2. CDC provides technical assistance to the Congenital Heart Public Health Consortium (CHPHC). The CHPHC is a group of organizations uniting resources and efforts in public health activities to prevent congenital heart defects and improve outcomes for affected children and adults. Their website provides resources for families and providers on CHDs.

More Information

To learn more about congenital heart defects, please visit

To learn more about screening for critical congenital heart defects, please visit

Key Findings Reference

Ailes EC, Gilboa SM, Honein MA, Oster ME. Estimated number of infants detected and missed by critical congenital heart defect screening. Pediatrics. 2015;135(6):1000-1008.

Additional References

  1. Reller MD, Strickland MJ, Riehle-Colarusso T, Mahle WT, Correa A. Prevalence of congenital heart defects in metropolitan Atlanta, 1998-2005. J Pediatr: 2008;153(6):807–813.
  2. Botto LD, Correa A, Erickson JD. Racial and temporal variations in the prevalence of heart defects. Pediatrics: 2001;107(3):E32.