Outcomes for infants with congenital heart disease (CHD) have improved dramatically in recent decades, largely as a result of improvements in medical and surgical treatment. Early diagnosis is essential to providing treatment before clinical deterioration. This is especially true for critical congenital heart disease (CCHD), a group of heterogeneous disorders in which surgical or catheter interventional therapy within the first year of life is mandatory to achieve survival. Together, these defects affect approximately 1.2 infants per 1,000 live births in the United States each year.
Clinical signs can be subtle, and as a result, CCHD is easily missed during a standard newborn physical examination. Indeed, the diagnosis of CCHD is missed in one in three affected newborns, leading to delayed treatment and contributing to preventable morbidity and mortality. To address this clinical gap, universal newborn screening is now recommended to increase the early detection of CCHD.
This three-article educational activity, Taking the Pulse of Neonatal Screening for Critical Congenital Heart Disease, is designed to provide guidance on screening for CCHD to improve detection in newborns across a range of care settings. Here, the first article provides an overview of the burden of CCHD and introduces the role of pulse oximetry as a simple, safe, and effective screening tool that complements the standard newborn physical examination to enhance the detection of CCHD.
Definition and types of CCHD
CHD is the most common congenital disorder in newborns and one of the leading causes of perinatal and infant mortality, accounting for 24% of infant deaths due to congenital malformations.1 Each year, approximately 1.35 million infants are born with CHD worldwide, although the incidence varies by region.2 In North America, CHD affects 8.2 per 1,000 live births, representing a major public health burden.2
For approximately one in four infants born with cardiac malformations, the defect is potentially life-threatening without prompt intervention. CCHD is defined as any congenital cardiac defect that will require surgery or catheter-based treatment during the first year of life. The term CCHD describes seven heterogeneous conditions that collectively affect approximately 1.2 per 1,000 babies born each year in the United States.1 Together, these malformations have also been described as critical congenital cyanotic heart defects, given the likelihood that they will present with significant hypoxemia.3 These conditions include:
Hypoplastic left heart syndrome (HLHS): a malformation in which the left side of the heart is underdeveloped, resulting in reduced cardiac output and the inability of the left heart to support systemic circulation.3
Pulmonary atresia with intact septum: a malformation characterized by atresia at the pulmonary valve or blockage in the pulmonary artery itself, causing cyanosis due to the mixing of oxygenated and deoxygenated blood from decreased pulmonary blood flow.3