Trends in Delayed Diagnosis of Critical Congenital Heart Defects in an Era of Enhanced Screening, 2004-2018.

While prenatal diagnosis of CCHD increased dramatically, there was no reduction in delayed diagnosis among postnatally diagnosed infants, even after pulse oximetry screening became mandatory. Pulse oximetry may not reduce delayed diagnosis in settings with high prenatal detection, and other strategies are needed to ensure timely diagnosis of well-appearing newborns.