Congenital heart defects are the most common type of birth defect. More information is available on the NHLBI website at: http://www.nhlbi.nih.gov/health/health-topics/topics/chd/
Regarding the statistic you referenced, our experts shared with us that:
From the AHA/AAP Scientific Statement on pulse oximetry screening, they quote a single study (from a birth defects surveillance system), which I’ve attached to this email, that says that the incidence of delayed or missed diagnosis of critical CHD is 7 in 100,000 live births. If there are approximately 4 million live births per year, this would translate into approximately 280 missed or delayed diagnoses of critical CHD per year. They note that because this was from a surveillance study with passive data collection, this probably represents an underestimate.
We hope this information is helpful.
Office of Communications
National Heart, Lung, and Blood Institute