Despite an increasing rate of prenatal diagnosis of critical congenital heart defects, delayed diagnosis still occurs in nearly 1 in 8 cases, a study in the journal Pediatrics suggests. Researchers used a Massachusetts registry of birth defects to examine records of 916 CCHD cases among nearly half a million live births to state residents between 2004 and 2009. Congenital heart defects were considered critical if intervention or death occurred in the first year. The authors found that 126 (13.8%) of CCHD cases had delayed diagnosis, meaning that diagnosis occurred after the baby was discharged home following delivery. The most common delayed diagnoses were coarctation, pulmonary valve stenosis and tetralogy of Fallot. While Massachusetts and other states have enacted legislation requiring pulse oximetry screening of newborns, some defects, such as tetralogy of Fallot, present with little blood flow obstruction. The authors conclude that understanding the risk factors for delayed diagnosis of CCHD could help to improve prenatal and postnatal screening efforts, including pulse oximetry testing. Read the article.