Delayed diagnosis of critical congenital heart defects: trends and associated factors.

OBJECTIVE: We aimed to examine trends in timing of diagnosis of critical congenital heart defects (CCHDs) and factors associated with delayed diagnosis (diagnosis after discharge home following delivery).

METHODS: We examined a population-based retrospective cohort of CCHD cases among live births identified through the Massachusetts Birth Defects Monitoring Program. Congenital heart defects were considered critical if the infant received corrective surgery, interventional catheterization, palliative care, or died as a result of the defect within 12 months of birth. Timing of initial diagnosis was classified as prenatal, postnatal before discharge home, or delayed. Demographic, perinatal, and mortality information was obtained from the Registry of Vital Records and Statistics. Prevalence ratios (PRs) were used to examine associations with delayed diagnosis.

RESULTS: Among 460 467 live births to Massachusetts residents between 2004 and 2009, we identified 916 CCHD cases, of which 126 (13.8%) had delayed diagnosis. Rates of prenatal CCHD diagnosis increased from 44.9% in 2004 to 63.8% in 2009, whereas rates of delayed diagnosis decreased from 17.1% to 10.6% over the same time period. Among cases with delayed diagnosis, the most common defects were coarctation, pulmonary valve stenosis, and tetralogy of Fallot. Delayed diagnosis was associated with delivery outside a tertiary hospital (adjusted PR: 3.6 [95% confidence interval: 2.5-5.2]) and isolated CCHD (adjusted PR: 1.7 [95% confidence interval: 1.1-2.7]).

CONCLUSIONS: Despite increasing prenatal diagnosis of CCHDs, delayed diagnosis still occurs in over 10% of cases. Understanding factors associated with delayed diagnosis could help to improve prenatal and postnatal screening efforts, including pulse oximetry testing.