Prenatal diagnosis has been shown to improve preoperative morbidity in newborns with congenital heart defects (CHDs), but there are conflicting data as to the association with mortality. We performed a population-based, retrospective, cohort study of infants with prenatally versus postnatally diagnosed CHDs from 1994 to 2005 as ascertained by the Metropolitan Atlanta Congenital Defects Program. Among infants with isolated CHDs, we estimated 1-year Kaplan-Meier survival probabilities for prenatal versus postnatal diagnosis and estimated Cox proportional hazard ratios adjusted for critical CHD status, gestational age, and maternal race/ethnicity. Of 539,519 live births, 4,348 infants had CHDs (411 prenatally diagnosed). Compared with those with noncritical defects, those with critical defects were more likely to be prenatally diagnosed (58% vs 20%, respectively, p <0.001). Of the 3,146 infants with isolated CHDs, 1-year survival rate was 77% for those prenatally diagnosed (n = 207) versus 96% for those postnatally diagnosed (n = 2,939, p <0.001). Comparing 1-year survival rate among those with noncritical CHDs alone (n = 2,455) showed no difference between prenatal and postnatal diagnoses (96% vs 98%, respectively, p = 0.26), whereas among those with critical CHDs (n = 691), prenatally diagnosed infants had significantly lower survival rate (71% vs 86%, respectively, p <0.001). Among infants with critical CHDs, the adjusted hazard ratio for 1-year mortality rate for those prenatally versus postnatally (reference) diagnosed was 2.51 (95% confidence interval 1.72 to 3.66). In conclusion, prenatal diagnosis is associated with lower 1-year survival rate for infants with isolated critical CHDs but shows no change for those with isolated noncritical CHDs. More severe disease among the critical CHD subtypes diagnosed prenatally might explain these findings.
