Mortality throughout early childhood for Michigan children born with congenital anomalies, 1992-1998.

BACKGROUND: Congenital anomalies are a leading cause of infant deaths, accounting for almost a fifth of all infant deaths. Few studies have researched the survival experience of infants born with congenital anomalies past the infant stage.

METHODS: Using birth and death files routinely linked to the Michigan Birth Defects Registry, we identified all singleton infants during calendar years 1992 through 1998 with reportable congenital anomalies for our study. A comparative file of children born without congenital anomalies during the same time period was developed using linked birth and death files. The mortality data were assessed by age at death (through age six) and race to determine mortality rates, relative risks, hazard ratios, and survival trends.

RESULTS: Throughout early childhood, children born with congenital anomalies had a high risk of mortality compared with all other children. The overall 7-year hazard ratio comparing children with congenital anomalies with all other children was 7.2. Overall mortality rates for black children were significantly higher than white children through the age of seven, irrespective of whether they had congenital anomalies. Among children with congenital anomalies, this disparity disappeared after adjusting for birth weight, sex, mother's age, mother's education, and number of organ systems affected.

CONCLUSIONS: Compared with children without congenital anomalies, children born with congenital anomalies had a higher risk of mortality well beyond the infant period. Racial disparities in mortality rates among children with congenital anomalies were due to confounding factors.