Population-based study of congenital diaphragmatic hernia: risk factors and survival in Metropolitan Atlanta, 1968-1999.

BACKGROUND

Congenital diaphragmatic hernia affects about 1000 United States infants a year. In most cases, the etiology of this condition is unknown. Treatment strategies have changed in recent years. We sought to calculate the birth prevalence, determine risk factors, examine associated defects, and assess trends in survival.

METHODS

We conducted a population-based cohort study of all infants born during 1968-99 whose mothers resided in the five-county metropolitan Atlanta area (n = 1,029,143). Infants with congenital diaphragmatic hernia were identified using the Metropolitan Atlanta Congenital Defects Program. To document vital status, we used data from hospital records, Georgia vital records, and the National Death Index.

RESULTS

The birth prevalence of congenital diaphragmatic hernia was 2.4 per 10,000 births. Infants with isolated congenital diaphragmatic hernia were more likely to be premature, macrosomic, and male than their birth cohort. About one-third of affected infants had additional major defects. Of infants with congenital diaphragmatic hernia, 8% had known syndromes, most commonly chromosomal abnormalities. During the study period, the percentage of infants with congenital diaphragmatic hernia who survived to 1 year of age increased from 19% (1968-71) to about 54% (1996-99). During the last 10 years of the study, infants who were of low birth weight, had a syndrome, or were prenatally diagnosed were more likely to die than other infants with congenital diaphragmatic hernia.

CONCLUSIONS

Despite new treatments, the death rate from congenital diaphragmatic hernia remains substantial, highlighting the need to identify mechanisms for primary prevention.