Incidence of congenital diaphragmatic hernia in Olmsted County, Minnesota: a population-based study.

Objective: The rate of congenital diaphragmatic hernia (CDH) varies, but most reports estimate the incidence to be less than three per 10,000 births. Our objective was to document the incidence of CDH in a geographically well-defined population using available resources for highly accurate incident case ascertainment.

Methods: We ascertained CDH cases in Olmsted County, Minnesota, United States of America, from 1981 through 2014 using resources of the Rochester Epidemiology Project. Overall and sex-specific incidence rates were calculated, and hospital survival was assessed.

Results: A total of 26 incident CDH cases were identified; the overall incidence of 3.6 (95% CI, 2.2-5.0) per 10,000 did not differ significantly over the 34-year study period (p = .28). The estimated incidence was 4.3 (95% CI, 2.2-6.5) for male infants and 2.9 (95% CI, 1.1-4.6) for female infants. The percentage of cases diagnosed prenatally was 33% from 1981 through 2000 and 50% from 2001 through 2014. The rate of survival to discharge in the two periods was 50% and 88%.

Conclusion: The incidence of CDH in Olmsted County exceeds the majority of published rates, which most likely can be attributed to our comprehensive case ascertainment.