P2.I178: National Trends in Incidence and Mortality Rate in Congenital Diaphragmatic Hernia in the United States

Background: The incidence of congenital diaphragmatic hernia (CDH) is about 2.6 in 10,000 livebirths based on birth defect registries in the United States (US). This may not reflect the true incidence of CDH nationwide. Further, previous studies from some children’s hospitals suggest that mortality in CDH is declining but this may not be nationally representative as many infants are managed in non-children’s hospitals. We conducted a population-based study to determine the trends in incidence and mortality in infants with CDH through 1 year of age.

Methods: We performed a retrospective, repeated cross-sectional analysis of the CDC WONDER database. First, we queried the 2016-2023 natality dataset for livebirths with CDH (ICD-10 code Q79.0). The natality dataset is derived from birth certificates and 99% of all births in the US are registered. We expressed CDH incidence as per 10,000 livebirths and we examined the changes in the incidence over time. Next, we queried the linked birth/infant death dataset from 2003-2019 for CDH-related infant mortality rate (IMR) through 1 year of age. Trends in CDH-IMR per 100,000 livebirths and by race and gender. We used Joinpoint regression to evaluate trends which were reported using average annual percentage change (AAPC) with 95% confidence intervals (CI).

Results: Among 29,880,509 live births between 2016 and 2023, 3,798 had CDH (1.3 per 10,000). Of these, 57% were male, 59% Non-Hispanic White (NHW), 11% Non-Hispanic Black (NHB), 82% were in metropolitan areas, the average gestational age was 37 weeks, the average birthweight was 2,852 gm, and 33.4% were transferred after birth. The CDH incidence was higher in males, in rural areas, in NHW, and in the Midwest (Table 1). There was no significant change in the CDH incidence during the study period (AAPC 0.93%; CI: -0.1, 2.0) [Figure 1A]. The overall CDH-IMR (per 100,000) was 5.9 and it declined significantly from 5.6 in 2002 to 5.1 in 2019 (AAPC: -0.7%; CI: -1.3, -0.1) [Figure 1B]. CDH-IMR was higher in males (6.3 vs 5.3 in females; P< 0.001) but there was no significant difference between NHW and NHB (6.2 vs 6.4; P=0.42). The CDH-IMR did not change in NHB (AAPC 0.03%; CI: -2.1, 2.2), males (AAPC: - 0.3%; CI: -1.3, 0.7), and females (AAPC: -0.3%; CI: -1.3, 0.7). For NHW, the CDH-IMR remained unchanged from 2002-2016, but declined significantly from 2016-2019 (APC: -8.9%; CI: -19.0, -1.8).

Conclusion: The CDH incidence was lower than previously reported and did not change from 2016 to 2023. The transfer of a third of CDH births post-delivery indicates that pathways that promote CDH births at tertiary perinatal centers should be given priority. The downward trend in mortality needs ongoing surveillance to monitor the impact of new management strategies on mortality rates.