OBJECTIVES: The etiology of biliary atresia (BA) is unclear and potentially involves viral triggers. We aimed to compare the incidence of BA in the United States before and during the coronavirus disease 2019 (COVID-19) pandemic, focusing on potential associations with viral circulation disruptions caused by nonpharmaceutical interventions (NPIs). METHODS: We queried the Pediatric Health Information System® (PHIS) for all patients discharged with BA between January 1, 2010, and January 31, 2024. Using CDC WONDER, we calculated monthly and overall incidence rates of BA per 1,000,000 live births. We fit a Poisson regression model to assess the association between the widespread implementation of stay-at-home orders (using April 1, 2020, as the cutoff date) and the incidence of BA, accounting for national natality fluctuations. RESULTS: We identified 3456 newborns with BA from 42 hospitals
2997 (86.7%) were born before and 459 (13.3%) were born during the pandemic. The mean monthly number of newborns with BA was 24.0 (95% confidence interval, 23.0-25.0) for an overall incidence rate of 74.4 (71.5-77.4) per 1,000,000 live births. We did not identify a statistically significant year-to-year contrast in the incidence of BA before (incidence rate ratio [IRR] = 0.995 [0.983-1.008]
p = 0.49) or after the cutoff date (IRR = 0.999 [0.895-1.116]
p = 0.99). In addition, we did not identify sufficient evidence that trends differed between the two periods (IRR = 1.00 [0.893-1.128]
p = 0.95). CONCLUSIONS: The NPIs implemented during the COVID-19 pandemic were not significantly associated with changes in the incidence or temporal pattern of BA.