Objective The study objective was to evaluate the association between maternal Karenia brevis (K. brevis) exposure during pregnancy and the prevalence of biliary atresia (BA) in offspring. Study Design This was a hospital-based, case-control study in which cases were infants diagnosed with BA at Johns Hopkins All Childrens Hospital from October 2001 to December 2019. Controls were matched 4:1 by age, randomly selected from healthy infants hospitalized during the study period for common pediatric diagnoses. Infants were excluded if they had congenital anomalies and/or were non-Florida residents. Gestational K. brevis exposure levels (cells/liter) were determined from Florida Fish and Wildlife Conservation Commission exposure data at 10- and 50-mile radii from the maternal zip code of residence. Multivariable conditional logistic regression determined adjusted odds of BA in offspring based on maternal gestational K. brevis exposure. Results Of 38 cases and 152 controls, no significant inter-group differences were observed in race/ethnicity, season of birth or coastal residence. Median gestational exposure at the 10-mile radius was 0 cells/liter in both groups. A greater proportion of cases had no K. brevis exposure (63.2%, n = 24) in comparison to controls (37.5%, n = 57; p = .04) at a 10-mile radius. At the 50-mile radius, cases had a peak median exposure at 6 months of gestation compared to controls peak at 9 months. After adjustment for sex, seasonality, race/ethnicity, and coastal residence, there was no significant association between BA and maximum K. brevis exposure per trimester of pregnancy at the 10- or 50-mile radius. Conclusion We observed no association between gestational K. brevis (cells/liter) exposure at a 10- and 50-mile radius from maternal zip code of residence and BA in offspring.

The authors have declared no competing interest.

This study did not receive any funding

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by Johns Hopkins All Childrens Hospital Institutional Review Board (IRB00252758) prior to initiation.

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All data produced in the present study are available upon reasonable request to the authors