Associations between cord blood acetaminophen biomarkers and childhood asthma with and without allergic comorbidities

Background Previous studies have linked prenatal acetaminophen use to increased asthma risk in children. However, none have explored this association while differentiating between asthma cases with and without other allergic conditions or by employing objective biomarkers to assess acetaminophen exposure. Objective Examine whether the detection of acetaminophen biomarkers in cord blood is associated with the subgroups of asthma both with and without allergic comorbidities in children. Methods Acetaminophen biomarkers, including unchanged acetaminophen and acetaminophen glucuronide, were measured in neonatal cord blood samples from the Boston Birth Cohort. Asthma subgroups were defined based on physician diagnoses of asthma and other allergic conditions (atopic dermatitis, allergic rhinitis). Multinomial regressions were used to examine the associations between acetaminophen biomarkers and asthma subgroups, adjusting for multiple confounders, including potential indications for maternal acetaminophen use such as maternal fever. Results The study included 142 children with asthma and at least one other allergic condition, 55 children with asthma but no other allergic condition, and 613 children free of asthma. Detection of acetaminophen in cord blood, reflecting maternal exposure to acetaminophen shortly before delivery, was associated with a 3.73 times the odds of developing asthma without allergic comorbidities (95% CI: 1.79, 7.80, p=0.0004). In contrast, detection of acetaminophen in cord blood was not associated with elevated risk of asthma with allergic comorbidities. Analysis of acetaminophen glucuronide yielded consistent results. Conclusion In a prospective birth cohort, cord blood acetaminophen biomarkers were associated with an increased risk of childhood asthma without allergic comorbidities, but were not associated with childhood asthma with allergic comorbidities.