Ogawa K, et al. - This study was formulated to investigate the association between intrauterine exposure to beta-2 receptor agonist (B2RA) and asthma in the offspring. In light of the results, analysts emphasized exposure to B2RA in utero as a potential risk for childhood asthma.

Methods

• Data were acquired from a hospital-based birth cohort study conducted in Tokyo, Japan.
• In addition, the outcomes of interest were three indicators, consisting of current wheeze, current asthma and ever asthma at 5 years of age, based on the International Study of Asthma and Allergies in Childhood questionnaire.
• The association between intrauterine B2RA exposure and outcomes was assessed by logistic regression analysis.
• Children were categorized into three groups according to both the cumulative dose and duration (days) and conducted trend analysis to evaluate dose-dependent risk.

Results

• 94 (8.1%) were exposed to B2RA in utero, and 191 (16.5%), 111 (9.6%) and 168 (14.5%) children experienced current wheeze, current asthma and ever asthma, respectively, among 1158 children.
• An increased risk of current asthma caused by B2RA exposure with an adjusted odds ratio of 2.04 (95% confidence interval: 1.02-4.05) was observed, after adjusting for confounders.
• An association of B2RA exposure in utero with a dose-dependent increased risk of current asthma in terms of both cumulative dose and duration (p values for trend were 0.015 and 0.017, respectively) was outlined by trend analysis.
• Moreover, these results were similar to those for other outcome measures.