Prenatal exposure to β2-adrenoreceptor agonists and the risk of autism spectrum disorders in offspring.

Purpose: We aimed to examine the risk of autism spectrum disorders (ASDs) in the offspring who were exposed to maternal use of β2-adrenoreceptor agonist (β2AA) during pregnancy.

Methods: This is a population-based cohort study including all live singleton births in Denmark from 1 January 1997 to 31 December 2008. Children born to mothers who used β2AA during pregnancy were categorized as exposed, and all other children were included in the unexposed group. Cases of ASDs were identified from the Danish Psychiatric Central Register and the Danish Patient Register. Incidence rate ratio (IRR) and 95% confidence interval were estimated by Poisson regression models.

Results: Among 751 888 children in the cohort, 9098 (1.21%) received a diagnosis of ASDs. We observed an increased risk of ASDs in the exposed children (IRR = 1.28, 1.11-1.47), especially for those who were exposed during the second trimester period (IRR = 1.38, 1.14-1.67). However, when extending the exposure time window to 1 year prior to pregnancy, we observed a similar association in children born to women who received β2AA treatment during pregnancy (IRR = 1.33, 1.11-1.59) to that in children born to women who received β2AA treatment 1 year prior to pregnancy (IRR = 1.35, 1.17-1.56).

Conclusion: Our finding suggested that children born to women who used β2AA during pregnancy have an increased risk of ASDs in later life, which is more likely due to underlying maternal diseases rather than the exposure to β2AA itself. However, further study, which would better differentiate the effects between indication and medicine, is needed to corroborate the finding. Copyright © 2017 John Wiley & Sons, Ltd.