In our quest to better understand who is at risk for autism, we see and in turn publish many interesting epidemiologic studies as do other pediatric peer review journals. This month is no exception as we find ourselves with three new studies in one issue of our journal –all focused on giving us a better understanding of what conditions are associated with a higher risk of having autism spectrum disorders (ASD).
For example, Gidaya et al. (10.1542/peds.2015-1316) decided to look at the association between beta-2 adrenergic receptor agonist drugs used during pregnancy and ASD. The authors did a case-control study involving 5200 cases and 52,000 controls matched by month and year of birth. Even after adjusting for a variety of confounders, even maternal asthma, the odds ratio of ASD was increased if the beta-2 agonists were used preconception and during each trimester of pregnancy. The authors speculate on what might be causing the association but also note the importance of weighing the risks of not using this type of drug when indicated medically in a pregnant woman.
A second epidemiologic study released from Li et al. (10.1542/peds.2015-2206) focuses on the association between maternal pre-pregnancy obesity, pre-gestational and gestational maternal diabetes or both disorders and ASD. This study involved more than 2700 children in a longitudinal Boston birth cohort followed over a 16 year time period. Interestingly enough, increased risk of ASD was seen if a mother was either obese or diabetic and in combination as well—whether the diabetes was pre-gestational or gestational. The authors also looked for other developmental disorders and again explain their findings and why the associations are occurring in their discussion of this thought-provoking study.
Finally a third study by Pritchard et al. (10.1542/peds.2015-1949) is included this week looking at the prevalence of ASD in toddlers born very preterm. Two birth cohorts of toddlers born before 29 weeks gestation were assessed in toddlerhood using valid and reliable screening interviews of parents and subsequent assessments of their young children who screened positive. In this case, while the number of children screening positive had a lower incidence of true ASD upon developmental assessment, other developmental delays were identified in this very preterm population.
So what do studies like this mean when we are helping families work through screening and identification of ASD or other developmental disorders in their children? Developmental specialists Geraldine Dawson and Catherine Rice share their perspective and help us better understand the import of studies like these in an accompanying commentary (REF). If you are following patients with ASD, these three articles and commentary are well worth your attention.