To the Editor The Original Investigation by Dr Xiang and colleagues1 showed an association between maternal diabetes diagnosed by 26 weeks’ gestation and autism spectrum disorders (ASD) in offspring. I question whether the analysis should have controlled for a maternal history of comorbidity (diagnosis of cancer and/or heart, lung, kidney, and liver diseases) prior to determining whether maternal preexisting type 2 diabetes was significantly associated with risk of ASD in offspring.
Zitser B. Maternal Diabetes and Autism in Offspring. JAMA. 2015;314(4):407. doi:10.1001/jama.2015.7250