"Among the 3 main types of diabetes complicating pregnancy, the risk of ASD [autism spectrum disorder] in offspring was elevated in mothers with T1D [type 1 diabetes], T2D [type 2 diabetes], and GDM [gestational diabetes mellitus] diagnosed by 26 weeks’ gestation compared with no diabetes."
So said the findings reported by Anny Xiang and colleagues  who undertook a look back at the records of over 400,000 children "born at 28 to 44 weeks’ gestation in Kaiser Permanente Southern California (KPSC) hospitals from January 1, 1995, through December 31, 2012." Specifically, authors were looking for a history of maternal diabetes - where diabetes refers to a state of high blood sugar levels over an extended period - as well as various potentially confounding variables as a function of a diagnosis of offspring ASD or not.
They describe how some 5800 children were diagnosed with autism over a typical follow-up period of about 7 years. Pertinent to their research question, researchers reported that relative to no exposure to maternal diabetes, various types of diabetes seemed to elevate the risk of a diagnosis of ASD. The statistics were: "the adjusted HRs [hazard ratios] for exposure to maternal diabetes were 2.36... for T1D, 1.45... for T2D, [and] 1.30... for GDM by 26 weeks’ gestation." The 'adjusted' part of those stats means that those potentially confounding variables - "birth year, maternal age at delivery, parity, education, self-reported race/ethnicity, median family household income based on residence census tract, history of comorbidity (≥1 diagnosis of heart, lung, kidney, or liver disease; cancer), and child’s sex" - were taken into consideration.
Should we be surprised by this *association*? Well, not really. On more than one occasion on this blog I've talked about how maternal diabetes seems to show 'some connection' to enhanced risk for autism in offspring (see here and see here). This work residing in a wider sphere where various conditions linked to the presentation of metabolic syndrome during pregnancy seem to show some connection to autism (see here).
Xiang et al also talk about how their T1D findings "add new information" but again, I'd be inclined to suggest that this is not the first time that T1D has cropped up with offspring autism in mind (see here). The possibility of a link with T1D does add an 'autoimmune' element to proceedings and *could* tie into other work mentioning this concept and autism (see here). Much more research in this area is indicated including that related to possible biological mechanisms.
 Xiang AH. et al. Maternal Type 1 Diabetes and Risk of Autism in Offspring. JAMA. 2018. June 23.