1. Preexisting maternal type II diabetes was not significantly associated with an increased risk of autism spectrum disorders (ASD) in children.
2. Gestational diabetes mellitus (GDM) diagnosed prior to 26 weeks gestation was found to pose a greater risk of ASD compared to GDM diagnosed after 26 weeks.
Evidence Rating Level: 2 (Good)
Study Rundown: While maternal diabetes is diagnosed prior to pregnancy, the diagnosis of gestational diabetes mellitus is made when hyperglycemia first occurs during pregnancy.
Maternal diabetes has been shown to increase a newborn child’s risk of intrauterine growth retardation, hypoglycemia, and obesity, but the association between either maternal or gestational diabetes and neurological complications such as ASD remains unclear. There is currently limited evidence for a connection between maternal type II diabetes and ASD while the association between gestational diabetes and ASD has not been properly investigated.
This study evaluated the association between both maternal and gestational diabetes and ASD in children. While maternal type II diabetes and gestational diabetes both increased the risk of ASD, the maternal diabetes association was not significant. Further, gestational diabetes diagnosed prior than 26 weeks gestation or earlier was shown to pose a greater risk to the fetus than when diagnosed after 26 weeks. While this study is weakened by its analysis of only a single health care system in California, thereby limiting generalizability, strengths include excellent follow-up and a large patient population. Based on these study results, it may be prudent for clinicians to consider early screening for infants of mothers with GDM diagnosed prior to 26 weeks gestation. Further research is required to validate these study findings and to determine the effect of GDM treatment on ASD risk.
Relevant Reading: Prenatal risk factors for autism: a comprehensive meta-analysis
In-Depth [retrospective cohort]: This study evaluated 322,323 children born at 28-44 weeks gestation in Kaiser Permanente Southern California hospitals between January 1, 1995 and December 31, 2009. 6,496 (2.0%) were exposed to preexisting type 2 diabetes, 25,035 (7.8%) were exposed to GDM, and 290, 792 (90.2%) were unexposed. Unadjusted average annual incidences of ASD for the unexposed, type II diabetes, and gestational diabetes groups were 1.77, 3.26, and 2.14 per 1000, respectively (P < .001). Compared to no exposure, fetal exposure to preexisting type 2 diabetes was associated with ASD with a hazard ratio (HR) of 1.59 (95% CI, 1.29-1.95). Exposure to GDM at any time during pregnancy had an HR of 1.18 (95% CI, 1.04-1.33). Risks of ASD in children exposed to preexisting type 2 diabetes (HR, 1.43; 95% CI, 1.06-1.92) or GDM diagnosed at 26 weeks or earlier (HR, 1.64; 95% CI, 1.27-2.11) were higher than in children exposed to GDM diagnosed after 26 weeks.
©2015 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.