Gestational diabetes mellitus (GDM) diagnosed by 26 weeks is linked to a greater risk for autism spectrum disorder (ASD) in the child, according to a new study. No significant link was found, however, between maternal pre-existing type II diabetes and ASD.
Earlier research has shown greater risks for obesity and related metabolic disorders in the children of women who had diabetes prior to pregnancy, as well as women with hyperglycemia first detected during maternal GDM.
Whether such exposure can disrupt fetal brain development and heighten risk of neurobehavioral developmental disorders in offspring has been less clear, however.
For the study, Anny H. Xiang, Ph.D., of Kaiser Permanente Southern California, Pasadena, California, and colleagues analyzed data from a single health care system to determine a potential link between maternal diabetes, both known prior to pregnancy and diagnosed during pregnancy, and the risk of ASD in children.
The researchers analyzed data on 322,323 children born from 1995-2009 at Kaiser Permanente Southern California (KPSC) hospitals. Children were followed from birth until the first of the following: date of clinical diagnosis of ASD, last date of continuous KPSC health plan membership, death due to any cause, or December 31, 2012.
Of all the children in the study, 6,496 (2.0 percent) were exposed to pre-existing type II diabetes, 25,035 (7.8 percent) were exposed to GDM, and 290,792 (90.2 percent) were unexposed.
At a median age of five years old, 3,388 children were diagnosed as having ASD: 115 had been exposed to pre-existing type II diabetes, 130 exposed to GDM at 26 weeks or less, 180 exposed to GDM at more than 26 weeks, and 2,963 unexposed.
After adjusting for various factors, including maternal age, household income, race/ethnicity, and sex of the child, the researchers found that GDM diagnosed by 26 weeks was significantly associated with risk of ASD in offspring, but maternal pre-existing type II diabetes was not.
The increased ASD risk was independent of maternal smoking, prepregnancy body mass index, and gestational weight gain. Use of antidiabetic medication by the mother was not independently associated with ASD risk in children.
The researchers write that the biological link between gestational diabetes and ASD may be the result of multiple pathways, such as hypoxia (a lower-than-normal concentration of oxygen in the blood) in the fetus, oxidative stress in cord blood and placental tissue, chronic inflammation, and epigenetics (something that affects a cell, organ, or individual without directly affecting its DNA).
The findings are published in the journal JAMA.