Intrauterine exposure to gestational diabetes mellitus diagnosed by 26 weeks' gestation was linked to an increased risk of autism spectrum disorder.
In the past, gestational diabetes had been correlated with interferences with organ development and even obesity risk in children, but its effect on the brain has been poorly understood, the JAMA Network Journals reported.
A team of researchers looked at data on 322,323 children from a single health care system. The children were born between the years of 1995 and 2009 at Kaiser Permanente Southern California (KPSC) hospitals. Two percent of the study subjects were exposed to pre-existing type 2 diabetes, 7.2 percent to gestational diabetes mellitus (GDM), and the remaining 90.2 percent were unexposed. Overall, 3,388 children were diagnosed as having ASD: "115 exposed to pre-existing type 2 diabetes, 130 exposed to GDM at 26 weeks or less, 180 exposed to GDM at more than 26 weeks, and 2,963 unexposed," the researchers reported.
The data suggests GDM diagnosed by 26 weeks significantly increased the risk of ASD in offspring, but maternal pre-existing type 2 diabetes did not.
The researchers believed biological mechanisms linking intrauterine hyperglycemia and ASD could included multiple pathways including hypoxia (low blood oxygen concentrations), oxidative stress in cord blood and placental tissue, chronic inflammation, and epigenetics.
"In this large, multiethnic clinical cohort of singleton children born at 28 to 44 weeks' gestation, exposure to maternal GDM diagnosed by 26 weeks' gestation was associated with risk of ASD in offspring," the researchers concluded in their study abstract.
The findings were published in a recent edition of JAMA.
