VIENNA — Toddlers whose mothers had gestational diabetes mellitus that required medication were more likely to be diagnosed with autism spectrum disorder compared with other children, in a new study of Californian women. But while this is an interesting observation, it is still too early to draw any inferences, experts warn.
In this cohort, the incidence of autism was 2.75/1000 per year for children whose mothers had gestational diabetes requiring medication vs 1.96/1000 per year for children whose mothers had diabetes and who did not take medical therapy and 1.77/1000 per year for children whose mothers were free of diabetes.
"Clearly, the children who are exposed to gestational diabetes mellitus requiring medication have an elevated risk of autism spectrum disorder," said lead author Anny H. Xiang, PhD, from Kaiser Permanente Southern California, presenting these findings at the European Association for the Study of Diabetes 2014 Meeting earlier this month.
Women with gestational diabetes requiring medication were more likely to be diagnosed with this condition earlier in the pregnancy (at 22.9 weeks vs 26.9 weeks of gestation), Dr. Xiang noted. Exposure to glucose at this earlier critical time for fetal brain development may partly explain the heightened risk of autism, she speculated.
However, these findings would need to be replicated and confirmed in other populations, session cochair Elisabeth R. Mathiesen, MD, from the Denmark Center for Pregnant Women with Diabetes, Copenhagen, told Medscape Medical News after the presentation.
"I find it very interesting that there might be some mental-[health] changes in the children of women who get diabetes, but we still certainly need more studies to say whether it is an incidental finding or if it's really true in other populations," she said.
Autism Etiology Remains a Mystery
The prevalence of autism spectrum disorder is increasing and is now around 7% in the United States, but the etiology remains largely unknown, Dr. Xiang said. A few studies have suggested that fetal exposure to high levels of glucose in pregnancy might be involved.
The researchers aimed to investigate a possible association of autism spectrum disorder with gestational diabetes — distinguishing between medically treated vs untreated.
They examined data from 315,827 children who were born between 1995 and 2010 and who were enrolled in the Kaiser Permanente health insurance plan by ages 1 to 2, whose mothers did not have diabetes prior to pregnancy.
The researchers analyzed follow-up data until December 31, 2012.
Of these singleton pregnancies, 290,792 women did not develop gestational diabetes; 19,144 women did develop it but did not take antidiabetic mediation; and 5891 developed gestational diabetes and received therapy for it.
About 80% of the women who took antidiabetic medication used insulin, while the rest were on oral medications, Dr. Xiang noted.
Among the women who developed diabetes, those who received antidiabetic medication were more likely to be older, have more children, a lower level of education, and a lower household income. They were also more likely to be Asian or Pacific Islanders, have more comorbidities, be diagnosed with gestational diabetes earlier in their pregnancy, and give birth to a heavier baby, with a slightly higher odds of having a boy.
According to the health insurance guidelines, the children were screened for autism spectrum disorder at 1 year, 18 months, 2 years, and beyond, Dr. Xiang said. About 8% of the children were diagnosed with autism spectrum disorder, consistent with the overall rate in the United States.
Compared with women free of diabetes, women who had gestational diabetes that was treated by medication had a 22% significant, increased relative risk of having a child with autism spectrum disorder, after adjustment for possible common confounders.
There was no significant increased risk of autism spectrum disorder among children whose mothers had gestational hyperglycemia that was not treated by medication.
Relative Risk of a Child With ASD, Among Mothers With Gestational Diabetes With or Without Medical Treatment vs No Gestational Diabetes
|Relative Risk||HR (95% CI)||p|
|GDM with therapy|
|Unadjusted||1.45 (1.18 – 1.79)||0.004|
|Adjusted*||1.22 (0.99 – 1.51)||0.06|
|GDM with no therapy|
|Unadjusted||1.08 (0.94 – 1.24)||0.27|
|Adjusted*||0.97 (0.85 – 1.12)||0.72|
In future work, the group plans to investigate the relationship between maternal obesity and possible autism spectrum disorder in the offspring in this cohort, Dr. Xiang concluded.
Dr. Xiang and Dr. Mathiesen have reported no relevant financial relationships.
European Association for the Study of Diabetes 2014; September 18, 2014; Vienna, Austria. Abstract 156
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Cite this: Medicated Gestational Diabetes May Up Risk for Autistic Child - Medscape - Sep 29, 2014.