A study looking at children with autism spectrum disorder and their mother’s prenatal records showed an association between maternal weight gain and risk for autism diagnosis.
“The risk of autism spectrum disorder associated with a modest yet consistent increase in pregnancy weight gain suggests that pregnancy weight gain may serve as an important marker for autism’s underlying gestational etiology,” study researcher Deborah A. Bilder, MD, an assistant professor of psychiatry at the University of Utah, said in a press release. “These findings suggest that weight gain during pregnancy is not the cause of [autism spectrum disorder] but rather may reflect an underlying process that it shares with autism spectrum disorders, such as abnormal hormone levels or inflammation.”
The study, published in Pediatrics, looked at two group of patients with autism spectrum disorder (ASD) in Utah — one population-based (n=128) and a second research-based (n=288). The population-based group was compared with a sex- and age-matched cohort from Utah (n=10,920), whereas the research-based cohort was compared with their unaffected siblings (n=493). Data were taken from the Utah Registry of Autism and Developmental Disabilities.
The data showed an association with prenatal weight gain but not pre-pregnancy BMI, and when restricted to ASD cases with normal IQ, these associations remained significant. The adjusted OR for the population-based study was 1.1 (95% CI, 1.03-1.17) and it was 1.17 for the research-based study (95% CI, 1.01-1.35 for each 5 lb gained).
“The findings in this study are important because they provide clues to what may increase the risk of having an autism spectrum disorder and provide a specific direction for researchers to pursue as they search for the causes for autism spectrum disorders,” Bilder said. “Doctors have known for a long time that proper nutrition is essential to a healthy pregnancy. Pregnant women should not change their diet based on these results. Rather, this study provides one more piece for the autism puzzle that researchers are exploring.”
Disclosure: Bilder reports no relevant financial disclosures.