Link found between pregnancy weight gain and ASD

There could be a link between the amount of weight a woman gains during pregnancy and autism spectrum disorders, according to a new study. Researchers from the University of Utah, US, have found that there could be a link between disorders related to the autism spectrum and increased weight gain during pregnancy.

The study 'Maternal Prenatal Weight Gain and Autism Spectrum Disorders', published in the journal 'Pediatrics', builds upon previous research that has linked prepregnancy body mass index (BMI) and an increased weight gain throughout pregnancy with autism spectrum disorders (ASD). However, the research looked at the link between weight gain during pregnancy and ASD in children after accounting for a number of important factors.

Doctor Deborah Bilder, lead author of the study and assistant professor of psychiatry at the University of Utah, said: "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.

"These findings suggest that weight gain during pregnancy is not the cause of ASD but rather may reflect an underlying process that it shares with autism spectrum disorders, such as abnormal hormone levels or inflammation."   

The difference in ASD was displayed in two separate study groups that were used for the research, which consisted of a total of 416 eight-year-olds. One group - 128 children - that had been diagnosed with ASDs was compared to a control group made up of 10,920 children of the same gender and age. The second group of 288 children from Utah that had been diagnosed with ASDs were compared to their siblings that were not affected by a disorder. 

Both groups were found to have a link between their disorders and the weight that their mothers gained throughout pregnancy. Pregnancy weight gain patterns were identified through birth certificates and were found to be a common factor in relation to the diagnosis of ASD in children.

Although the findings were small , the fact that they were consistent suggests that ASD and changes in weight gain throughout pregnancy may have a similar or the same underlying cause. However, ASD was not linked to BMI prior to pregnancy in either of the two study groups.

 "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. 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."