A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Fall, 2019 | Number 4, Volume 33

Second study indicates link between morning sickness, ASD

New research supports an earlier study indicating that the odds of receiving an autism spectrum disorder (ASD) diagnosis are increased for children of mothers who experience hyperemesis gravidarum (HG), or extreme morning sickness. 

The first study (see ARRI 33/1), by Marlena Fejzo and colleagues, involved 267 children of mothers with HG and 93 children of mothers who did not experience HG. The researchers found that by 12 years of age, children of mothers with HG had a more than three-fold increase in the odds of having a diagnosis of neurodevelopmental disorder. In this study, eight percent of the children of mothers with HG had an ASD diagnosis, compared to none in the control group. 

The new study by Darios Getahun and colleagues, focused specifically on ASD. The researchers reviewed the electronic health records of nearly 500,000 women and their children, all patients at Kaiser Permanente facilities. They found that children whose mothers had HG were 53 percent more likely to be diagnosed with ASD than children of mothers who did not have HG. 

The researchers also found that HG was associated with an increased risk of autism when it was diagnosed during the first and second trimesters of pregnancy, but not when it was diagnosed only in the third trimester. HG was associated with ASD risk regardless of the severity of the HG, and medications used to treat HG did not appear to be related to ASD risk. The association between HG and ASD was stronger for girls than for boys and stronger for white and Hispanic women than for African-American women or those from the Pacific Islands. 

The researchers comment, “HG diagnosis is associated with ASD risk and may be helpful in identifying at-risk children who could benefit from enhanced surveillance and earlier diagnosis and intervention.”


“Autism spectrum disorders in children exposed in utero to hyperemesis gravidarum,” D. Getahun, M. J. Fassett, S. J. Jacobsen, A. H. Xiang, H. S. Takhar, D. A. Wing, and M. R. Peltier, American Journal of Perinatology, October 3, 2019 (epub prior to print publication). Address: Darios Getahun, [email protected]


 “Severe morning sickness linked with higher risk of autism,” news release, Kaiser Permanente, October 3, 2019.