A new study discovers children whose mothers had a severe form of a morning sickness during pregnancy were 53 percent more likely to be diagnosed with autism spectrum disorder. Kaiser Permanente researchers said the condition, known as hyperemesis gravidarum, is rare and occurs in less that 5 percent of all pregnancies.
Nevertheless, researchers believe the findings are important because the research suggests that children born to women with hyperemesis may be at an increased risk of autism. “Awareness of this association may create the opportunity for earlier diagnosis and intervention in children at risk of autism,” explains lead study author Darios Getahun, M.D., Ph.D., of Kaiser Permanente Southern California Department of Research and Evaluation.
The study appears in the American Journal of Perinatology.
Experts explain that women with the severe form of morning sickness experience intense nausea and are unable to keep down food and fluids. This can lead to dangerous dehydration and inadequate nutrition during pregnancy.
To determine the extent of the association between hyperemesis gravidarum and autism spectrum disorder, researchers reviewed electronic health records of nearly 500,000 pregnant women and their children born between 1991 and 2014 at Kaiser Permanente in Southern California. They compared children whose mothers had a diagnosis of hyperemesis gravidarum during pregnancy to those whose mothers did not.
Other findings from the research included:
• Exposure to hyperemesis gravidarum was associated with increased risk of autism when hyperemesis gravidarum was diagnosed during the first and second trimesters of pregnancy, but not when it was diagnosed only in the third trimester;
• Exposure to hyperemesis gravidarum was associated with risk of autism regardless of the severity of the mother’s hyperemesis gravidarum;
• The association between hyperemesis gravidarum and autism spectrum disorder was stronger in girls than boys and among whites and Hispanics than among blacks and Pacific Islanders;
• The medications used to treat hyperemesis gravidarum did not appear to be related to autism risk.
Investigators explain that the results are consistent with the hypothesis that women experiencing hyperemesis gravidarum have poor nutritional intake. This may, in turn lead to potential long-term neurodevelopment impairment in their children.
The study cannot, however, rule out other possible explanations, such as perinatal exposures to some medications and maternal smoking.
Source: Kaiser Permanente/EurekAlert