It’s common for women to suffer from morning sickness when pregnant; however, there is a small majority that experience a severe form of it called hyperemesis gravidarum. The latter type of illness occurs throughout most of the nine months, not just early on in the pregnancy. For those women, there is a higher risk of giving birth to a child that will be diagnosed with autism spectrum disorder.
A new study by Kaiser Permanente researchers found that mothers who experience hyperemesis gravidarum are 53% more likely to have an autistic child. The research has been published in the American Journal of Perinatology.
Lead study author Darios Getahun, MD, Ph.D., of Kaiser Permanente Southern California Department of Research and Evaluation, said:
This study is important because it 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.
Fortunately, this severe form of morning sickness occurs in less than 5% of pregnancies. A woman that happens to be in that percentile will suffer from intense nausea and will not be able to keep down food and fluids. The condition leads to inadequate nutrition and dangerous dehydration during pregnancy, which harms the malnourished fetus. The lack of adequate and balanced diet interferes with the neurodevelopment of the child resulting in long-term impairment of neurological function.
The Study
- Electronic health records of almost 500,000 pregnant women and their children born between 1991 and 2014 at Kaiser Permanente in Southern California were reviewed. The intent was to determine the extent of the association between autism spectrum disorder and hyperemesis gravidarum.
- Children of mothers who had been diagnosed with hyperemesis gravidarum during pregnancy were compared to children whose mothers had not.
The Results
- An association was made between exposure to hyperemesis gravidarum and an increased risk of autism. The risk was applicable when the diagnosis was made during the first and second trimesters, but not if the diagnosis was made only in the third trimester.
- The risk is the same regardless of the severity of the woman’s hyperemesis gravidarum.
- The association was strongest in girls (vs. boys).
- The association was strongest among Hispanics and whites (vs. blacks and pacific islanders).
- The risk of autism did not appear to be related to the medications used to treat hyperemesis gravidarum.
Conclusion
Mothers with hyperemesis gravidarum end up with inadequate nutritional intake, which leads to the risk of long-term neurodevelopment impairment in their children. However, more studies are required to confirm this because there could be other explanations, such as maternal smoking or perinatal exposures to some medications.
