The causes of autism are myriad and complex. Now a new study as published in the journal JAMA Pediatrics finds that mothers of children diagnosed with autism spectrum disorder (ASD) were more than twice as likely to have suffered from preeclampsia during pregnancy than mothers of children without the disorder. The likelihood of an ASD diagnosis further increased as the severity of preeclampsia increased. The findings suggest a link between preeclampsia and autism.
Autism is a developmental disorder that manifests during the first three years of life. The disorder is characterized by impaired social interaction and verbal and non-verbal communication and by restricted, repetitive, or stereotyped behavior.
Preeclampsia is a serious and potentially life-threatening pregnancy complication characterized by high blood pressure and significant amounts of protein in the urine. Symptoms include swelling, sudden weight gain, headaches, and changes in vision. The only cure for the condition, which generally appears after twenty weeks of pregnancy, is giving birth. Preeclampsia is the most common dangerous pregnancy complication. The condition affects about three to five percent of pregnancies and accounts for 40 to 60 percent of maternal deaths in developing countries.
For the present study, researchers led by Cheryl Walker — assistant professor in the Department of Obstetrics and Gynecology Division of Maternal Fetal Medicine and a researcher affiliated with the UC Davis MIND Institute — used a population-based, case-controlled study that investigated the links between autism and preeclampsia as well as whether autism risk is associated with preeclampsia severity.
The study involved over 1,000 children between the ages of 2 and 3 who took part in the Childhood Risks of Autism from Genetics and the Environment (CHARGE) Study in Northern California. More than 500 children were diagnosed with autism and 200 with development delay while 350 were developing typically. All of the mothers of the children in the study had confirmed preeclampsia during pregnancy.
According to the study, children with ASD were more than twice as likely to have mothers who suffered from preeclampsia during pregnancy than children without the disorder.
The researchers also found that mothers of both children with autism and children with developmental delay (with or without autism) were more likely to have experienced placental insufficiency, severe preeclampsia, or both.
Preeclampsia can affect the developing fetal brain in several ways including limited nutrients and oxygen, which may explain the link to autism and developmental delay.
“We found significant associations between preeclampsia and ASD that increased with severity. We also observed a significant association between severe preeclampsia and developmental delay.”
Adds the researcher on the findings:
“The level of detail obtained by the CHARGE Study on predictors, confounders, and outcomes enabled a comprehensive exploration of this topic. While single studies cannot establish causality, the cumulative evidence supports efforts to reduce preeclampsia and diminish severity, to improve neonatal outcomes.”
Another recent study found that women suffering from a vitamin D deficiency during pregnancy, specifically during the first 26 weeks of pregnancy, have an increased risk of developing severe preeclampsia.
Preeclampsia during mother’s pregnancy associated with greater autism risk: http://www.ucdmc.ucdavis.edu/publish/news/newsroom/9342
Preeclampsia during pregnancy and child’s autism risk linked: http://www.medicalnewstoday.com/articles/286712.php
Preeclampsia and Autism: http://www.freeimages.com/photo/145195