According to a study, having flu increases risk of autism when the child is born.
In the study, published in the journal mSphere, scientist found evidence of a link between catching influenza during pregnancy and an unborn baby developing the condition.
Known properly as Autism Spectrum Disorder (ASD), it affects a person’s social interaction, communication, interests and behaviour.
The exact cause is unknown, but affected children will normally show signs of it before the age of three.
Researchers found a trend towards ASD risk in mothers with a laboratory diagnosis of influenza and self-reported symptoms of severe illness.
The study is the first to look at this link based on laboratory-verified maternal influenza infection, not just survey data or medical records.
Questionnaires and blood samples of 338 mothers of children with autism and 348 matched controls were looked at.
Positive blood tests for past influenza A or influenza B infection were not associated with increased ASD risk.
But when they combined reports of influenza-like illness with the blood test results, they did find a link to ASD.
The researchers acknowledge that random error could be responsible, but believe that due to the magnitude of the association it shouldn’t be dismissed.
Indeed, mothers with laboratory-verified flu and matching symptoms had nearly double the odds of later being diagnosed with autism compared to women without flu and symptoms.
Doctor Milada Mahic, of Columbia University’s Mailman School of Public Health in the US and the Norwegian Institute of Public Health and first study author, said: “Symptoms are important because they may indicate the extent to which the mother’s immune system is fighting the flu.
“If infection is contributing to increased risk, it likely comes from inflammation related to maternal immune system response rather than the flu infection itself.
“Further research is warranted.”
Past research has suggested that admission to hospital for maternal viral infection…