A study published by JAMA Pediatrics found no link between flu during pregnancy and increased risk of autism spectrum disorders (ASDs) in children. The study also did not find any association between increased risk of ASD and influenza vaccination during the second and third trimesters of pregnancy.
The study involved analyzing over 196,000 children born between 2000 and 2010 and had a gestational age of at least 24 weeks. Overall, 1,400 mothers, or 0.7 percent of the mothers, got diagnosed with influenza and 45,231 mothers or 23 percent got vaccinated against influenza during their pregnancy.
Only 3,101 children, or 1.6 percent of them, were diagnosed with ASD. The research team concluded that influenza as well as getting vaccinated against it during pregnancy, does not increase the risk of ASD in children.
Previously, it was thought that maternal vaccination during the first trimester of pregnancy may cause autism but the new research team asserts that this may be due to chance and is not statistically significant after other factors have all been taken into account.
“We found no association between ASD risk and influenza infection during pregnancy or influenza vaccination during the second to third trimester of pregnancy. However, there was a suggestion of increased ASD risk among children whose mothers received influenza vaccinations early during pregnancy, although the association was insignificant after statistical correction for multiple comparisons. While we do not advocate changes in vaccine policy or practice, we believe that additional studies are warranted to further evaluate any potential associations between first-trimester maternal influenza vaccination and autism,” the study stated.
This new research, however, has its own limitations. The researchers pointed out in a press release that their analysis was based on diagnoses on medical records and was not validated by the standardized clinical assessment. They also added that they cannot control other factors that could have caused autism.