A retrospective cohort study conducted by Kaiser Permanente of more than 80,000 children born over a four-year period showed that the prenatal Tdap vaccination (tetanus, diphtheria, acellular pertussis) was not associated with increased risk of autism spectrum disorder (ASD) in children. The study was published today in Pediatrics.
"Infants are at the highest risk of hospitalization and death among any population subgroup after contracting a pertussis infection, a highly contagious respiratory disease also known as the whooping cough," said Tracy A. Becerra-Culqui, Ph.D., a post-doctoral research fellow with Kaiser Permanente and lead author of the study. "With waning immunity against pertussis in the United States, it has become very important for pregnant women to be immunized against pertussis. It is an immunity they pass on to their unborn baby."
"Pregnant women can be reassured by this study that there is no indication of an increased risk of autism spectrum disorder in children after being exposed prenatally to the Tdap vaccine," Becerra-Culqui added.
The Advisory Committee on Immunization Practices, which provides guidance on the use of vaccines for the United States, recommends pregnant women receive the Tdap vaccine to prevent pertussis infection, but some women still hesitate.
"The link between vaccination and development of autism has been refuted by many rigorous scientific investigations. Unfortunately, the misconceptions still generate concerns," said the paper's senior author, Hung Fu Tseng, Ph.D.
"Given the increasing practice to vaccinate pregnant women with Tdap vaccine, it was important to address the concern of a link between maternal vaccination and subsequent development of autism spectrum disorder in children," he added. "We hope that our findings reassure parents that Tdap vaccination during pregnancy was not associated with autism in children."