This new study, however, sought to assess whether there was a link between prenatal Tdap vaccination and development of ASD. Researchers studied more than 109,000 mothers at Kaiser Permanente Southern California hospitals between 2011 and 2014. The children of the vaccinated mothers were followed for several years, and ASD was diagnosed in 1.6% of the children of mothers vaccinated during their pregnancies.
The report reveals that the incidence of autism diagnoses declined throughout the study period, from 2% to 1.5% in children of mothers who were not vaccinated during pregnancy, and from 1.8% to 1.2% in mothers who did receive the vaccination. Overall, researchers note, the incidence of ASD in the vaccinated group was 3.78 per 1000 person-years compared with 4.05 per 1000 person-years in the unvaccinated group.
“We found no evidence of increased risk for ASD diagnosis associated with Tdap vaccination during pregnancy,” the report concludes.
Read more here in Contemporary Pediatrics.