Pasadena, CA—Especially since a study last year showed that administering the tetanus, diphtheria, acellular pertussis (Tdap) vaccine during the third trimester of pregnancy prevents 78% of pertussis cases in infants younger than 2 months, the CDC strongly urges expectant mothers to follow that protocol.
However, the CDC reports that less than half—49%—of pregnant women who delivered between fall 2015 and spring 2016 received the vaccine, partly because of concerns about damage to the fetus.
A new Kaiser Permanente study of more than 80,000 children born over a 4-year period should offer some assurance. The research, published in the journal Pediatrics, determined that the prenatal Tdap vaccination was not associated with increased risk of autism spectrum disorder (ASD) in children.
“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,” explained lead author Tracy A. Becerra-Culqui, PhD, a post-doctoral research fellow with Kaiser Permanente Southern California’s Department of Research & Evaluation. “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 in a Kaiser Permanente press release.
The retrospective cohort study of mother-child pairs was focused on deliveries from January 1, 2011 to December 31, 2014 at Kaiser Permanente Southern California hospitals. Electronic records were used to document the mothers’ Tdap vaccinations from pregnancy start to delivery date, while a diagnosis was obtained by using International Classification of Diseases, Ninth and Tenth Revision codes. Children were followed from birth to first ASD diagnosis, end of membership, or end of follow-up in June 2017.
Women who had received the vaccine were more likely to be Asian American or Pacific Islander, be nulliparous, have a higher education, receive influenza vaccination prenatally, and give birth at term, researchers pointed out.
With ASD diagnosed in 1.6% of the offspring, the study team determined that the incidence rate was 3.78 per 1,000 person-years in the Tdap-exposed group and 4.05 per 1,000 person-years in the unexposed group (hazard ratio [HR]: 0.98, 95% confidence interval: [CI] 0.88–1.09). Autism rates in the U.S. are about 1.7%, background information in the study noted.
Using inverse probability of treatment weighting–adjusted analyses, the study determined that prenatal Tdap vaccination was not associated with an increased ASD risk (HR: 0.85, 95% CI: 0.77–0.95).
“We support recommendations to vaccinate pregnant women to protect infants, who are at highest risk of death after pertussis infection,” the study authors emphasized.
“The link between vaccination and development of autism has been refuted by many rigorous scientific investigations. Unfortunately, the misconceptions still generate concerns,” said senior author Hung Fu Tseng, PhD. “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. We hope that our findings reassure parents that Tdap vaccination during pregnancy was not associated with autism in children.”
« Click here to return to Weekly News Update.However, the CDC reports that less than half—49%—of pregnant women who delivered between fall 2015 and spring 2016 received the vaccine, partly because of concerns about damage to the fetus.
A new Kaiser Permanente study of more than 80,000 children born over a 4-year period should offer some assurance. The research, published in the journal Pediatrics, determined that the prenatal Tdap vaccination was not associated with increased risk of autism spectrum disorder (ASD) in children.
“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,” explained lead author Tracy A. Becerra-Culqui, PhD, a post-doctoral research fellow with Kaiser Permanente Southern California’s Department of Research & Evaluation. “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 in a Kaiser Permanente press release.
The retrospective cohort study of mother-child pairs was focused on deliveries from January 1, 2011 to December 31, 2014 at Kaiser Permanente Southern California hospitals. Electronic records were used to document the mothers’ Tdap vaccinations from pregnancy start to delivery date, while a diagnosis was obtained by using International Classification of Diseases, Ninth and Tenth Revision codes. Children were followed from birth to first ASD diagnosis, end of membership, or end of follow-up in June 2017.
Women who had received the vaccine were more likely to be Asian American or Pacific Islander, be nulliparous, have a higher education, receive influenza vaccination prenatally, and give birth at term, researchers pointed out.
With ASD diagnosed in 1.6% of the offspring, the study team determined that the incidence rate was 3.78 per 1,000 person-years in the Tdap-exposed group and 4.05 per 1,000 person-years in the unexposed group (hazard ratio [HR]: 0.98, 95% confidence interval: [CI] 0.88–1.09). Autism rates in the U.S. are about 1.7%, background information in the study noted.
Using inverse probability of treatment weighting–adjusted analyses, the study determined that prenatal Tdap vaccination was not associated with an increased ASD risk (HR: 0.85, 95% CI: 0.77–0.95).
“We support recommendations to vaccinate pregnant women to protect infants, who are at highest risk of death after pertussis infection,” the study authors emphasized.
“The link between vaccination and development of autism has been refuted by many rigorous scientific investigations. Unfortunately, the misconceptions still generate concerns,” said senior author Hung Fu Tseng, PhD. “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. We hope that our findings reassure parents that Tdap vaccination during pregnancy was not associated with autism in children.”
