As a pregnant mother, it's natural to want to get as much information as you can about anything you're going to put into your body while carrying your baby. Vaccines are one topic moms have a lot of questions about, and American Academy of Pediatrics just released a new study on the safety of the tetanus, diphtheria, and pertussis (Tdap) vaccination widely recommended for pregnant mothers.
The AAP's study found there is no association between a prenatal exposure to the Tdap vaccination and autism spectrum disorder (ASD).
This vaccine is recommended by the Centers for Disease Control for pregnant mothers as a means to protect babies against pertussis, also known as whooping cough, and the AAP backs up the CDC in the new study, recommending the vaccine for pregnant women to protect infants, who are at highest risk for fatal pertussis infection.
Dr. Heather Sankey, an obstetrician and gynecologist practicing at Massachusetts's Baystate Medical Center, previously told Newsweek, the Tdap vaccine is important in pregnancy because it's the only way to protect newborns. "You can't vaccinate children until they are a year old," she says, explaining the baby receives a healthy immunity from the mother's vaccination.
The AAP's retroactive cohort study involved 82,000 children born between 2011 and 2014 at Kaiser Permanente Southern California hospitals.
"Among this cohort of infants the prevalence of ASD was 1.6%, which is comparable to the U.S. autism rates," Tracy A. Becerra-Culqui, one of the study's authors, explains in a video abstract posted by the AAP. "Our results show that the Tdap vaccine administered in pregnancy is not associated with an increased risk of ASD in infants."
"You can see the results are consistent across birth years and among those who were first born," she continues.
One of two recommended immunizations for pregnant people
The Tdap vaccine is one of two immunizations recommended during every pregnancy, along with the inactivated influenza vaccination, according to the American Congress of Obstetricians and Gynecologists (ACOG).
The ACOG recently released a new, straightforward set of pregnancy immunization guidelines to to clarify the rules around which immunizations expecting mothers should get and when, noting that "there is no evidence of adverse fetal effects from vaccinating pregnant women with inactivated virus, bacterial vaccines or toxoids, and a growing body of data demonstrate the safety of such use."
"Our goal was to increase vaccination rates among pregnant women and make it easier for providers to routinely prescribe them," Dr. Laura Riley, one of the guide's authors and chair of the ACOG immunization work group, told Newsweek.
Beyond Tdap and the flu shot, other vaccines may be recommended at the discretion of the woman's health care provider on the basis on the mother's age, previous immunizations, disease risk factors or chronic conditions.
The immunizations for measles-mumps-rubella and varicella (which are live vaccines) are not to be administered during pregnancy, but may be given postpartum even among breastfeeding mothers.
Why Tdap is recommended
The AAP notes that cases of pertussis have risen over the last decade, and according to the Centers for Disease Control and Prevention (CDC), half of the babies infected with whooping cough must be treated in the hospital and there are fatalities every year.
The AAP says evidence has shown that when moms get the Tdap shot while pregnant, "antibodies are passed along to newborns and that the vaccine was 91.4 percent effective in providing some immunity until newborns reached 2 months of age."
Knowing that there is no association between a prenatal exposure to the Tdap vaccination and autism may mean more mothers get the shot, which could mean fewer newborns will be hospitalized.
[Update, August 14, 2018: This post was originally published July 9, 2018, but has been updated to reflect the American Academy of Pediatrics new study, "Prenatal Tetanus,Diphtheria, Acellular Pertussis Vaccination and Autism Spectrum Disorder," published online Aug. 13 ]