The administration of Tdap vaccine during pregnancy was not significantly associated with increased risk for microcephaly or structural congenital disabilities in offspring, according to an analysis that included more than 300,000 births. The Tdap vaccine is administered to offer protection against three serious diseases: tetanus, diphtheria, and pertussis. In 2012, the U.S. Advisory Committee on Immunization Practices recommended that Tdap vaccine be administered during every pregnancy, ideally between 27 and 36 weeks' gestation. Previously, Tdap was recommended for unvaccinated pregnant women since 2010 in California and since 2011 across the United States. Cases of microcephaly (an abnormally small head due to the failure of brain growth) in Brazil increased substantially during 2015, likely associated with maternal Zika virus infections. However, these cases overlapped with the November 2014 initiation of Brazil's maternal Tdap program. Previous small observational studies reported no increased risks for birth defects following maternal Tdap vaccination; none focused on microcephaly. ‘Routine Tdap vaccination during pregnancy was not significantly associated with increased risk for microcephaly and structural defects in infants.’ In this study, Malini DeSilva, M.D., M.P.H., of HealthPartners Institute, Minneapolis, and colleagues included data from live births at 7 Vaccine Safety Datalink sites (Northern California, Southern California, Colorado, Minnesota, Oregon, Washington, and Wisconsin) from January 2007 through September 2013 and compared prevalence of structural birth defects between infants born to women who received Tdap during pregnancy and unvaccinated women. Analyses of maternal Tdap vaccination from 27 to 36 weeks' gestation were limited to 2010-2013 for California sites and to 2012-2013 for other sites. Any structural defect, selected major structural defects, and microcephaly alone were identified from diagnostic codes assigned at medical visits during the first year of life. Analyses included 324,463 live births. The researchers found that maternal Tdap was not significantly associated with increased risk for microcephaly for vaccinations occurring at less than 14 weeks' gestation (n = 3,321), between 27 and 36 weeks' gestation (n = 20,568), or during any week of pregnancy (n = 41,654). Adjusted analyses were similar for any structural birth defect and selected major structural defects. The authors note that the findings are potentially limited by incomplete data on Tdap vaccinations (making it possible to misclassify women's immunization status), diagnosed structural birth defects, and important covariates (including maternal alcohol use), as well as an inability to study birth defects resulting in pregnancy loss or elective termination. "The findings support recommendations for routine Tdap administration during pregnancy," the researchers write. The study is published in JAMA. Source: Medindia << Gene Linked to Microcephaly in Infants Could Treat Brain Can... Schizophrenic Stem Cells Do Not Differentiate Properly into... >> Recommended Reading Effectiveness of Routine Tdap Booster Wanes in Adolescents Despite high levels of vaccine coverage, the U.S. and other countries have experienced an increase in whooping cough cases in the following years. READ MORE Administration of Tdap Vaccine During Pregnancy Not Associated With Preterm Delivery Administration of Tdap Vaccine during pregnancy is not linked with increased risk of preterm delivery or hypertensive disorders of pregnancy, says a new study. READ MORE Effect of Receiving Tdap Vaccine During Pregnancy Examined in Study Receipt of the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in the third trimester of pregnancy did not increase the risk of adverse events. READ MORE Gene Linked to Microcephaly in Infants Could Treat Brain Cancer Seckel syndrome is a genetic condition that causes microcephaly, understanding the condition better, helps block brain tumor growth. READ MORE Seckel Syndrome Seckel syndrome is a rare genetic disorder characterized by an abnormally small head, birdlike facial features, mental retardation, and blood malignancies. READ MORE Top 10 Vaccine Myths Debunked Childhood vaccination has saved many lives, yet lots more has to be done to increase awareness and eliminate myths regarding vaccines. READ MORE Traveling with Children Abroad? - Parents, Stay Alert! Traveling with children is always challenging as it involves careful planning. Here are some precautions that need to be taken when traveling abroad with kids. READ MORE Most Popular on Medindia Noscaphene (Noscapine) Color Blindness Calculator Sanatogen More News on: Seckel SyndromeTop 10 Vaccine Myths DebunkedTraveling with Children Abroad? - Parents, Stay Alert!