TABLE 3

Rates and Associations Between Tdap Vaccination During Pregnancy and ASD Among Children Born Between 2011 and 2014

ASD Incidence Rate per 1000 Person yHR (95% CI)
UnvaccinatedVaccinatedUnadjustedIPTW-Adjusteda
Overall4.053.780.98 (0.88–1.09)0.85 (0.77–0.95)
Birth y
 20113.573.220.91 (0.74–1.12)0.86 (0.70–1.07)
 20124.023.180.80 (0.62–1.02)0.80 (0.63–1.03)
 20134.484.461.00 (0.81–1.23)0.99 (0.80–1.23)
 20144.874.140.89 (0.68–1.18)0.85 (0.65–1.12)
Nulliparous4.884.560.99 (0.85–1.15)0.88 (0.75–1.02)
  • a Adjustments were made for child’s birth y, gestational age at birth (<37 or ≥37 wk); maternal age, race and/or ethnicity, and education; Medicaid insurance, medical center of delivery, parity, start of prenatal care, and influenza vaccination during pregnancy.