Timing of First Tetanus Toxoid Vaccine in Pregnancy
For pregnant women with unknown or incomplete tetanus vaccination history, the first tetanus toxoid-containing vaccine should be administered as soon as feasible upon recognition of the vaccination gap, regardless of gestational age. 1
Primary Vaccination Series for Unvaccinated or Incompletely Vaccinated Pregnant Women
Women who have never received tetanus vaccination or have incomplete vaccination require a 3-dose primary series:
- First dose: Administer immediately upon identification, as soon as feasible during pregnancy 1
- Second dose: At least 4 weeks after the first dose 1
- Third dose: 6 months after the second dose (may extend to 6-12 months) 1
Td (tetanus-diphtheria) is the preferred vaccine for the primary series during pregnancy. 1 However, providers may substitute a single dose of Tdap for one dose of Td during pregnancy, preferably between 27-36 weeks gestation, and complete the remaining doses with Td. 1
Critical Rationale for Immediate Administration
The urgency of starting vaccination immediately stems from the need to prevent maternal and neonatal tetanus, which carries significant morbidity and mortality risk. 1 Delaying the first dose reduces the likelihood of completing the series before delivery and achieving adequate protective antibody levels (>0.1 IU/mL by ELISA). 1
Timing Considerations by Trimester
While second or third trimester administration is preferred to minimize perception of association with first-trimester adverse pregnancy outcomes (which are more common in the first trimester for unrelated reasons), this preference should not delay necessary vaccination. 1 The key principle is that protection against tetanus takes priority over timing preferences. 1
For Women with Prior Vaccination History
If a pregnant woman has completed the primary tetanus series but the last booster was >10 years ago:
- Administer Tdap between 27-36 weeks gestation (preferably earlier in this window) 1, 2, 3
- This timing maximizes maternal antibody response and passive transfer to the infant 2, 3
If the last tetanus-containing vaccine was within the past 10 years:
- Tdap should still be given at 27-36 weeks gestation during each pregnancy, regardless of prior Tdap history 1, 2, 3
Special Circumstances Requiring Immediate Vaccination
For wound management during pregnancy:
- If ≥5 years have elapsed since the last tetanus booster, administer Tdap immediately regardless of gestational age 1, 2
- Do not delay for optimal timing windows when wound prophylaxis is indicated 1, 2
Common Pitfalls to Avoid
- Do not delay the first dose in unvaccinated pregnant women waiting for the "optimal" trimester—start immediately 1
- Do not assume vaccination history is complete without documentation; treat uncertain histories as unvaccinated 1
- Do not skip Tdap during pregnancy even if the woman received it recently outside of pregnancy—each pregnancy requires Tdap at 27-36 weeks 1, 2, 3
- Do not restart the series if doses are delayed; simply continue from where the patient left off 1, 4