Vaccines Safe During Pregnancy by Trimester
Inactivated vaccines are generally safe during pregnancy, while live vaccines are contraindicated. Specifically, influenza vaccine is recommended during any trimester, and Tdap is recommended between 27-36 weeks of each pregnancy to protect both mother and infant from severe disease.1
Safe Vaccines During All Trimesters
| Vaccine | First Trimester | Second Trimester | Third Trimester | Notes |
|---|---|---|---|---|
| Inactivated Influenza (IIV) | ✓ | ✓ | ✓ | Recommended for all pregnant women during any trimester [2] |
| Hepatitis B | ✓ | ✓ | ✓ | Recommended for women at risk for HBV infection [2] |
| Hepatitis A | ✓ | ✓ | ✓ | For women at increased risk [2] |
| Pneumococcal | ✓ | ✓ | ✓ | For women at increased risk [2] |
| Meningococcal | ✓ | ✓ | ✓ | For women at increased risk [2] |
| IPV (Inactivated Polio) | ✓ | ✓ | ✓ | For women at risk of exposure [2] |
| Yellow Fever | ✓ | ✓ | ✓ | Only if travel to high-risk areas is unavoidable [2] |
Vaccines with Specific Timing Recommendations
| Vaccine | First Trimester | Second Trimester | Third Trimester | Notes |
|---|---|---|---|---|
| Tdap | ○ | ○ | ✓ | Recommended between 27-36 weeks (ideally 27-28 weeks) in every pregnancy [2,3] |
| Td (Tetanus-diphtheria) | ✓ | ✓ | ✓ | For wound management or if >10 years since last dose [2,4] |
Contraindicated Vaccines During Pregnancy
| Vaccine | First Trimester | Second Trimester | Third Trimester | Notes |
|---|---|---|---|---|
| MMR | ✗ | ✗ | ✗ | Live virus vaccine [2,5] |
| Varicella | ✗ | ✗ | ✗ | Live virus vaccine [2,5] |
| Live Attenuated Influenza | ✗ | ✗ | ✗ | Live virus vaccine [2] |
| Smallpox | ✗ | ✗ | ✗ | Known to cause fetal harm [2] |
Key Clinical Considerations
- Pregnant women are at significantly higher risk for severe complications from influenza, with 7.2% greater hospitalization risk compared to non-pregnant women 2
- Influenza infection during pregnancy is associated with adverse outcomes including late pregnancy loss (adjusted hazard ratio 10.7) 2
- Tdap vaccination during pregnancy provides passive immunity to infants who are at high risk for pertussis complications in the first months of life 1, 3
- Optimal timing for Tdap (27-36 weeks) maximizes maternal antibody response and passive antibody transfer to the infant 3
- For wound management during pregnancy, if a tetanus booster is indicated (≥5 years since previous dose), Tdap should be administered regardless of trimester 2, 3
Common Pitfalls to Avoid
- Delaying influenza vaccination until a specific trimester - it can be safely given at any time during pregnancy 2
- Missing the optimal window (27-36 weeks) for Tdap administration 3
- Failing to recognize that maternal antibodies wane quickly, making Tdap vaccination necessary during each pregnancy 3
- Not addressing vaccine hesitancy through education about benefits to both mother and infant 1
- Administering live vaccines during pregnancy, which poses theoretical risks to the fetus 2, 5
Special Situations
- For pregnant women with unknown or incomplete tetanus vaccination history, a series of three vaccinations is recommended (0,4 weeks, and 6-12 months), with Tdap replacing one dose, preferably between 27-36 weeks gestation 2, 3
- If Tdap is not administered during pregnancy, it should be given immediately postpartum 2, 3
- Women susceptible to rubella and varicella should be vaccinated immediately after delivery 1