Yes, you can refuse the Tdap vaccine during pregnancy. No vaccine is legally mandated for pregnant people in the United States, and you have the right to decline any medical intervention after being informed of the risks and benefits. That said, every major medical organization strongly recommends it, and understanding why can help you make a fully informed choice.
Why Tdap Is Recommended During Pregnancy
The core problem Tdap solves is a timing gap. Babies don’t start their own whooping cough (pertussis) vaccine series until 2 months of age, which leaves newborns completely unprotected during the weeks when pertussis is most dangerous to them. Most pertussis deaths occur in infants younger than 3 months, and the majority of those babies contracted the infection from a family member or caregiver, often the mother.
When you get the Tdap vaccine during pregnancy, your body produces antibodies that cross the placenta and reach your baby before birth. This gives your newborn a temporary shield during those vulnerable first weeks. A CDC evaluation found that Tdap vaccination during the third trimester prevents about 78% of pertussis cases in infants under 2 months old and is 91% effective at preventing cases severe enough to require hospitalization.
Both ACOG and the CDC recommend the vaccine during every pregnancy, regardless of whether you received Tdap before. The ideal window is between 27 and 36 weeks of gestation, with earlier in that range being better. Vaccinating at least 2 weeks before delivery gives your body enough time to build antibodies and transfer them to the baby.
What the Safety Data Shows
A large study of pregnant active-duty U.S. military women found no association between Tdap vaccination and miscarriage, preeclampsia, preterm labor, stillbirth, placental abruption, or neonatal death. First-trimester exposure (which is earlier than recommended) was not linked to birth defects, growth problems in the womb, preterm birth, or low birth weight. Current Tdap vaccines used in the United States do not contain thimerosal, a preservative that has been a common concern.
What Happens if You Decline
If you refuse Tdap during pregnancy, your baby will be born without the passive antibody protection that the vaccine provides. This doesn’t mean your baby will definitely get pertussis, but it does mean they’ll have no immune defense against it until they begin their own vaccine series at 2 months.
During the 2010 California pertussis epidemic, infants under 3 months had the highest infection rates, made up 55% of hospitalized pertussis cases, and had a case fatality rate of 1.3%. Of the 10 infant deaths during that epidemic, 9 were in babies younger than 8 weeks who hadn’t yet received any doses of the childhood pertussis vaccine. Nearly all fatal cases (98%) required intubation before death.
Some parents consider a “cocooning” strategy instead, where everyone around the baby gets vaccinated to create a protective bubble. While this helps, the CDC notes that postpartum Tdap does not provide passive immunity to the infant. It also takes about 2 weeks after vaccination for the mother herself to develop protection, leaving a window where she could still catch and transmit pertussis to her newborn. Maternal vaccination during pregnancy is considered more reliable because it protects the baby directly from birth.
How Refusal Works in Practice
Your provider will likely bring up Tdap at a prenatal visit in your third trimester. If you decline, expect a conversation about the risks. Some practices may ask you to sign a refusal form documenting that you were informed of the recommendation and chose to decline. This is standard practice for vaccine refusals across medicine and serves as a record that the discussion happened. It is not a legal waiver, and signing it doesn’t change your rights or your access to care.
Declining Tdap will not affect your birth plan, your hospital admission, or your baby’s pediatric care. No hospital will refuse to deliver your baby because you skipped a vaccine. Your provider may revisit the topic at a later visit or offer it again postpartum, but the decision remains yours throughout.
If you have specific concerns driving your decision, whether about ingredients, side effects, or personal health conditions, raising them directly with your provider can help you get answers tailored to your situation rather than general recommendations. Some concerns, like thimerosal content, are based on outdated information about vaccine formulations that no longer apply.