Is Tdap vaccine safe during pregnancy?

What does the evidence say about Tdap vaccine during pregnancy?

1. Getting the Tdap shot during pregnancy hasn't been linked to a higher chance of birth defects, preterm delivery, or miscarriage. 1
2. The recommended window is 27 to 36 weeks, and getting your shot earlier in that window matters, since most babies who die from whooping cough are younger than 3 months, before their own vaccine series even starts. 2
3. Timing matters more than you might expect: one study found babies had protective antibody levels about 80% of the time when their mom was vaccinated in the second trimester, compared with 55% in the third trimester. 3
4. The antibodies you make after the shot cross over to your baby through your placenta's natural transport system, and researchers have used Tdap specifically to study how gestational timing changes how much protection actually gets through. 4
5. In a study that followed more than 400 babies whose moms got Tdap during pregnancy, researchers found no unusual safety issues, and none of those babies came down with whooping cough even though the disease was circulating in their community. 5

Is Tdap vaccine safe in each trimester?

• First trimester. Tdap usually isn't given in the first trimester. The shot is timed for later in pregnancy on purpose, though your provider can still give it early if you have an injury that needs tetanus protection right away.
• Second trimester. Tdap is typically held until the third trimester rather than given in the second, since the recommended window doesn't open until 27 weeks. Your provider will let you know exactly which visit to plan it around.
• Third trimester. This is when you'll get your Tdap shot, ideally between 27 and 36 weeks and as early in that window as your schedule allows. That timing gives your body the most time to build antibodies and pass them along to your baby before delivery.