A 30-year-old woman, gravida 2, para 1, at 28 weeks' gestation comes to the office for a routine prenatal visit. She received Tdap vaccine during her first pregnancy 3 years ago. She received her annual influenza vaccine 2 weeks ago. She asks about vaccinations needed during this pregnancy to protect her newborn. Her immunization record shows she is up to date on all routine adult vaccines. Which of the following is the most appropriate recommendation regarding pertussis vaccination?
Practise this USMLE Step 3 Medical Prep question free, then download the PDF, watch the video walkthrough, or unlock timed mock exams for the full web bank.
ADefer Tdap vaccination until after delivery since she received it within 3 years
BAdminister Tdap vaccine at the 6-week postpartum visit along with other catch-up vaccines
CAdminister Tdap vaccine during this pregnancy, preferably at 27-36 weeks' gestation
DNo additional Tdap needed since she received it during her previous pregnancy
EAdminister Tdap vaccine immediately postpartum before hospital discharge to protect newborn
✓ Correct answer: C. Administer Tdap vaccine during this pregnancy, preferably at 27-36 weeks' gestationTdap is recommended during each pregnancy (preferably 27-36 weeks) to maximize transplacental antibody transfer and provide neonatal pertussis protection, regardless of previous vaccination history. Maternal antibodies wane, so repeat vaccination optimizes infant protection during vulnerable early months before infant series completion. Distractor1 is outdated guidance (one-time adult Tdap no longer sufficient for pregnancy). Distractor2 misses optimal timing for antibody transfer. Distractor3 represents inappropriate delay. Distractor4 confuses postpartum timing with prenatal recommendation.
Keep practising. Use the free USMLE Step 3 Medical Prep PDF, watch the YouTube walkthrough, or unlock all 10 web questions with timed mock exams.
Free practice here. Timed mocks when you are ready.
Study the USMLE Step 3 Medical Prep free question explanations, download the PDF, then unlock timed mock exams on the web when you want exam-day practice.
Theory