Women vaccinated before conception had consistently lower SC rates than unvaccinated women. SCs for vaccinated women were disproportionately low relative to their share of the total population: Example: In June 2021, 39% of women were vaccinated, but they accounted for only 7% of SCs. Throughout 2022, SC rates in unvaccinated women were about 1.5× higher than in vaccinated women. In other words, successful conceptions for vaccinated women were ~33% lower compared to unvaccinated women in 2022. The total fertility rate in the Czech Republic declined during the study period (from 1.83 in 2021 to 1.45 in 2023 - 21% decrease).