To analyze the impact of COVID-19 on the number of births in Yucatan, Mexico during 2020 and 2021. A total of 470 651 live births occurred in Yucatan from January 1st, 2008, to December 31st, 2021, and were included in the analysis. The monthly number of births observed during January 2008-February 2020 was used to describe pre-pandemic trends. Time-series analysis was applied to examine whether the number of births observed from December 2020 (9 months after the beginning of the pandemic) to December 2021 differed from the expected values. Trends in the number of births according to maternal age, parity and education were examined to identify changes differentiated by sociodemographic characteristics. The number of births in 2021 decreased by 18% (5869 births) compared with 2019, which represents a reduction from 12.89 to 12.48 per thousand inhabitants. The observed number of births from December 2020 to July 2021 was significantly lower than the figure expected. April (expected=2863 vs. observed=1722), May (expected=2948 vs. observed=1990), and June (expected=2997 vs. observed=1978) 2021 showed the largest differences between expected and observed values. Then, from August to December 2021, the observed number of births fell within the expected range. Birth decline was slightly more pronounced among mothers between 20 and 29 years of age and in those without previous offspring. We provide evidence of birth decline in Yucatan during the COVID-19 pandemic. Birth rate reduction in Yucatan doubled the world average and young women without children were the most affected.