IntroductionThe COVID-19 pandemic led to a decline in fertility rates worldwide. Although many regions have experienced a temporary drop in fertility rates with the spread of the infection, subsequent recovery has varied across countries. This study aimed to evaluate the impact of COVID-19 infection rates and regional sociodemographic factors on the recovery of fertility rates in Japan following the state of emergency.MethodsThis study examined prefectural fertility data from before the COVID-19 pandemic to forecast fertility rates up to 2022 using a seasonal autoregressive integrated moving average model. A regression analysis was conducted on fertility rates during the first state of emergency and the subsequent recovery rate with respect to the number of new COVID-19 cases and sociodemographic factors specific to each prefecture.ResultsDuring the first state of emergency, the monthly fertility rate decreased by an average of −13.8% (SD: 6.26, min: −28.78, max: 0.15) compared with the previous year. Over the following 22 months, the average fertility recovery rate was +2.31% (SD: 3.57; min: −8.55, max: 19.54). Multivariate analysis of the impact of the pandemic on fertility changes during the first emergency indicated a negative correlation between new COVID-19 cases per capita and the proportion of nuclear households. No significant correlation was found between fertility recovery rate and new COVID-19 cases or emergency duration. When classifying fertility rate fluctuation patterns before and after the emergency into four clusters, variations were noted in the proportion of the elderly population, marriage divorce rate and the number of internet searches related to pregnancy intentions across the clusters.ConclusionsNo association was found between pregnancy intentions related to the spread of infection, such as the number of new cases and the fertility recovery rate following the first state of emergency. Differences in the patterns of decline and recovery during the pandemic were observed based on population composition and internet searches for infection and pregnancy across different prefectures.