Impact of COVID-19 Vaccination on Female Fertility.

Despite evidence in previous literature regarding vaccine safety, more data were needed as concerns about COVID-19 vaccines were raised, particularly regarding their effects on female fertility, exacerbated by the widespread dissemination of information without scientific evidence. This study aims to answer the question: does COVID-19 vaccination have any impact on female fertility at a population level. In this ecological study, vaccination rates against COVID-19 and birth rates in 100 different countries were correlated. In addition, the correlation between these two rates of interest and the Gini index were also analyzed. Data were retrieved from the World Population Prospects document produced by the Population Division of the United Nations Department of Economic and Social Affairs, from the World Health Organization (WHO) website, and from the World Bank website. Statistical analyses were conducted using the ANOVA test, and Pearson's correlation using the JASP software. For all analyses, results were considered significant if P < 0.05. In evaluating the trend of the birth rate in the countries included in the study, a persistent reduction of approximately 1.66% per year was observed between 2010 and 2022. From 2019 to 2022, the decline was close to 5%, resulting in an annual average reduction of 1.68%, which is similar to previous years. Among the selected countries, until December 2021, the average number of vaccine doses administered was 137 per 100 inhabitants. There was no observed correlation between the number of vaccine doses administered in different countries and the variation in the birth rate per thousand inhabitants between 2019 and 2022 (Pearson's r = 0.075; P = 0.455). A correlation was found between the Gini index and the birth rate, considering the base year of 2022, with a Pearson's r value of 0.376 (P < 0.01). This correlation remained consistent for all other years. A negative correlation was found between vaccine doses and the Gini index, with a Pearson's r value of -0.219 (P = 0.040). The findings of this article, as well as previous scientific evidence, do not identify any correlation between COVID-19 vaccines and female fertility issues. The associations analyzed in this study indicate the safety of vaccines for reproductive health and contribute to reducing vaccine hesitancy among the population of childbearing age.