In many parts of the world, except for sub-Saharan Africa, birth rates are declining sharply. This trend is becoming a growing political concern, as highlighted by the Belgian newspaper Le Soir, which notes the wide-ranging effects: fewer working-age people compared to retirees, lower school enrollments, and increased healthcare demands due to an aging population. For a population to sustain itself, the average number of children per woman—known as the fertility rate—must be at least 2.1. However, all European countries fall below this threshold. In 2024, the fertility rate ranged from 1.75 in Montenegro to less than 1.2 in Italy, Spain, and Malta. In France, it was 1.61. The situation is also critical in Japan and South Korea, with South Korea recording the lowest fertility rate of 0.72 in 2023. To better understand this phenomenon, researchers have introduced a new indicator: the "period infertility rate." This measures the proportion of women who may remain childless throughout their lives, reflecting a trend where more women are choosing or being forced to have no children at all. As noted in a study published in the Regards économiques journal by researchers from the University of Louvain-la-Neuve, infertility is no longer a rare occurrence but a central factor in today’s low fertility rates. The "period infertility rate" projects the likelihood of women of childbearing age remaining childless if current conditions remain unchanged. In Belgium, this rate is around 25%, though it is higher in countries like Finland, Japan, Spain, and South Korea, where up to 45% of women might remain childless under current conditions. Several factors contribute to this shift. In many societies, having children often depends on being in a stable relationship, though such unions are less common and less stable than in previous generations. Economic and material conditions also play a role—lack of income, unstable jobs, or unaffordable housing can delay or prevent parenthood. Additionally, the impact of motherhood on career advancement can deter women from starting a family. Researchers also point to global uncertainties, such as economic instability, climate change, or political unrest, which can make delaying parenthood seem more rational. These factors often combine, making it increasingly difficult for some women to achieve their childbearing goals. Finally, changing social norms are making it more acceptable to choose not to have children. As traditional expectations around family life evolve, more individuals are opting for child-free lifestyles without facing the same social stigma as previous generations. This shift reflects broader changes in how people view personal fulfillment, career, and lifestyle choices, further contributing to the decline in birth rates worldwide.