I will examine the impact of extending female fertility, possible through oocyte donation, and more specifically the impact on the meaning of an age limit for maternity in Switzerland, where this technology is prohibited. By focusing on the experiences of women who turn to oocyte donation because of age-related infertility, I will show how this technology opens the door to disputes and discussions on the biological limits of fertility. In the first section, I will examine how biological and statistical standards on the decline in fertility are used for diagnosis. In the second section, I will show how the meaning of age limits is transformed as assisted reproductive technology (ART) develops. In the third section, I will highlight some of the techniques used to reset the biological clock.