| Abstract [eng] |
In recent decades, delayed childbearing has become increasingly common in developed countries. This results in a growing number of women seeking fertility treatment after the age 40. This trend is caused by educational, professional, and social economic factors, but these choices often run up against the biological limits of female fertility. As reproductive aging significantly affects both oocyte quantity and quality, understanding the effectiveness and limitations of fertility treatments in this age group is essential for clinical practice and patient counseling. The aim of this thesis was to evaluate the effectiveness and limitations of fertility treatments in women over 40, with particular emphasis on the biological factors influencing reproductive outcomes. The objectives included assessing the impact of ovarian aging, analyzing success rates of current treatments, identifying key clinical limiting factors, and evaluating the role of alternative approaches such as oocyte donation. This research included a thorough review of recent scientific studies on reproductive aging and fertility treatments. I examined peer-reviewed articles, systematic reviews, and meta-analyses to explore the biological mechanisms, treatment outcomes, and clinical effects associated with advanced maternal age. The results show that fertility decline after 40 is mainly driven by ovarian aging. This results in reduced ovarian reserve and, more importantly, deterioration in oocyte quality. Increased rates of aneuploidy, mitochondrial dysfunction, oxidative stress, and other molecular changes lead to lower implantation rates, higher miscarriage rates, as well as reduced live birth rates. While assisted reproductive technologies, particularly in vitro fertilization, provide opportunities for conception, their success rates decline strongly with age and remain limited when using autologous oocytes. Modifications to stimulation protocols and adjuvant hormonal therapies have minimal impact on live birth outcomes. However, oocyte donation significantly improves success rates by overcoming age-related decline in oocyte quality, although maternal age still influences implantation and pregnancy outcomes. This suggests that uterine aging also plays a role. Additionally, fertility treatment for women of advanced maternal age is associated with increased obstetric risks and complicated ethical aspects. In conclusion, fertility treatment after the age of 40 is still a clinically relevant but biologically challenging option. Ovarian aging, particularly the decline in oocyte quality, is the primary limiting factor that current medical interventions cannot fully overcome. While assisted reproductive technologies can improve the chances of pregnancy, especially through oocyte donation, they do not eliminate age-related reproductive limitations. Therefore, effective fertility care requires realistic counseling, individualized treatment strategies, and increased awareness of reproductive aging to support informed decision making. |
