Twenty years of development in fertility preservation of women and girls and the challenges that remain

The high probability of surviving cancer today is continuously improving, making long-term survivorship issues, including the preservation of fertility, exceedingly relevant when treating young patients with cancer. International guidelines have clearly stated that timely information on methods for fertility preservation should be provided to all patients of a young age as well as to parents or guardians of children when planning gonadotoxic treatments.1, 2 Despite these guidelines and recommendations, young patients still report fertility preservation as the most common unmet need within cancer care.3 Preservation methods are also indicated when treatments for benign diseases are threatening to fertility, or when genetic conditions are predisposing to premature fertility loss.2, 4 Although fertility preservation methods are available to both men and women, women seem to be disadvantaged when in similar clinical situations as men and report receiving less information and access to fertility preservation than men.5 Several reports of advances in fertility preservation have been previously published in AOGS.6-10 In this Special Issue of AOGS, worldwide leading researchers in the field of fertility preservation have contributed with state-of-the-art reviews that cover the most relevant aspects of fertility preservation among women and girls. They contribute with historical perspectives that take us back in time to the first translational experiments on ovarian tissue transplantation in the UK in the early 1990s, as well as reports on challenges in the development of appropriate methods for the cryopreservation of oocytes and how these were overcome. General aspects of fertility preservation are also discussed in this issue, including the use of biomarkers of ovarian reserve, cases of women with benign indications and women undergoing elective controlled ovarian stimulation aimed at oocyte cryopreservation for future use. The field of Reproductive Oncology is specifically highlighted, with several original articles reporting on large cohorts of women and girls and their long-term follow-up, particularly focused on investigating the safety aspects and long-term outcomes of fertility preservation. The importance of psychological assistance and support when counseling cancer patients is also reviewed, as well as oncologists’ and pediatrician oncologists’ perspectives on fertility preservation. Finally, a short vision into the future of fertility preservation is presented, with major contribution from leading research groups in translational fertility preservation research. Additionally, this Special Issue addresses an emerging field of medicine, namely cell therapy. Despite the preservation of oocytes, or embryos, women with a non-responsive endometrium currently remain infertile, with no treatment options for their depleted endometrial tissue. Fertility preservation has grown into a truly multidisciplinary clinical field over the last two decades. This exciting progress has been documented through the increasing number of scientific publications during this period (Figure 1). Of note, a substantial number of these publications are dedicated to the specific case of fertility preservation for children. Since the methods that can be offered to children are still in need of further development, the proportion of preclinical research within these publications is constantly on the rise. As editors of this Special Issue in Fertility Preservation, we are most grateful to our contributors who have shared with us their knowledge and expertise. One crucial barrier in fertility preservation is the low confidence in knowledge on fertility preservation among healthcare professionals who work outside the area of reproductive medicine. We hope that this issue will be useful to the various professional healthcare groups involved in the care of women and girls suffering from malignant, chronic benign or genetic conditions.