There are large variations in the number of oocytes within each woman, and biologically, the total quantity is at its maximum before the woman is born. Scientific knowledge is limited about factors controlling the oocyte pool and how to measure it. Within fertility clinics, there is no uniform agreement on the diagnostic criteria for each common measure of ovarian reserve in women, and thus, studies often conflict. While declining oocyte quantity/quality is a normal physiologic occurrence as women age, some women experience diminished ovarian reserve (DOR) much earlier than usual and become prematurely infertile. Key clinical features of DOR are the presence of regular menstrual periods and abnormal-but-not-postmenopausal ovarian reserve test results. A common clinical challenge is counseling patients with conflicting ovarian reserve test results. The clinical diagnosis of DOR and the interpretation of ovarian reserve testing are complicated by changing lab testing options and processing for anti-mullerian hormone since 2010. Further, complicating the diagnostic and research scenario is the existence of other distinct yet related clinical terms, specifically premature ovarian failure, primary ovarian insufficiency, poor ovarian response, and functional ovarian reserve. The similarities and differences between the definitions of DOR with each of these four terms are reviewed. We recommend greater medical community involvement in terminology decisions, and the addition of DOR-specific medical subject-heading search terms.

Ovarian tissue auto-transplantation in post-pubertal women is capable of restoring fertility with over 80 live births currently reported with a corresponding pregnancy rate of 23 to 37%. The recently reported successes of live births from transplants, both in orthotopic and heterotopic locations, as well as the emerging methods of in vitro maturation (IVM), in vitro culture of primordial follicles, and possibility of in vitro activation (IVA) suggest new fertility options for many women and girls. Vitrification, as an ovarian tissue cryopreservation technique, has also demonstrated successful live births and may be a more cost-effective method to freezing with less tissue injury. Further, transplantation via the artificial ovary with an extracellular tissue matrix (ECTM) scaffolding as well as the effects of sphingosine-1-phosphate (SIP) and fibrin modified with heparin-binding peptide (HBP), heparin, and a vascular endothelial growth factor (VEGF) have demonstrated important advancements in fertility preservation. As a fertility preservation method, ovarian tissue cryopreservation and auto-transplantation are currently considered experimental, but future research may pave the way for these modalities to become a standard of care for women facing the prospect of sterility from ovarian damage.

Fertility preservation in the young cancer survivor is recognized as a key survivorship issue by the American Society of Clinical Oncology and the American Society of Reproductive Medicine. Thus, health-care providers should inform women about the effects of cancer therapy on fertility and should discuss the different fertility preservation options available. It is also recommended to refer women expeditiously to a fertility specialist in order to improve counseling. Women’s age, diagnosis, presence of male partner, time available, and preferences regarding use of donor sperm influence the selection of the appropriate fertility preservation option. Embryo and oocyte cryopreservation are the standard techniques used while ovarian tissue cryopreservation is new, yet promising. Despite the importance of fertility preservation for cancer survivors’ quality of life, there are still communication and financial barriers faced by women who wish to pursue fertility preservation.