Improving oocyte quality by transfer of autologous mitochondria from fully grown oocytes.

Older women are often the most challenging group of patients in fertility clinics due to a decline in both number and overall quality of oocytes. The quality of oocytes has been linked to mitochondrial dysfunction. In this mini-review, we discuss this hypothesis and suggest alternative treatment options using autologous mitochondria to potentially augment pregnancy potential in ART. Autologous transfer of mitochondria from the patient's own germline cells has attracted much attention as a possible new treatment to revitalize deficient oocytes. IVF births have been reported after transfer of oogonial precursor cell-derived mitochondria; however, the source and quality of the mitochondria are still unclear. In contrast, fully grown oocytes are loaded with mitochondria which have passed the genetic bottleneck and are likely to be of high quality. An increased supply of such oocytes could potentially be obtained by in vitro follicle activation of ovarian cortical biopsies or from surplus immature oocytes collected from women undergoing ART or fertility preservation of ovarian tissue. Taken together, autologous oocytes are not necessarily a limiting resource in ART as fully grown oocytes with high quality mitochondria can be obtained from natural or stimulated ovaries and potentially be used to improve both quality and quantity of oocytes available for fertility treatment.