Infertility affects approximately 1 in 6 people in their lifetime worldwide according to the World Health Organization (WHO). Infertility -;as defined by the American Society for Reproductive Medicine (ASRM)-; is a disease, condition, or status characterized by "the inability to achieve a successful pregnancy based on a patient's medical, sexual, and reproductive history, age, physical findings, diagnostic testing, or any combination of those factors" or requiring medical intervention such as the use of mature donor gametes "to achieve a successful pregnancy either as an individual or with a partner". Although assisted reproductive technologies (ARTs), such as in vitro fertilization (IVF), have had a tremendous impact in treating certain forms of infertility -;not all forms of infertility (as defined by the ASRM) can be targeted with existing strategies.
Recently, one powerful technology has emerged -;known as human in vitro gametogenesis (IVG)-; using pluripotent stem cells (PSCs) such as induced pluripotent stem cells (iPSCs) from patients, to generate human germ cells with the capacity to potentially give rise to mature gametes in culture, offering a gateway to treating all form of infertility -;independent of gender. Nevertheless, human IVG research still remains in its infancy, with the current goal being to reconstitute the complete process of human gametogenesis. To date, one major challenge has been to recapitulate in the founder population of germ cells, or the human.