Defining quality assurance and quality control measures in connection with ovarian tissue cryopreservation and transplantation: a call to action.

Freezing of ovarian tissue for fertility preservation has been gaining ground as a valid method in recent years. More than 100 children have been born from this procedure worldwide. As a result, many fertility clinics are now implementing this method. However, the practical procedures that need to be mastered to successfully implement the freezing of ovarian tissue are different in many aspects from those normally used in fertility clinics and are not well defined. Furthermore, success is difficult to measure since patients usually do not return for transplantation until several years after freezing, which puts extra emphasis of good quality control and quality assurance measures to secure a transplantation of tissue with surviving follicles that can sustain fertility. The present paper describes the procedures and a checklist implemented in Denmark in order to secure a successful clinical service. To standardize and implement uniform measures for this new method, we suggest a consensus conference to collectively agree on the best technical and clinical practice.