How long can oocytes be frozen with vitrification and still produce competent embryos? A series of six cases

Cryopreservation of oocytes is a relatively new and valuable option for fertility preservation. The duration since vitrification of embryos may be associated with a lower likelihood of success. We do not know how long the oocytes can be vitrified to produce viable pregnancies. We present six cases in which oocytes were vitrified for >10 years for social freezing or cancer. Two patients returned after 11 years, one after 12 years, and one returned after 13 years to use their vitrified oocytes for pregnancy. Four singleton live births were recorded. The two remaining patients returned after 13 years and again after 14 and 15 years, respectively, and failed to conceive. This has raised the burden of the literature on oocyte vitrification for more than 10 years. Oocyte vitrification is an effective option for long-term fertility preservation in women.