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Cryopreservation and transplantation of ovarian tissue exclusively to postpone menopause: technically possible but endocrinologically doubtful
Transplantation of cryopreserved ovarian tissue has been shown to induce pregnancies and puberty successfully. Therefore, using cryopreserved ovarian tissue to postpone menopause (tissue hormone therapy [THT]) seems to be an interesting option to avoid conventional menopause hormone therapy (MHT). Pregnancy induction and replacing MHT by THT, however, are completely different topics as different requirements need to be met. First, MHT requires long-lasting and continuous hormone production. It still needs to be proven if the transplanted tissue is active for at least 5 years with a continuous follicle growth to avoid phases with low oestrogen production, which would otherwise cause menopausal symptoms and could reduce the postulated benefit for women's health.Open versus closed systems for vitrification of human oocytes and embryos
Vitrification is now the dominant approach for cryopreservation of human oocytes and embryos; however, serious disagreement persists, particularly about biosafety issues. Techniques are categorized as either ‘open’ or ‘closed’ according to occurrence of direct contact between the medium and liquid nitrogen during cryopreservation. Advocates of closed systems emphasize the potential danger of disease transmission mediated through liquid nitrogen, and praise the safety of their approach; those who use the open systems refer to the lack of evidence of disease transmission and regard their systems as more consistent and efficient.Fertility in cancer patients after cryopreservation of one ovary
This questionnaire study describes the fertility and ovarian function in 143 adult female cancer survivors with only one ovary due to cryopreservation of the other. The women were asked about their ovarian function (as defined by the presence of a spontaneous menstrual cycle), pregnancies and their outcome. The mean follow-up time was 58 months after cryopreservation (range 24–129 months). The risk of premature ovarian failure was high in the group of patients with leukaemia (13/15; 87%) but low in the breast cancer group (5/54; 9%).The Alpha consensus meeting on cryopreservation key performance indicators and benchmarks: proceedings of an expert meeting
This proceedings report presents the outcomes from an international workshop designed to establish consensus on: definitions for key performance indicators (KPIs) for oocyte and embryo cryopreservation, using either slow freezing or vitrification; minimum performance level values for each KPI, representing basic competency; and aspirational benchmark values for each KPI, representing best practice goals. This report includes general presentations about current practice and factors for consideration in the development of KPIs.Long-term duration of function of ovarian tissue transplants: case reports
These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian tissue transplanted, and two women underwent fresh ovarian tissue transplants. The function of ovarian cortical strips has continued for more than 7 years in these three women, with the birth of eight healthy babies following a single graft per patient.Synchronization between embryo development and endometrium is a contributing factor for rescue ICSI outcome
Recent evidence shows that the outcome of rescue intracytoplasmic sperm injection (ICSI) is unsatisfactory on account of a poor clinical pregnancy rate. These outcomes may be due to either the in-vitro ageing of cultured oocytes before ICSI or the asynchrony between the embryo developmental stage and the endometrial secretory pattern. To address the latter issue, this study performed a retrospective analysis of 534 fresh cycles after rescue ICSI and 64 frozen–thawed cycles in subsequent treatment.Simple vitrification for small numbers of human spermatozoa
Conventional freezing procedures and containers are not appropriate for spermatozoa from the testis because of their low number and poor in-situ motility, and various types of container have been utilized to freeze small numbers of spermatozoa. This study tried to develop a vitrification method for small numbers of spermatozoa using the Cell Sleeper, which is a closed type of cell-cryopreservation container. The container with spermatozoa were cooled in liquid nitrogen vapour and then stored in a cryotank.Retrospective analysis of outcomes following transfer of previously cryopreserved oocytes, pronuclear zygotes and supernumerary blastocysts
Oocyte cryopreservation still bears the experimental label. Remarkable innovation in this field has led to immense improvement in clinical outcomes and has even resulted in outcomes comparable to those achieved following fresh embryo transfers. Such success has prompted this centre to investigate outcomes of cryopreservation options (oocyte versus pronuclear zygote versus supernumerary day-5 blastocyst after fresh embryo transfer). This study retrospectively analysed 200 cryopreservation cycles which were divided into three groups according to cryopreservation option, which were all cultured to blastocyst-stage post thaw/warming from January 2005 to December 2008, and compared them with 400 fresh embryo transfer cycles from the same time period.
