Cumulative live birth rate in freeze-all cycles is comparable to that of a conventional embryo transfer policy at the cleavage stage but superior at the blastocyst stage.

OBJECTIVE: To determine whether the freeze-all policy ensures a higher efficacy in terms of cumulative live birth rate (CLBR) in comparison with a conventional fresh/frozen embryo transfer (ET) approach in patients with normal ovarian response. DESIGN: Retrospective, matched, multicenter cohort study. SETTING: Private IVF centers. PATIENT(S): This study analyzed 564 completed IVF cycles in which an average of 12-18 oocytes were retrieved. In 435 cycles the conventional strategy was applied, with initial ET followed by frozen embryo replacements, whereas in 129 cycles the freeze-all policy was performed, with elective cryopreservation and deferred use of all viable embryos. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The primary endpoint was CLBR. The secondary endpoint was cumulative clinical pregnancy rate. RESULT(S): Overall, statistically comparable CLBRs were achieved in the fresh/frozen and freeze-all groups (45.5% vs. 53.5%). Stratification of data for age and number of retrieved oocytes confirmed the absence of differences between the two groups. In a subanalysis in which the day of ET and cryopreservation were taken into account, a similar outcome was achieved in cleavage-stage groups (45.6% vs. 46.4%), whereas when ET was performed at the blastocyst stage the CLBR was significantly higher in the freeze-all group (45.3% vs. 66.7%). CONCLUSION(S): Our CLBR analysis indicates that clinical performance of the freeze-all policy is equivalent to that of the conventional strategy when ET is carried out at the cleavage stage. However, it seems to be superior if associated with cryopreservation and transfer at the blastocyst stage.

Successful Oocyte Cryopreservation in Reproductive-Aged Cancer Survivors.

OBJECTIVE: To demonstrate that oocyte cryopreservation is a feasible reproductive option for patients with cancer of childbearing age who require gonadotoxic therapies. METHODS: This study is a university-based retrospective review of reproductive-aged cancer patient treatment cycles that included ovarian stimulation, transvaginal oocyte retrieval, oocyte cryopreservation, and, in some cases, subsequent oocyte thaw, in vitro fertilization, and embryo transfer. Outcome measures included ovarian stimulation response, number of oocytes retrieved, cryopreserved, and thawed, and pregnancy data. RESULTS: From 2005 to 2014, 176 reproductive-aged patients with cancer (median age 31 years, interquartile range 24-36) completed 182 oocyte cryopreservation cycles. Median time between consult request and oocyte retrieval was 12 days (interquartile range 10-14). Median peak stimulation estradiol was 1,446 pg/mL (interquartile range 730-2,687); 15 (interquartile range 9-23) oocytes were retrieved and 10 (interquartile range 5-18) metaphase II oocytes were cryopreserved per cycle. Ten patients (11 cycles) have returned to attempt pregnancy with their cryopreserved oocytes. Among thawed oocytes, the cryopreservation survival rate was 86% (confidence interval [CI] 78-94%). Nine of 11 thaw cycles resulted in embryos suitable for transfer. The embryo implantation rate was 27% (CI 8-46%) and the live birth rate was 44% (CI 12-77%) per embryo transfer. Chance for live birth with embryos created from cryopreserved oocytes was similar between the patients with cancer in this study and noncancer patients who underwent the same treatment at our center (44% [CI 12-77%] compared with 33% [CI 22-44%] per embryo transfer). CONCLUSION: Oocyte cryopreservation is now a feasible fertility preservation option for reproductive-aged patients with cancer who require gonadotoxic therapies.

Meiotic spindle recovery is faster in vitrification of human oocytes compared to slow freezing.

OBJECTIVE: To investigate spindle behavior during and after slow freezing at room temperature (RT) and vitrification at different temperatures. DESIGN: Randomized, comparative study. SETTING: University hospital. PATIENT(S): Patients undergoing IVF treatment volunteered for the study and donated part of their supernumerary oocytes. INTERVENTION(S): Metaphase II oocytes were divided into group A: slow freezing RT /thawing RT; group B: vitrification RT/warming RT; group C: vitrification RT/warming 37 degrees C; and group D: vitrification 37 degrees C/warming 37 degrees C. Spindle presence was evaluated at each step of the four procedures and in culture. MAIN OUTCOME MEASURE(S): Cumulative spindle recovery rate comparing warming phase of the three vitrification groups and culture phase among the four groups. RESULT(S): During warming, the three vitrification groups showed a significantly fast spindle recovery rate compared to the thawing of the slow freezing group. A progressively significant fast cumulative recovery rate was observed in the three vitrification groups by increasing the number of phases at physiological temperature (hazard rate = 2.68; 95% confidence interval 1.71-4.02). CONCLUSION(S): The present study demonstrates that spindle recovery is faster in vitrification than in slow freezing. These data support a possible protective effect of vitrification/warming at 37 degrees C on the meiotic spindle structure and, therefore, on the subsequent clinical outcome of the procedure, although comparative clinical studies are needed.

Human oocyte cryopreservation in infertility and oncology.

PURPOSE OF REVIEW: To evaluate the present state of research and clinical application of human oocyte cryopreservation in infertility and oncology. RECENT FINDINGS: Recent literature documents have an increasing interest in cryopreserving human eggs. A number of studies report on different freezing protocols and various types of clinical application. Increasing attention is paid to vitrification as an alternative to slow cooling for oocyte cryopreservation. Several studies cover the modification of meiotic spindle during cryopreservation in order to assess the less damaging cryopreservation system. The first births with cryopreserved oocytes in cancer patients are reported. SUMMARY: Egg freezing may circumvent the ethical and legal concerns regarding embryo cryopreservation, increase assisted reproduction flexibility and be a concrete option to save fertility in women with cancer. Recently, egg survival and pregnancy rates improved, with the birth of more than 500 children. The birth rate per thawed oocyte is around 5-6%. As regards safety, data on birth defects seems to be reassuring so far but must be monitored by an international registry. Comparative studies between slow freezing and vitrification in the same patient population are needed to elucidate pros and cons of each technique.