Oocyte Banking Research Articles

Single blastocyst transfer in patients utilizing vitrified donor oocytes from a donor bank

Compared to fresh donor oocytes, cryopreserved donor oocytes are more convenient for a recipient since no synchronization is needed between recipient and donor cycles. We assessed the outcome and feasibility of single blastocyst transfer in patients utilizing vitrified donor oocytes from an oocyte bank.

Oocyte bank set up by comparing different vitrification devices

Our goal is to determine the effects of elevated serum progesterone (P4) at the day of human chorionic gonadotropin (hCG) trigger on the clinical outcomes following in vitro fertilization-embryo transfer (IVF-ET). Retrospective case control study. We reviewed 655 IVF-ET cycles in which ovulation were performed using antagonist protocol. The thresholds of serum P4 were set at 1.4, 2.0 and 2.5 ng/ml. Patients with a level of P4 less than the threshold were subjected to control group, and those with a level higher than threshold were subjected to elevated p4 group. The clinical outcomes between two groups were compared. The total number of retrieved oocytes was significantly higher in elevated P4 group (18.8±10.8, 22.2±10.8 and 25.2±10.8) than in control(12.2±7.7, 14.0±9.1 and 14.8±9.5) at all three P4 thresholds(p=0.000). The number of blastocysts was also significantly higher in elevated P4 group (4.5±4.5, 5.6+5.5 and 6.2±5.9) than in control (2.7±3.1, 3.2±3.5 and 3.2±3.6) at all thresholds (p=0.000). However, when the thresholds were set to 2.0 and 2.5ng/ml, the clinical pregnancy rate was lower in the elevated P4 group (41.6% and 37.3%) than in control (46.3% and 46.0%), but the difference were not statistically significant (p=0.197, p=0.144 respectively). The fertilization rate was not different.Tabled 1HSVHomemadeCryotoptotal% Survived81.484.671.482.6Fertilization Rate88.678.26081.1Transferred2222Blastocyst Rate19.434.910031.2% Positive HCG10062.510077Implantation Rate62.554.557.9 Open table in a new tab Our data demonstrated that higher serum progesterone reflects good follicular recruitment and better chance of obtaining blastocysts for transfer or cryopreservation.Our data suggested that elevated P4 levels may adversely affect clinical pregnancy rate in IVF-ET patients. However, the difference was not sufficient to warrant a clinical intervention such as deferring fresh embryo transfer and freezing all embryos for future transfer.To elucidate the mechanisms underlying the increased probability of pregnancy in FET than ET, additionalfactors should be analyzed.

Oocyte vitrification is a viable reproductive option for women seeking fertility preservation

Vitrification has proven to be a highly efficient method for donor oocyte cryopreservation. Fertility preservation is another indication for oocyte cryopreservation allowing female cancer patients and women seeking oocyte banking alternative reproductive choices. This study investigated the clinical efficiency of oocyte vitrification and warming techniques for fertility preservation patients.

Oocyte bank set up by comparing different vitrification devices

to determine which vitrification device for oocyte cryoperservation yields the highest oocyte survival rate, blastulation rate, implantantion rate, and pregnancy rate to optimize our pregnancy rates using cryopreserved ova.

Emergency IVF versus ovarian tissue cryopreservation: decision making in fertility preservation for female cancer patients

Hundreds of thousands of women in their reproductive years are diagnosed with cancer each year. As the number of female patients who survive cancer increases, the demand for effective and individualized fertility preservation options grows. Currently there are limited clinical options for fertility preservation, and the paucity of publications describing clinical experience and outcomes data has limited accessibility to these options. Decision making for patients diagnosed with cancer requires up-to-date knowledge of the efficacy and safety of available techniques. This article describes a step-by-step approach to evaluation of the cancer patient and presents an accumulation of clinical experience with challenges unique to patients with breast cancer and leukemia. Current data on reproductive outcomes of fertility preservation techniques are examined, demonstrating increasing evidence that these techniques are becoming effective enough to offer routinely to patients facing gonadotoxic cancer therapies, including those still considered to be "experimental."

Motherhood after Malignancy: Embracing Oocyte Banking (OB) as a Means to Preserve Fertility between Diagnosis and Cure

and outcomes Age (y) (mean) E2 Day of ov trigger (pg/ml) Total no. retrieved eggs Total no. MII eggs had such a prediction based on age alone. Compared with age-based controls, PredictIVF-D showed 75% improved predictive power, ability to discriminate cases with differential prognoses (10% improvement in area-underthe-curve in a receiver operating characteristic analysis), while extending the dynamic range from four discrete, age-based probabilities to a continuous spectrum ranging from 7 to 60%. Table 1 shows the population distribution and error for five different prognostics groups. CONCLUSION(S): Using a validated, multi-center IVF prediction model, we showed that a large portion of patients with prior IVF would receive a significantly different predicted probability compared with agebased counseling, at improved predictive power and discrimination, and reliable accuracy.

Breeding or Assisted Reproduction? Relevance of the Horse Model Applied to the Conservation of Endangered Equids

Many wild equids are at present endangered in the wild. Concurrently, increased mechanization has pushed back the numbers of some old native horse breeds to levels that are no longer compatible with survival of the breed. Strong concerns arose in the last decade to preserve animal biodiversity, including that of rare horse breeds. Genome Resource Banking refers to the cryostorage of genetic material and is an approach for ex situ conservation, which should be applied in combination with in situ conservation programmes. In this review, we propose that, owing to the great reproductive similarity among the different members of the genus Equus, the domestic horse can be used to optimize cryopreservation and embryo production protocols for future application in wild equids. We will give this hypothesis a scientific underpinning by listing successful applications of epididymal sperm freezing, embryo freezing, intracytoplasmic sperm injection, oocyte vitrification and somatic cell nuclear transfer in domestic horses. Some ART fertilization methods may be performed with semen of very low quality or with oocytes obtained after the death of the mare.

A persistent misperception: assisted reproductive technology can reverse the “aged biological clock”

Delaying motherhood should be a free choice made in full knowledge of all the consequences, but modern women have alarming misconceptions about their own reproductive systems and the effectiveness of assisted reproductive technologies. Doctors and health professionals must begin to discuss fertility preservation with their patients and make sure that young women truly understand all their options. Preventing age-related infertility is the responsibility not only of doctors and medical practitioners but also of society at large. Social, economic, and personal pressures are causing women to decide to conceive later in life, yet those who choose to delay motherhood are stigmatized as being selfish and unconcerned about starting a family. This stigma must be banished, and age-related infertility should be faced as a medical problem.

Oocyte cryopreservation in a patient with sickle cell disease prior to hematopoietic stem cell transplantation: first report

To report the first occurrence of successful ovarian stimulation, oocyte retrieval and oocyte cryopreservation for fertility preservation in an adolescent with severe sickle cell disease scheduled to undergo a hematopoietic stem cell transplant Case report. A 19 year old female with severe sickle cell disease presented for fertility preservation counseling prior to hematopoietic stem cell transplantation. She ultimately underwent ovarian stimulation using a minimal stimulation GnRH antagonist protocol resulting in the successful banking of oocytes prior to transplant. The unique hazards associated with ovarian stimulation in patients with sickle cell disease, such as thrombosis and vaso-occlusive events, are discussed and the methods undertaken to minimize these risks are described. Controlled ovarian hyperstimulation and oocyte banking for fertility preservation is feasible in young women with sickle cell disease requiring hematopoietic stem cell transplant and deserves further investigation. Given the elevated risk of thrombosis and predisposition to painful vaso-occlusive events, controlled ovarian hyperstimulation in patients with sickle cell disease is not straightforward and requires a multi-disciplinary team approach to adequately address and minimize the risks in this unique patient population.

Fertility Preservation in Women After the Cancer

Thanks to the recent advances in cancer care, more and more young women can survive but suffer from infertility as a result of cancer treatment that had to be submitted. There are a variety of methods to preserve fertility, as chemoprotection, ovariopexy, and some assisted reproductive technologies, although some of these are promising but still highly experimental techniques. Cryopreservation of embryos for example is already established, while the oocyte banking is still considered an experimental practice. Many experiments have been conducted around the world on the cryopreservation of ovarian tissue and maturation of ovarian follicles, in an attempt to demonstrate its potential use in fertility preservation. Although in recent years there has been major improvements in the preservation of ovarian tissue, there are still many unresolved technical issues related to these procedures. In this chapter we examine the recent evidence of the pathophysiology of chemotherapy / radiotherapy-induced gonadal toxicity, and recent data regarding the indications and results of the techniques used to preserve fertility in women with cancer.

Maturation outcomes are improved following Cryoleaf vitrification of immature human oocytes when compared to choline-based slow-freezing

The cryopreservation of immature oocytes permits oocyte banking for patients at risk of losing their fertility. However, the optimum protocol for such fertility preservation remains uncertain. The present study investigated the survival, maturation, cytoskeletal and chromosome organization of sibling immature oocytes leftover from controlled ovarian stimulation cycles, that were either slow-frozen (with choline-substitution) or vitrified. A comparison group included oocytes that were never cryopreserved. Among the three groups, comparable rates were observed for both survival (67-70%) and polar body extrusion (59-79%). Significantly more oocytes underwent spontaneous activation after IVM following slow-freezing compared with either vitrification or no cryopreservation. Likewise, the incidence of spindle abnormalities was greatest in the slow-frozen group, with no differences in spindle morphometrics or chromosome organization. While the overall incidence of mature oocytes with normal bipolar spindles from warmed immature oocytes was low, the yield using Cryoleaf vitrification was slightly superior to choline-based slow-freezing.

Prospective randomized comparison of non-cryopreserved and vitrified sibling oocyte function and resulting embryo development

Vitrification of donor oocytes and establishment of a “Donor Oocyte Bank” has practical, quarantine/disease-testing, and economic advantages. Study aims were to compare oocyte function and embryo development in a pool of sibling oocytes used both as non-cryopreserved oocytes and following vitrification and warming. Prospective randomized clinical study Couples undergoing ICSI elected to participate in this IRB-approved study. Sibling MII oocytes were randomly used in a fresh cycle (NoCryo) or vitrified (Vit). Oocytes were vitrified with dimethyl sulfoxide/ethylene glycol/sucrose with a Cryotip (Irvine Sci). After warming oocytes were observed for survival, incubated for 4h, and inseminated by ICSI. No/normal/abnormal fertilization and oocyte lysis were assessed. Zygotes were placed in G1 media (VitroLife) for growth and assessed for cleavage and embryo development. Statistical analyses were performed by paired Student's t-test. Sixty-nine patients (age: 34 ± 1; ave ± sem) with an average of 18 MII oocytes participated in this study. Post-warming survival was 83 ± 3%. Following ICSI, no fertilization (14 ± 2% vs 11 ± 2%) or abnormal fertilization (1 ± 0.2% vs 2 ± 0.6%) were not significantly different between NoCryo and Vit, respectively. Normal fertilization was significantly higher in the NoCryo group (82 ± 2%) compared to Vit (76 ± 2%; P<0.05), due to increased incidence of post-ICSI oocyte lysis (4 ± 1% vs 9 ± 2%, respectively; P<0.01). Cleavage rate was similar between groups. Day 3 embryos had significantly more cells (6.4 ± 0.1 vs 6.1 ± 0.1; P<0.05) in NoCryo compared to Vit, respectively. Degree of embryo fragmentation was similar between groups. In an infertile population, vitrification of oocytes resulted in acceptable fertilization and embryo development, yet not equivalent to non-cryopreserved oocytes. Knowledge of these oocyte functional and embryo developmental differences will assist in future planning for efficient donor oocyte cryo-banking.

The efficiency of oocyte vitrification for donor oocyte cycles and oocyte banking in ART

OBJECTIVE: Vitrification is proving to be a highly efficient method for oocyte cryopreservation. Fertilization, embryo development and clinical outcome from vitrified oocytes have been shown to be comparable to results achieved with fresh oocytes. This study analyzed the efficiency of vitrification techniques for both donor oocyte cycles and oocyte banking in a human ART program. DESIGN: Retrospective study. MATERIALS AND METHODS: The study population consisted of Group A = 14 oocyte donors (mean maternal age = 28.9 years) and Group B = 25 patients presenting for ooycte banking (mean maternal age = 34.8 years). Reasons for oocyte banking included no sperm, uterine anomaly or ovarian hyperstimulation risk. Following controlled ovarian hyperstimulation, a total of 533 mature oocytes (Group A=219 and Group B=314) were vitrified using the Cryotop method. An embryo transfer was scheduled after endometrial preparation. RESULTS: Following warming, a total of 451 oocytes survived the vitrification process; Group A=195 (89.04%) and Group B=256 (81.53%) (P<0.05). Comparable fertilization (Group A=79.38% and Group B=78.52%) and cleavage rates (Group A=89.61% and Group B=89.06%) were observed between the groups. In addition, implantation (Group A=44.83% and Group B=40.98%) and clinical pregnancy (Group A=64.29% and Group B=58.33%) rates were also not significantly different. In relation to the day of transfer, Group A consisted of n=8 D3 and n=6 D5 embryo transfers, while Group B included a higher proportion of D3 embryo transfers (n=15; 62.5%) (ns). Only one patient in Group B did not receive a transfer due to no oocytes surviving. CONCLUSION: Vitrification of oocytes using the Crytop method results in excellent clinical outcome including survival post warming, fertilization, cleavage and pregnancy rates. This procedure represents a viable option for women participating in donor oocyte programs, healthy women requesting oocyte banking and fertility preservation for indicated cancer patients prior to chemotherapy treatment.

Efficiency of using vitrified donor oocytes from cryopreserved oocyte bank

OBJECTIVE: Splitting a cohort of fresh donor oocytes among several recipients is an effective practice in reducing the cost of donor oocyte treatment. Compared to fresh donor oocytes, cryopreserved donor oocytes are more convenient for a recipient since no synchronization is needed between recipient and donor. We evaluated the efficiency of vitrified donor oocytes from oocyte bank.

Impact of embryo quality in fresh versus vitrified oocytes in an egg donation program

OBJECTIVE: The objective of this study was to compare the embryo quality and gestational results in an egg donation program using fresh and vitrified/thawed oocytes, previously stored in an oocyte bank. DESIGN: Retrospective, comparative, observational and transversal study. MATERIALS AND METHODS: A total of 43 patients who underwent 49 embryo transfers from January 1st to December 31st 2009 were analyzed. Group I involved 27 patients whose treatment was carried out using fresh oocytes, while group II involved 16 patients using vitrified/thawed oocytes by Cryotop method. Endometrial preparation consisted of increasing doses of estradiol valerate and micronized progesterone. Recipients with ovarian function were down-regulated with GnRH agonist in the lutheal phase of the previous cycle. Donor stimulation was performed with recombinant FSH (starting dose from 150 to 300 UI/day, according to antral follicle account) and GnRH antagonist. RESULTS: Mean age of the patients was 41 ± 4,0 (group I) and 42,06 ± 2,9 (group II). Survival rate of vitrified oocytes was 86,6%. Fertilization rate after ICSI was 75,7% and 67,0%, respectively. Embryo development was similar in both groups, as well as top quality embryo (29,2% and 31,9% respectively). Pregnancy and implantation rates were 47,1% and 24,02% in group I; 46,7% and 28,8% in group II. There were no statistically significant differences in none of the outcomes analyzed. CONCLUSION: Vitrification preserves oocyte potential to fertilize and further development. Our results show that oocyte vitrification procedure is equal to fresh egg donation with regard to embryo development and gestational results. This technique provides an excellent tool to establish an oocyte bank which in turn optimizes egg donation programs.

Fertility Preservation with Immature and in Vitro Matured Oocytes

The development of an effective oocyte-freezing program will have a major impact on clinical practice in reproductive medicine and will serve as a powerful tool to preserve fertility for teenage girls and young women without male partners or for those individuals who are affected by malignancies. It will also be beneficial to infertile couples who have moral or religious objections about embryo cryopreservation. In addition, a successful oocyte cryopreservation program will eliminate the need for donor and recipient menstrual cycle synchronization and will enable the establishment of oocyte banks, which would facilitate the logistics of coordinating egg donors with recipients. Recent advances in vitrification technology have markedly improved the oocyte survival rate after thawing, and the pregnancy rate is comparable with that achieved with fresh oocytes. However, most studies were performed using in vivo matured oocytes for vitrification. The objective of this article was to review whether immature and in vitro matured human oocytes can be vitrified successfully. The results indicated that although healthy live births can be achieved from the combination of in vitro maturation (IVM) oocytes and vitrification, vitrification of in vitro matured oocytes is less effective than vitrification of in vivo matured oocytes. The results suggest that oocytes should be vitrified at the mature metaphase II stage following IVM rather than at the immature germinal vesicle (GV) stage because the potential of oocyte maturation is reduced by the vitrification of immature oocytes at the GV stage.

Cryopreservation of Immature Bovine Oocytes to Reconstruct Artificial Gametes by Germinal Vesicle Transplantation

Joining immature gamete cryopreservation and germinal vesicle transplantation (GVT) technique could greatly improve assisted reproductive technologies in animal breeding and human medicine. The present work was aimed to assess the most suitable cryopreservation protocol between slow freezing and vitrification for immature denuded bovine oocytes, able to preserve both nuclear and cytoplasmic competence after thawing. In addition, the outcome of germinal vesicle transfer procedure and gamete reconstruction was tested on the most effective cryopreservation system. Oocytes, isolated from slaughterhouse ovaries, were stored after cumulus cells removal either by slow freezing or by vitrification in open pulled straws. After thawing, oocytes were matured for 24 h in co-culture with an equal number of just isolated intact cumulus enclosed oocytes, and fixed in order to evaluate the stage of meiotic progression and cytoskeleton organization. Our results showed that after warming, vitrified oocytes reached metaphase II (MII) in a percentage significantly higher than oocytes cryopreserved by slow freezing (76.2% and 36.5% respectively, p < 0.05). Moreover, vitrification process preserved the organization of cytoskeleton elements in a higher proportion of oocytes than slow freezing procedure. Therefore vitrification has been identified as the elective method for denuded immature oocytes banking and it has been applied in the second part of the study. Our results showed that 38.3% of oocytes reconstructed from vitrified gametes reached the MII of meiotic division, with efficiency not different from oocytes reconstructed with fresh gametes. We conclude that vitrification represents a suitable method of GV stage denuded oocyte banking since both nuclear and cytoplasmic components derived from cryopreserved immature oocytes can be utilized for GVT.

Vitrification of immature mouse oocyte using stepwise equilibration before or after in vitro maturation

Immature mouse oocytes before or after in vitro maturation (IVM) were vitrified by the use of either conventional one-step or three-step equilibration. Although vitrification after IVM using the stepwise method does not affect the cleavage rate, the early embryonic development was profoundly impaired in both protocols.

Nuclear transfer and oocyte cryopreservation

Somatic cells can be reprogrammed to a totipotent state through nuclear transfer or cloning, because it has been demonstrated that the oocyte has the ability to reprogramme an adult nucleus into an embryonic state that can initiate the development of a new organism. Therapeutic cloning, whereby nuclear transfer is used to derive patient-specific embryonic stem cells, embraces an entire new opportunity for regenerative medicine. However, a key obstacle for human therapeutic cloning is that the source of fresh human oocytes is extremely limited. In the present review, we propose prospective sources of human oocytes by using oocyte cryopreservation, such as an oocyte bank and immature oocytes. We also address some potential issues associated with nuclear transfer when using cryopreserved oocytes. In the future, if the efficacy and efficiency of cryopreserved oocytes are comparable to those of fresh oocytes in human therapeutic cloning, the use of cryopreserved oocytes would be invaluable and generate a great impact to regenerative medicine.

Successful vitrified oocyte donation program with blastocyst transfer. One year of follow up study in Mexico city

OBJECTIVE: Up to now few clinical data are available about large series of vitrified egg donation and there are a lot of doubts if the vitrification method affect spindle morphology, aberrant chromatin alignment or premature cortical granule releases that can be affect embryo development and pregnancy, implantation and/or miscarriage rates. Blastocyst development stage allow self selection from those embryos capable of blastulation and self exclusion from those which have a lack of embryonic development or arrestment. Our objective is to show that oocyte vitrification and the sequential culture is a good combination to have a success in a oocyte donation program with an oocyte bank. DESIGN: Retrospective and descriptive study. MATERIALS AND METHODS: We included sixteen patient's cycles receptors, done from May 2006 to December 2007. 30 oocytes donors were frozen by vitrificaction, and Sixten cycles were thawed. Donators were stimulated with conventional down regulation protocols. For this study a requirement was that all of the donors had a proven in vivo or in vitro fertility. Oocytes were retrieved by ultrasound-guided transvaginal aspiration and vitrified with the Cryotop method. 154 oocytes were thawed, and a mean of 7 oocytes MII were assigned for each recipient. The survived oocytes were inseminated by intracytoplasmic sperm injection. The zygotes were further cultured in vitro for up to 120 hours until time of embryo transfer, day 5 or 6 according to embryo development. RESULTS: The oocyte survival rate observed was 96.7%. Fertilization rate was 85,71%, day 2 cleavage (93,9%), day 3 cleavage (77,41%), and blastocyst development (41,6%). A total of 29 embryos were transferred on the 5th or 6th day. The media of embyos transferred were two. The refreezing rate by vitrification was (27,5 %) blastocyst, that are still frozen. Pregnancy, implantation and miscarriage rates, were 66,67%, 31,06%, and 22,22%, respectively. Our pregnancy, implantation and miscarriage rates in fresh egg donation are (70,55 %), (36,11 %) and (13,04 %) respectively. CONCLUSIONS: Excellent clinical outcome indicates the possibility to use of the egg donation program technology and establishes oocyte banking. The costs and time of this procedure are other benefits for patients waiting for oocytes. Sequential culture is a strategy to consider to selected embryos with a high potential implantation to transfer. More studies should be done to confirm these results.