Ovarian tissue and oocyte cryopreservation

Tissue Engineering in Gynecology

Female gynecological organ dysfunction can cause infertility and psychological distress, decreasing the quality of life of affected women. Incidence is constantly increasing due to growing rates of cancer and increase of childbearing age in the developed world. Current treatments are often unable to restore organ function, and occasionally are the cause of female infertility. Alternative treatment options are currently being developed in order to face the inadequacy of current practices. In this review, pathologies and current treatments of gynecological organs (ovaries, uterus, and vagina) are described. State-of-the-art of tissue engineering alternatives to common practices are evaluated with a focus on in vivo models. Tissue engineering is an ever-expanding field, integrating various domains of modern science to create sophisticated tissue substitutes in the hope of repairing or replacing dysfunctional organs using autologous cells. Its application to gynecology has the potential of restoring female fertility and sexual wellbeing.

Donor oocyte recipients do not benefit from preimplantation genetic testing for aneuploidy to improve pregnancy outcomes

STUDY QUESTION

Do donor oocyte recipients benefit from preimplantation genetic testing for aneuploidy (PGT-A)?

SUMMARY ANSWER

PGT-A did not improve the likelihood of live birth for recipients of vitrified donor oocytes, but it did avoid embryo transfer in cycles with no euploid embryos.

WHAT IS KNOWN ALREADY

Relative to slow freeze, oocyte vitrification has led to increased live birth from cryopreserved oocytes and has led to widespread use of this technology in donor egg IVF programs. However, oocyte cryopreservation has the potential to disrupt the meiotic spindle leading to abnormal segregation of chromosome during meiosis II and ultimately increased aneuploidy in resultant embryos. Therefore, PGT-A might have benefits in vitrified donor egg cycles. In contrast, embryos derived from young donor oocytes are expected to be predominantly euploid, and trophectoderm biopsy may have a negative effect relative to transfer without biopsy.

STUDY DESIGN, SIZE, DURATION

This is a paired cohort study analyzing donor oocyte-recipient cycles with or without PGT-A performed from 2012 to 2018 at 47 US IVF centers.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Vitrified donor oocyte cycles were analyzed for live birth as the main outcome measure. Outcomes from donors whose oocytes were used by at least two separate recipient couples, one couple using PGT-A (study group) and one using embryos without PGT-A (control group), were compared. Generalized estimating equation models controlled for confounders and nested for individual donors contributing to both PGT-A and non-PGT-A cohorts, enabling a single donor to serve as her own control.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 1291 initiated recipient cycles from 223 donors were analyzed, including 262 cycles with and 1029 without PGT-A. The median aneuploidy rate per recipient was 25%. Forty-three percent of PGT-A cycles had only euploid embryos, whereas only 12.7% of cycles had no euploid embryos. On average 1.09 embryos were transferred in the PGT-A group compared to 1.38 in the group without PGT-A (P < 0.01). Live birth occurred in 53.8% of cycles with PGT-A versus 55.8% without PGT-A (P = 0.44). Similar findings persisted in cumulative live birth from per recipient cycle.

LIMITATIONS, REASONS FOR CAUTION

Pooled clinical data from 47 IVF clinics introduced PGT-A heterogeneity as genetic testing were performed using different embryology laboratories, PGT-A companies and testing platforms.

WIDER IMPLICATIONS OF THE FINDINGS

PGT-A testing in donor oocyte-recipient cycles does not improve the chance for live birth nor decrease the risk for miscarriage in the first transfer cycle but does increase cost and time for the patient. Further studies are required to test if our findings can be applied to the young infertility patient population using autologous oocytes.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

[Preservation of fertility in transgender people]

Young transgender people increasingly seek medical help to assist them in their gender transition with hormone therapy and/or sex reassignment surgery. However, these treatments limit fertility and may make them irreversibly infertile. Studies show that the transgender population wishes to have biological children and, to help them achieve this desire for parenthood, there are techniques for preserving fertility, such as cryopreservation of gametes, embryos and ovarian or testicular tissue. However, alongside these techniques, there are ethical issues and several challenges before, during and after these procedures, that may lead young transgender people to reject these methods of preserving fertility. In conclusion, health professionals should be informed about all these dynamics between gender transition therapies and their impact on fertility, in order to better guide these individuals in their decision.

Infertility - Prevention and Management

Infertility and subfertility, menstrual irregularities, and decreased parity may occur in women with autoimmune diseases due to multiple factors, including underlying inflammatory disease, gonadotoxic medications, and psychosocial issues related to living with chronic disease. Awareness of these factors, as well as validation and support of patients confronting reproductive challenges, is important for providing comprehensive care to these women. An understanding of the expanding options for fertility preservation strategies during gonadotoxic medications is essential. Referral to a reproductive endocrinology clinic is indicated in this patient population.

Understanding Fertility in Young Female Cancer Patients

Young women diagnosed with cancer today have a greater chance of long-term survival than ever before. Successful survivorship for this group of patients includes maintaining a high quality of life after a cancer diagnosis and treatment; however, lifesaving treatments such as chemotherapy, radiation, and surgery can impact survivors by impairing reproductive and endocrine health. Studies demonstrate that future fertility is a concern for many women diagnosed with cancer, but physician knowledge and attitudinal barriers can still prevent females from receiving care. Today, fertility preservation is an option for girls and women facing a cancer diagnosis, and emerging research is providing clinicians with an increasing number of reproductive and hormonal management tools. Physicians can play an important role in fertility by working closely with oncologists, providing patients with information about fertility preservation options prior to the start of cancer treatment, monitoring reproductive capacity after treatment, and working with cancer survivors to explore potential avenues to parenthood.

Fertility preservation in female cancer patients: An overview

Fertility preservation is becoming increasingly important to improve the quality of life in cancer survivors. Despite guidelines suggesting that discussion of fertility preservation should be done prior to starting cancer therapies, there is a lack of implementation in this area. A number of techniques are available for fertility preservation, and they can be used individually or together in the same patient to maximize efficiency. Oocyte and embryo cryopreservation are now established techniques but have their limitations. Ovarian tissue cryopreservation though considered experimental at present, has a wider clinical application and the advantage of keeping the fertility window open for a longer time. Both chemotherapy and radiotherapy have a major impact on reproductive potential and fertility preservation procedures should be carried out prior to these treatments. The need for fertility preservation has to be weighed against morbidity and mortality associated with cancer. There is thus a need for a multidisciplinary collaboration between oncologists and reproductive specialists to improve awareness and availability.

Oncofertility in Canada: cryopreservation and alternative options for future parenthood

BACKGROUND

Cancer can be a devastating diagnosis. In particular, malignancy and its indicated treatments have profoundly negative effects on the fertility of young cancer patients. Oncofertility has emerged as a new interdisciplinary field to address the issue of gonadotoxicity associated with cancer therapies and to facilitate fertility preservation. In Canada, these fertility issues are often inadequately addressed despite the availability of resources. The goal of this four-part series is to facilitate systemic improvements in fertility preservation for adolescent and young adult Canadians with a new diagnosis of cancer.

METHODS

This article reviews fertility preservation options that use cryopreservation techniques. It also outlines some of the alternative options for future parenthood.

RESULTS

Cryopreservation of a woman's gametes and gonadal tissue may involve embryo, oocyte, and ovarian tissue cryopreservation with or without ovarian stimulation. Similarly, male gametes and gonadal tissue may be cryopreserved. Techniques and success rates continue to improve. Third-party assistance through gamete donation, gestational carriers, and adoption are also alternative options for parenthood.

CONCLUSIONS

Cryopreservation techniques are especially feasible options for fertility preservation in the newly diagnosed cancer patient.

Maintaining the reproductive potential of cancer patients during cancer treatment

Cancer therapies are known to alter the reproductive potential in cancer patients. Due to improved survival rates in cancer patients of reproductive age, considerations of the long-term effects of cancer therapy have become more significant. Oncofertility is a new discipline in medicine that deals with maintaining the reproductive potential of cancer patients while they are receiving gonadotoxic cancer treatment. The purpose of this review is to explore how cancer treatment impairs reproductive functioning and present the current options for preservation of fertility in women. All patients with reproductive potential should be made aware of the possible treatment-related infertility and be offered appropriate fertility preservation options before cancer treatment is instituted. The hope is that, in the future, mechanism(s) can be developed to preserve immature germ cells in the ovary, so that they can be used for fertilization in vivo or in vitro.

Is vitrification of oocytes useful for fertility preservation for age-related fertility decline and in cancer patients?

The aim of this review is to provide current knowledge on oocyte cryopreservation, with special emphasis on vitrification as a means to preserve fertility in different indications. Major advancements achieved in the past few years in the cryolaboratory have facilitated major changes in our practice. Areas such as fertility preservation for social or oncologic reasons, the possibility to create oocyte banks for egg donation programs, the opportunity to avoid ovarian hyperstimulation syndrome, or to accumulate oocytes in low-yield patients, or even to offer treatment segmentation by stimulating the ovaries, vitrifying, and then transferring in a natural cycle are some of the options that are now available with the development of cryopreservation. We present general experience from our group and others on fertility preservation for age-related fertility decline as well as in oncologic patients, confirming that oocyte vitrification is a standardized, simple, reproducible, and efficient option.

Fertility-preserving treatment options in patients with malignant hematological diseases

The number of patients of reproductive age diagnosed with various malignant hematological diseases increases every year. These patients undergo chemotherapy, radiotherapy, and various other treatments that may have gonadotoxic effects. The life expectancy of these patients is increasing rapidly due to the variety of treatment options. As such, an increasing number of patients-as well as their parents and spouses-express their concerns about the patient's fertility post treatment. In the present review it was aimed to provide an overview of current fertility-preserving treatment options and the future of fertility preservation.

Fertility Preservation Methods in Breast Cancer

Thanks to the recent advances in reproductive medicine, more and more young women with breast cancer may be offered the possibility of preserving their fertility. Fertility can be endangered by chemotherapy, by treatment duration and by patient's age at diagnosis. The currently available means to preserve a young woman's fertility are pharmacological protection with gonadotrophin-releasing hormone analogues during chemotherapy, and ovarian tissue or oocyte/embryo freezing before treatment. New future venues, including in vitro maturation, will improve the feasibility and efficacy of the fertility preservation methods in breast cancer patients.

Redefining reproductive surgery

With the availability of and improvements in in vitro fertilization (IVF), the role of reproductive surgery has been questioned. Yet, the scope of reproductive surgery today is much larger than in the past. Hysteroscopic correction of intrauterine disease is an important endoscopic procedure in women with infertility. Evidence suggests that correction of intrauterine disease is often followed by spontaneous pregnancy and improved IVF outcome. Hysteroscopic examination should be considered after 1 failed IVF. Today, it is clear that removal of the hydrosalpinx leads to a higher IVF-related live birth rate. The procedure should be performed thoroughly without compromising the ovarian blood supply. The IVF pregnancy rate is not affected by the presence of ovarian endometriomas, and small endometriomas need not be removed; however, large and symptomatic endometriomas that interfere with oocyte retrieval should be excised. When excision of the cyst wall is difficult, fenestration and ablation should be considered. This might lead to an increased recurrence rate, but is associated with less interference of the ovarian reserve. Although the role of reproductive surgery as primary treatment for tuboperitoneal infertility is limited, it has an important role in enhancing the outcome of IVF treatment and in preservation of fertility. Surgical preservation of fertility consists of ovarian suspension, ovarian excision for cryopreservation, and ovarian tissue transplantation.

Topic update: effects of colorectal cancer treatments on female fertility and potential methods for fertility preservation

PURPOSE

Preservation of fertility in young females with a diagnosis of colorectal cancer is gaining increasing importance as survival rates of cancer increase. This review examines the effects of pelvic surgery, chemotherapy, and radiotherapy on fecundity. It also discusses the options available to patients including ovarian transposition, gonadotropin-releasing hormone analogs, embryo and ovarian cryopreservation, and ovarian tissue transplantation.

METHODS

A search of MEDLINE, EMBASE, and the Cochrane library was performed using keywords and exploded Mesh search headings and the subsequent articles were reviewed. Relevant studies were included.

RESULTS

There are no studies that examine the effect of surgery for colorectal cancer on female fertility, in particular, surgery below the peritoneal reflection for rectal cancer. However, patients with familial adenomatous polyposis have a similar fecundity before and after proctocolectomy with ileal pouch-anal anastomosis. These patients did significantly better than patients with ulcerative colitis who underwent the same procedure. There is conflicting evidence regarding the effects of open vs laparoscopic surgery on fertility. Oxaliplatin, an adjuvant therapy, has moderate gonadotoxic effects. Fluorouracil is considered to have almost no effect on human reproductive function. Gonadotropin-releasing hormone agonists are currently used to preserve female fecundity during chemotherapy. A recent update of patients treated for Hodgkin lymphoma showed that significantly fewer women treated with a gonadotropin-releasing hormone agonist during chemotherapy exhibited premature ovarian failure. Ovarian transposition reduces the radiation dose to approximately 5% to 10% of the dose to the ovaries in their normal position. Other options are available to women with cancer who wish to preserve their germ line, including embryo and oocyte cryopreservation and ovarian tissue cryopreservation.

CONCLUSION

Significant advances are now allowing females to preserve their fertility after cancer treatment. It is essential that patients receive adequate fertility counseling before any intervention to give them an opportunity to consider fertility alternatives.

Psychological aspects of fertility preservation in men and women affected by cancer and other life-threatening diseases

BACKGROUND

With advances in treatment, the number of young cancer survivors who may benefit from fertility preservation is growing. The aim of this study was to review the literature investigating psychological aspects of fertility issues and fertility preservation in patients undergoing fertility-compromising therapy for cancer or other life-threatening diseases, previous to or during their reproductive lifespan.

METHODS

Articles were identified in PubMed, Embase and PsycLIT as well as manually retrieved from literature citations for the time period from 1999 to 2008. Inclusion criteria were (i) qualitative or quantitative design, (ii) focus on patients previous to or during their reproductive lifespan and (iii) dealing with aspects such as (1) impact of fertility issues in cancer patients or (2) health professionals' and/or patients' attitudes towards fertility preservation or (3) counselling.

RESULTS

Twenty-four studies were identified. According to the studies on aspect (1), fertility is an important issue for cancer patients. Health professionals as well as patients and parents consider fertility preservation as an important option for young cancer patients; all parties involved, however, were noted to have knowledge and information deficits. Patients recalling counselling about the impact of cancer treatment on fertility ranged from 34% to 72%. Counselling is far from being offered globally to all patients at risk, and providing information seems to be selective.

CONCLUSIONS

The existing literature demonstrates the need for and the limits of current counselling. Future research should target the means to facilitate the decision-making process for patients and health professionals.

Feasibility of fertility preservation in young females with Turner syndrome

Women with Turner syndrome (TS) are at risk of premature ovarian failure. The objective of this retrospective study was to identify patients with TS who could be potential candidates for fertility preservation and to determine their present reproductive and fertility status. Criteria for fertility preservation included: (i) spontaneous menarche; (ii) confirmation by ultrasound examination of the presence of at least one normal ovary; and (iii) serum FSH concentrations below 40 IU/l. Using the Montreal Children's Hospital Cytogenetic Database from 1990 to 2006, 28 patients with complete or partial absence of one X chromosome were identified: 13 (46%) were 45,X; nine (32%) had mosaic karyotypes; and six (21%) had karyotypes containing isochromosome or ring X chromosome. Six patients (21%) had spontaneous pubertal development and four (14%) were identified as potential candidates for fertility preservation. One underwent an ovarian stimulation protocol of gonadotrophin-releasing hormone agonist down-regulation followed by recombinant FSH and human menopausal gonadotrophin stimulation. Two metaphase-II-stage oocytes were aspirated and vitrified using the McGill Cryoleaf vitrification system. Another patient conceived spontaneously at the age of 24 years. In conclusion, fertility preservation may not be feasible for most patients with TS. However, after careful consideration of increased pregnancy-associated risks, fertility preservation may be offered to young females with mosaic TS.

Cryopreservation/transplantation of ovarian tissue and in vitro maturation of follicles and oocytes: challenges for fertility preservation

Cryopreservation of ovarian tissue and in vitro follicle maturation are two emerging techniques for fertility preservation, especially in cancer patients. These treatment regimes are opening up more options and allow for more suitable choices to preserve fertility according to the patient's specific circumstances. If these technologies are to become widely accepted, they need to be safe, easy to perform and must obtain favorable results. The generation of healthy eggs with the normal genetic complement and the ability to develop into viable and healthy embryos requires tight regulation of oocyte development and maturation. Novel freezing techniques such as vitrification, along with whole ovary cryopreservation and three-dimensional follicle cultures, have shown favorable outcomes. The scope of this article is to take a comprehensively look at the challenges still faced in order for these novel technologies to be routinely employed with the aim of successful fertility preservation.

Obstetric and perinatal outcome in 200 infants conceived from vitrified oocytes

Cryopreservation of oocytes by vitrification is a promising new technique for assisted human reproduction. Any new technical development must be accompanied with data concerning obstetric and perinatal outcome. This study analysed the obstetric and perinatal outcomes in 165 pregnancies and 200 infants conceived following oocyte vitrification cycles in three assisted reproduction centres. The results indicate that the mean birth weight and the incidence of congenital anomalies are comparable to that of spontaneous conceptions in fertile women or infertile women undergoing in-vitro fertilization treatment. These preliminary findings may provide reassuring evidence that pregnancies and infants conceived following oocyte vitrification are not associated with increased risk of adverse obstetric and perinatal outcomes.

Ovarian cryopreservation for fertility preservation: indications and outcomes

Female fertility preservation provides significantly different challenges to that for the male, with the only established method being cryopreservation of embryos thus necessitating the involvement of a male. Other, experimental, options include oocyte or ovarian tissue cryopreservation. The latter has been regarded as a potential method for more than a decade, but has resulted in the birth of only five babies. It is not possible to be certain how many women have had ovarian tissue cryopreserved. Oocyte cryopreservation also remains experimental, but approximately 100-fold more babies have been born through this technique over the last two decades. Ovarian tissue cryopreservation has the potential advantages of preservation of a large number of oocytes within primordial follicles, it does not require hormonal stimulation when time is short and indeed may be appropriate for the pre-pubertal. Disadvantages include the need for an invasive procedure, and the uncertain risk of ovarian contamination in haematological and other malignancies. We here review this approach in the context of our own experience of 36 women, highlighting issues of patient selection especially in the young, and uncertainties over the effects of cancer treatments on subsequent fertility. Of these 36 women, 11 have died but 5 have had spontaneous pregnancies. So far, none have requested reimplantation of their stored ovarian tissue. Ovarian cryopreservation appears to be a potentially valuable method for fertility preservation, but the indications and approaches best used remain unclear.

Obstetric outcomes following vitrification of in vitro and in vivo matured oocytes

OBJECTIVE

To evaluate obstetric outcomes with oocyte vitrification after ovarian stimulation (OS) and in vitro maturation (IVM) of immature oocytes.

DESIGN

A prospective trial from October 2003 to April 2007.

SETTING

University-based medical center.

PATIENT(S)

OS group: 38 patients undergoing intrauterine insemination who overresponded to OS. IVM group: 20 patients who had previous unsuccessful intrauterine insemination.

INTERVENTION(S)

Mature oocyte retrieval following OS. Immature oocyte retrieval and IVM. Oocyte vitrification, thawing, insemination, and transfer of the resulting embryos.

MAIN OUTCOME MEASURE(S)

Live-birth rates and obstetric outcomes.

RESULT(S)

The OS group was superior to the IVM group in terms of oocyte survival (81.4 +/- 22.6% vs. 67.5 +/- 26.1%), fertilization rate (75.6 +/- 22.5% vs. 64.2 +/- 19.9%), and cumulative embryo score (38.4 +/- 22.3 vs. 20.0 +/- 13.8). However, the differences in the implantation rate per embryo (19.1 +/- 25.8% vs. 9.6 +/- 24.1%), clinical pregnancy rate per cycle started (44.7%, vs. 20.0%), and live-birth rate per cycle started (39.5% vs. 20.0%) were not statistically significant. Twenty healthy babies were born in the OS group and four in the IVM group.

CONCLUSION(S)

Pregnancies achieved with vitrification of oocytes after OS and IVM treatments do not appear to be associated with adverse pregnancy outcomes. Vitrification of IVM oocytes represents a novel option for fertility preservation.

Fertility preservation for women with malignancies: current developments of cryopreservation

The preservation of fertility in female cancer survivors has become an important health issue. The different cryopreservation options available for fertility preservation are embryo, oocyte, and ovarian tissue cryopreservation. Oocyte cryopreservation is available for women without partners, but there is a limited experience with this technique and the pregnancy rate is still low. In spite of recent reports of successful birth after autotransplantation of cryopreserved-thawed human ovarian cortical tissues, clinical experience is also limited and this technique remains still experimental. Whole ovary cryopreservation itself poses several challenges. Further researches for establishing optimal cryopreservation and thawing protocols and increasing post-thawing survival, pregnancy, and delivery rates are necessary. In this article, the strategies for fertility preservation in cancer survivors are discussed. The different options and their results are discussed, as well as their indications, efficacy and ethical issues.

Live birth after vitrification of in vitro matured human oocytes

OBJECTIVE

To report the first healthy live birth from immature oocytes retrieved in a natural menstrual cycle, followed by in vitro maturation (IVM) and cryopreservation of the oocytes by vitrification.

DESIGN

Case report.

SETTING

University-based tertiary medical center.

PATIENT(S)

A 27-year-old woman with tubal disease and polycystic ovaries.

INTERVENTION(S)

Immature oocytes were retrieved by transvaginal ultrasound guided follicle aspiration on day 13 of her natural menstrual cycle, matured in vitro and vitrified. The oocytes were thawed in a subsequent menstrual cycle, inseminated by intracytoplasmic sperm injection, and the resulting embryos transferred.

MAIN OUTCOME MEASURE(S)

Oocyte maturation and survival rates, pregnancy, and live birth.

RESULT(S)

One metaphase II and 18 germinal vesicle stage oocytes were collected; 16 out of 18 germinal vesicle oocytes matured, and a total of 17 oocytes were vitrified. After thawing, four IVM oocytes survived; three embryos were transferred. The woman went on to deliver a single healthy live baby at term.

CONCLUSION(S)

We provide proof-of-principle evidence that the novel fertility preservation strategy of immature oocyte retrieval, IVM, and vitrification of oocytes can lead to successful pregnancy and healthy live birth.

Human oocyte vitrification: the permeability of metaphase II oocytes to water and ethylene glycol and the appliance toward vitrification

OBJECTIVE

To determine the permeability of human metaphase II oocytes to ethylene glycol and water in the presence of ethylene glycol, and to use this information to develop a method to vitrify human oocytes.

DESIGN

An incomplete randomized block design.

SETTING

A university-affiliated assisted reproductive center.

PATIENT(S)

Women undergoing assisted reproduction in the Center for Reproductive Medicine at Shandong University.

INTERVENTION(S)

Oocytes were exposed to 1.0 molar ethylene glycol in a single step and photographed during subsequent volume excursions.

MAIN OUTCOME MEASURE(S)

A two-parameter model was employed to estimate the permeability to water and ethylene glycol.

RESULT(S)

Water permeability ranged from 0.15 to 1.17 microm/(min.atm), and ethylene glycol permeability ranged from 1.5 to 30 microm/min between 7 degrees C at 36 degrees C. The activation energies for water and ethylene glycol permeability were 14.42 Kcal/mol and 21.20 Kcal/mol, respectively.

CONCLUSION(S)

Despite the lower permeability of human metaphase II oocytes to ethylene glycol compared with previously published values for propylene glycol and dimethylsulfoxide, methods to add and remove human oocytes with a vitrifiable concentration of ethylene glycol can be designed that prevent excessive osmotic stress and minimize exposure to high concentrations of this compound.

Researching human oocyte cryopreservation: ethical issues

OBJECTIVE

To evaluate some ethical concerns related to the selection of participants for oocyte cryopreservation research.

DESIGN

Review of ethical issues related to human oocyte cryopreservation research.

SETTING

Academic medical center.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

A discussion of some ethical concerns surrounding selection of participants for oocyte cryopreservation research.

RESULT(S)

Human oocyte cryopreservation has the potential to expand reproductive options for infertile couples. Care needs to be taken, however, to carefully select participants in ways that maximizes benefits to them and to society and minimizes risks. Infertility programs can do so by trying to recruit women who stand to benefit the most from participating in oocyte cryopreservation protocols.

CONCLUSION(S)

Biomedical research is necessary to improve current medical therapies. Oocyte cryopreservation can increase the flexibility of assisted reproductive programs and offer hope to a significant number of infertile couples. Nonetheless, scientific research cannot be attentive only to the creation of new knowledge and new technologies; it also is inextricably tied to ethical considerations about the well-being of participants.

Live birth after the transfer of human embryos developed from cryopreserved oocytes harvested before cancer treatment

OBJECTIVE

To document the first successful fertility preservation with freezing mature oocytes for a cancer patient.

DESIGN

Case report.

SETTING

Private IVF center.

PATIENT(S)

A woman with Hodgkin's disease and her gestational carrier.

INTERVENTION(S)

Metaphase II oocytes cryopreserved before cancer treatments were thawed and fertilized for transfer to a gestational carrier.

MAIN OUTCOME MEASURE(S)

Post-thaw survival and pregnancy.

RESULT(S)

Ten of the 12 metaphase II oocytes survived the thawing process. Nine oocytes were fertilized after microinjection with her husband's sperm. All fertilized oocytes developed into good quality embryos and were transferred to a gestational carrier in three cycles. A biochemical pregnancy was achieved after the second transfer. A singleton pregnancy was achieved after the last transfer of three embryos, resulting in the birth of a healthy male.

CONCLUSION(S)

Our findings suggest that oocyte cryopreservation should be considered as a preferred strategy for the cancer patient who has time to cryopreserve oocytes before cancer treatment.

Membrane Transport Properties of Equine and Macaque Ovarian Tissues Frozen in Mixtures of Dimethylsulfoxide and Ethylene Glycol

The rate at which equine and macaque ovarian tissue sections are first cooled from +25°Cto+4°C has a significant effect on the measured water transport when the tissues are subsequently frozen in 0.85M solutions of glycerol, dimethylsulfoxide (DMSO), or ethylene glycol (EG). To determine whether the response of ovarian tissues is altered if they are suspended in mixtures of cryoprotective agents (CPAs), rather than in solutions of a single CPA, we have now measured the subzero water transport from ovarian tissues that were suspended in mixtures of DMSO and EG. Sections of freshly collected equine and macaque ovaries were suspended either in a mixture of 0.9M EG plus 0.7M DMSO (equivalent to a mixture of ∼5%v∕v of EG and DMSO) or in a 1.6M solution of only DMSO or only EG. The tissue sections were cooled from +25°Cto+4°C and then frozen to subzero temperatures at 5°C∕min. As the tissues were being frozen, a shape-independent differential scanning calorimeter technique was used to measure water loss from the tissues and, consequently, the best fit membrane permeability parameters (Lpg and ELp) of ovarian tissues during freezing. In the mixture of DMSO+EG, the respective values of Lpg and ELp for equine tissue first cooled at 40°C∕min between +25°C and +4°C before being frozen were 0.15μm∕minatm and 7.6kcal∕mole. The corresponding Lpg and ELp values for equine tissue suspended in 1.6M DMSO were 0.12μm∕minatm and 27.2kcal∕mole; in 1.6M EG, the values were 0.06μm∕minatm and 21.9kcal∕mole, respectively. For macaque ovarian tissues suspended in the mixture of DMSO+EG, the respective values of Lpg and ELp were 0.26μm∕minatm and 26.2kcal∕mole. Similarly, the corresponding LLg and ELp values for macaque tissue suspended in 1.6M DMSO were 0.22μm∕minatm and 31.4kcal∕mole; in 1.6M EG, the values were 0.20μm∕minatm and 27.9kcal∕mole. The parameters for both equine and macaque tissue samples suspended in the DMSO+EG mixture and first cooled at 0.5°C∕min between +25°C and +4°C were very similar to the corresponding values for samples cooled at 40°C∕min. In contrast, the membrane parameters of equine and macaque samples first cooled at 0.5°C∕min in single-component solutions were significantly different from the corresponding values for samples cooled at 40°C∕min. These results show that the membrane properties of ovarian cells from two species are different, and that the membrane properties are significantly affected both by the solution in which the tissue is suspended and by the rate at which the tissue is cooled from +25°Cto+4°C before being frozen. These observations suggest that these variables ought to be considered in the derivation of methods to cryopreserve ovarian tissues.

Fertility preservation options for women with malignancies

Cancer is not rare in younger women. There has been a remarkable improvement in the survival rates due to progress in cancer treatment. The necessary treatment for most of the common cancer types occurring in younger women implies either removal of the reproductive organs or cytotoxic treatment that could partially or definitively affect reproductive function. Early loss of ovarian function not only puts the patients at risk for menopause-related complications at a very young age, but is also associated with loss of fertility. Further, women in the western hemisphere have been delaying initiation of childbearing to later in life. The results of these changes have led to an increase in patients facing the risk of premature ovarian failure, and therefore seeking help in preserving their fertility. This increase in demand has resulted in a proliferation of techniques to preserve fertility. Indeed, the number of options is increasing; some are more established procedures, such as embryo cryopreservation, and some are still experimental, such as ovarian cryopreservation. Because of the variations in type and dose of chemotherapy, the type of cancer, the time available before onset of treatment, the patient's age and the partner status, each case is unique and requires a different strategy of fertility preservation.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall the potential early loss of ovarian function secondary to radiotherapy and/or chemotherapy for cancer at a young age; explain the increasing demands for fertility preservation; and summarize the limited number of proven, safe, and efficacious methods.

Outcome of 518 salvage oocyte-cryopreservation cycles performed as a routine procedure in an in vitro fertilization program

OBJECTIVE

To document outcomes of oocyte cryopreservation performed as a routine procedure in an IVF program.

DESIGN

Describing the rate of oocyte survival, embryo transfer (ET), implantation, and live births of IVF-intracytoplasmic sperm injection performed on thawed oocytes.

SETTING

Reproductive medicine center in Italy.

PATIENT(S)

Women (n = 696) who failed to conceive after IVF-intracytoplasmic sperm injection with fresh oocytes.

INTERVENTION(S)

Surplus oocytes obtained during a failed cycle with fresh oocytes were frozen and then were thawed, micromanipulated, and transferred in a later cycle.

MAIN OUTCOME MEASURE(S)

Rates of oocyte survival, ETs, implantation, and live births were calculated in the entire cohort and in patients aged <or=38 and >38 years.

RESULT(S)

There were 29 pregnancies, for a total implantation rate of 6.3% (95% CI: 4.3, 9.0) per 456 ET cycles. The clinical-pregnancy rate was 19 (4.2%; 95% CI: 2.6, 6.4) of 456 ET cycles, with a take-home-baby rate of 7 (1.5%; 95% CI: 0.7, 3.0) of 456 ET cycles.

CONCLUSION(S)

Cryopreservation performed as a routine procedure for so-called salvaging of surplus oocytes is associated with poor implantation rates and with a probability of 1 live birth in 65 ET cycles.

Assessment of United States fertility clinic websites according to the American Society for Reproductive Medicine (ASRM)/Society for Assisted Reproductive Technology (SART) guidelines

OBJECTIVE

To evaluate SART-member fertility clinic websites for their compliance with the 2004 ASRM/SART guidelines for advertising (which is deemed mandatory for clinic membership), to survey the general characteristics of the websites, and to assess differences between academic and private clinic websites.

DESIGN

Cross-sectional evaluation.

SETTING

The Internet.

PATIENTS

None.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Eleven objective criteria based on 2004 ASRM/SART guidelines for advertising and eight objective criteria for general characteristics of fertility clinic websites.

RESULTS

All 384 SART-registered clinics were evaluated; 289 (75.3%) had functional websites (211 private, 78 academic). Success rates were published on 51% of websites (117 private, 31 academic), the majority of which were private clinics (p=.025). The percentage of fertility clinic websites adhering to ASRM/SART guidelines was low in all categories (ranging from 2.8%-54.5% in private centers and 1.3%-37.2% in academic centers). No statistically significant difference was found in the services offered at private versus academic clinics.

CONCLUSION

A significant proportion of SART-member fertility clinics, both private and academic, that have websites are not following the ASRM/SART guidelines for advertising. Increased dissemination and awareness of the guidelines is warranted.

Oocyte cryopreservation

OBJECTIVE

To review historical and contemporary advances in oocyte-cryopreservation techniques and outcomes.

DESIGN

Publications related to oocyte cryopreservation were identified through MEDLINE and other bibliographic databases.

CONCLUSION(S)

Oocyte cryopreservation can be used as an adjunct to conventional IVF and as an option for fertile women to electively cryopreserve their gametes. Recent reports indicate pregnancy rates comparable to those for cryopreserved embryos by either slow-freeze or vitrification methods. Larger prospective trials are needed to determine the true efficacy and safety of oocyte cryopreservation. Until a sufficient number of births is reached and adequate outcome data are collected, oocyte cryopreservation should continue to be considered experimental and to be performed under the oversight of an institutional review board.

The advent of international 'mail-order' egg donation

The rising demand and increasing scarcity of donor oocytes in developed countries have led to some fertility clinics sourcing oocyte donors from abroad, particularly from poorer countries, in what is referred to as 'transnational' or 'international' oocyte donation. In a further new 'twist' to this scheme, frozen sperm of the recipient's male partner is exported abroad through courier mail and is used to fertilise donor oocytes in a foreign clinic to produce embryos, which are then cryopreserved and imported back by mail for transfer to the woman. There are numerous ethical concerns with regards to such means of procuring donor oocytes. First, there is an issue of exploiting economically underprivileged women in poorer countries and disproportionate gains on the part of medical doctors and fertility clinics. Second, there is a question of abdication of responsibility for the donor's welfare on the part of the fertility doctor who takes charge of the recipient's treatment abroad if oocyte donors were to develop severe ovarian hyperstimulation syndrome. Third, the issue of responsibility and accountability becomes even more contentious if congenital defects were to appear in offsprings born from transnational oocyte donation or in the case of transmission of communicable diseases such as hepatitis B, syphilis and AIDS to the recipient. Last, cost savings from the lower prescription price of fertility drugs in economically less-developed countries may not be passed down to the oocyte recipient but instead be exploited to boost the already substantial profit margin of fertility clinics and doctors.

The interface between assisted reproductive technologies and genetics: technical, social, ethical and legal issues

The interface between assisted reproductive technologies (ART) and genetics comprises several sensitive and important issues that affect infertile couples, families with severe genetic diseases, potential children, professionals in ART and genetics, health care, researchers and the society in general. Genetic causes have a considerable involvement in infertility. Genetic conditions may also be transmitted to the offspring and hence create transgenerational infertility or other serious health problems. Several studies also suggest a slightly elevated risk of birth defects in children born following ART. Preimplantation genetic diagnosis (PGD) has become widely practiced throughout the world for various medical indications, but its limits are being debated. The attitudes towards ART and PGD vary substantially within Europe. The purpose of the present paper was to outline a framework for development of guidelines to be issued jointly by European Society of Human Genetics and European Society of Human Reproduction and Embryology for the interface between genetics and ART. Technical, social, ethical and legal issues of ART and genetics will be reviewed.

Major Advances Associated with Reproduction in Dairy Cattle

The purpose of this overview is to review some of the major advances in reproductive technologies, and how they may be applied to meet the challenge of enhancing reproductive efficiency in the high-producing dairy cow of the 21st century. The current population of high-producing dairy cows is considered to be subfertile, as characterized by low pregnancy rates and high rates of embryonic mortality. Coordinated systems of reproductive management have been developed based upon a thorough understanding of the endocrine, cellular, and molecular factors controlling ovarian and uterine function. These systems will partially restore herd reproductive performance. Advances in other reproductive technologies offer possibilities for wider use of superior germplasm. Technologies such as sexed semen, cloning, transgenesis, and preimplantation genetic diagnosis offer the potential to enhance the influence of superior animals on production of food for human consumption. However, at this time, additional research is needed to counteract the higher rates of embryonic and fetal mortality associated with some of these technologies. Furthermore, use of genomics, proteomics, and bioinformatics in the study of reproduction will undoubtedly provide investigators with a greater understanding of the limitations to efficient reproductive processes in the subfertile lactating dairy cow.

Clinical potential and putative risks of fertility preservation in children utilizing gonadal tissue or germline stem cells

Rapid progress in the development of novel experimental strategies to generate fertile gametes from cryo-preserved ovarian and testicular tissue motivates oncologists to investigate ways in which gonadal tissue might be preserved. Childhood cancer patients remain the major pediatric group which can benefit from these techniques. Other potential candidates include patients with systemic diseases, which require gonadotoxic chemotherapy, patients undergoing gonadectomy, patients with Turner or Kleinefelter's syndrome, and boys with cryptorchid testes. This review aims to present an overview of the current state of knowledge in experimental germ stem cell transplantation in higher primates including humans, and the clinical risks and limitations related to such procedures in children. This area of research is discussed in the context of the potential future options that may become available for preserving fertility in boys and girls.

Suprazero cooling conditions significantly influence subzero permeability parameters of mammalian ovarian tissue

To model the cryobiological responses of cells and tissues, permeability characteristics are often measured at suprazero temperatures and the measured values are used to predict the responses at subzero temperatures. The purpose of the present study was to determine whether the rate of cooling from +25 to +4 degrees C influenced the measured water transport response of ovarian tissue at subzero temperatures in the presence or absence of cryoprotective agents (CPAs). Sections of freshly collected equine ovarian tissue were first cooled either at 40 degrees C/min or at 0.5 degrees C/min from 25 to 4 degrees C, and then cooled to subzero temperatures. A shape-independent differential scanning calorimeter (DSC) technique was used to measure the volumetric shrinkage during freezing of equine ovarian tissue sections. After ice was induced to form in the extracellular fluid within the specimen, the sample was frozen from the phase change temperature to -50 degrees C at 5 degrees C/min. Replicate samples were frozen in isotonic medium alone or in medium containing 0.85 M glycerol or 0.85 M dimethylsulfoxide. The water transport response of ovarian tissue samples cooled at 40 degrees C/min from 25 to 4 degrees C was significantly different (confidence level >95%) from that of tissue samples cooled at 0.5 degrees C/min, whether in the presence or absence of CPAs. We fitted a model of water transport to the experimentally-derived volumetric shrinkage data and determined the best-fit membrane permeability parameters (L(pg) and E(Lp)) of equine ovarian tissue during freezing. Subzero water transport parameters of ovarian tissue samples cooled at 0.5 degrees C/min from 25 to 4 degrees C ranged from: L(pg) = 0.06 to 0.73 microm/min.atm and E(Lp) = 6.1 to 20.5 kcal/mol. The corresponding parameters of samples cooled at 40 degrees C/min from 25 to 4 degrees C ranged from: L(pg) = 0.04 to 0.61 microm/min.atm and E(Lp) = 8.2 to 54.2 kcal/mol. Calculations made of the theoretical response of tissue at subzero temperatures suggest that the optimal cooling rates to cryopreserve ovarian tissue are significantly dependent upon suprazero cooling conditions.

Fertility preservation in female cancer patients: current developments and future directions

OBJECTIVE

To review the current advances in fertility preservation strategies and to discuss future directions with an emphasis on ovarian tissue cryobanking.

DESIGN

The publications related to fertility preservation in cancer patients were identified through Medline and other bibliographic databases, focusing on the most recent developments.

CONCLUSION(S)

There are several options for fertility preservation in cancer patients. Even though most of them are still experimental and their efficacy and reliability have not been determined, the future of fertility preservation in women with cancer is promising. In particular, the recent report of a live birth after transplantation of human ovarian tissue has reinforced the clinical potential of ovarian tissue banking for fertility preservation. Many exciting studies are underway to improve the efficacy and solve the problems with current fertility preservation strategies. It is inevitable that we will see the emergence of more complex ethical problems with the application of new technologies to humans. However, continuous efforts to improve current strategies and to develop new strategies will benefit many women and children who are facing premature ovarian failure and sterility.

Effective method for in-vitro culture of cryopreserved human ovarian tissue

It is widely accepted that it is possible to successfully cryopreserve human ovarian tissue by direct plunging into liquid nitrogen using permeable cryoprotectants only, without disaccharides. This study aimed to search for and test a new method for in-vitro culture of vitrified tissue. Ovarian biopsies were obtained during operative laparoscopy. Pieces of ovarian tissue were vitrified and warmed. After warming, tissue pieces were randomly distributed into three groups for further culture: in 2 ml of culture medium which was regularly renewed (group 1), in 30 ml of culture medium without agitation (group 2) and in 30 ml of culture medium with agitation (group 3). During the 2-week and 6-week culture, the growth of follicles within the vitrified-warmed ovarian tissue pieces was investigated. After 2 weeks of culture, mean numbers of non-degenerated follicles per mm(2) of tissue were 1.5, 1.7 and 4.5 for groups 1, 2 and 3 respectively (groups 1 and 2 versus group 3, P < 0.05). Agitation during culture of ovarian tissue is beneficial, and can be used as a prognostic tool for future warming and autotransplantation of ovarian tissue.

Human oocyte cryopreservation: past, present and future

Despite inferior results in the past compared with embryo freezing, oocyte cryopreservation has made great strides in recent years. In fact, it has become a necessity in assisted reproduction technology, providing alternatives to legal, moral and religious problems originating from embryo freezing. Recent advances in freezing technology, modifications of conventional protocols used and continuing optimization of vitrification have efficiently improved the method. A historical description of the method's progression over time, and a comparison of principles, procedures and results as reported in the literature are presented in this review.

Ovarian tissue cryopreservation: benefits and risks

An increasing number of women have been subjected to cytotoxic chemoradiotherapy for various malignant and nonmalignant diseases. Women who face the possibility of premature or imminent ovarian failure caused by cytotoxic therapy may retain their fertility potential with ovarian tissue cryopreservation. Until recently, this technique could only be performed in a few highly specialized institutions. However, with the latest advances in cryobiology, ovarian tissue cryopreservation is rapidly becoming a more widely offered technique by many medical centers around the world. The indications now extend beyond cancer. Even though the risk of re-implanting pre-existing cancer cells is minimal or non-existent for most types of cancer, this risk needs to be ascertained according to the cancer type and disease stage. The objective of this manuscript is to review the indications, risks and benefits of ovarian tissue cryopreservation.

Use of a gonadotropin-releasing hormone analog for protection against premature ovarian failure during cyclophosphamide therapy in women with severe lupus

OBJECTIVE

Cyclophosphamide (CYC) therapy for systemic lupus erythematosus (SLE), a disease predominantly affecting women of childbearing age, causes an unacceptably high incidence of irreversible premature ovarian failure (POF). This study was performed to evaluate the effectiveness of depot leuprolide acetate, a synthetic gonadotropin-releasing hormone analog (GnRH-a), for protection against POF during CYC therapy.

METHODS

Young women with severe SLE treated in a standardized protocol of monthly intravenous bolus CYC were offered treatment with GnRH-a (depot leuprolide acetate; a 3.75-mg monthly injection during the standard CYC regimen). Patients treated with GnRH-a were compared with controls individually matched by age (+/-5 years) and by cumulative CYC dose (+/-5 gm). Reproductive status was determined after a minimum followup of 3 years after CYC therapy. The primary outcome was time to POF. Paired summary statistical analyses, Kaplan-Meier survival estimates, and Cox regression analyses were performed to assess differences in outcome between groups.

RESULTS

POF developed in 1 of 20 women treated with GnRH-a (5%) compared with 6 of 20 controls (30%) matched by age and cumulative CYC dose (matched odds ratio 0.09, P < 0.05). Kaplan-Meier estimates demonstrated improved cumulative ovarian protection over time in the GnRH-a-treated group (P = 0.04).

CONCLUSION

Treatment with GnRH-a during CYC therapy was associated with a significant reduction of POF in young women with severe SLE.

Ovarian cortical transplantation may be an alternative to hormone therapy in patients with early climacterium

OBJECTIVE

To discuss the 18-month follow-up results of fresh ovarian cortical tissue transplant.

DESIGN

Case study.

SETTING

Academic medical center.

PATIENT(S)

A 46-year-old patient who was operated on for uterine fibroids, and who then received an ovarian tissue transplant in July 2003.

INTERVENTION(S)

Serum hormone levels were measured at 3-month intervals.

MAIN OUTCOME MEASURE(S)

Follicular development evident by ultrasound examination; serum hormone levels (FSH, LH, E2).

RESULT(S)

Preoperative and 3rd-, 6th-, 9th-, 12th-, 15th-, and 18th-month hormone levels were, respectively, as follows: FSH: 9.06, 79.5, 13.7, 16.66, 51.91, 44.37, and 24.17 mIU/mL; LH: 5.91, 33.92, 8.78, 21.83, 38.31, 40.85, and 22.4 mIU/mL; E2: 166, 46, 48, 117, 31, 14.4, and 137.7 pg/mL. Folliculogenesis was confirmed by ultrasonography at the 6th, 9th, and 18th months during the follow-up period.

CONCLUSION(S)

Fresh ovarian autotransplantation may be a logical alternative for hormonal support for a specific patient group.

The role of cryopreservation for women prior to treatment of malignancy

PURPOSE OF REVIEW

The purpose of this review is to investigate recent advances in xenografting, as well as in orthotopic and heterotopic autotransplantation of human cryopreserved ovarian tissue.

RECENT FINDINGS

The first livebirth after orthotopic transplantation of cryopreserved ovarian tissue was reported recently. We discuss this case and other cases of reimplantation of cryopreserved ovarian tissue, bearing in mind that many questions remain.

SUMMARY

Finally, we report the latest developments in research on the transplantation of an intact ovary and the reimplantation of isolated follicles.

Fertility preservation options for female patients with malignancies

PURPOSE OF REVIEW

Preservation of fertility in female patients diagnosed with cancer has recently been an area of intensive investigation. This review summarizes available options and discusses recently published data concerning experimental methods. Specific strategies for fertility preservation in women with gynecologic malignancies are also presented.

RECENT FINDINGS

Success with ovarian stimulation protocols using tamoxifen or aromatase inhibitors has recently been reported for women with breast cancer who attempt embryo cryopreservation prior to chemotherapy. The first embryo transfer using oocytes retrieved from cryopreserved ovarian tissue implanted at a heterotopic location, the first pregnancy following orthotopic transplantation of cryopreserved ovarian tissue, and increasing success with oocyte cryopreservation were also reported.

SUMMARY

Fertility preservation in female patients with cancer has become an important health issue due to increasing survival rates and delayed childbearing especially in Western countries. Radical vaginal trachelectomy for cervical cancer, conservative surgery for ovarian tumors, and progestin treatment in endometrial cancers may be considered at early stages in order to preserve fertility. Embryo cryopreservation is an established technique that is available for fertility preservation, providing a delay in the initiation of chemotherapy or radiotherapy is acceptable, and a partner or donor sperm is available. Additional techniques that could be offered after counseling the patient about their experimental nature include oocyte cryopreservation, ovarian cryopreservation, and gonadotropin-releasing hormone agonist co-treatment with chemotherapy. Improvement of these techniques as well as better characterization of their success rates and risks await further investigation.

Fertility preservation and reproduction in cancer patients

Cancer treatment often results in reduced fertility. Cancer patients should be informed of options for fertility preservation and future reproduction prior to cancer treatment. Reproduction in the context of cancer raises a number of ethical issues related to both patient and offspring welfare.