Christine Wyns

Options for fertility preservation in prepubertal boys

BACKGROUND Fertility in adult life may be severely impaired by gonadotoxic therapies. For young boys who do not yet produce spermatozoa, cryopreservation of immature testicular tissue (ITT) is an option to preserve their fertility, albeit still experimental. This paper covers current options for ITT cryopreservation and fertility restoration. METHODS Relevant studies were identified by an extensive Medline search of English and French language articles. Search terms were: gonadotoxicity, cytoprotection, cryopreservation, ITT, spermatogonia, testicular transplantation, testicular grafting and in vitro maturation (IVM). RESULTS Although no effective gonadoprotective drug is yet available for in vivo spermatogonial stem cell protection in humans, current evidence supports the feasibility of ITT cryopreservation before gonadotoxic treatment with a view to fertility preservation. Controlled slow freezing with dimethyl sulfoxide allows survival and proliferation of human spermatogonia after xenotransplantation, but only partial differentiation. Animal data look promising, since healthy offspring have been obtained after transplantation of frozen testicular cell suspensions or tissue pieces. However, none of the fertility restoration options from frozen tissue, i.e. cell suspension transplantation, tissue grafting and IVM have proved efficient and safe in humans as yet. CONCLUSION While additional evidence is required to define optimal conditions for ITT cryopreservation with a view to transplantation or IVM, the putative indications for such techniques, as well as their limitations according to disease, are outlined.

Does ovarian surgery for endometriomas impair the ovarian response to gonadotropin

OBJECTIVE To evaluate the ovarian response to stimulation conducted for IVF treatment in women who have undergone conservative surgery for endometriomas. DESIGN Retrospective study with prospective selection of participants and controls. SETTING University infertility clinic. PATIENT(S) A series of 374 women who underwent in vitro fertilization (IVF). The study group consisted of 85 patients with ovarian endometriomas who had undergone laparoscopic surgery in an attempt to become pregnant, but had failed within a year of surgery. The control group consisted of 289 patients with tubal factor infertility. INTERVENTION(S) IVF-embryo transfer procedures. MAIN OUTCOME MEASURE(S) Stimulation parameters, fertilization, implantation, and pregnancy rates were analyzed in both groups. RESULT(S) There was no significant difference between the two groups in stimulation parameters or IVF outcome. CONCLUSION(S) A total of 820 cycles were analyzed. A similar IVF-ET outcome was observed in patients with endometriosis after ablation of endometriomas compared to women with tubal factors. In conclusion, endometrioma surgery by internal wall vaporization does not impair IVF outcome. The clinical pregnancy rate was respectively 37.4% and 34.6% in the endometriosis group and the control group.

Long-term spermatogonial survival in cryopreserved and xenografted immature human testicular tissue

BACKGROUND Preservation of the male germ line in prepubertal boys undergoing gonadotoxic treatment is a crucial consideration in terms of their future quality of life. As these patients do not yet produce spermatozoa for freezing, only immature tissue is available for storage. We studied the survival, proliferation and differentiation capacity of spermatogonia after cryopreservation and long-term transplantation of immature testicular tissue pieces. METHODS Single pieces of testicular tissue (2-8 mm(3)) from prepubertal boys (7-14 years) were cryopreserved, thawed and transplanted into the scrotum of mice for 6 months. Upon removal, histological, immunohistochemical and ultrastructural analyses and testicular sperm extraction (TESE) were used to evaluate the tissue. RESULTS Histology showed 55 +/- 42% of tubules to be intact. MAGE-A4 immunostaining showed mean spermatogonial recovery to be 3.7 +/- 5.5%, with 35% of these cells expressing Ki67, evidencing proliferation in tissue from boys <14 years of age. No apoptosis was found, as demonstrated by the absence of active caspase-3 and TUNEL staining. Numerous premeiotic spermatocytes, a few spermatocytes at the pachytene stage and spermatid-like cells were observed. No immunostaining was observed for lactate dehydrogenase-C, ACE or proacrosin, indicating that the spermatid-like structures observed by histology did not express the meiotic and post-meiotic markers characteristic of normal spermatids. No ultrastructural alterations of the tissue were encountered. CONCLUSIONS The present study demonstrates that spermatogonia are able to survive and proliferate after cryopreservation and long-term transplantation. Complete regeneration of normal spermatogenesis was not observed since, beyond the pachytene stage, no adequate characterization of germ cells was obtained. Further studies are thus required to investigate the differentiation potential of cryopreserved germ cells.

Assisted reproductive technology in Europe, 2012: results generated from European registers by ESHRE.

STUDY QUESTION The 16th European IVF-monitoring (EIM) report presents the data of the treatments involving assisted reproductive technology (ART) and intrauterine insemination (IUI) initiated in Europe during 2012: are there any changes compared with previous years? SUMMARY ANSWER Despite some fluctuations in the number of countries reporting data, the overall number of ART cycles has continued to increase year by year, the pregnancy rates (PRs) in 2012 remained stable compared with those reported in 2011, and the number of transfers with multiple embryos (3+) and the multiple delivery rates were lower than ever before. WHAT IS KNOWN ALREADY Since 1997, ART data in Europe have been collected and re-ported in 15 manuscripts, published in Human Reproduction. STUDY DESIGN, SIZE, DURATION Retrospective data collection of European ART data by the EIM Consortium for the European Society of Human Reproduction and Embryology (ESHRE). Data for cycles between 1 January and 31 December 2012 were collected from National Registers, when existing, or on a voluntary basis by personal information. PARTICIPANTS/MATERIALS, SETTING, METHODS From 34 countries (+1 compared with 2011), 1111 clinics reported 640 144 treatment cycles including 139 978 of IVF, 312 600 of ICSI, 139 558 of frozen embryo replacement (FER), 33 605 of egg donation (ED), 421 of in vitro maturation, 8433 of preimplantation genetic diagnosis/preimplantation genetic screening and 5549 of frozen oocyte replacements (FOR). European data on intrauterine insemination using husband/partners semen (IUI-H) and donor semen (IUI-D) were reported from 1126 IUI labs in 24 countries. A total of 175 028 IUI-H and 43 497 IUI-D cycles were included. MAIN RESULTS AND THE ROLE OF CHANCE In 18 countries where all clinics reported to their ART register, a total of 369 081 ART cycles were performed in a population of around 295 million inhabitants, corresponding to 1252 cycles per million inhabitants (range 325-2732 cycles per million inhabitants). For all IVF cycles, the clinical PRs per aspiration and per transfer were stable with 29.4 (29.1% in 2011) and 33.8% (33.2% in 2011), respectively. For ICSI, the corresponding rates also were stable with 27.8 (27.9% in 2011) and 32.3% (31.8% in 2011). In FER cycles, the PR per thawing/warming increased to 23.1% (21.3% in 2011). In ED cycles, the PR per fresh transfer increased to 48.4% (45.8% in 2011) and to 35.9% (33.6% in 2011) per thawed transfer, while it was 45.1% for transfers after FOR. The delivery rate after IUI remained stable, at 8.5% (8.3% in 2011) after IUI-H and 12.0% (12.2% in 2011) after IUI-D. In IVF and ICSI cycles, 1, 2, 3 and 4+ embryos were transferred in 30.2, 55.4, 13.3 and 1.1% of the cycles, respectively. The proportions of singleton, twin and triplet deliveries after IVF and ICSI (added together) were 82.1, 17.3 and 0.6%, respectively, resulting in a total multiple delivery rate of 17.9% compared with 19.2% in 2011 and 20.6% in 2010. In FER cycles, the multiple delivery rate was 12.5% (12.2% twins and 0.3% triplets). Twin and triplet delivery rates associated with IUI cycles were 9.0%/0.4% and 7.2%/0.5%, following treatment with husband and donor semen, respectively. LIMITATIONS, REASONS FOR CAUTION The method of reporting varies among countries, and registers from a number of countries have been unable to provide some of the relevant data such as initiated cycles and deliveries. As long as data are incomplete and generated through different methods of collection, results should be interpreted with caution. WIDER IMPLICATIONS OF THE FINDINGS The 16th ESHRE report on ART shows a continuing expansion of the number of treatment cycles in Europe, with more than 640 000 cycles reported in 2012 with an increasing contribution to birthrate in many countries. However, the need to improve and standardize the national registries, and to establish validation methodologies remains manifest. STUDY FUNDING/COMPETING INTERESTS The study has no external funding; all costs are covered by ESHRE. There are no competing interests.

Management of fertility preservation in prepubertal patients: 5 years’ experience at the Catholic University of Louvain

BACKGROUND Since prepubertal boys cannot benefit from sperm banking, a potential alternative strategy for fertility preservation involves immature testicular tissue (ITT) banking aimed at preservation of spermatogonial stem cells. Survival of spermatogonia has been demonstrated after ITT freezing, which is considered ethically acceptable. We report the results of a pilot program set up for fertility preservation in prepubertal boys. METHODS All boys undergoing ITT cryobanking from May 2005 were identified from our clinical register. Data were collected from medical files. RESULTS Testicular tissue was retrieved from 52 prepubertal patients under 12 years of age and 10 peripubertal patients aged between 12 and 16 years, in whom no spermatozoa were identified in testicular biopsies. Malignant disease accounted for 80.6% of cases; the remaining patients suffered from benign disorders requiring gonadotoxic treatments. Mean ages, Tanner stages and occurrence rates of urogenital pathology were 6.43 ± 3.32 and 14 ± 1.23 years, I and I-IV, and 13.5 and 20% for pre- and peripubertal patients, respectively. Mean volumes of removed tissue were 20.1 ± 8.6 and 42.4 ± 15.6 mm(3) for pre- and peripubertal patients, respectively. No complications occurred during or after tissue retrieval and 93.5% of referred patients accepted ITT storage. The presence of spermatogonia, and thus the potential for later tissue use, was established in all of these patients. CONCLUSIONS The majority of cryopreserved samples showed reproductive potential. Storage was accepted by most parents. All parents and children considered this fertility preservation strategy a positive approach.

A European perspective on testicular tissue cryopreservation for fertility preservation in prepubertal and adolescent boys

STUDY QUESTION What clinical practices, patient management strategies and experimental methods are currently being used to preserve and restore the fertility of prepubertal boys and adolescent males? SUMMARY ANSWER Based on a review of the clinical literature and research evidence for sperm freezing and testicular tissue cryopreservation, and after consideration of the relevant ethical and legal challenges, an algorithm for the cryopreservation of sperm and testicular tissue is proposed for prepubertal boys and adolescent males at high risk of fertility loss. WHAT IS KNOWN ALREADY A known late effect of the chemotherapy agents and radiation exposure regimes used to treat childhood cancers and other non-malignant conditions in males is the damage and/or loss of the proliferating spermatogonial stem cells in the testis. Cryopreservation of spermatozoa is the first line treatment for fertility preservation in adolescent males. Where sperm retrieval is impossible, such as in prepubertal boys, or it is unfeasible in adolescents prior to the onset of ablative therapies, alternative experimental treatments such as testicular tissue cryopreservation and the harvesting and banking of isolated spermatogonial stem cells can now be proposed as viable means of preserving fertility. STUDY DESIGN, SIZE, DURATION Advances in clinical treatments, patient management strategies and the research methods used to preserve sperm and testicular tissue for prepubertal boys and adolescents were reviewed. A snapshot of the up-take of testis cryopreservation as a means to preserve the fertility of young males prior to December 2012 was provided using a questionnaire. PARTICIPANTS/MATERIALS, SETTING, METHODS A comprehensive literature review was conducted. In addition, survey results of testis freezing practices in young patients were collated from 24 European centres and Israeli University Hospitals. MAIN RESULTS AND THE ROLE OF CHANCE There is increasing evidence of the use of testicular tissue cryopreservation as a means to preserve the fertility of pre- and peri-pubertal boys of up to 16 year-old. The survey results indicate that of the 14 respondents, half of the centres were actively offering testis tissue cryobanking as a means of safeguarding the future fertility of boys and adolescents as more than 260 young patients (age range less than 1 year old to 16 years of age), had already undergone testicular tissue retrieval and storage for fertility preservation. The remaining centres were considering the implementation of a tissue-based fertility preservation programme for boys undergoing oncological treatments. LIMITATIONS, REASONS FOR CAUTION The data collected were limited by the scope of the questionnaire, the geographical range of the survey area, and the small number of respondents. WIDER IMPLICATIONS OF THE FINDINGS The clinical and research questions identified and the ethical and legal issues raised are highly relevant to the multi-disciplinary teams developing treatment strategies to preserve the fertility of prepubertal and adolescent boys who have a high risk of fertility loss due to ablative interventions, trauma or genetic pre-disposition.

Can prepubertal human testicular tissue be cryopreserved by vitrification

OBJECTIVE To assess vitrification of prepubertal human testicular tissue in vitro. DESIGN Case report. SETTING Academic research unit. PATIENT(S) Two patients (6 and 12 years of age) who were to start gonadotoxic treatment for chronic granulomatous disease and acute lymphoblastic leukemia. INTERVENTION(S) Long-term (10-day) organotypic culture performed immediately after vitrification and warming. Fresh tissue and tissue cryopreserved by slow-freezing were used as control samples. MAIN OUTCOMES MEASURE(S) Spermatogonial cell survival (MAGE-A4) and proliferation (Ki67) were evaluated by immunohistochemistry (IHC) and tubular integrity by light microscopy. RESULT(S) Qualitative analysis revealed that histologic characteristics of spermatogonia and Sertoli cells were preserved, as were cell-cell cohesion and cell adhesion to the basement membrane, in vitrified tissue as well as in frozen and fresh control samples. Survival of spermatogonia and their ability to proliferate as evidenced by IHC was also confirmed in cultured fresh, slow-frozen, and vitrified tissue. CONCLUSION(S) Vitrification, having the advantage of being a faster and more convenient method, shows promise as an alternative strategy to slow-freezing in the emerging field of immature testicular tissue cryopreservation.

Vitrification preserves proliferation capacity in human spermatogonia

STUDY QUESTION Does vitrification of human immature testicular tissue (ITT) have potential benefits for future fertility preservation? Does vitrification of human ITT have potential benefits in an in vivo murine xenotransplantation model? SUMMARY ANSWER Vitrification is able to maintain proliferation capacity in spermatogonial cells after 6 months of xenografting. WHAT IS KNOWN ALREADY Controlled slow-freezing is the procedure currently applied for ITT cryobanking in clinical practice. Vitrification has been proposed as a promising technique for long-term storage of ITT, with a view to preserving spermatogonial stem cells (SSCs) for future fertility restoration in young boys suffering from cancer. After vitrification of ITT, in vitro survival of SSCs was demonstrated, but their functionality was not evaluated. STUDY DESIGN, SIZE, DURATION Ten ITT pieces issuing from 10 patients aged 2-12 years were used. Fragments of fresh tissue (serving as controls) and fresh, frozen-thawed and vitrified-warmed testicular pieces xenografted to the scrotum of nude mice for 6 months were compared. MATERIALS, SETTING, METHODS Upon graft removal, histological and immunohistochemical analyses were performed to evaluate spermatogonia (SG) (MAGE-A4), intratubular proliferation (Ki67), proliferating SG and Leydig cells (3β-HSD). The entire piece of grafted tissue was assessed in each case. MAIN RESULTS AND THE ROLE OF CHANCE Seminiferous tubules showed good integrity after cryopreservation and xenografting for 6 months in all three groups. Survival of SG and their ability to proliferate was observed by immunohistochemistry in all grafted groups. SG were able to initiate spermatogenesis, but blockage at the pachytene stage was observed. The recovery rate of SG was 3.4 ± 3.8, 4.1 ± 7.3 and 7.3 ± 6.3%, respectively, for fresh, slow-frozen and vitrified-warmed tissue after 6 months of xenografting. LIMITATIONS, REASONS FOR CAUTION The study is limited by the low availability of ITT samples of human origin. The mouse xenotransplantation model needs to be refined to study human spermatogenesis. WIDER IMPLICATIONS OF THE FINDINGS The findings of the present study have potential implications for cryobanking of ITT and fertility preservation. Spermatogonial loss recorded after fresh ITT transplantation indicates that the avascular grafting technique needs to be optimized. There are so far no convincing data justifying modification of current clinical practice for ITT storage with slow-freezing, but this study demonstrates that it is worth pursuing optimization of ITT vitrification as an alternative for preservation of SSCs. STUDY FUNDING/COMPETING INTEREST(S) The present study was supported by a grant from the Fonds National de la Recherche Scientifique de Belgique (grant Télévie N° 7. 4.572.09.F). The authors declare that there is no conflict of interest.

Cryopreservation of prepubertal mouse testicular tissue by vitrification

OBJECTIVE To compare cryopreservation of prepubertal testicular tissue after vitrification (V) and slow-freezing (SF). DESIGN Prospective experimental study. SETTING Academic research unit. ANIMAL(S) Six-day-old mice. INTERVENTION(S) After cryopreservation, viability tests (n = 10) and short-term culture (1 and 3 days) (n = 5) were performed. A comparison was made with fresh (FR) and noncultured controls (FR Ctrl). MAIN OUTCOMES MEASURE(S) Tissue viability was assessed by lactate dehydrogenase release assay. Apoptosis (caspase-3) and proliferation (Ki67) were evaluated by immunohistochemistry, and tubular diameter, integrity, and cell density by light microscopy. RESULT(S) Lactate dehydrogenase release was greater after SF than V (54.6% vs. 26.7%), whereas the mean number of apoptotic cells/tubule was higher after V than SF (2.13 vs. 0.07). On day 1, a decrease in cell density was noted in both cryopreserved groups, but this difference was not subsequently observed. On day 3, an increase in proliferation was seen in the SF and V groups versus FR tissue, and similar tubular diameter, integrity, and cell density were found in all cultured groups. CONCLUSION(S) This study shows that both SF and V protocols preserve survival, development, and integrity of prepubertal mouse testicular tissue in short-term organotypic culture. Additional investigation should now be conducted to assess tissue functionality.

The efficacy of medical and surgical treatment of endometriosis-associated infertility and pelvic pain.

This article is a review of the efficacy of medical and surgical treatment of endometriosis-associated infertility and pelvic pain. Endometriosis is the cause of pelvic pain (dysmenorrhea, dyspareunia) and infertility in more than 35% of women of reproductive age. Complete resolution of endometriosis is not yet possible but therapy has essentially three main objectives: (1) to reduce pain; (2) to increase the possibility of pregnancy; (3) to delay recurrence for as long as possible. It could be concluded that a consensus will probably never be reached on minimal and mild endometriosis. Nevertheless, because the Canadian study reported a large number of cases, we strongly support the view that visible endometriosis must be removed at the time of surgery. In cases of moderate and severe endometriosis-associated infertility, the combined approach (operative laparoscopy with GnRH-a) must be considered as ‘first-line’ treatment. The mean pregnancy rate of 50% reported in the literature following surgery provides scientific proof that operative treatment should be undertaken first to give our patients the best chance of conceiving naturally.