Ovarian tissue transplantation: 10 years of experience at the Bologna University.

Objective: The efficiency of ovarian tissue transplantation (OTT) was established in terms of ovarian function recovery (95% of cases), number of live births (over 200 worldwide to date) and induction of puberty. Unfortunately, the lack of international registries and the fact that many centers have not yet reported their outcomes, lead to poor knowledge of the exact fertility data. The aim of the study is to describe our experience with OTT to restore ovarian function and fertility. Methods: This study was designed as a single-center, observational, retrospective, cohort study that includes women who underwent OTT between December 2012 and June 2023 at our center. After approval by the oncologist/hematologist, a small fragment of ovarian tissue was thawed and analyzed to detect the presence of micrometastases before OTT. Thawed ovarian tissue was grafted laparoscopically at multiple sites, including the remaining ovary and pelvic side wall (orthotopic transplantation) and/or abdominal wall (heterotopic transplantation). After OTT, ovarian function was monitored by hormonal assay, ultrasound and color Doppler at approximately 4-week intervals. Results: Between December 2012 and June 2023, 30 women performed OTT. Prior to OTT, immunohistochemical and molecular analyses revealed no micrometastases in all thawed ovarian tissue samples. In our series of 30 women, 20 of women were on premature ovarian insufficiency (POI), and the remaining ten cases still had oligomenorrhea and difficulty getting pregnant. Among the women with POI before OTT and at least 6 months follow-up, recovery of endocrine function was observed in all but one woman who underwent orthotopic transplantation (13 of 14 cases), in one out of two women who underwent both orthotopic and heterotopic transplantation (1 of 2 cases) and in all women who underwent heterotopic transplantation (4 of 4 cases). Women who underwent OTT to enhance fertility had no alterations in menstrual cycle and hormonal levels. In total, ten pregnancies were obtained in 25 women, resulting in four live births, two ongoing pregnancies and four spontaneous abortions. Conclusion: Our data can help patients and physicians in their discussions and decisions about the need and possibilities of preserving fertility.

Detection of Non-Hodgkin Lymphoma Within Ovarian Tissue.

This case report describes the detection of non-Hodgkin lymphoma (NHL) within ovarian tissue after cryopreservation. The 27-year-old woman presented no gynecological symptoms such as pelvic pain or abnormal uterine bleeding. During laparoscopy for ovarian tissue cryopreservation, the ovaries appeared markedly modified and some solid content cysts were highlighted. Microscopically the cysts revealed the presence of lymphoid infiltrate, whereas the histological assessment of some fragments of the ovarian cortical tissue revealed no evidence of pathological lymphoid infiltration. This case report describes the presence of pathological lymphoid infiltration in ovarian cysts but not in the cortical tissue of a young woman with secondary NHL. Despite the absence of the positivity in cortical tissue it was recommended to avoid the cryopreserved ovarian tissue transplantation to reduce the risk of reseeding of the malignancy in the woman.

Corrigendum: Ovarian tissue cryopreservation and transplantation: 20 years experience in Bologna University.

[This corrects the article DOI: 10.3389/fendo.2022.1035109.].

Ovarian tissue cryopreservation and transplantation: 20 years experience in Bologna University.

Objective: To report the 20-year experience in ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT) of the Bologna clinical center (Bologna, Italy). Design: Retrospective cohort study. Patients: 1026 pediatrics and women aged between 2 and 38 years who underwent OTC and OTT between January 2002 to January 2022. Results: Of the 1026 patients, 238 (22.8%) were pediatrics (≤ 17 years, Group 1) and 788 (77.2%) were adult women (range 18-38 years, Group 2). In Group 1, 184 (77.3%) patients had malignant diseases and 54 (22.7%) had non-malignant diseases. In Group 2, 746 (94.7%) patients had malignant diseases and 42 (5.3%) had non-malignant diseases. No real complications were observed during surgery. In all the samples analyzed most of the follicles were in the resting stage, while only a few follicles were growing. In both fresh and thawed samples, follicular density was higher in Group 1 than in Group 2 (p < 0.01). Regardless of age, good preservation of follicles and stroma was observed in fresh and thawed ovarian tissue by histological and immunohistochemical analyses (estrogen and progesterone receptors; Ki67 and Bcl2 markers; TUNEL). To date, out of 1026 total women, 812 (79.1%) had their tissue stored. Sixty-eight (6.6%) patients died from their primary disease. Twenty-four (2.3%) women performed 33 OTTs between December 2011 and January 2022. Restoration of menstruation was observed in 15 out of 17 menopausal women. Six pregnancies were achieved, two hesitated in abortion and four in the birth of healthy babies. Conclusion: OTC is the only fertility preservation technique applicable in pre-pubertal/pediatrics and in adult patients when stimulation for oocytes/embryos cryopreservation is not possible. The reported data can help future patients and physicians in their discussions and decisions about the need and possibilities of preserving ovarian function.

Impact of the COVID-19 pandemic on ovarian tissue cryopreservation planning in the Bologna clinical center.

Introduction: Treatment of patients with COVID-19 has been a priority by competing with the treatment of any other disease due to limited hospital resources. The current pandemic situation has focused the attention of healthcare providers around the world away from all other non-emergency health problems, including oncofertility. The aim of the study was to evaluate the repercussions of the COVID-19 pandemic on the activity levels of ovarian tissue cryopreservation (OTC) in the our center. Methods: The study analyzed the number of patients treated for OTC in our center during three periods: pre-pandemic period: March 2019-February 2020, pandemic period: March 2020-February 2021 and post-pandemic period: March 2021-February 2022. Results: In our center routine hospital operation was completely reorganized, allowing only urgent interventions. Continuing to urgently preserve fertility during the pandemic required rapid changes to our standard practices for the care of these vulnerable patients. Despite the modifications, there was no difference in the number of OTC performed among the periods analyzed. Similarly, the number of patients who did not perform OTC was the same over the three years analyzed. Discussion: Despite the local and national restructuring of care to conserve resources and protect the community, it is significant to continue offering fertility-sparing treatment to cancer patients. This emphasis on the importance of preserving fertility despite the pandemic further highlights the essential and urgent nature of this procedure.

Description of the Follicular Fluid Cytokine and Hormone Profiles in Human Physiological Natural Cycles.

PURPOSE: Exogenous gonadotrophins administration during in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles could significantly alter the endogenous follicular regulation system and could influence oocyte quality. The analysis of the follicular fluid (FF) cytokine and hormone profiles in physiological natural cycles is crucial to appreciate the role of FF milieu on follicle development. So far, the FF cytokine profile has been analyzed only in controlled ovarian stimulation cycles and in modified natural cycles. Our study defines, in physiological natural cycles, the cytokine and hormone profiles of individual FF aspirated from antral follicles. METHODS: A total of 203 FFs obtained from 83 women with regular menstrual cycles undergoing ovarian tissue cryopreservation were analyzed: 115 FFs from Group 1 (10 to 29 years of age) and 88 FFs from Group 2 (30 to 40 years of age). In individual FF, 27 cytokines were measured with xMAP technology, and progesterone, estrone, estradiol, testosterone, androstenedione concentrations were determined by liquid chromatography-tandem mass spectrometry. RESULTS: FF hormone profiles were not different in follicular and luteal phase, suggesting that FF hormones are regulated independently of the endogenous gonadotrophins-possibly because 74% of the punctured follicles, which were ≤6 mm, did not require cyclic pituitary function. The follicle size was influenced not only by the FF cytokine profile but also by the FF hormone profile, both of which are dependent on age. MAIN CONCLUSIONS: In physiological natural cycles, FF hormones seems to be regulated independently of the endogenous gonadotropins. Age influences FF hormone and cytokine profiles and the compelling relationship between FF hormones and FF cytokines could influence the follicle development.

Preliminary results of a counselling programme for fertility preservation in female cancer patients: The experience of the GEMME DORMIENTI network.

OBJECTIVE: To describe a population of patients referred for fertility preservation (FP), how to efficiently provide FP care, and how FP care changed over time. METHODS: This longitudinal observational study enrolled 281 female cancer patients referred between 2013 and 2016 to the non-profit organisation Gemme Dormienti ONLUS (GD) for FP care. All patients underwent the same battery of instrumental and laboratory diagnostic tests. GnRHa therapy was started at least seven days before CTh treatment. RESULTS: From 2013 to 2016, we observed a progressive increase in the number of patients referred for FP care. Out of 251 eligible patients, 135 patients were treated with GnRHa only, and 72 patients underwent GnRHa therapy and cryopreservation. The median time from GD referral to oocyte and ovarian tissue cryopreservation was 11 and 5 days respectively. Tissue cryopreservation requests increased during our study period (from four cases in 2013 to 17 cases in 2016). During follow-up, 17ß-estradiol and FSH levels were significantly increased (p < .0001), and AMH levels were significantly decreased (p < .0001). CONCLUSION: The rapid increase in the number of patients who requested FP care and in the complexity of FP procedures overtime reflects the need to improve quality of life for cancer patients.

Altered morphokinetics in equine embryos from oocytes exposed to DEHP during IVM.

Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with endocrine-disrupting properties. In this study, we used an equine model to investigate DEHP concentrations in ovarian follicular fluid (FF), and to determine the effects of exposure of oocytes to potentially toxic concentrations of DEHP during in vitro maturation (IVM) on embryo development and quality. Embryo development was evaluated using time-lapse monitoring (TLM), a photomicroscopic tool that reveals abnormalities in cleavage kinetics unobservable by conventional morphology assessment. Blastocyst bioenergetic/oxidative status was assessed by confocal analysis. The possibility that verbascoside (VB), a bioactive polyphenol with antioxidant activity, could counteract DEHP-induced oocyte oxidative damage, was investigated. DEHP was detected in FF and in IVM media at concentrations up to 60 nM. Culture of oocytes in the presence of 500 nM DEHP delayed second polar body extrusion, reduced duration of the second cell cycle, and increased the percentage of embryos showing abrupt multiple cleavage, compared with controls. Mitochondrial activity and intracellular levels of reactive oxygen species were reduced in blastocysts from DEHP-exposed oocytes. VB addition during IVM limited DEHP-induced blastocyst damage. In conclusion, DEHP is detectable in equine FF and culture medium, and oocyte exposure to increased concentrations of DEHP during IVM affects preimplantation embryo development. Moreover, TLM, reported for the first time in the horse in this study, is an efficient tool for identifying altered morphokinetic parameters and cleavage abnormalities associated with exposure to toxic compounds.

Update on oogenesis in vitro.

INTRODUCTION: Ovarian tissue is increasingly being collected from cancer patients and cryopreserved for fertility preservation. Alternately to the autologous transplantation, the development of culture systems that support oocyte development from the primordial follicle stage represent a valid strategy to restore fertility. The aim of this study is to review the most recent data regarding oogenesis in vitro and to provide an up-to-date on the contemporary knowledge of follicle growth and development in vitro. EVIDENCE ACQUISITION: A comprehensive systematic MEDLINE search was performed since February 2018 for English-language reports by using the following terms: "ovary," "animal and human follicle," "in vitro growth and development," "ovarian tissue culture," "fertility preservation," "IVM," "oocyte." Previous published reviews and recent published original articles were preferred in order to meet our study scope. EVIDENCE SYNTHESIS: Over time, many studies have been conducted with the aim to optimize the characteristics of ovarian tissue culture systems and to better support the three main phases: 1) activation of primordial follicles; 2) isolation and culture of growing preantral follicles; 3) removal from the follicle environment and maturation of oocyte cumulus complexes. While complete oocyte in vitro development has been achieved in mouse, with the production of live offspring, the goal of obtaining oocytes of sufficient quality to support embryo development has not been completely reached into higher mammals despite decades of effort. CONCLUSIONS: Over the years, many improvements have been made on ovarian tissue cultures with the future purpose that patients will be provided with a greater number of developmentally competent oocytes for fertility preservation.

Transplantation of cryopreserved ovarian tissue in a patient affected by metastatic struma ovarii and endometriosis.

In this case report, the outcomes of cryopreserved ovarian tissue transplantation performed in a patient affected by struma-ovarii associated with mature cystic teratoma, recurrent endometriotic cysts and diffuse peritoneal malignant struma-ovarii implants were described. Before cryopreservation, the patient underwent two left ovarian surgeries for enucleation cysts 8 years after righ salpingo-oophorectomy for struma-ovarii. Ovarian biopsy was collected in another hospital and transported to our laboratory for cryopreservation. The patient was submitted to radioiodine-therapy for metastases from malignant struma-ovarii. After treatment she experienced premature ovarian failure. Ten years after cryopreservation, a first orthotopic transplantation was performed in the left ovary and in a peritoneal pocket. Before transplantation, ovarian samples were analyzed to assess neoplastic contamination and tissue quality. Three years later, a second transplantation was heterotopically performed in abdominal subcutaneous sites. The analysis on thawed ovarian tissue did not reveal micrometastasis and they showed follicle and stroma damages. After transplantation few small follicles were observed at ultrasound examination and hormonal levels remained at menopausal values. To date no ovarian function recovery has been observed. The report highlights that ovarian tissue cryopreservation after multiple ovarian surgery may have some limitations. An accurate counseling should be offered to patients who wish to preserve fertility.

First Italian birth after cryopreserved ovarian tissue transplantation in a patient affected by non-Hodgkin's lymphoma.

This case report describes the first Italian live birth obtained by cryopreserved ovarian tissue transplantation in a woman affected by non-Hodgkin's lymphoma. Before anticancer treatments, several fertility preservation options were proposed. At 29 years the patient underwent laparoscopy for ovarian tissue cryopreservation. After treatments she experienced premature ovarian failure (POF) and asked for cryopreserved ovarian tissue transplantation. Before transplantation, ovarian samples were analyzed to assess neoplastic contamination and tissue quality. Two subsequent ovarian tissue transplantations were performed 4 and 7 years after cryopreservation. The follicle-stimulating hormone and luteinizing hormone reduction, estradiol increase and first menstrual cycle appeared 2 months after the second transplantation. The woman conceived spontaneously 5 months after the second transplantation. After 39 weeks of uneventful gestation, a healthy male baby was born. Ovarian tissue cryopreservation, thawing and transplantation successfully restored ovarian function and fertility after tissue storage.

Long-term storage does not impact the quality of cryopreserved human ovarian tissue.

BACKGROUND: Ovarian tissue cryopreservation is an emerging technique, also addressed to very young cancer patients, for whom it is not possible to perform an ovarian stimulation for oocytes freezing, before gonadotoxic treatment. In this cases, ovarian tissue must be cryopreserved for a long period of time and it is very important to know if it maintains fertility function after a long period of storage. Here we aimed to assess the effect of long-term storage on preservation and viability of cryopreserved human ovarian tissue. METHODS: Descriptive study of three cases of cancer patients whose cryopreserved ovarian tissue remained stored for 18 years. Long-term stored tissue was examined by histological and immunohistochemical analysis, transmission electron microscopy, TUNEL assay and LIVE/DEAD viability/citotoxicity test. RESULTS: Ovarian tissue stored for 18 years showed a good morphology. Follicles presented negative staining for estrogen and progesterone receptors, positive staining for ki67 in granulosa cells and/or oocytes and for bcl2 in granulosa cells. Regarding stroma, patch/focal positive expression was found for estrogen receptor and ki67, diffusely positive expression for progesterone receptor and bcl2. After long-term storage, ultrastructural examination showed sub-cellular integrity of follicles and interstitial oedema foci. No apoptosis was observable by TUNEL assay. Stromal cell viability remained >97 % during the culture period. CONCLUSION: The evaluation of different aspects of the tissue provides evidence that the storage time does not impact on tissue quality and gives hope especially to cancer girls, whose tissues could remain cryopreserved for a very long time.

High cytokine expression and reduced ovarian reserve in patients with Hodgkin lymphoma or non-Hodgkin lymphoma.

OBJECTIVE: To investigate the ovarian reserve in female lymphoma patients and the potential relationships with the cytokine network. DESIGN: Age-matched control study. SETTING: Women's university hospital. PATIENT(S): Seventy-three lymphoma patients (57 with classic Hodgkin lymphoma [HL] and 16 with non-Hodgkin lymphoma [NHL]), approaching our center for ovarian tissue cryopreservation (study group) were compared with 25 age-matched healthy volunteers (control group). INTERVENTION(S): Measurements of antimüllerian hormone (AMH), soluble interleukin-2 receptor (SIL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor α (TNF-α) levels. MAIN OUTCOME MEASURE(S): The AMH and cytokine levels of the lymphoma patients and the healthy volunteers were compared. Correlations between AMH with SIL-2R, IL-6, and IL-8 levels were performed. RESULT(S): The AMH showed significant lower concentrations in lymphoma patients than in the control group. Higher significant concentrations in lymphoma patients than in control group were found for SIL-2R and IL-6. No differences were observed comparing HL and NHL groups and within the stages of HL group for AMH and all the cytokines analyzed. Finally, significant inverse correlations were observed in lymphoma patients between AMH and SIL-2R, IL-6, and IL-8 levels, but not with TNF-α levels. Positive correlations between SIL-2R with IL-6, and IL-6 with IL-8 were also shown. CONCLUSION(S): In patients with HL or NHL at baseline the cytokine network is particularly active and the ovarian reserve is reduced. A strong negative correlation between AMH and SIL-2R, IL-6, and IL-8 has been also evidenced.

Doxorubicin and cisplatin induce apoptosis in ovarian stromal cells obtained from cryopreserved human ovarian tissue.

AIM: To investigate mechanisms by which doxorubicin (DOX) and cisplatin (CIS) cause human ovarian stroma injury. PATIENTS & METHODS: Stromal cells from human cryopreserved ovarian tissue were cultured in the presence of 1 µM DOX and 10 µM CIS. Ovarian damage induced by treatments was evaluated by 'Live/Dead' and sulforhodamine-B assays, the expression of different apoptosis markers. RESULTS: Stromal cell growth was inhibited by DOX and CIS, and this effect was accompanied by apoptosis through mitochondrial pathway activation: Bax, cleaved-caspase 9, cleaved-PARP1 induction and Akt1, Bcl2, phospho-44/42-MAPK/ERK1/2 reduction were observed. CONCLUSION: DOX and CIS induced apoptosis in human ovarian stromal cells. Knowledge of mechanisms by which the drugs act is important to identify possible ways to counteract side effects of chemotherapy on ovaries.

New insights in the selection and management of cancer patients applicants for ovarian tissue cryopreservation.

Ovarian tissue cryopreservation (OTC), representing a promising strategy to preserve ovarian function in cancer patients, is recommended to women younger than 35 years. This study aimed to identify endocrine and biometric parameters as additional selection criteria for OTC. One hundred and ninety-one cancer patients before chemoradiotherapy and OTC and 43 controls were investigated. Mean ± SD, median, quartiles, 5th and 95th centiles and correlations of FSH, LH, estradiol, inhibin-B, anti-Mullerian hormone (AMH), ovarian volume and antral follicle count (AFC) were assessed. Most ovarian reserve parameters presented typical variations of ovulatory menstrual cycle, except AMH and AFC showing minimal fluctuations across the menstrual cycle. The 5th centiles of AMH (0.31and 0.4 ng/mL in controls and cancer patients, respectively) and AFC (five follicular structures in both groups) could be conjectured as minimum thresholds to include patients aged <35 years in OTC; below this threshold patients of any age should be excluded from OTC. Conversely, patients with AMH and AFC above the 25th centiles (1.2-1.6 ng/mL and 9-10 follicular structures in controls and cancer patients, respectively) might be inserted in OTC regardless of age. Baseline assessment of AMH and AFC might be considered as selection criteria, in addition to chronological age, to take decision of OTC in cancer patients.

Effects of N-acetylcysteine on human ovarian tissue preservation undergoing cryopreservation procedure.

The aim of the study was to evaluate the effects of the antioxidant N-acetylcysteine (NAC), added in freezing/thawing solutions, on reactive oxygen species (RRS) levels and on ovarian tissue preservation after cryopreservation. Ovarian samples from 10 subjects suffering from cancer diseases were cryopreserved using the slow freezing/rapid thawing standard protocol without or with NAC supplementation. RRS levels produced during cryopreservation were monitored by electron paramagnetic resonance (EPR) spectroscopy. The preservation of fresh ovarian tissue (t0), thawed tissue (t1 and t1 NAC) and thawed tissue maintained at 4°C for 2 hrs (t2 and t2 NAC) was analysed by light microscopy, transmission electron microscopy, Ki67 immunohistochemical and TUNEL analysis. It was possible to design a maximum peak for RRS production at t1, which slightly decreased at t2. NAC reduced the extent of RRS levels in cryopreserved ovarian tissues if compared with non-supplemented ones, although not restoring RRS production to baseline values. Comparative analysis between the two cryopreservation protocols showed that a better preservation of morphological characteristics, proliferation index and DNA integrity of ovarian tissue was obtained using NAC and no differences between t1NAC and t2NAC were observed. The employment of NAC during cryopreservation procedure could be an useful strategy for preserving the function of endogenous cellular systems. Nevertheless, further studies on the viability of thawed ovarian tissue are needed to support the feasibility of this approach in clinical settings.

Anti-Müllerian hormone as an ovarian reserve marker in young cancer women who undergo ovarian tissue cryopreservation.

AIM: To evaluate if anti-Müllerian hormone (AMH) is a reliable marker of ovarian reserve in young women undergoing ovarian tissue cryopreservation. PATIENTS & METHODS: Relationships of serum AMH levels with primordial follicle density, age and reproductive hormones were investigated using the Pearson or Spearman correlation coefficient in 86 women with cancer (12-38 years) undergoing ovarian tissue cryopreservation. AMH variations through the menstrual cycle were assessed by the Kruskal-Wallis test. p < 0.05 was accepted as significant. RESULTS: AMH positively correlated with primordial follicle density (p = 0.03), showed great interindividual variability at all ages and negatively correlated with estradiol (p = 0.007) in the early follicular phase. AMH did not vary across the menstrual cycle (p = 0.415). CONCLUSION: AMH appears a valid ovarian reserve marker in young cancer women.

The techniques and outcomes of hysteroscopic metroplasty.

PURPOSE OF REVIEW: To evaluate the reproductive outcomes and surgical techniques of the hysteroscopic metroplasty in women with septate uterus and recurrent abortions or primary unexplained infertility. RECENT FINDINGS: Septate uterus is the most frequent congenital uterine anomaly caused by inadequate resorption of the Müllerian ducts. Hysteroscopic metroplasty has replaced the traditional laparotomy approach because of its positive and satisfactory outcomes in pregnancy and live-birth rates, and also many different postoperative benefits. The aim of metroplasty is to restore a normal anatomy of the uterine cavity as a prerequisite for a positive implantation and subsequent good obstetrical outcomes. This treatment clearly demonstrates its effectiveness both in recurrent abortion and in primary unexplained infertility. SUMMARY: The hysteroscopic metroplasty with its simplicity, safety, and improved reproductive outcomes has liberalized the approach to treatment. Today, hysteroscopic metroplasty is a common practice to treat septate uterus with salutary effects both in infertile patients and in patients with recurrent pregnancy loss or premature labor, especially if in-vitro fertilization is being contemplated. Decisions on when to treat uterine septa are discussed in particular because of lack of prospective, randomized controlled trials.

A wide range of 3243A>G/tRNALeu(UUR) (MELAS) mutation loads may segregate in offspring through the female germline bottleneck.

Segregation of mutant mtDNA in human tissues and through the germline is debated, with no consensus about the nature and size of the bottleneck hypothesized to explain rapid generational shifts in mutant loads. We investigated two maternal lineages with an apparently different inheritance pattern of the same pathogenic mtDNA 3243A>G/tRNALeu(UUR) (MELAS) mutation. We collected blood cells, muscle biopsies, urinary epithelium and hair follicles from 20 individuals, as well as oocytes and an ovarian biopsy from one female mutation carrier, all belonging to the two maternal lineages to assess mutant mtDNA load, and calculated the theoretical germline bottleneck size (number of segregating units). We also evaluated "mother-to-offspring" segregations from the literature, for which heteroplasmy assessment was available in at least three siblings besides the proband. Our results showed that mutation load was prevalent in skeletal muscle and urinary epithelium, whereas in blood cells there was an inverse correlation with age, as previously reported. The histoenzymatic staining of the ovarian biopsy failed to show any cytochrome-c-oxidase defective oocyte. Analysis of four oocytes and one offspring from the same unaffected mother of the first family showed intermediate heteroplasmic mutant loads (10% to 75%), whereas very skewed loads of mutant mtDNA (0% or 81%) were detected in five offspring of another unaffected mother from the second family. Bottleneck size was 89 segregating units for the first mother and 84 for the second. This was remarkably close to 88, the number of "segregating units" in the "mother-to-offspring" segregations retrieved from literature. In conclusion, a wide range of mutant loads may be found in offspring tissues and oocytes, resulting from a similar theoretical bottleneck size.

Autotransplantation of cryopreserved ovarian tissue in oncological patients: recovery of ovarian function.

AIM: To present preliminary results of autotransplantation of cryopreserved ovarian tissue performed at Sant'Orsola-Malpighi Hospital, Bologna, Italy. MATERIALS & METHODS: Orthotopic transplantation was performed in two women with colorectal and breast cancer, and heterotopic transplantation was performed in one Hodgkin's lymphoma woman. The presence of micrometastasis in the ovarian tissue was checked, and morphological features of ovarian tissue were evaluated before transplantation. Ovarian function was monitored by hormonal and ultrasound-color Doppler examination after transplantation. RESULTS: In all three women, no micrometastasis was found; light and transmission electron microscopy showed well-preserved thawed ovarian tissue. Ovarian function recovery was observed 2-4 months after transplantation. Spontaneous menstrual cycles occurred in two women with normal follicular densities. No periods occurred in the woman with low follicular density at the time of tissue collection. CONCLUSION: Ovarian tissue cryopreservation and transplantation is a promising approach for preserving ovarian function in women with cancer.