Autologous stem cell ovarian transplantation to increase reproductive potential in patients who are poor responders

Poor ovarian response classification systems in the clinical setting - time for an update?

PURPOSE OF REVIEW

Poor ovarian response (POR) remains a key challenge to the success of assisted reproductive technology. Here, we offer a comprehensive review of the two main classification systems for POR, discussing their promises and pitfalls, evaluating their performance, and exploring potential avenues for improving upon these definitions of POR.

RECENT FINDINGS

The Bologna criteria represented the first meaningful attempt to create a universal POR definition. Subsequently, the POSEIDON classification system was published to provide a more nuanced view of POR, classifying patients into four groups based on age and ovarian reserve markers. A recent study evaluated the likelihood of achieving at least one euploid embryo for transfer and found that, indeed, these classification systems are effective predictors of this outcome.While these criteria provide an effective counseling tool, several limitations - not considering underlying conditions, selecting somewhat arbitrary cutoffs, and evaluating the number of oocytes retrieved regardless of maturity - highlight the importance of improving upon these systems to create a more useful tool to more accurately predict ovarian response for clinical and research purposes.

SUMMARY

In the era of personalized medicine, it is time to reconsider whether diagnostic criteria for a continuous metric such as ovarian response should be based on meeting all-or-nothing thresholds for specific parameters.

Efficacy of intra-ovarian injection of autologous platelet-rich plasma in women with poor responders: a systematic review and meta-analysis

CONTEXT

The effect of platelet-rich plasma (PRP) on ovarian reserve markers in poor ovarian response (POR) is challenging.

AIM

This systematic review and meta-analysis was, therefore, designed to evaluate the effectiveness of intra-ovarian injection of autologous PRP on improving ovarian reserve markers and assisted reproductive technology (ART) outcomes in infertile women with POR.

METHODS

A systematic search was conducted for the efficacy of intra-ovarian injection of autologous PRP on the improvement of ovarian reserve markers and ART outcomes in infertile women with POR. The methodological quality of the included studies was checked and eligible studies were included in the meta-analysis to find pooled results. Keywords were primary ovarian insufficiency, premature menopause, poor responder, poor ovarian response, diminished/decreased ovarian reserve, platelet-rich plasma, and intra-ovarian or a combination of them. The effect of PRP on fertility indices was evaluated using the standardized mean difference (SMD). The analysis was performed through STATA version 13.

KEY RESULTS

13 studies containing 1289 patients were included. Mean age, body mass index (BMI) and duration of infertility was 37.63 ± 2.66 years, 24 ± 1.23 kg/m2 and 4.79 ± 1.64 years, respectively. Most of the studies measured the outcomes 2-3/3 months after intra-ovarian injection of autologous PRP. The antral follicular count (AFC) after treatment by PRP is higher with an SMD of 0.95 compared to before treatment. The day 3 follicle-stimulating hormone (FSH) after treatment by PRP is lower with an SMD of - 0.25 compared to before treatment. The day 3 estradiol (E2) after treatment by PRP is higher with an SMD of 0.17 compared to before treatment. The anti-Mullerian hormone (AMH) after treatment by PRP is higher with an SMD of 0.44 compared to before treatment. The total oocytes number after treatment by PRP is higher with an SMD of 0.73 compared to before treatment. The number of MII oocytes after treatment by PRP is higher with an SMD of 0.63 compared to before treatment. The number of cleavage-stage embryos after treatment by PRP is higher with an SMD of 1.31 compared to before treatment. The number of day 5 embryo after treatment by PRP is higher with an SMD of 1.28 compared to before treatment. Pooled estimation of a meta-analysis of prevalence studies reported a prevalence of 22% for clinical pregnancy, 5% for spontaneous pregnancy and 21% for ongoing pregnancy following PRP therapy.

CONCLUSION

Intra-ovarian injection of PRP improved ovarian reserve markers with increasing AFC, serum level of AMH and day 3 E2 and decreasing serum level of day 3 FSH. In addition, this treatment improved ART outcomes through the increasing of number total oocytes, number of MII oocytes, number of cleavage-stage embryos and number of day 5 embryos in POR women.

IMPLICATIONS

Although treatment of POR women remains challenging, the use of intra-ovarian injection of autologous PRP in POR patients prior to IVF/ICSI cycles is a sign of new hope for increasing the success of IVF/ICSI. However, further well-organized, randomized controlled trials should be conducted to substantiate this result and recommend intra-ovarian injection of PRP as part of routine treatment in women with POR.

The Reproductive Lifespan of Ovarian Follicle

The functional unit within mammalian ovaries is the ovarian follicle. The development of the ovarian follicle is a lengthy process beginning from the time of embryogenesis, passing through multiple different stages of maturation. The purpose of this review is to describe the most basic events in the journey of ovarian follicle development, discussing the importance of ovarian reserve and highlighting the role of several factors that affect oocyte quality and quantity during aging including hormonal, genetic and epigenetic factors. Novel, promising anti-aging strategies are also discussed.

Platelet-rich plasma (PRP) treatment of the ovaries significantly improves fertility parameters and reproductive outcomes in diminished ovarian reserve patients: a systematic review and meta-analysis

INTRODUCTION

The incidence of infertility caused by diminished ovarian reserve has become a significant problem worldwide. The beneficial effect of PRP treatment of the ovaries has already been described, but the high-level evidence of its effectiveness has not yet been proven.

MATERIALS AND METHODS

A systematic search was performed in five databases, until March 12th, 2024. Both randomized and non-randomized studies that compared PRP treatment of the ovaries to self-control among women with diminished ovarian reserve were eligible for inclusion. Hormonal levels (Anti-Müllerian hormone (AMH), Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Estradiol (E2), In-vitro fertilization parameters (Antral follicle count, oocyte, and embryo count), biochemical and spontaneous pregnancy and livebirth were measured.

RESULTS

38 eligible studies were identified reporting on 2256 women. The level of AMH rised, the level of FSH decreased significantly after the PRP treatment. AMH 1 month MD 0.20 (n = 856, p > 0.001, 95% CI: [0.12;0.28]), 2 months MD 0.26 (n = 910, p = 0.013, 95% CI: [0.07;0.44]), 3 months MD 0.36 (n = 881, p = 0.002,95% CI: [0.20;0.52]). FSH 1 month MD -10.20 (n = 796, p > 0.039, 95% CI: [-19.80;-0.61]), 2 months MD -7.02 (n = 910, p = 0.017, 95% CI: [-12.48; -1.57]), 3 months MD -8.87 (n = 809, p = 0.010, 95% CI: [-14.19; -3.55]). The antral follicle count elevated significantly MD 1.60 (n = 1418, p =  < 0.001, 95% CI: [0.92; 2.27]). Significant improvement was observed in the number of retrieved oocytes MD 0.81 (n = 802, p = 0.002, 95% CI: [0.36; 1.26]), and embryos created MD 0.91 (n = 616, p = 0.001, 95% CI: [0.45;1.36]). The incidence of spontaneous pregnancy following PRP treatment showed a rate with a proportion of 0.07 (n = 1370, 95% CI: 0.04-0.12), the rate of biochemical pregnancy was 0.18 (n = 1800, 95% CI: 0.15-0.22), livebirth was 0.11 (n = 1482, 95% CI: 0.07-0.15).

CONCLUSIONS

Our meta-analysis showed that based on protocolized analysis of the widest scientific literature search to date, containing predominantly observational studies, PRP treatment resulted in a statistically significant improvement in the main fertility parameters of diminished ovarian reserve women. Further multicenter, randomized trials, with large patient numbers and a longer follow-up period are needed to certify our results and develop the most effective treatment protocol.

Combination of bone marrow mesenchymal stem cells and moxibustion restores cyclophosphamide-induced premature ovarian insufficiency by improving mitochondrial function and regulating mitophagy

BACKGROUND

Premature ovarian insufficiency (POI) is a major cause of infertility. In this study, we aimed to investigate the effects of the combination of bone marrow mesenchymal stem cells (BMSCs) and moxibustion (BMSCs-MOX) on POI and evaluate the underlying mechanisms.

METHODS

A POI rat model was established by injecting different doses of cyclophosphamide (Cy). The modeling of POI and the effects of the treatments were assessed by evaluating estrous cycle, serum hormone levels, ovarian weight, ovarian index, and ovarian histopathological analysis. The effects of moxibustion on BMSCs migration were evaluated by tracking DiR-labeled BMSCs and analyzing the expression of chemokines stromal cell-derived factor 1 (Sdf1) and chemokine receptor type 4 (Cxcr4). Mitochondrial function and mitophagy were assessed by measuring the levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), ATP, and the mitophagy markers (Drp1, Pink1, and Parkin). Furthermore, the mitophagy inhibitor Mdivi-1 and the mitophagy activator CCCP were used to confirm the role of mitophagy in Cy-induced ovarian injury and the underlying mechanism of combination therapy.

RESULTS

A suitable rat model of POI was established using Cy injection. Compared to moxibustion or BMSCs transplantation alone, BMSCs-MOX showed improved outcomes, such as reduced estrous cycle disorders, improved ovarian weight and index, normalized serum hormone levels, increased ovarian reserve, and reduced follicle atresia. Moxibustion enhanced Sdf1 and Cxcr4 expression, promoting BMSCs migration. BMSCs-MOX reduced ROS levels; upregulated MMP and ATP levels in ovarian granulosa cells (GCs); and downregulated Drp1, Pink1, and Parkin expression in ovarian tissues. Mdivi-1 significantly mitigated mitochondrial dysfunction in ovarian GCs and improved ovarian function. CCCP inhibited the ability of BMSCs-MOX treatment to regulate mitophagy and ameliorate Cy-induced ovarian injury.

CONCLUSIONS

Moxibustion enhanced the migration and homing of BMSCs following transplantation and improves their ability to repair ovarian damage. The combination of BMSCs and moxibustion effectively reduced the excessive activation of mitophagy, which helped prevent mitochondrial damage, ultimately improving ovarian function. These findings provide a novel approach for the treatment of pathological ovarian aging and offer new insights into enhancing the efficacy of stem cell therapy for POI patients.

Efficacy and safety of mesenchymal stem cell therapy for ovarian ageing in a mouse model

BACKGROUND

Ovarian ageing is one of the major issues that impacts female fertility. Mesenchymal stem cell (MSC)-based therapy has made impressive progress in recent years. However, the efficacy and safety of MSCs, as nonautologous components, remain to be further verified.

METHODS

Two common sources of MSCs, umbilical cord-derived MSCs (UC-MSCs) and adipose tissue-derived MSCs (AD-MSCs), were orthotopically transplanted into a mouse model of ovarian ageing to evaluate their therapeutic effects. The safety of the treatment was further evaluated, and RNA sequencing was performed to explore the underlying mechanisms involved.

RESULTS

After orthotopic transplantation of MSCs into the ovary, the oestrous cycle, ovarian weight, number and proportion of primary follicles, granulosa cell proliferation, and angiogenesis were improved. The effects of AD-MSCs were superior to those of UC-MSCs in several indices, such as post-transplant granulosa cell proliferation, ovarian weight and angiogenesis. Moreover, the tumorigenesis, acute toxicity, immunogenicity and biodistribution of MSCs were evaluated, and both AD-MSCs and UC-MSCs were found to possess high safety profiles. Through RNA sequencing analysis, enhancement of the MAPK cascade was observed, and long-term effects were mainly linked to the activation of immune function.

CONCLUSIONS

Orthotopic transplantation of MSCs displays significant efficacy and high safety for the treatment of ovarian ageing in mice.

Current Status and Future Prospects of Stem Cell Therapy for Infertile Patients with Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI), also known as premature menopause or premature ovarian failure, signifies the partial or complete loss of ovarian endocrine function and fertility before 40 years of age. This condition affects approximately 1% of women of childbearing age. Although 5-10% of patients may conceive naturally, conventional infertility treatments, including assisted reproductive technology, often prove ineffective for the majority. For infertile patients with POI, oocyte donation or adoption exist, although a prevalent desire persists among them to have biological children. Stem cells, which are characterized by their undifferentiated nature, self-renewal capability, and potential to differentiate into various cell types, have emerged as promising avenues for treating POI. Stem cell therapy can potentially reverse the diminished ovarian endocrine function and restore fertility. Beyond direct POI therapy, stem cells show promise in supplementary applications such as ovarian tissue cryopreservation and tissue engineering. However, technological and ethical challenges hinder the widespread clinical application of stem cells. This review examines the current landscape of stem cell therapy for POI, underscoring the importance of comprehensive assessments that acknowledge the diversity of cell types and functions. Additionally, this review scrutinizes the limitations and prospects associated with the clinical implementation of stem cell treatments for POI.

Comparison of luteal phase stimulation with follicular phase stimulation in poor ovarian response: a single-blinded randomized controlled trial

BACKGROUND

In the last decade, luteal-phase ovarian stimulation (LPOS) has been suggested as an alternative controlled ovarian stimulation (COS) protocol for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles mainly in women with a history of poor ovarian response (POR). The present randomized controlled trial study aimed to compare the outcomes of follicular phase ovarian stimulation (FPOS) and LPOS protocols in POR cases undergoing ICSI cycles.

METHODS

Seventy-eight POR patients who met the Bologna criteria and underwent an ICSI cycle were included. In this study, 39 POR cases were allocated to the FPOS group, and 39 POR cases were allocated to the LPOS group. The primary outcome was the number of metaphase II (MII) oocytes. In addition, the total number of oocytes, number of top-quality day 3 embryo, day 3 embryo development rate, chemical pregnancy and clinical pregnancy rates were defined as secondary outcomes.

RESULTS

The obtained results demonstrated that the number of MII oocytes significantly increased in the LPOS group compared to the FPOS group (P = 0.007). However, there was no significant difference between the two groups regarding the number of GV and MI oocytes, number of top-quality day 3 embryos and day 3 embryo development rate among both categories of patients. Also, the number of total and MII oocytes was significantly higher in the LPOS group (P = 0.016).

CONCLUSION

These results suggest that LPOS protocol effectively increases the number of mature oocytes in women with a history of POR.

TRIAL REGISTRATION

IRCT20210405050852N1 (Registered at Iranian registry of clinical trials; available at https://en.irct.ir/trial/55402 ).

Stem cell therapy for premature ovarian insufficiency: a systematic review and meta-analysis of animal and clinical studies

PURPOSE

The aim of this systematic review and meta-analysis is to evaluate the efficacy of stem cell therapy in mouse models of POI and patients with POI.

METHODS

The PubMed, Web of Science, and Embase databases were searched from inception to February 2022 for relevant animal and clinical studies. The reference lists of the included reviews were manually searched to identify additional eligible studies. Data were independently extracted by two investigators, and disagreements were resolved by discussion. SYRCLE's risk of bias tool and the MINORS tool were used to assess the quality of animal and clinical studies by two independent investigators. All statistical analyses were conducted using Review Manager 5.3 software.

RESULTS

A total of twenty animal studies and six clinical studies were included in this meta-analysis. In animal studies, the results showed that stem cells could improve hormone levels, follicle count, estrous cycle and pregnancy outcome. For hormone levels, stem cells increased serum E2 and AMH levels and decreased serum FSH and LH levels compared with the control group (serum E2 level: SMD: 5.05, 95% CI 4.21-5.90, P < 0.00001; serum AMH level: SMD: 4.42, 95% CI 3.06-5.79, P < 0.00001; serum FSH level: SMD: - 3.79, 95% CI - 4.87 to -  2.70, P < 0.00001; serum LH level: SMD: - 1.31, 95% CI - 1.65 to - 0.96, P < 0.00001). All follicle counts, except for the antral follicle count, were significantly changed compared with the control group. (primordial follicle count: SMD: 4.61, 95% CI 3.65-5.56, P < 0.00001; primary follicle count: SMD: 3.35, 95% CI 1.08-5.63, P = 0.004; secondary follicle count: SMD: 3.23, 95% CI 1.92-4.55, P < 0.00001; total follicle count: SMD: 4.84, 95% CI 2.86-6.83, P < 0.00001; oocyte count: SMD: 7.56, 95% CI 5.92-9.20, P < 0.00001; atretic follicle count: SMD: - 1.79, 95% CI - 2.59 to - 1.00, P < 0.00001). For the estrous cycle, stem cell therapy increased the number of estrous cycles (WMD: 2.72, 95% CI 2.07-3.37, P < 0.00001) and decreased the duration of the estrous cycle (WMD: - 1.26, 95% CI - 1.84 to - 0.69, P < 0.0001) compared with the control group. For pregnancy outcomes, stem cell therapy increased the fertility rate (RR: 3.00, 95% CI 1.74-5.17, P < 0.0001) and litter size (WMD: 3.82, 95% CI 0.36-7.28, P = 0.03) compared with the control group. In animal studies, the asymmetric funnel plot of serum E2 and FSH levels indicated the possibility of publication bias. Unpublished and negative studies may be the source of publication bias. In clinical studies, the results showed that stem cell therapy could decrease serum FSH level (MD: - 30.32, 95% CI - 59.03 to - 1.01, P = 0.04) and increase AFC (MD: 1.07, 95% CI 0.70-1.43, P < 0.00001), pregnancy rate (RD: 0.19, 95% CI 0.04-0.34, P = 0.01) and live birth rate (RD: 0.19, 95% CI 0.07-0.31, P = 0.001) in POI patients. In addition, there was no significant difference in menstrual function regained (RD: 0.22, 95% CI - 0.03-0.46, P = 0.09), oocytes retrieved (MD: 1.00, 95% CI - 0.64-2.64, P = 0.23) and embryos (MD: 0.80, 95% CI - 0.15-1.76, P = 0.10) between different groups.

CONCLUSION

This meta-analysis suggested that stem cell therapy might be effective in POI mouse models and patients and could be considered a potential treatment to restore fertility capability in POI patients.

Systemic changes induced by autologous stem cell ovarian transplant in plasma proteome of women with impaired ovarian reserves

Patients with poor ovarian response (POR) and premature ovarian insufficiency (POI) are challenging to treat, with oocyte donation remaining as the only feasible option to achieve pregnancy in some cases. The Autologous stem cell ovarian transplantation (ASCOT) technique allows follicle development, enabling pregnancies and births of healthy babies in these patients. Previous results suggest that growth factors and cytokines secreted by stem cells are partially responsible for their regenerative properties. Indeed, ASCOT beneficial effects associate with the presence of different bone marrow derived stem cell- secreted factors in plasma. Therefore, the aim of this study was to assess whether ASCOT induce any modifications in the plasma proteomic profile of patients with impaired ovarian reserves. Discriminant analysis highlighted clear distinctions between the plasma proteome before (PRE), during stem cell mobilization and collection (APHERESIS) and three months after ASCOT (POST) in patients with POR and POI. Both the stem cell mobilization and ASCOT technique induced statistically significant modifications in the plasma composition, reversing some age-related protein expression changes. In the POR group, functional analysis revealed an enrichment in processes related to the complement cascade, immune system, and platelet degranulation, while in the POI group, enriched processes were also associated with responses to oxygen-containing compounds and growth hormones, and blood vessel maturation. In conclusion, our findings highlight the potential proteins and biological processes that may promote the follicle activation and growth observed after ASCOT. Identifying plasma proteins that regenerate aged or damaged ovaries could lead to more effective, targeted and/or preventive therapies for patients.

Stem-Cell-Derived Extracellular Vesicles: Unlocking New Possibilities for Treating Diminished Ovarian Reserve and Premature Ovarian Insufficiency

Despite advancements in assisted reproductive technology (ART), achieving successful pregnancy rates remains challenging. Diminished ovarian reserve and premature ovarian insufficiency hinder IVF success-about 20% of in vitro fertilization (IVF) patients face a poor prognosis due to a low response, leading to higher cancellations and reduced birth rates. In an attempt to address the issue of premature ovarian insufficiency (POI), we conducted systematic PubMed and Web of Science research, using keywords "stem cells", "extracellular vesicles", "premature ovarian insufficiency", "diminished ovarian reserve" and "exosomes". Amid the complex ovarian dynamics and challenges like POI, stem cell therapy and particularly the use of extracellular vesicles (EVs), a great potential is shown. EVs trigger paracrine mechanisms via microRNAs and bioactive molecules, suppressing apoptosis, stimulating angiogenesis and activating latent regenerative potential. Key microRNAs influence estrogen secretion, proliferation and apoptosis resistance. Extracellular vesicles present a lot of possibilities for treating infertility, and understanding their molecular mechanisms is crucial for maximizing EVs' therapeutic potential in addressing ovarian disorders and promoting reproductive health.

The effects of intraovarian injection of autologous menstrual blood-derived mesenchymal stromal cells on pregnancy outcomes in women with poor ovarian response

BACKGROUND

Assisted reproduction faces a significant obstacle in the form of poor ovarian response (POR) to controlled ovarian stimulation. To address this challenge, mesenchymal stem cell therapy has been proposed as a potential treatment for female infertility and/or restoration of ovarian function in POR women. Our previous research has demonstrated that menstrual blood-derived-mesenchymal stromal cells (MenSCs) injected into the ovaries of women with POR can increase pregnancy rates. The objective of this study was to examine whether MenSC therapy could enhance ovarian reserve parameters and pregnancy outcomes in a larger population of individuals with POR.

METHOD

This study consisted of 180 infertile individuals with POR who declined oocyte donation. Participants were divided into two groups: those who received bilateral MenSCs intraovarian injection and those who received no intervention. Our primary aim was to compare the rates of spontaneous pregnancy between the two groups, followed by an investigation of any alterations in the ovarian reserve parameters, such as serum FSH, AMH, and AFC levels, as well as the ICSI/IVF outcomes, in both groups of participants.

RESULTS

The MenSC therapy exhibited a favourable tolerability profile and did not raise any safety concerns. Following the 2-month follow-up period, women who received MenSC treatment demonstrated a significantly higher rate of spontaneous pregnancy (P < 0.005) and an improvement in anti-Müllerian hormone (AMH) levels (P = 0.0007) and antral follicle count (AFC) (P < 0.001), whereas the control group demonstrated a considerable decline in these parameters (Both P < 0.001). The MenSC therapy led to a greater number of mature oocytes and embryos among women who underwent ICSI/IVF. Our age subgroup analysis demonstrated a significant difference in the number of spontaneous pregnancies and ICSI/IVF outcomes between the treatment and control groups only among individuals below 40 years of age.

CONCLUSION

The results of our study indicate that MenSCs treatment may be a viable option for treating women experiencing POR. However, in order to be widely implemented in clinical practice, the clinical effectiveness of MenSCs therapy will need to be established through rigorous prospective randomized clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05703308. Registered 01/26/2023, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05703308 . IRCT, IRCT20180619040147N4. Registered 08/01/2020.

Use of mesenchymal stem cells to enhance or restore fertility potential: a systematic review of available experimental strategies

STUDY QUESTION

To what extent does regenerative medicine with stem cell therapy help to address infertility issues for future clinical application?

SUMMARY ANSWER

Regenerative medicine using different stem cell sources is yielding promising results in terms of protecting the ovarian reserve from damage and senescence, and improving fertility potential in various preclinical settings.

WHAT IS KNOWN ALREADY

Regenerative medicine using stem cell therapy is emerging as a potential strategy to address a number of issues in the field of human reproduction. Indeed, different types of adult and fetal mesenchymal stem cells (MSCs) have been tested with promising results, owing to their ability to differentiate into different tissue lineages, move toward specific injured sites (homing), and generate a secretome with wound-healing, proangiogenic, and antioxidant capacities.

STUDY DESIGN SIZE DURATION

Guided by the checklist for preferred reporting items for systematic reviews and meta-analyses, we retrieved relevant studies from PubMed, Medline, and Embase databases until June 2023 using the following keywords: 'mesenchymal stem cells' AND 'ovarian follicles' OR 'ovarian tissue culture' OR 'ovarian follicle culture' OR 'cumulus oocyte complex'. Only peer-reviewed published articles written in English were included.

PARTICIPANTS/MATERIALS SETTING METHODS

The primary outcome for the experimental strategies was evaluation of the ovarian reserve, with a focus on follicle survival, number, and growth. Secondary outcomes involved analyses of other parameters associated with the follicle pool, such as hormones and growth factors, ovarian tissue viability markers including oxidative stress levels, oocyte growth and maturation rates, and of course pregnancy outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Preclinical studies exploring MSCs from different animal origins and tissue sources in specific conditions were selected (n = 112), including: in vitro culture of granulosa cells, ovarian tissue and isolated ovarian follicles; ovarian tissue transplantation; and systemic or intraovarian injection after gonadotoxic or age-related follicle pool decline. Protecting the ovarian reserve from aging and gonadotoxic damage has been widely tested in vitro and in vivo using murine models and is now yielding initial data in the first ever case series of patients with premature ovarian insufficiency. Use of MSCs as feeder cells in ovarian tissue culture was found to improve follicle outcomes and oocyte competence, bringing us one step closer to future clinical application. MSCs also have proved effective at boosting revascularization in the transplantation site when grafting ovarian tissue in experimental animal models.

LIMITATIONS REASONS FOR CAUTION

While preclinical results look promising in terms of protecting the ovarian reserve in different experimental models (especially those in vitro using various mammal experimental models and in vivo using murine models), there is still a lot of work to do before this approach can be considered safe and successfully implemented in a clinical setting.

WIDER IMPLICATIONS OF THE FINDINGS

All gathered data on the one hand show that regenerative medicine techniques are quickly gaining ground among innovative techniques being developed for future clinical application in the field of reproductive medicine. After proving MSC effectiveness in preclinical settings, there is still a lot of work to do before MSCs can be safely and effectively used in different clinical applications.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS-PDR T.0077.14, FNRS-CDR J.0063.20, and grant 5/4/150/5 awarded to Marie-Madeleine Dolmans), Fonds Spéciaux de Recherche, and the Fondation St Luc. None of the authors have any competing interest to disclose.

REGISTRATION NUMBER

N/A.

Deciphering reproductive aging in women using a NOD/SCID mouse model for distinct physiological ovarian phenotypes

Female fertility is negatively correlated with age, with noticeable declines in oocyte quantity and quality until menopause. To understand this physiological process and evaluate human approaches for treating age-related infertility, preclinical studies in appropriate animal models are needed. Thus, we aimed to characterize an immunodeficient physiological aging mouse model displaying ovarian characteristics of different stages during women's reproductive life. NOD/SCID mice of different ages (8-, 28-, and 36-40-week-old) were employed to mimic ovarian phenotypes of young, Advanced Maternal Age (AMA), and old women (~18-20-, ~36-38-, and >45-years-old, respectively). Mice were stimulated, mated, and sacrificed to recover oocytes and embryos. Then, ovarian reserve, follicular growth, ovarian stroma, mitochondrial dysfunction, and proteomic profiles were assessed. Age-matched C57BL/6 mice were employed to cross-validate the reproductive outcomes. The quantity and quality of oocytes were decreased in AMA and Old mice. These age-related effects associated spindle and chromosome abnormalities, along with decreased developmental competence to blastocyst stage. Old mice had less follicles, impaired follicle activation and growth, an ovarian stroma inconducive to growth, and increased mitochondrial dysfunctions. Proteomic analysis corroborated these histological findings. Based on that, NOD/SCID mice can be used to model different ovarian aging phenotypes and potentially test human anti-aging treatments.

The Aging Ovary and the Tales Learned Since Fetal Development

BACKGROUND

While the term "aging" implies a process typically associated with later life, the consequences of ovarian aging are evident by the time a woman reaches her forties, and sometimes earlier. This is due to a gradual decline in the quantity and quality of oocytes which occurs over a woman's reproductive lifespan. Indeed, the reproductive potential of the ovary is established even before birth, as the proper formation and assembly of the ovarian germ cell population during fetal life determines the lifetime endowment of oocytes and follicles. In the ovary, sophisticated molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance.

SUMMARY

The mechanisms thought to contribute to overall aging have been summarized under the term the "hallmarks of aging" and include such processes as DNA damage, mitochondrial dysfunction, telomere attrition, genomic instability, and stem cell exhaustion, among others. Similarly, in the ovary, molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance. In this review, we outline critical processes involved in ovarian aging, highlight major achievements for treatment of ovarian aging, and discuss ongoing questions and areas of debate.

KEY MESSAGES

Ovarian aging is recognized as what may be a complex process in which age, genetics, environment, and many other factors contribute to the size and depletion of the follicle pool. The putative hallmarks of reproductive aging outlined herein include a diversity of plausible processes contributing to the depletion of the ovarian reserve. More research is needed to clarify if and to what extent these putative regulators do in fact govern follicle and oocyte behavior, and how these signals might be integrated in order to control the overall pattern of ovarian aging.

Granulocyte colony-stimulating factor priming improves embryos and pregnancy rate in patients with poor ovarian reserve: a randomized controlled trial

BACKGROUND

Granulocyte colony-stimulating factor (G-CSF) administration increased ovarian preantral follicles and anti-Müllerian hormone (AMH) in animal models with diminished ovarian reserve. We investigated whether G-CSF priming before treatment with assisted reproductive technology (ART) improved embryo development and pregnancy rate while increasing serum AMH in patients with poor ovarian reserve.

METHODS

In this prospective randomized open-label controlled trial, 100 patients 20 to 42 years old with AMH below 2 ng/mL were randomized to priming or control groups (50 patients each). None had over 1 ART failure, day-3 follicle-stimulating hormone (FSH) above 30 IU/L, uterine anomalies, or a partner with azoospermia. All patients initially underwent conventional infertility treatment for 2 consecutive cycles in which the priming group but not controls received a subcutaneous G-CSF priming injection during the early luteal phase. Each group then underwent 1 cycle of in vitro fertilization/intracytoplasmic sperm injection and fresh embryo transfer (IVF/ICSI-fresh ET), followed by cryopreserved ET if needed until live birth or embryo depletion. AMH was measured before and after priming.

RESULTS

Fertilization rate, embryonic development, and implantation rate by fresh ET were significantly improved by priming. Clinical and ongoing pregnancy rates by IVF/ICSI-fresh ET were significantly higher with priming (30% and 26% in 47 ART patients; 3 delivered with conventional treatment) than in controls (12% and 10% in 49 ART patients; 1 dropped out). With priming, significantly more patients achieved cryopreservation of redundant blastocysts. The cumulative live birth rate was 32% in 50 patients with priming, significantly higher than 14% in 49 controls (relative risk, 2.8; 95% confidence interval, 1.04-7.7). Infants derived from priming had no congenital anomalies, while infant weights, birth weeks, and Apgar scores were similar between groups. Among 4 variables (age, day-3 FSH, AMH, and priming), logistic regression significantly associated age and priming with cumulative live birth. Priming significantly increased serum AMH. No adverse effects of priming were observed.

CONCLUSION

G-CSF priming improved embryonic development and pregnancy rate during ART treatment and increased AMH in patients with poor ovarian reserve. Enhanced preantral follicle growth likely was responsible.

TRIAL REGISTRATION

UMIN registration in Japan (UMIN000013956) on May 14, 2014.  https://www.umin.ac.jp/ctr/index.htm .

Ovarian rescue in women with premature ovarian insufficiency: facts and fiction

The ovary has a comparatively short functional lifespan compared with other organs, and genetic and pathological injuries can further shorten its functional life. Thus, preserving ovarian function should be considered in the context of women with threats to ovarian reserve, such as ageing, premature ovarian insufficiency (POI) and diminished ovarian reserve (DOR). Indeed, one-third of women with POI retain resting follicles that can be reactivated to produce competent oocytes, as proved by the in-vitro activation of dormant follicles. This paper discusses mechanisms and clinical data relating to new therapeutic strategies using ovarian fragmentation, stem cells or platelet-rich plasma to regain ovarian function in women of older age (>38 years) or with POI or DOR. Follicle reactivation techniques show promising experimental outcomes and have been successful in some cases, when POI is established or DOR diagnosed; however, there is scarce clinical evidence to warrant their widespread clinical use. Beyond these contexts, also discussed is how new insights into the biological mechanisms governing follicular dynamics and oocyte competence may play a role in reversing ovarian damage, as no technique modifies oocyte quality. Additional studies should focus on increasing follicle number and quality. Finally, there is a small but important subgroup of women lacking residual follicles and requiring oocyte generation from stem cells.

Single intraovarian dose of stem cell- and platelet-secreted factors mitigates age-related ovarian infertility in a murine model

BACKGROUND

Systemic administration of soluble factors from bone marrow-derived stem cells combined with activated platelet-rich plasma (SC-PRP) restored ovarian function, mediated through paracrine signaling, in murine models of chemotherapy-induced ovarian damage and human tissue from poor responder patients. However, the effects against age-related infertility and the efficacy of local administration have not been evaluated yet.

OBJECTIVE

This study aimed to assess whether a single intraovarian dose of stem cells combined with activated platelet-rich plasma can recover ovarian function, oocyte quality, and developmental competence in older mice.

STUDY DESIGN

The effects of stem cells combined with activated platelet-rich plasma against age-related infertility were assessed following controlled ovarian stimulation in an aging murine model reproducing 3 physiological stages of women's reproductive life, namely young, advanced maternal age, and menopausal (n=12 animals per group). Female mice were randomized to receive a single intraovarian injection (10 μL/ovary) of either saline, activated platelet-rich plasma, or stem cells combined with activated platelet-rich plasma. Seven days later, the mice were stimulated, naturally mated, and sacrificed to harvest their ovaries for histologic assessment and molecular analysis and their oviducts to evaluate oocyte maturation and to assess early embryo development.

RESULTS

A single intraovarian injection of stem cells combined with activated platelet-rich plasma promoted follicle activation and development in young, advanced maternal age, and old mice. Furthermore, stem cells combined with activated platelet-rich plasma rescued fertility in older mice by enhancing the quantity and quality of ovulated mature oocytes and supporting early embryo development to the blastocyst stage in all the evaluated ages. These fertility outcomes were positively associated with mitochondrial quality, treatment-increased mitochondrial DNA copy numbers, and reduced oxidative damage and apoptosis. Finally, the effects observed by histologic analysis were supported at the proteomic level. Functional proteomic analyses revealed molecular mechanisms involved in oocyte maturation and quality, mitochondrial function, and recovery of the ovarian stroma.

CONCLUSION

Bone marrow-derived stem cells combined with activated platelet-rich plasma is a promising treatment with the potential to improve the reproductive outcomes of women with age-related infertility, exceeding the restorative effects of platelet-rich plasma alone. Although further research in human ovarian samples is still required, the autologous nature of stem cell factors collected by noninvasive mobilization, their combination with platelet-rich plasma, and the local administration route suggest that stem cells combined with activated platelet-rich plasma treatment could be a potentially effective and safe application for future clinical practice.

Autologous Human Mesenchymal Stem Cell-Based Therapy in Infertility: New Strategies and Future Perspectives

Infertility could be associated with a few factors including problems with physical and mental health, hormonal imbalances, lifestyles, and genetic factors. Given that there is a concern about the rise of infertility globally, increased focus has been given to its treatment for the last several decades. Traditional assisted reproductive technology (ART) has been the prime option for many years in solving various cases of infertility; however, it contains significant risks and does not solve the fundamental problem of infertility such as genetic disorders. Attention toward the utilization of MSCs has been widely regarded as a promising option in the development of stem-cell-based infertility treatments. This narrative review briefly presents the challenges in the current ART treatment of infertility and the various potential applications of autologous MSCs in the treatment of these reproductive diseases.

The Therapeutic Potential of Human Umbilical Cord Derived Mesenchymal Stem Cells for the Treatment of Premature Ovarian Failure

Premature ovarian failure (POF) affects 1% of women under 40, leading to infertility. The clinical symptoms of the POF include hypoestrogenism, lack of mature follicles, hypergonadotropinism, and amenorrhea. POF can be caused due to genetic defects, autoimmune illnesses, and environmental factors. The conventional treatment of POF remains a limited success rate. Therefore, an innovative treatment strategy like the regeneration of premature ovaries by using human umbilical cord mesenchymal stem cells (hUC-MSCs) can be a choice. To summarize all the theoretical frameworks for additional research and clinical trials, this review article highlights all the results, pros, and cons of the hUC-MSCs used to treat POF. So far, the data shows promising results regarding the treatment of POF using hUC-MSCs. Several properties like relatively low immunogenicity, multipotency, multiple origins, affordability, convenience in production, high efficacy, and donor/recipient friendliness make hUC-MSCs a good choice for treating basic POF. It has been reported that hUC-MSCs impact and enhance all stages of injured tissue regeneration by concurrently stimulating numerous pathways in a paracrine manner, which are involved in the control of ovarian fibrosis, angiogenesis, immune system modulation, and apoptosis. Furthermore, some studies demonstrated that stem cell treatment could lead to hormone-level restoration, follicular activation, and functional restoration of the ovaries. Therefore, all the results in hand regarding the use of hUC-MSCs for the treatment of POF encourage researchers for further clinical trials, which will overcome the ongoing challenges and make this treatment strategy applicable to the clinic in the near future.

Graphical Abstract

Bone marrow mesenchymal stem cells in premature ovarian failure: Mechanisms and prospects

Premature ovarian failure (POF) is a common female reproductive disorder and characterized by menopause, increased gonadotropin levels and estrogen deficiency before the age of 40 years old. The etiologies and pathogenesis of POF are not fully clear. At present, hormone replacement therapy (HRT) is the main treatment options for POF. It helps to ameliorate perimenopausal symptoms and related health risks, but can't restore ovarian function and fertility fundamentally. With the development of regenerative medicine, bone marrow mesenchymal stem cells (BMSCs) have shown great potential for the recovery of ovarian function and fertility based on the advantages of abundant sources, high capacity for self-renewal and differentiation, low immunogenicity and less ethical considerations. This systematic review aims to summarize the possible therapeutic mechanisms of BMSCs for POF. A detailed search strategy of preclinical studies and clinical trials on BMSCs and POF was performed on PubMed, MEDLINE, Web of Science and Embase database. A total of 21 studies were included in this review. Although the standardization of BMSCs need more explorations, there is no doubt that BMSCs transplantation may represent a prospective therapy for POF. It is hope to provide a theoretical basis for further research and treatment for POF.

“Adipose-derived mesenchymal stem cell therapy for the management of female sexual dysfunction: Literature reviews and study design of a clinical trial”

Hormone imbalance and female sexual dysfunction immensely affect perimenopausal female health and quality of life. Hormone therapy can improve female hormone deficiency, but long-term use increases the risk of cardiovascular diseases and cancer. Therefore, it is necessary to develop a novel effective treatment to achieve long-term improvement in female general and sexual health. This study reviewed factors affecting syndromes of female sexual dysfunction and its current therapy options. Next, the authors introduced research data on mesenchymal stromal cell/mesenchymal stem cell (MSC) therapy to treat female reproductive diseases, including Asherman’s syndrome, premature ovarian failure/primary ovarian insufficiency, and vaginal atrophy. Among adult tissue-derived MSCs, adipose tissue-derived stem cells (ASCs) have emerged as the most potent therapeutic cell therapy due to their abundant presence in the stromal vascular fraction of fat, high proliferation capacity, superior immunomodulation, and strong secretion profile of regenerative factors. Potential mechanisms and side effects of ASCs for the treatment of female sexual dysfunction will be discussed. Our phase I clinical trial has demonstrated the safety of autologous ASC therapy for women and men with sexual hormone deficiency. We designed the first randomized controlled crossover phase II trial to investigate the safety and efficacy of autologous ASCs to treat female sexual dysfunction in perimenopausal women. Here, we introduce the rationale, trial design, and methodology of this clinical study. Because aging and metabolic diseases negatively impact the bioactivity of adult-derived MSCs, this study will use ASCs cultured in physiological oxygen tension (5%) to cope with these challenges. A total of 130 perimenopausal women with sexual dysfunction will receive two intravenous infusions of autologous ASCs in a crossover design. The aims of the proposed study are to evaluate 1) the safety of cell infusion based on the frequency and severity of adverse events/serious adverse events during infusion and follow-up and 2) improvements in female sexual function assessed by the Female Sexual Function Index (FSFI), the Utian Quality of Life Scale (UQOL), and the levels of follicle-stimulating hormone (FSH) and estradiol. In addition, cellular aging biomarkers, including plasminogen activator inhibitor-1 (PAI-1), p16 and p21 expression in T cells and the inflammatory cytokine profile, will also be characterized. Overall, this study will provide essential insights into the effects and potential mechanisms of ASC therapy for perimenopausal women with sexual dysfunction. It also suggests direction and design strategies for future research.

Stem cell-based therapy for human diseases

Recent advancements in stem cell technology open a new door for patients suffering from diseases and disorders that have yet to be treated. Stem cell-based therapy, including human pluripotent stem cells (hPSCs) and multipotent mesenchymal stem cells (MSCs), has recently emerged as a key player in regenerative medicine. hPSCs are defined as self-renewable cell types conferring the ability to differentiate into various cellular phenotypes of the human body, including three germ layers. MSCs are multipotent progenitor cells possessing self-renewal ability (limited in vitro) and differentiation potential into mesenchymal lineages, according to the International Society for Cell and Gene Therapy (ISCT). This review provides an update on recent clinical applications using either hPSCs or MSCs derived from bone marrow (BM), adipose tissue (AT), or the umbilical cord (UC) for the treatment of human diseases, including neurological disorders, pulmonary dysfunctions, metabolic/endocrine-related diseases, reproductive disorders, skin burns, and cardiovascular conditions. Moreover, we discuss our own clinical trial experiences on targeted therapies using MSCs in a clinical setting, and we propose and discuss the MSC tissue origin concept and how MSC origin may contribute to the role of MSCs in downstream applications, with the ultimate objective of facilitating translational research in regenerative medicine into clinical applications. The mechanisms discussed here support the proposed hypothesis that BM-MSCs are potentially good candidates for brain and spinal cord injury treatment, AT-MSCs are potentially good candidates for reproductive disorder treatment and skin regeneration, and UC-MSCs are potentially good candidates for pulmonary disease and acute respiratory distress syndrome treatment.

Bioactive engineered scaffolds based on PCL-PEG-PCL and tumor cell-derived exosomes to minimize the foreign body reaction

Long-term presence of M1 macrophages causes serious foreign body reaction (FBR), which is the main reason for the failure of biological scaffold integration. Inducing M2 polarization of macrophages near scaffolds to reduce foreign body response has been widely researched. In this work, inspired by the special capability of tumor exosomes in macrophages M2 polarization, we integrate tumor-derived exosomes into biological scaffolds to minimize the FBR. In brief, breast cancer cell-derived exosomes are loaded into polycaprolactone-b-polyethylene glycol-b-polycaprolactone (PCL-PEG-PCL) fiber scaffold through physical adsorption and entrapment to constructed bioactive engineered scaffold. In cellular experiments, we demonstrate bioactive engineered scaffold based on PCL-PEG-PCL and exosomes can promote the transformation of macrophages from M1 to M2 through the PI3K/Akt signaling pathway. In addition, the exosomes release gradually from scaffolds and act on the macrophages around the scaffolds to reduce FBR in a subcutaneous implant mouse model. Compared with PCL-PEG-PCL scaffolds without exosomes, bioactive engineered scaffolds reduce significantly inflammation and fibrosis of tissues around the scaffolds. Therefore, cancer cell-derived exosomes show the potential for constructing engineered scaffolds in inhibiting the excessive inflammation and facilitating tissue formation.

The use of intraovarian injection of autologous platelet rich plasma (PRP) in patients with poor ovarian response and premature ovarian insufficiency

PURPOSE OF REVIEW

Intraovarian injection of platelet rich plasma (PRP) is a novel treatment for patients with poor ovarian response (POR) and primary ovarian insufficiency (POI). This article reviews the latest literature on the effect of PRP on markers of ovarian reserve, oocyte and embryo yield, and live birth for these poor prognosis patients.

RECENT FINDINGS

Several case series and one prospective trial have demonstrated improvements in markers of ovarian reserve in patients with POI and POR and improved oocyte and embryo yields in patients with POR. These studies report multiple live births in patients who had previously failed treatment. The positive effects of PRP persist throughout the literature despite the fact that multiple protocols for preparing and injecting PRP exist, with no consensus on the optimal protocol.

SUMMARY

Intra-ovarian injection of PRP is a promising new technology for poor prognosis patients. Rigorous and appropriately controlled clinical trials are warranted to confirm the utility of this treatment for improving patients' ability to successfully conceive.

Recent scaffold-based tissue engineering approaches in premature ovarian failure treatment

Recently, tissue engineering and regenerative medicine have received significant attention with outstanding advances. The main scope of this technology is to recover the damaged tissues and organs or to maintain and improve their function. One of the essential fields in tissue engineering is scaffold designing and construction, playing an integral role in damaged tissues reconstruction and repair. However, premature ovarian failure (POF) is a disorder causing many medical and psychological problems in women. POF treatment using tissue engineering and various scaffold has recently made tremendous and promising progress. Due to the importance of the subject, we have summarized the recently examined scaffolds in the treatment of POF in this review.

Whole ovary laparoscopic incisions improve hormonal response and fertility in extremely poor ovarian response patients

STUDY OBJECTIVE

Recent findings have shown mechanical fragmentation of ovarian cortex and ovarian drilling could promote follicle growth in patients with premature ovarian insufficiency (POI) and polycystic ovarian syndrome, respectively. A common element shared by these treatments is the mechanical disturbance of ovarian extracellular matrix (ECM) tissues. We thus hypothesized a simplified whole ovary laparoscopic incision (WOLI) procedure may provide the intrinsic stimuli needed to activate resting follicles in extremely poor ovarian response (EPOR) patients who had negligible chance of becoming pregnant with their own oocytes via modern IVF practice.

DESIGN

Retrospective pilot study SETTING: The study was conducted in a research medical center in Taiwan.

PATIENTS

Women who had multiple canceled ovarian stimulation cycles due to the lack of follicle growth were recruited. A total of 6 EPOR patients received the WOLI procedure, which covers the whole surface of ovaries, in 2015-2017.

INTERVENTIONS

After receiving an outpatient WOLI procedure, ovarian response and follicle growth were monitored for 90 days with or without gonadotropin stimulation. Embryo quality and clinical outcomes were analyzed.

MEASUREMENTS AND MAIN RESULTS

Following the WOLI treatment, 5 out of 6 patients had significant increases in serum estradiol level and improved follicle growth (p = 0.000537). Multiple oocytes were retrieved from each of these patients, and it led to thawed embryo transfer cycles in four patients (p = 0.010). On average, the duration from the WOLI procedure to the first ovum pickup was 24 days (11-58 days). Following embryo transfer, two patients became pregnant and delivered healthy babies. Two other patients received embryo transfer, and one led to a chemical pregnancy. One patient had cryopreserved embryos with pending transfer.

CONCLUSION

The standardizable WOLI procedure restored hormonal responses in a majority of EPOR patients. Further validation of this novel and yet simple laparoscopic procedure, which requires only one laparoscopic surgery, may provide a practical option to reactivate the aging ovarian environment in EPOR and POI patients.

The need to identify novel biomarkers for prediction of premature ovarian insufficiency (POI)

Background

Premature ovarian failure (POF)/premature ovarian insufficiency (POI) is characterized by disrupting ovarian function under 40 years old. A major health problem of this disorder is female infertility. There are no proven treatments to increase the rate of pregnancy with autologous oocytes in these patients. This review aims to summarize our present knowledge about POI-induced infertility treatments and to highlight the importance of future researches in the discovery of diagnostic biomarkers and treatment of patients with this disorder.

Methods

A literature review was carried out using PubMed and Google Scholar databases by relevant keywords, such as POI, POF, premature ovarian failure, premature ovarian insufficiency, and biomarkers.

Results

Two hundred three studies were included in the study following the search for the keywords. Titles and abstracts of the identified articles were evaluated for detecting relevant full-length articles.

Conclusion

Anti-Mullerian hormone (AMH) level appears to have considerable value as a diagnostic test for POI, but it is not reliable enough to be able to predict accurately the timing of onset of impending POI. Using an accurate biomarker, POI can be diagnosed early and infertility treatment that is concerned about can be done on time. Biomarkers in combination with other diagnostic tests could result in prediction of POI before the development of complete ovarian failure.

Ovarian reserve parameters and IVF outcomes in 510 women with poor ovarian response (POR) treated with intraovarian injection of autologous platelet rich plasma (PRP)

The aim of the current study was to characterize ovarian reserve parameters and IVF outcomes in women with a history of poor ovarian response (POR) treated with intraovarian injection of autologous platelet rich plasma (PRP). Reproductive age women (N=510; age range 30-45yo) diagnosed with POR based on Poseidon criteria were included in the study. PRP treatment resulted in higher AFC, higher serum AMH, lower serum FSH, and a higher number of mature oocytes and cleavage and blastocyst stage embryos. After PRP injection, 22 women (4.3%) conceived spontaneously, 14 (2.7%) were lost to follow up, and 474 (92.9%) attempted IVF. Among women who attempted IVF, 312 (65.8%) generated embryos and underwent embryo transfer, 83 (17.5%) achieved a pregnancy, and 54 (11.4%) achieved sustained implantation/live birth (SI/LB). In total, of the 510 women with POR and mean age of 40.3, PRP resulted in improvement of ovarian reserve parameters, a pregnancy rate of 20.5% and SI/LB rate of 12.9%. Our findings suggest that PRP treatment may be considered in women with POR. For wider clinical application, its clinical efficacy will need to be demonstrated in prospective randomized clinical trials.

Aging conundrum: A perspective for ovarian aging

Progressive loss of physiological integrity and accumulation of degenerative changes leading to functional impairment and increased susceptibility to diseases are the main features of aging. The ovary, the key organ that maintains female reproductive and endocrine function, enters aging earlier and faster than other organs and has attracted extensive attention from society. Ovarian aging is mainly characterized by the progressive decline in the number and quality of oocytes, the regulatory mechanisms of which have yet to be systematically elucidated. This review discusses the hallmarks of aging to further highlight the main characteristics of ovarian aging and attempt to explore its clinical symptoms and underlying mechanisms. Finally, the intervention strategies related to aging are elaborated, especially the potential role of stem cells and cryopreservation of embryos, oocytes, or ovarian tissue in the delay of ovarian aging.

Research Progress on the Treatment of Premature Ovarian Failure Using Mesenchymal Stem Cells: A Literature Review

Premature ovarian failure (POF) has become one of the main causes of infertility in women of childbearing age and the incidence of POF is increasing year by year, seriously affecting the physical and mental health of patients and increasing the economic burden on families and society as a whole. The etiology and pathogenesis of POF are complex and not very clear at present. Currently, hormone replacement therapy is mainly used to improve the symptoms of low estrogen, but cannot fundamentally solve the fertility problem. In recent years, stem cell (SC) transplantation has become one of the research hotspots in the treatment of POF. The results from animal experiments bring hope for the recovery of ovarian function and fertility in patients with POF. In this article, we searched the published literature between 2000 and 2020 from the PubMed database (https://pubmed.ncbi.nlm.nih.gov), and summarized the preclinical research data and possible therapeutic mechanism of mesenchymal stem cells (MSCs) in the treatment of POF. Our aim is to provide useful information for understanding POF and reference for follow-up research and treatment of POF.

Making More Womb: Clinical Perspectives Supporting the Development and Utilization of Mesenchymal Stem Cell Therapy for Endometrial Regeneration and Infertility

The uterus is a homeostatic organ, unwavering in the setting of monthly endometrial turnover, placental invasion, and parturition. In response to ovarian steroid hormones, the endometrium autologously prepares for embryo implantation and in its absence will shed and regenerate. Dysfunctional endometrial repair and regeneration may present clinically with infertility and abnormal menses. Asherman's syndrome is characterized by intrauterine adhesions and atrophic endometrium, which often impacts fertility. Clinical management of infertility associated with abnormal endometrium represents a significant challenge. Endometrial mesenchymal stem cells (MSC) occupy a perivascular niche and contain regenerative and immunomodulatory properties. Given these characteristics, mesenchymal stem cells of endometrial and non-endometrial origin (bone marrow, adipose, placental) have been investigated for therapeutic purposes. Local administration of human MSC in animal models of endometrial injury reduces collagen deposition, improves angiogenesis, decreases inflammation, and improves fertility. Small clinical studies of autologous MSC administration in infertile women with Asherman's Syndrome suggested their potential to restore endometrial function as evidenced by increased endometrial thickness, decreased adhesions, and fertility. The objective of this review is to highlight translational and clinical studies investigating the use of MSC for endometrial dysfunction and infertility and to summarize the current state of the art in this promising area.

Menstrual blood CD146+ mesenchymal stem cells reduced fibrosis rate in the rat model of premature ovarian failure

Here, the regenerative potential of menstrual blood-derived mesenchymal stem cells (MenSCs) was examined on restoration of premature ovarian failure (POF) ovaries in rats' POF model. Freshly isolated CD146⁺ MenSCs using magnetic-activated cell storing method were immediately injected into ovaries of POF rats. Four and eight weeks after cell administration, both ovarian tissues were sampled for histological examination and the expression of fibrosis-related genes. Serum samples were also prepared for hormonal analysis. At the endpoint, mating trials were performed to assess the fertility of POF rats following MenSC transplantation. Histopathological examination revealed the induction of POF after Ceftriaxone injection by increasing atretic follicles and abnormal morphologies. MenSCs transplantation increased the number of normal follicles and coincided with the reduction of follicular atresia. Biochemical analyses exhibited the reduction and increase of systemic follicle-stimulating hormone (FSH) and E2 respectively after MenSCs transplantation compared to the POF rats (P < .05). No significant differences in anti-mullerian hormone (AMH) blood levels were detected in this study between POF controls and MenSCs-treated rats. We noted moreover the transcriptional up-regulation of Smad 2, 4, and TGF-β1 in POF rats, and these values were decreased after MenSCs transplantation (P < .01). By contrast, the RNA expression of Smad 6 remained increased in both pre- and post-treatment with MenSCs groups (P < .05). Finally, we found an increase in neonate births in POF rats treated with MenSCs, and that this feature was associated with ovarian rejuvenation through amelioration of fibrosis. These data showed that MenSCs are promising cell lineage for the alleviation of POF in the rat model by controlling the fibrosis rate.

Pathways and factors regulated by bone marrow-derived stem cells in human ovarian tissue

OBJECTIVE

To describe molecular and paracrine signaling changes produced by human bone marrow-derived stem cells (BMDSC) in human ovarian cortex.

DESIGN

Experimental study.

SETTING

University hospital research laboratories.

PATIENT(S)

Ovarian cortex from poor responder women (n = 7).

ANIMALS

Immunodeficient NOD/SCID female mice (n = 18).

INTERVENTION(S)

Human ovarian cortex strips were xenografted into ovariectomized NOD/SCID female mice. A week later, mice were infused with phosphate-buffered saline, 1 × 106 BMDSC, or 3 × 105 CD133+ cells via tail vein. Gene expression changes and enriched pathways were assessed by RT2 Profiler Arrays. Several upregulated genes were validated in individual samples by real-time quantitative PCR, and transcriptomic results were reinforced by a proteomic assessment.

MAIN OUTCOME MEASURE(S)

Gene expression changes, enriched Kyoto Encyclopedia of Genes and Genomes pathways, and paracrine factors.

RESULT(S)

Seventy-four Kyoto Encyclopedia of Genes and Genomes pathways were upregulated, with the PI3K-Akt signaling pathway the most enriched after BMDSC and CD133 treatments. The greatest transcriptomic changes were seen on day 14 in the BMDSC group, affecting the regulation of paracrine factors such as KITLG, THBS1, SERPINF1, and TIMP2. Proteomics data verified changes in FoxO signaling, actin cytoskeleton remodeling, and apoptosis by BMDSC.

CONCLUSION(S)

We identified paracrine factors and pathways regulated by BMDSC that may be future targets of treatment for the increasing number of poor responder women. Our findings suggest that BMDSC upregulated soluble factors such as KITLG, THBS1, SERPINF1, and TIMP2 as well as PI3K-Akt signaling and regulation of actin cytoskeleton pathways. The identification of these putative underlying mechanisms informs future experiments aiming to optimizing clinical application of BMDSC.

Novel Approaches in Addressing Ovarian Insufficiency in 2019: Are We There Yet?

Ovarian insufficiency is described as a multifaceted issue typically encountered in the field of assisted reproduction. The three main identified diagnoses of ovarian insufficiency include premature ovarian failure (POF), poor ovarian response (POR), and advanced maternal age (AMA). Patient heterogeneity in the era of individualized medicine drives research forward leading to the emergence of novel approaches. This plethora of innovative treatments in the service of adequately managing ovarian insufficiency is called to undertake the challenge of addressing infertile patients exploring their reproductive options. This review provides an all-inclusive presentation and critical analysis on novel treatments that have not achieved routine clinical practice status yet, but have recently emerged as promising. In light of the lack of randomized controlled trials conveying safety and efficiency, clinicians are left puzzled in addressing the "how" and "for whom" these approaches may be beneficial. From ovarian injection employing platelet-rich plasma (PRP) or stem cells to artificial gametes and ovaries, ovarian transplantation, and mitochondrial replacement therapy, this descriptive review provides insight toward assisting the practitioner in decision making regarding these cutting-edge treatments. Biological mechanisms, invasiveness levels, efficiency, as well as possible complications, the current status along with bioethical concerns are discussed in the context of identifying future optimal treatment.

Stem cell-secreted factor therapy regenerates the ovarian niche and rescues follicles

BACKGROUND

Ovarian senescence is a normal age-associated phenomenon, but increasingly younger women are affected by diminished ovarian reserves or premature ovarian insufficiency. There is an urgent need for developing therapies to improve ovarian function in these patients. In this context, previous studies suggest that stem cell-secreted factors could have regenerative properties in the ovaries.

OBJECTIVE

This study aimed to test the ability of various human plasma sources, enriched in stem cell-secreted factors, and the mechanisms behind their regenerative properties, to repair ovarian damage and to promote follicular development.

STUDY DESIGN

In the first phase, the effects of human plasma enriched in bone marrow stem cell soluble factors by granulocyte colony-stimulating factor mobilization, umbilical cord blood plasma, and their activated forms on ovarian niche, follicle development, and breeding performance were assessed in mouse models of chemotherapy-induced ovarian damage (n=7 per group). In addition, the proteomic profile of each plasma was analyzed to find putative proteins and mechanism involved in their regenerative properties in ovarian tissue. In the second phase, the most effective plasma treatment was validated in human ovarian cortex xenografted in immunodeficient mice (n=4 per group).

RESULTS

Infusion of human plasma enriched bone marrow stem cell soluble factors by granulocyte colony-stimulating factor mobilization or of umbilical cord blood plasma-induced varying degrees of microvessel formation and cell proliferation and reduced apoptosis in ovarian tissue to rescue follicular development and fertility in mouse models of ovarian damage. Plasma activation enhanced these effects. Activated granulocyte colony-stimulating factor plasma was the most potent inducing ovarian rescue in both mice and human ovaries, and proteomic analysis indicated that its effects may be mediated by soluble factors related to cell cycle and apoptosis, gene expression, signal transduction, cell communication, response to stress, and DNA repair of double-strand breaks, the most common form of age-induced damage in oocytes.

CONCLUSION

Our findings suggested that stem cell-secreted factors present in both granulocyte colony-stimulating factor-mobilized and umbilical cord blood plasma could be an effective treatment for increasing the reproductive outcomes in women with impaired ovarian function owing to several causes. The activated granulocyte colony-stimulating factor plasma, which is already enriched in both stem cell-secreted factors and platelet-enclosed growth factors, seems to be the most promising treatment because of its most potent restorative effects on the ovary together with the autologous source.

Mitochondrial enrichment in infertile patients: a review of different mitochondrial replacement therapies

Poor ovarian responders exhibit a quantitative reduction in their follicular pool, and most cases are also associated with poor oocyte quality due to patient’s age, which leads to impaired in vitro fertilisation outcomes. In particular, poor oocyte quality has been related to mitochondrial dysfunction and/or low mitochondrial count as these organelles are crucial in many essential oocyte processes. Therefore, mitochondrial enrichment has been proposed as a potential therapy option in infertile patients to improve oocyte quality and subsequent in vitro fertilisation outcomes. Nowadays, different options are available for mitochondrial enrichment treatments that are encompassed in two main approaches: heterologous and autologous. In the heterologous approach, mitochondria come from an external source, which is an oocyte donor. These techniques include transferring either a portion of the donor’s oocyte cytoplasm to the recipient oocyte or nuclear material from the patient to the donor’s oocyte. In any case, this approach entails many ethical and safety concerns that mainly arise from the uncertain degree of mitochondrial heteroplasmy deriving from it. Thus the autologous approach is considered a suitable potential tool to improve oocyte quality by overcoming the heteroplasmy issue. Autologous mitochondrial transfer, however, has not yielded as many beneficial outcomes as initially expected. Proposed mitochondrial autologous sources include immature oocytes, granulosa cells, germline stem cells, and adipose-derived stem cells. Presently, it would seem that these autologous techniques do not improve clinical outcomes in human infertile patients. However, further trials still need to be performed to confirm these results. Besides these two main categories, new strategies have arisen for oocyte rejuvenation by improving patient’s own mitochondrial function and avoiding the unknown consequences of third-party genetic material. This is the case of antioxidants, which may enhance mitochondrial activity by counteracting and/or preventing oxidative stress damage. Among others, coenzyme-Q10 and melatonin have shown promising results in low-prognosis infertile patients, although further randomised clinical trials are still necessary.

Potential roles of experimental reproductive technologies in infertile women with diminished ovarian reserve

In assisted reproductive technology treatment, diminished ovarian reserve (DOR) is a condition of utmost clinical and scientific relevance because of its negative influence on patient outcomes. The current methods of infertility treatment may be unsuitable for many women with DOR, which support the need for development of additional approaches to achieve fertility restoration. Various techniques have been tried to improve the quality and increase the quantity of oocytes in DOR patients, including mitochondrial transfer, activation of primordial follicles, in vitro culture of follicles, and regeneration of oocytes from various stem cells. Herein, we review the science behind these experimental reproductive technologies and their potential use to date in clinical studies for infertility treatment in women with DOR.

Emerging follicular activation strategies to treat women with poor ovarian response and primary ovarian insufficiency

PURPOSE OF THE REVIEW

Female reproductive aging remains one of the key unsolved challenges in the field of reproductive medicine. This article reviews three of the most recent and cutting-edge strategies that are currently being investigated to address the issues of poor ovarian response (POR) and primary ovarian insufficiency (POI).

RECENT FINDINGS

Publications revealing the mechanism of mechanical disruption of the Hippo signaling pathway paved the way to studies on its potential application for fertility treatments. This, in combination with Akt stimulation, resulted in live births and ongoing pregnancies in women with POI. Building on previous reports on the effects of bone marrow transplants on fertility after chemotherapy, another approach involved autologous stem cell ovarian transplantation (ASCOT). The method proved effective in achieving live births in women previously diagnosed with POR. A third approach, intraovarian injection of autologous platelet-rich plasma, resulted in live births and ongoing pregnancies both spontaneously and via in vitro fertilization (IVF) in women with POI and POR.

SUMMARY

New paths are being charted to address the issues of POI and POR. Although these are preliminary studies that should be interpreted with caution, they represent great promise for the women affected by these conditions and the physicians treating them.

Three-dimensional bioprinting of artificial ovaries by an extrusion-based method using gelatin-methacryloyl bioink

PURPOSE

The aim of this study was to design and fabricate a three-dimensional (3D) printed artificial ovary.

METHODS

We first compared the printability of gelatin-methacryloyl (GelMA), alginate and GelMA-alginate bioinks, of which GelMA was selected for further investigation. The swelling properties, degradation kinetics and shape fidelity of GelMA scaffolds were characterized by equilibrium swelling/lyophilization, collagenase processing and micro-computed tomography evaluation. Commercial ovarian tumor cell lines (COV434, KGN, ID8) and primary culture ovarian somatic cells were utilized to perform cell-laden 3D printing, and the results were evaluated by live/dead assays and TUNEL detection. Murine ovarian follicles were seeded in the ovarian scaffold and their diameters were recorded every day. Finally, in vitro maturation was performed, and the ovulated oocytes were collected and observed.

RESULTS

Our results indicated that GelMA was suitable for 3D printing fabrication. Its scaffolds performed well in terms of hygroscopicity, degradation kinetics and shape fidelity. The viability of ovarian somatic cells was lower than that of commercial cell lines, suggesting that extrusion-based 3D culture fabrication is not suitable for primary ovarian cells. Nevertheless, the GelMA-based 3D printing system provided an appropriate microenvironment for ovarian follicles, which successfully grew and ovulated in the scaffolds. Metaphase II oocytes were also observed after in vitro maturation.

CONCLUSIONS

The GelMA-based 3D printing culture system is a viable alternative option for follicular growth, development and transfer. Accordingly, it shows promise for clinical application in the treatment of female endocrine and reproductive conditions.

Human Mesenchymal Stem Cell Therapy and Other Novel Treatment Approaches for Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition characterized by amenorrhea, hypergonadotropic hypogonadism, estrogen deficiency, and reduced follicle counts leading to infertility under the age of 40. POI occurs in approximately 1-3% of women in the general population. Evaluation is warranted when the diagnosis of POI is made to rule out underlying etiologies, which could be multifactorial. This review serves to cover the novel treatment approaches reported in the literature.

Is It Possible to Treat Infertility with Stem Cells?

Infertility is a major health problem, and despite improved treatments over the years, there are still some conditions that cannot be treated successfully using a conventional approach. Therefore, new options are being considered and one of them is cell therapy using stem cells. Stem cell treatments for infertility can be divided into two major groups, the first one being direct transplantation of stem cells or their paracrine factors into reproductive organs and the second one being in vitro differentiation into germ cells or gametes. In animal models, all of these approaches were able to improve the reproductive potential of tested animals, although in humans there is still too little evidence to suggest successful use. The reasons for lack of evidence are unavailability of proper material, the complexity of explored biological processes, and ethical considerations. Despite all of the above-mentioned hurdles, researchers were able to show that in women, it seems to be possible to improve some conditions, but in men, no similar clinically important improvement was achieved. To conclude, the data presented in this review suggest that the treatment of infertility with stem cells seems plausible, because some types of treatments have already been tested in humans, achieving live births, while others show great potential only in animal studies, for now.

Effects of Intraovarian Injection of Autologous Platelet-Rich Plasma on Ovarian Rejuvenation in Poor Responders and Women with Primary Ovarian Insufficiency

Injection of intraovarian platelet-rich plasma (PRP) was recently presented in terms of improvement ovarian function in women with a poor ovarian response (POR) or primary ovarian insufficiency (POI). In a before and after study, 17 poor responder women and 9 women with the diagnosis of POI were recruited. The multifocal intramedullary infusion of 1.5 ml activated PRP was performed into each ovary. The majority of women in both groups received the second PRP injection with the twofold increase in the dosage to 3ml, 3 months after the first injection. Evaluation of serum anti-mullerian hormone ( AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) was performed. In addition, all women were followed with regard to pregnancy outcome up to delivery. In the POI group, menstrual restoration was monitored. The significant difference was not detected regarding the hormonal profile between the three time points in both groups. With regard to pregnancy outcome, 8/17 (47%) of PORs had spontaneous pregnancy in response to PRP injection. Of those, three women (37.55%) had abortions, whereas 4 pregnancies (50%) led to healthy live births, and one woman (12.5%) was in the 24^th week of her pregnancy. Menstruation recovery occurred among 22.2% of women with POI after the second PRP injection, but no one became pregnant. Intraovarian injection of autologous PRP might be considered an alternative treatment in poor responders. As for women with POI, it is questionable whether PRP could induce menstrual recovery.

Premature ovarian insufficiency: pathogenesis and therapeutic potential of mesenchymal stem cell

Primary ovarian insufficiency (POI) is defined as a reduction in ovarian function before the expected age of menopause. POI is known to increase the risk of cardiovascular disorders, osteoporosis, cognitive decline, and mood disorders, resulting in a reduced quality of life. Appropriate hormone replacement for premenopausal women decreases these adverse health risks and improves quality of life for women with POI, but does not prolong life expectancy. The potential etiologies of POI include chromosomal abnormalities and genetic mutations, autoimmune factors, and iatrogenic causes, including surgery, chemotherapy, and radiation therapy. A major association is suggested to exist between reproductive longevity and the DNA damage pathway response genes. DNA damage and repair in ovarian granulosa cells is strongly associated with POI. Depletion of oocytes with damaged DNA occurs through different cell death mechanisms, such as apoptosis, autophagy, and necroptosis, mediated by the phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/forkhead transcription factors 3 (FOXO3) pathway. Mesenchymal stem cells (MSCs) are characterized by the ability of self-renewal and differentiation and play an important role in the regeneration of injured tissues. Transplantation of MSCs has been shown to functionally restore ovarian reserve in a POI mouse model. Recent advances in stem cell therapy are likely to be translated to new therapeutic options bringing new hope to patients with POI. The aim of this review is to summarize the pathogenic mechanisms that involve cell death and DNA damage and repair pathways and to discuss the stem cell-based therapies as potential therapeutic options for this gynecologic pathology.

Novel approaches to fertility restoration in women with premature ovarian insufficiency

The diagnosis of premature ovarian insufficiency (POI) brings with it the loss of fertility, an immediate concern for many affected women, and a future one for many others. While there is a low natural conception rate, for most the choice is between oocyte donation and alternative methods of family building such as adoption. There is, however, a lot of research into novel methods for increasing or restoring the fertility of women with POI, which are discussed in this review. Many approaches involve the use of mesenchymal stem cells, from a variety of sources including bone marrow, placenta and umbilical cord, and menstrual blood. These seem to have efficacy in animal models of POI, although through unclear mechanisms. Activation of remaining primordial follicles is also being explored, through physical or chemical manipulation of key regulatory pathways, notably the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) and Hippo pathways. Much of the clinical data are uncontrolled, and mostly in women with a reduced ovarian reserve rather than POI, as are the results thus far for administration of platelet-rich plasma. Clinical studies with appropriate controls are needed to substantiate the preliminary claims of effectiveness of these approaches.

Combined Use of Autologous Bone Marrow-derived Stem Cells and Platelet-rich Plasma for Ovarian Rejuvenation in Poor Responders

Background:

The management of poor responders is still a challenge in modern-assisted reproductive technology. Several researches are showing encouraging results with autologous bone marrow-derived stem cells (ABMDSCs) and platelet-rich plasma (PRP) individually. Hence, we decided to study the synergistic effect of ABMDSCs with PRP.

Aims and Objective:

The aim of the study was to assess the safety and efficacy of intraovarian instillation of ABMDSCs combined with PRP in poor responders.

Design:

This was an interventional pilot study. Study Period: January 2017 to January 2019.

Materials and Methods:

We designed a pilot study using Patient-oriented Strategies Encompassing IndividualizeD Oocyte Number (POSEIDON) Group 3 and 4 poor responder patients (n = 20). The study group underwent laparoscopic/transvaginal intraovarian instillation of ABMDSCs combined with PRP and the outcome was analyzed – primary outcome – antral follicular count (AFC) and mature MII oocytes and secondary outcome – Anti-Mullerian hormone (AMH) levels and number of Grade A and B embryos frozen on day 3. The Wilcoxon signed-rank test and Pearson correlation were used for the statistical analysis and P < 0.05 was considered statistically significant.

Results:

After 6 weeks of intraovarian instillation ABMDSCs mixed with PRP, patients were reassessed for AFC and AMH and their response to subsequent controlled ovarian stimulation (COS) cycle was observed. Statistically significant improvement was seen in AFC, MII oocytes, and Grade A and Grade B embryos. AMH was also increased in some patients, but the result was not statistically significant.

Conclusion:

Our results suggest that intraovarian instillation of ABMDSCs combined with PRP is safe and it optimized the recruitment of existing dormant primordial follicles to improve oocyte yield and hence the number and quality of embryos after COS in POSEIDON Group 3 and 4 poor responders.

Diminished Ovarian Reserve Chemotherapy-Induced Mouse Model: A Tool for the Preclinical Assessment of New Therapies for Ovarian Damage

Diminished ovarian reserve (DOR) and primary ovarian insufficiency (POI) are primary factors leading to infertility. However, there is a lack of appropriate animal models of DOR usable for assessing new therapeutic strategies. In this study, we aimed to evaluate whether chemotherapy treatment in mice could reproduce features similar of that observed in women with DOR. Twenty-one Nonobese diabetic/severe combined immunodeficiency (NOD/SCID) female mice were allocated to 3 groups (n = 7/group): control, single dose of vehicle (Dimethyl Sulfoxide [DMSO]); DOR, single reduced chemotherapy dose; and POI, single standard chemotherapy dose. After 21 days, mice underwent ovarian hyperstimulation and mating. Part of the animals were harvested to analyze ovarian reserve, ovulation and fertilization rates, and morphology, apoptosis, and vascularization of the ovarian stroma. The remaining mice underwent multiple matings to assess pregnancy rates and litter sizes. The DOR and POI mice showed an impaired estrous cyclicity and a decrease in ovarian mass, number of follicles, Metaphase II (MII) oocytes, and embryos as well as in ovarian stroma vascularization. Mice in both models showed also an increase in the percentage of morphologically abnormal follicles, stromal degeneration, and apoptosis. Similar to that observed in DOR and POI patients, these impairments were less severe in DOR than in POI mice. None of the POI females were able to achieve a pregnancy. Meanwhile, DOR females achieved several consecutive pregnancies, although litter size was decreased when compared to controls. In conclusion, a mouse model which displayed most of the ovarian characteristics and fertility outcomes of women with DOR has been established using a single dose of chemotherapy.

Fertility Preservation: The Challenge of Freezing and Transplanting Ovarian Tissue

Cancer treatments are increasingly effective, but can result in iatrogenic premature ovarian insufficiency. Ovarian tissue cryopreservation is the only option available to preserve fertility in prepubertal girls and young women who require immediate chemotherapy. Ovarian tissue transplantation has been shown to restore hormonal cycles and fertility, but a large proportion of the follicle reserve is lost as a consequence of exposure to hypoxia. Another crucial concern is the risk of reimplanting malignant cells together with the grafted tissue. In this review, the authors advance some challenging propositions, from prevention of chemotherapy-related gonadotoxicity to ovarian tissue cryopreservation and transplantation, including the artificial ovary approach.

Impact of Ovarian Aging in Reproduction: From Telomeres and Mice Models to Ovarian Rejuvenation

The trend in our society to delay procreation increases the difficulty to conceive spontaneously. Thus, there is a growing need to use assisted reproduction technologies (ART) to form a family. With advanced maternal age, ovaries not only produce a lower number of oocytes after ovarian stimulation but also a lower quality-mainly aneuploidies-requiring further complex analysis to avoid complications during implantation and pregnancy. Although there are different options to have a child at advanced maternal age (like donor eggs), this is not the preferred choice for most patients. Unless women had cryopreserved their eggs at a younger age, reproductive medicine should try to optimize their opportunities to become pregnant with their own oocytes, when chances of success are reasonable. Aging has many causes, but telomere attrition is ultimately one of the main pathways involved in this process. Several reports link telomere biology and reproduction, but the molecular reasons for the rapid loss of ovarian function at middle age are still elusive. This review will focus on the knowledge acquired during the last years about ovarian aging and disease, both in mouse models of reproductive senescence and in humans with ovarian failure, and the implication of telomeres in this process. In addition, the review will discuss recent results on ovarian rejuvenation, achieved with stem cell therapies that are currently under study, or ovarian reactivation by tissue fragmentation and the attempts to generate oocytes in vitro.