Premature ovarian failure: etiology and prospects

Novel Advances in Cell-Free Therapy for Premature Ovarian Failure (POF): A Comprehensive Review

Premature ovarian failure (POF), is a condition characterized by the early decline of ovulation function. POF is a complex disorder that can be caused by various factors, and the idiopathic form represents a significant proportion of POF patients. Hormone replacement therapy (HRT) is currently considered the first-line treatment for POF. This review aims to provide a comprehensive overview of recent advancements in platelet-rich plasma (PRP), in vitro activation (IVA), stem cell therapy, exosome therapy, microRNAs, and mitochondrial targeting therapies as a promising cell-free therapeutic approach in reproductive medicine. PLT-Exos, a new generation of cells, has been used to treat POF for more than a decade and has been shown to attenuate oocyte morphology and promote the differentiation of theca cells through the upregulation of PI3K/Akt and Bcl2, as well as the downregulation of the Smad and Bax signaling pathways. This review summarizes the current state of the art in the field of PLT-Exos and discusses the advantages and limitations of their potential clinical applications.

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.

Effects of low intensity pulsed ultrasound on expression of B-cell lymphoma-2 and BCL2-Associated X in premature ovarian failure mice induced by 4-vinylcyclohexene diepoxide

BACKGROUND

Premature ovarian failure (POF) is a common disease in the field of Gynecology. Low intensity pulsed ultrasound (LIPUS) can promote tissue repair and improve function. This study was performed to determine the effects of LIPUS on granulosa cells (GCs) apoptosis and protein expression of B-cell lymphoma-2 (Bcl-2) and BCL2-Associated X (Bax) in 4-vinylcyclohexene diepoxide (VCD)-induced POF mice and investigate the mechanisms of LIPUS on ovarian function and reserve capacity.

METHODS

The current POF mice model was administrated with VCD (160 mg/kg) by intraperitoneal injection for 15 consecutive days. The mice were divided into the POF group, LIPUS group and control group. In the LIPUS group, the right ovary of mice was treated by LIPUS (acoustic intensity was 200 mW/cm², frequency was 0.3 MHz, and duty cycle was 20%) for 20 min, 15 consecutive days from day 16. The mice of the POF group and control group were treated without ultrasonic output. The basic observation and body weight were recorded. Hematoxylin and eosin staining (H&E staining) and enzyme-linked immunosorbent assay (ELISA) were applied to detect ovarian follicle development, ovarian morphology and sex hormone secretion. Ovarian GCs apoptosis was detected by TUNEL assay and immunohistochemistry.

RESULTS

The results showed that VCD can induce estrus cycle disorder, follicular atresia, sex hormone secretion decreased and GCs apoptosis in mice to establish POF model successfully. LIPUS significantly promoted follicular development, increased sex hormone secretion, inhibited excessive follicular atresia and GCs apoptosis. The mechanism might be achieved by increasing the protein expression of Bcl-2 and decreasing the expression of Bax in ovaries.

CONCLUSIONS

LIPUS can improve the POF induced by VCD. These findings have the potential to provide novel methodological foundation for the future research, which help treat POF patients in the clinic.

Assessment of premature menopause on the sexual function and quality of life in women

INTRODUCTION

Premature Ovarian Insufficiency (POI) is characterized by ending menstruation in women under 40 years of age. It has a significant effect on women's sexuality and mental health and quality of life. This study aimed to evaluate the sexual function and quality of life of premature menopausal women.

METHODS

This study was a case-control study on 132 people (66 women with a diagnosis of POF and 66 women of reproductive age with normal ovarian function) who were matched in terms of the age, presenting to Women's Clinic in Jahrom in 2019. The WHOQOL-BREF questionnaire and the Female Sexual Function Index (FSFI) questionnaire were used to collect data. p < .05 was considered statistically significant.

RESULTS

The mean score of sexual function in premature menopausal women was 21.35 ± 4.82 and in non-menopausal women was 25.4 ± 6.61 (OR = 0.11, 95% CI = 0.04-0.28). All areas of sexual function; desires disorder (OR = 0.21 95% CI = 0.07-0.56), Arousal disorder(OR = 0.28, 95% CI = 0.08-0.93), orgasm disorder (OR = 0.36 95% CI = 0.16-0.80), lubrication disorder (OR = 0.21 95% CI= 0.05-0.78), satisfaction disorder (OR = 0.11, 95% CI = 0.04-0.28) and quality of life domains: physical health (OR = 0.4 95%CI = 0.06-0.3), mental health (OR = 0.28 95% CI = 0.06-0.1), environmental health (OR = 0.22 95%CI = 0.04-0.6) and social health (OR = 0.28 95%CI = 0.01-0.2) saw a decrease in the premature menopausal women group compared to the control group.

CONCLUSION

The results demonstrated that premature menopausal women are found to be weaker than the control group in all areas of sexual function and quality of life. Among the areas of sexual function, such as libido, arousal, satisfaction, and pain have the most impact on quality of life. Therefore, based on the results from improving sexual function, this issue can improve the quality of life.

Adult Stem Cell Therapy for Premature Ovarian Failure: From Bench to Bedside

Premature ovarian failure (POF) is a devastating condition for women of childbearing age with serious health consequences, including distress, infertility, osteoporosis, autoimmune disorders, ischemic heart disease, and increased mortality. In addition to the mainstay estrogen therapy, stem cell therapy has been tested as the result of rapid progress in cell biology and reprogramming research. We hereby provide a review for the latest research and issues related with stem cell-based therapy for POF, and provide a commentary on various methods for enhancing its effect. Large amount of animal studies have demonstrated an extensive benefit of stem cells for failed ovarian recovering. As shown by such studies, stem cell therapy can result in recovery of hormonal levels, follicular activation, ovarian angiogenesis, and functional restoration. Meanwhile, a study of molecular pathways revealed that the function of stem cells mainly depends on their paracrine actions, which can produce multiple factors for the promotion of ovarian angiogenesis and regulation of cellular functions. Nevertheless, studies using disease models also revealed certain drawbacks. Clinical trials have shown that menstrual cycle and even pregnancy may occur in POF patients following transplantation of stem cells, although the limitations, including inadequate number of cases and space for the improvement of transplantation methodology. Only with its safety and effect get substantial improvement through laboratory experiments and clinical trials, can stem cell therapy really bring benefits to more patients. Additionally, effective pretreatment and appropriate transplantation methods for stem cells are also required. Taken together, stem cell therapy has shown a great potential for the reversal of POF and is stepping from bench to bedside. Impact statement Premature ovarian failure (POF) is a devastating condition with serious clinical consequences. The purpose of this review was to summarize the current status of stem cell therapy for POF. Considering the diversity of cell types and functions, a rigorous review is required for the guidance for further research into this field. Meanwhile, the challenges and prospect for clinical application of stem cell treatment, methodological improvements, and innovations are addressed.

The Effects of Inhibin B in the Chemotherapy Drug-Induced Premature Ovarian Insufficiency Mice and hPMSCs Treatment

Human placenta mesenchymal stem cells (hPMSCs), have been extensively investigated on the treatment of many diseases. This study was to explore the effects of hPMSCs treatment on the chemotherapy drug-induced premature ovarian insufficiency (POI) mice. Cyclophosphamide (120 mg/kg) and busulfan (30 mg/kg) or cyclophosphamide (70 mg/kg) induced POI mice were used and hPMSCs were injected through tail vein. The hormone levels of serum, morphological changes, the expression and quantitative analysis of inhibin B (INHBB) and FSHR protein, and apoptosis of granulosa cells in ovary were detected. The granulosa cells (GCs) were detected from ovaries of mice and the different concentration of cyclophosphamide on GCs were detected by MTT assay. The apoptosis of GCs was detected by FITC Annexin V Apoptosis Detection Kit. The significant increase in FSH and decrease in E₂ and INHBB were observed. Expression of human nuclei was observed in the stroma of ovaries. INHBB and FSHR levels of ovaries were reduced in the POI mice. Following hPMSCs treatment, the amounts of INHBB and FSHR significantly increased close to normal levels. The granulosa cells apoptosis increased in the POI ovaries but decreased after hPMSCs treatment. Moreover, cyclophosphamide has no effect on the GCs and no statistic difference was measured in vitro. The effects of hPMSCs treatment reduce the apoptosis of granulosa cells and restore the ovarian reserve capacity in chemotherapeutic drug-induced POI mice. The data help to further explore new potential clinical therapeutic approach for POI patients.

Deficiency of Pdk1 contributes to primordial follicle activation via the upregulation of YAP expression and the pro‑inflammatory response

The molecular mechanisms underlying the activation of primordial follicles are poorly understood. The serine/threonine protein kinase phosphoinositide‑dependent kinase 1 (PDK1), a pivotal downstream effector of phosphatidyl inositol‑3 kinase (PI3K) signaling, plays a vital role in cellular signaling. In order to identify the function of PDK1 in ovarian follicle development, this study used conditional Pdk1 deletion in mouse oocytes by crossing Pdk1loxP/loxP mice with transgenic mice carrying Gdf‑9 promoter‑mediated Cre recombinase and found that Pdk1flx/flxGdf9Cre mice were subfertile with increased serum follicle‑stimulating hormone (FSH) and luteinizing hormone (LH) levels compared with Pdk1flx/flx mice. The deletion of Pdk1 in oocytes induced massive primordial follicle activation, leading to premature ovarian failure (POF). Further investigation revealed that enhanced Yes‑associated protein (YAP) expression and an increased pro‑inflammatory response also contributed to massive primordial follicle activation. PDK1 formed the complex with the core kinases of Hippo signaling and regulated the expression levels of YAP. On the whole, the findings of the present study demonstrate that PDK1 serves as an indispensable gatekeeper for maintaining the primordial follicle pool and provide a deeper understanding of POF treatment.

Clinical characteristics and relationship between myasthenia gravis and premature ovarian failure: report of two cases

Myasthenia gravis (MG) and premature ovarian failure (POF) are rare. MF and POF greatly affect patients’ health. Combined occurrence of MF and POF in young women can have serious consequences. We report two cases of MG with POF. Case 1 was a 20-year-old woman who presented with myasthenic crisis and menopause in September 2015 and November 2015, respectively. The patient’s estradiol and follicle-stimulating hormone levels were abnormal. She was administered plasmapheresis and methylprednisolone pulse therapy. She improved and was discharged with normal restoration of menstruation after 3 months. Case 2 was a 21-year-old woman who had right eyelid droop and double vision in June 2014. She presented with menstrual disorder and menopause in August 2014 and September 2014, respectively. Estradiol and follicle-stimulating hormone levels were abnormal. She underwent progesterone therapy. She was admitted to hospital again in March 2016 with a myasthenic crisis. She received methylprednisolone pulse therapy and underwent thymectomy, but menstruation was not restored. In conclusion, there is comorbidity of POF in MG, and there is a close relationship between these two diseases. MG may subsequently lead to development of POF, and timely immunotherapy for MG may normalize POF.

Inflamm-Aging: A New Mechanism Affecting Premature Ovarian Insufficiency

The normal function of ovaries, along with the secretion of sex hormones, is among the most important endocrine factors that maintain the female sexual characteristics and promote follicular development and ovulation. Premature ovarian insufficiency (POI) is a common cause in the etiology of female infertility. It is defined as the loss of ovarian function before the age of 40. The characteristics of POI are menstrual disorders, including amenorrhea and delayed menstruation, accompanied by a raised gonadotrophin level and decreased estradiol level. Inflammatory aging is a new concept in the research field of aging. It refers to a chronic and low-degree proinflammatory state which occurs with increasing age. Inflammatory aging is closely associated with multiple diseases, as excessive inflammation can induce the inflammatory lesions in certain organs of the body. In recent years, studies have shown that inflammatory aging plays a significant role in the pathogenesis of POI. This paper begins with the pathogenesis of inflammatory aging and summarizes the relationship between inflammatory aging and premature ovarian insufficiency in a comprehensive way, as well as discussing the new diagnostic and therapeutic methods of POI.

Fertility Preservation in Endometriosis Patients: Anti-Müllerian Hormone Is a Reliable Marker of the Ovarian Follicle Density

OBJECTIVE

To analyze the ovarian reserve via measurement of follicular density and anti-Müllerian hormone (AMH) in endometriosis patients participating to a clinical program of cortical ovarian cryopreservation.

DESIGN

Retrospective analysis of serum AMH levels and prospective investigation of ovarian follicle number.

SETTING

University Hospital.

PATIENTS

Two hundred and two women with endometriosis and 400 controls.

INTERVENTIONS

Blood samples and ovarian biopsies.

MAIN OUTCOME MEASURES

Correlation of serum AMH levels and the number of non-growing follicles in the biopsied cortical tissues in endometriosis and control subjects, including age, type of AMH kit, and the laboratory performing the analysis as covariates.

RESULTS

AMH levels were shown to decrease with age in untreated endometriosis patients (P < 1.0 × 10^-5) but they were significantly lower in endometriosis compared to controls only in patients over 36 years old (P = 2.7 × 10^-4). The AMH decrease was faster in endometriosis compared to controls (beta = 0.27, P = 4.0 × 10^-4). Primordial follicle number decreased with the reduction of AMH levels in both cases and controls (beta = 0.3; P = 0.04).

CONCLUSION

AMH is a reliable marker of ovarian reserve in endometriosis patients, and it can predict follicular density in women undergoing ovarian tissue cryopreservation.

Evaluation of ovarian reserve using anti-müllerian hormone and antral follicle count in Sjögren's syndrome: Preliminary study

AIM

The aim of this study was to determine ovarian reserve status using anti-müllerian hormone (AMH) level and antral follicle count (AFC) in patients with Sjögren's syndrome (SS).

METHODS

Twenty-four women with SS diagnosed according to the classification criteria proposed by the American-European Consensus Group and 25 healthy women as controls were enrolled in this study. Ovarian reserve was assessed on clinical findings, AFC, and serum AMH and reproductive hormone levels.

RESULTS

Compared with the healthy controls, in the SS patients, the duration of menstrual cycle was significantly shorter (P = 0.043); serum AMH (P = 0.001) and AFC (P = 0.001) were significantly lower, and serum luteinizing hormone (LH) was significantly higher (P = 0.019). The right (P = 0.555) and left ovarian (P = 0.386) volumes were also lower but this did not reach statistical significance. Serum follicle-stimulating hormone (P = 0.327), estradiol (P = 0.241), and prolactin (P = 0.55) were similar between the two groups.

CONCLUSIONS

Ovarian reserve may be reduced in SS patients. For the assessment of ovarian reserve, serum AMH and ovarian AFC with serum LH may be useful. Further studies with long-term follow-up are required to determine the course of ovarian reserve abnormalities and best possible biomarkers of reduced ovarian reserve in SS patients.

Effect of Premature Menopause on Sexuality

Premature menopause, that is, menopause – spontaneous or iatrogenic – occurring at or before the age of 40 years, affects sexual identity, sexual function and sexual relationships. The woman's health, wellbeing and achievement of life's goals may be variably impaired. Factors modulating the individual's sexual outcome after premature menopause include: etiological heterogeneity of premature menopause and associated medical and sexual comorbidities; psychosexual vulnerability to premature menopause and associated infertility in survivors of childhood and adolescent cancers; impact of premature menopause on women's sexual identity, sexual function – particularly the biological basis of desire, arousal, orgasm and vaginal receptivity – and sexual relationships; partner-related factors; fertility issues; and preventive/therapeutic measures. Hormone therapy is indicated but long-term safety data are lacking. An interdisciplinary medical and psychosexual approach comprises appropriate counseling, fertility protection, when feasible, individualized hormone therapy and specific psychosexual treatment(s). Further research on fertility protection and the safety of long-term hormone therapy after premature menopause is needed.

Ovarian function after hematopoietic cell transplantation: a descriptive study following the use of GnRH agonists for myeloablative conditioning and observation only for reduced-intensity conditioning

Gonadal failure is a health and quality-of-life concern in hematopoietic cell transplant (HCT) survivors. While ovarian dysfunction is nearly universal following myeloablative (MA) conditioning, the risk is unclear after reduced-intensity conditioning (RIC). Gonadotropin-releasing hormone agonists decrease ovarian failure rates following conventional chemotherapy, but little is known about its effectiveness with HCT. We investigated the impact of leuprolide on ovarian function after MA conditioning and monitored ovarian function after RIC in this descriptive pilot study. Post-menarchal females <50 years undergoing HCT with adequate baseline ovarian function (follicle-stimulating hormone (FSH) level <40 mIU/mL and normal menstruation) were eligible. Prior to MA conditioning, leuprolide was administered. Those undergoing RIC were observed. FSH was measured at various time points. Seventeen women aged 12-45 years were evaluated (7 in the intervention group and 10 in the observation group). Compared to the historical high rate of ovarian failure after MA conditioning, 3 of 7 evaluable Lupron recipients had ovarian failure at a median of 703 days post transplant. Ovarian failure occurred in 1 of 10 recipients of RIC at a median follow-up of 901 days. In conclusion, leuprolide may protect ovarian function after MA conditioning. Additionally, RIC with cyclophosphamide, fludarabine and low-dose TBI has a low risk of ovarian failure.

Gonadotrophin releasing hormone analogues for ovarian function preservation in young females undergoing chemotherapy

Chemotherapy has significantly improved the prognosis of cancer patients with various malignancies. However, female patients, especially those whoich are premenopausal, suffer from significant chemotherapy induced ovarian function impairment, which decreases their quality of life. Many new techniques for ovarian preservation have been established in recent years. Although the use of gonadotrophin releasing hormone analogues (GnRHa) for this purpose is not a new concept, its effectiveness in protection of ovarian function is still debatable. This article deals with studies and metaanalyses which have been undertaken in the past, demonstrating the impact of GnRHa in ovarian function preservation, and whether their use can be implemented in routine practice.

MicroRNA-133b stimulates ovarian estradiol synthesis by targeting Foxl2

Forkhead L2 (Foxl2) is expressed in ovarian granulosa cells and participates in steroidogenesis by transcriptionally regulating target genes such as steroidogenic acute regulatory protein (StAR) and CYP19A1. In this study, a direct link between microRNA-133b (miR-133b) and Foxl2-mediated estradiol release in granulosa cells was established. miR-133b was involved in follicle-stimulating hormone (FSH)-induced estrogen production. Luciferase assays confirmed that miR-133b was bound to the 3' untranslated region (3'UTR) of Foxl2 mRNA. Consistent with this finding, miR-133b overexpression reduced the Foxl2 levels. Furthermore, miR-133b inhibited Foxl2 binding to the StAR and CYP19A1 promoter sequences. These results demonstrate that miR-133b down-regulates Foxl2 expression in granulosa cells by directly targeting the 3'UTR, thus inhibiting the Foxl2-mediated transcriptional repression of StAR and CYP19A1to promote estradiol production.

Investigating the role of X chromosome breakpoints in premature ovarian failure

The importance of the genetic factor in the aetiology of premature ovarian failure (POF) is emphasized by the high percentage of familial cases and X chromosome abnormalities account for 10% of chromosomal aberrations. In this study, we report the detailed analysis of 4 chromosomal abnormalities involving the X chromosome and associated with POF that were detected during a screening of 269 affected women. Conventional and molecular cytogenetics were valuable tools for locating the breakpoint regions and thus the following karyotypes were defined: 46,X,der(X)t(X;19)(p21.1;q13.42)mat, 46,X,t(X;2)(q21.33;q14.3)dn, 46,X,der(X)t(X;Y)(q26.2;q11.223)mat and 46,X,t(X;13)(q13.3;q31)dn. A bioinformatic analysis of the breakpoint regions identified putative candidate genes for ovarian failure near the breakpoint regions on the X chromosome or on autosomes that were involved in the translocation event. HS6ST1, HS6ST2 and MATER genes were identified and their functions and a literature review revealed an interesting connection to the POF phenotype. Moreover, the 19q13.32 locus is associated with the age of onset of the natural menopause. These results support the position effect of the breakpoint on flanking genes, and cytogenetic techniques, in combination with bioinformatic analysis, may help to improve what is known about this puzzling disorder and its diagnostic potential.

A molecular and cytogenetic investigation of FMR1 gene premutations in Polish patients with primary ovarian insufficiency

OBJECTIVE

The aim of this study was to determine the prevalence of premutations in the FMR1 gene that cause primary ovarian insufficiency (POI) in a group of affected women.

STUDY DESIGN

Forty DNA samples were purified from peripheral blood collected from women with ovarian failure who were under 40 years of age. A routine cytogenetic test was performed to eliminate chromosomal aberrations as the cause of POI. The DNA was analysed by polymerase chain reaction (PCR) with primers specific to the FMR1 gene region. The PCR products were then separated in denaturing polyacrylamide gels using an ABI Prism 377 sequencer.

RESULTS

Cytogenetic analysis of the samples revealed two X/autosome translocations. DNA analysis identified FMR1 gene premutations in three patients. The frequency of X/autosome translocations in the studied group was 2/40 (5.0%), and the frequency of FMR1 gene premutations was 3/38 cases (7.9%). Thus, genetic tests allowed for the identification of POI in five (12.5%) out of 40 women.

CONCLUSION

FMR1 gene premutation is a common genetic cause of POI.

Skewed X chromosome inactivation may be not associated with premature ovarian failure

BACKGROUND

In view of the controversies about the skewed X chromosome inactivation (XCI) and premature ovarian failure (POF) association, a meta-analysis of the published data was performed to evaluate the relationship between XCI skewing and POF.

METHODS

We searched for all published articles indexed in MEDLINE (1950 approximately 2009) and CNKI (1994 approximately 2009). Any case-control or cohort study that tested the association between skewed XCI and POF was included and data were extracted independently by two reviewers. We performed this meta-analysis involving 325 cases and 403 controls with Review Manager 4.2 software.

RESULTS

Four eligible studies were selected for meta-analysis. It suggested that there was no significant difference between the incidence of skewed XCI (XCI >or=70% skewing) in POF cases comparing to healthy controls, odds ratio (OR) = 1.13 [95% confidence interval (CI): 0.84 approximately 1.53, P = 0.42]. The link between extremely skewed XCI (XCI >or=90% skewing) and POF was also analysed, and no significant difference was found, either, OR = 1.46 (95% CI: 0.79 approximately 2.69, P = 0.22).

CONCLUSIONS

Skewed XCI had no association with POF. However, more case-control and cohort studies are needed in the future.

Ovarian preservation by GnRH agonists during chemotherapy: a meta-analysis

PURPOSE

Treatment with cyclophosphamide (CYC) confers up to a 40% risk of ovarian failure in women of reproductive age. The use of GnRH agonists (GnRHa) to preserve ovarian function has been investigated in several small studies. We performed a systematic review of studies examining whether a GnRHa administered during chemotherapy is protective of ovarian function and fertility.

METHODS

We searched the English-language literature (1966-April 2007) using MEDLINE and meeting abstracts and included studies that reported an association between GnRHa and ovarian preservation in women receiving chemotherapy. Studies without a control group were excluded. Ovarian preservation was defined as the resumption of menstrual cycles and a premenopausal follicle-stimulating hormone (FSH) after chemotherapy. Fertility was determined by a woman's ability to become pregnant. We estimated the summary relative risk (RR) and associated 95% confidence intervals (95% CI) using a random-effects model.

RESULTS

Nine studies included 366 women. Three studies included women with autoimmune disease receiving CYC; six included women with hematologic malignancy receiving combination chemotherapy. In total, 178 women were treated with GnRHa during chemotherapy, 93% of whom maintained ovarian function. Of the 188 women not treated with GnRHa, 48% maintained ovarian function. The use of a GnRHa during chemotherapy was associated with a 68% increase in the rate of preserved ovarian function compared with women not receiving a GnRHa (summary RR = 1.68, 95% CI 1.34-2.1). Among the GnRHa-treated women, 22% achieved pregnancy following treatment compared with 14% of women without GnRHa therapy (summary RR = 1.65, CI 1.03-2.6).

CONCLUSIONS

Based on the available studies, GnRHa appear to improve ovarian function and the ability to achieve pregnancy following chemotherapy. Several randomized trials are underway to define the role and mechanism of GnRHa in ovarian function preservation. In the meantime, premenopausal women facing chemotherapy should be counseled about ovarian preservation options, including the use of GnRHa therapy.

Connexin expression and gap junctional coupling in human cumulus cells: contribution to embryo quality

Gap junctional coupling among cumulus cells is important for oogenesis since its deficiency in mice leads to impaired folliculogenesis. Multiple connexins (Cx), the subunits of gap junction channels, have been found within ovarian follicles in several species but little is known about the connexins in human follicles. The aim of this study was to determine which connexins contribute to gap junctions in human cumulus cells and to explore the possible relationship between connexin expression and pregnancy outcome from in vitro fertilization (IVF). Cumulus cells were obtained from IVF patients undergoing intra-cytoplasmic sperm injection (ICSI). Connexin expression was examined by RT-PCR and confocal microscopy. Cx43 was quantified by immunoblotting and gap junctional coupling was measured by patch-clamp electrophysiology. All but 5 of 20 connexin mRNAs were detected. Of the connexin proteins detected, Cx43 forms numerous gap junction-like plaques but Cx26, Cx30, Cx30.3, Cx32 and Cx40 appeared to be restricted to the cytoplasm. The strength of gap junctional conductance varied between patients and was significantly and positively correlated with Cx43 level, but neither was correlated with patient age. Interestingly, Cx43 level and intercellular conductance were positively correlated with embryo quality as judged by cleavage rate and morphology, and were significantly higher in patients who became pregnant than in those who did not. Thus, despite the presence of multiple connexins, Cx43 is a major contributor to gap junctions in human cumulus cells and its expression level may influence pregnancy outcome after ICSI.

Hormone-dependent gynaecological disorders: a pathophysiological perspective for appropriate treatment

Hormonal changes are involved in several gynaecological disorders. Correct functioning of the hypothalamus-pituitary-ovarian (HPO) axis is critical for ovulatory function, as well as the growth and differentiation of uterine tissue (myometrium and endometrium). However, the correct functioning of other endocrine glands (thyroid, adrenal cortex, pancreas) is also crucial for correct reproductive function. Genes and environmental factors have an influence on women's fertility through their effect on hormonal function. Consequently, dysfunction of the HPO axis and/or other endocrine systems may cause infertility and gynaecological disorders. The pathogenetic basis can be used to help make the correct clinical decision for treating these diseases. Disturbances related to the menstrual cycle, i.e. amenorrhoea, polycystic ovary syndrome (PCOS) and premenstrual syndrome (PMS), have a close correlation with hypo- or hypersecretion of hormones of the HPO axis. The roles of hypothalamic neurohormones and neurotransmitters in the various forms of amenorrhoea and PMS are well established. PCOS has a complex endocrine/metabolic origin, so a variety of hormonal treatments have been proposed. Hormone derangement has also been proposed as the cause of endometriosis and uterine fibroids. These disorders do not have hyper- or hyposecretion of reproductive hormones, but hyperactivity of oestrogen receptors coupled with a genetic predisposition. The relevance of the endocrine changes is confirmed by the clinical effectiveness of hormonal treatments. In order to establish the correct treatment approach in gynaecological disorders, it is important to understand the endocrine pathophysiology.

Premature ovarian failure

The diagnosis of premature ovarian failure is based on the finding of amenorrhoea before age 40 associated with follicle-stimulating hormone levels in the menopausal range. Screening for associated autoimmune disorders and karyotyping, particularly in early onset disease, constitute part of the diagnostic work up. There is no role for ovarian biopsy or ultrasound in making the diagnosis. Management essentially involves hormone replacement and infertility treatment, the most successful being assisted conception with donated oocytes. Embryo cryopreservation, ovarian tissue or oocyte cryopreservation and in vitro maturation of oocytes hold promise in cases where ovarian failure is foreseeable as in women undergoing cancer treatments.

Treatment-related premature ovarian failure as a long-term complication after Hodgkin's lymphoma

BACKGROUND

One of the medical sequelae that chemo- and radiotherapy may cause is premature ovarian failure (POF). The scope of this study was to investigate the risk of developing POF as a long-term complication in young women treated for Hodgkin's lymphoma.

PATIENTS AND METHODS

The 99 women included in the study were treated between 1975 and 1992 at the Norwegian Radium Hospital. All patients received radiotherapy and 67 of the women also received chemotherapy.

RESULTS

POF was found in 37.4% of the patients. The risk of developing POF was significantly higher if the patient received chemotherapy in addition to radiotherapy. Furthermore, the risk increased if chemotherapy included alkylating agents. Long-term follow-up revealed that women who at the time of treatment were under 30 years of age developed POF later, but with the same cumulative risk as women above 30 years of age.

CONCLUSIONS

The risk of developing POF after radio- and chemotherapy is higher than earlier estimates suggest. After an observation time of 15 years the cumulative risk is 38% independent of age at the time of treatment. Age below 30 years at the time of treatment delays the development of POF, but does not decrease the life-time risk.

Premature ovarian failure

Premature ovarian failure (POF) causing hypergonadotrophic hypogonadism occurs in 1% of women. In majority of cases the underlying cause is not identified. The known causes include: (a) Genetic aberrations, which could involve the X chromosome or autosomes. A large number of genes have been screened as candidates for causing POF; however, few clear causal mutations have been identified. (b) Autoimmune ovarian damage, as suggested by the observed association of POF with other autoimmune disorders. Anti-ovarian antibodies are reported in POF by several studies, but their specificity and pathogenic role are questionable. (c) Iatrogenic following surgical, radiotherapeutic or chemotherapeutic interventions as in malignancies. (d) Environmental factors like viral infections and toxins for whom no clear mechanism is known. The diagnosis is based on finding of amenorrhoea before age 40 associated with FSH levels in the menopausal range. Screening for associated autoimmune disorders and karyotyping, particularly in early onset disease, constitute part of the diagnostic work-up. There is no role of ovarian biopsy or ultrasound in making the diagnosis. Management essentially involves hormone replacement and infertility treatment, the only proven means for the latter being assisted conception with donated oocytes. Embryo cryopreservation, ovarian tissue cryopreservation and oocyte cryopreservation hold promise in cases where ovarian failure is foreseeable as in women undergoing cancer treatments.

Successful pregnancy after cladribine therapy for hairy cell leukemia

Hairy cell leukemia (HCL) is predominantly seen in men with a median age of 52, and often treated with 2-chlorodeoxyadenosine (cladribine, 2-CdA). Perhaps as a result of the demographics of HCL, studies of ovarian function after such therapy are lacking, even though cladribine can induce DNA strand breaks. In this report, the first case of a patient diagnosed with HCL who then went on to a successful pregnancy is described, suggesting that fertility may be preserved in at least some female patients treated with this agent.