Endometriosis-induced alterations in mouse metaphase II oocyte microtubules and chromosomal alignment: a possible cause of infertility

Infertility following trisomic pregnancies: A nationwide cohort study

OBJECTIVE

To study whether gynecologic or reproductive disorders show association with trisomic conceptions.

METHODS

This nationwide cohort study utilized the Registry of Congenital Malformations to identify women who had a trisomic pregnancy (n = 5784), either with trisomy 13 (T13; n = 351), trisomy 18 (T18; n = 1065) or trisomy 21 (T21; n = 4369) from 1987 to 2018. We used the Finnish Maternity cohort to match the cases to population controls (n = 34 422) on the age, residence, and timing of pregnancy. These data were cross-linked to the ICD-10 diagnoses of the national Care Registry for Health Care data on specialized health care in Finland during 1996 to 2019. Both inflammatory (ICD-10 diagnoses: N70-N77) and noninflammatory disorders of the genital tract (N80-N98) were studied. Crude odds ratios (ORs) with 95% CIs were calculated for associations between diagnoses and trisomic conceptions.

RESULTS

The diagnosis of female infertility (N97) at any time was associated with trisomic conceptions (OR: 1.19, 95% CI: 1.08-1.32). In the subgroup analysis, this association was found for T18 (OR: 1.29, 95% CI: 1.03-1.61) and T21 (OR: 1.17, 95% CI: 1.04-1.32), but not for T13 (OR: 1.15, 95% CI: 0.75-1.72). When restricting the timing of the diagnosis of female infertility, an elevated OR was found only after the index pregnancy (OR: 1.81, 95% CI: 1.56-2.09). These increased odds for infertility after trisomic conceptions were observed both in women <35 years (T18 OR: 1.91, 95% CI: 1.21-3.00; T21 OR: 1.68, 95% CI: 1.31-2.14) and in women ≥35 years (T18 OR: 2.17, 95% CI: 1.40-3.33; T21 OR: 1.87; 95% CI: 1.47-2.39), but not after T13 conceptions.

CONCLUSION

Our observational data suggest a link between trisomic conceptions and subsequent diagnoses of infertility but do not demonstrate causality. These data implicate that partially similar mechanisms might predispose to trisomy and infertility, regardless of maternal age.

Does endometriosis inflict harm on embryos? A systematic review of embryo morphokinetics analysed by time lapse monitoring in women with endometriosis

Endometriosis has been shown to be associated with unfavorable development and maturation of oocytes, as well as aberrancies in embryonal development, including arrest after fertilization, following in vitro fertilization (IVF). Time-lapse monitoring (TLM) enables continuous and non-invasive monitoring of embryo morphokinetics during the IVF process and might be useful in the assessment of embryos from women with endometriosis. In this review, five eligible studies were evaluated to determine if embryo morphokinetics assessed under TLM differ in patients with endometriosis and subsequently predict blastocyst quality, implantation and success of pregnancy. The studies showed overall inferior morphokinetic parameters of embryos from endometriosis patients when compared to controls, independent of the severity of endometriosis. Embryos with optimal early morphokinetic parameters (t2, s2, t5, tSB, tEB) and late developmental events (compaction, morulation, and blastulation) had better implantation rates than those who had suboptimal ranges. However, due to few studies available with mostly retrospective data, the validity of these findings and their generalizability for clinical practice needs to be further assessed. Prospective studies with larger sample sizes are needed to determine whether using TLM for embryo selection in endometriosis improves pregnancy and live birth outcomes.

Reproductive outcomes of single frozen-thawed embryo transfer in patients with endometriosis after preimplantation genetic testing

PURPOSE

The reproductive outcomes of patients with endometriosis who are infertile have attracted recent attention. We aimed to explore whether endometriosis affects endometrial receptivity by observing pregnancy outcomes following a euploid blastocyst frozen embryo transfer.

METHODS

This retrospective cohort study analyzed the data of patients with endometriosis from the reproductive hospital affiliated to Shandong University between January 2015 and December 2021. Control groups were matched using the 1:3 propensity score. The live birth, clinical pregnancy, biochemical pregnancy, clinical abortion, premature birth, and aneuploid rates were compared between the control group and endometriosis group.

RESULTS

A total of 625 patients who underwent preimplantation genetic testing (PGT) prior to embryo implantation were included in the analysis. There were no significant differences in the live birth, clinical pregnancy, biochemical pregnancy, clinical abortion, and premature birth rates between the two groups. The aneuploidy rate of blastocysts obtained from the endometriosis group was higher than that of the control group (P = 0.012).

CONCLUSION

Pregnancy outcomes using frozen embryos after PGT in patients with endometriosis did not differ from those in other women experiencing infertility. However, endometriosis may affect the quality of oocytes, resulting in a higher rate of aneuploidy.

A cohort study on IVF outcomes in infertile endometriosis patients: the effects of rapamycin treatment

RESEARCH QUESTION

Can rapamycin, used as an anti-senescence drug before IVF cycles, improve the IVF outcomes of women with endometriosis by reducing oxidative stress and senescence?

DESIGN

This retrospective analysis involved 168 endometriosis patients undergoing two successive IVF cycles. The treatment group (n = 80) received 3 months of rapamycin before the second IVF cycle, while the non-treatment group (n = 88) had no adjuvant treatment. The first and second IVF cycles were compared between and within groups. Follicular fluid from both IVF cycles (treatment group n = 28, non-treatment group n = 32) were tested for senescence-associated and oxidative stress-related markers.

RESULTS

Comparing the follicular fluid from the second cycles, the rapamycin treatment group showed decreased markers of oxidative stress (8-hydroxydesoxyguanosine, malondialdehyde) and increased antioxidant markers (superoxidase dismutase, glutathione peroxidase) (all P < 0.001); the expression of senescence-related markers p16 and p21 was also significantly lower in the treatment group than in the non-treatment group (P < 0.001). Comparing the second IVF cycles, the treatment group needed fewer days of ovarian stimulation, with increased numbers of oocytes obtained and mature oocytes compared with the non-treatment group (all P < 0.001). Furthermore, rates of fertilization, implantation and clinical pregnancy were significantly higher in the treatment group (P = 0.008, 0.034 and 0.038 respectively), as was the live birth rate (P = 0.003). No structural abnormalities were seen in fetuses born to women treated with rapamycin.

CONCLUSIONS

This study suggested an association between short-term rapamycin treatment and improved pregnancy outcomes via IVF. This result needs to be further investigated in prospective randomized controlled clinical trials.

Patient experiences of being advised by a healthcare professional to get pregnant to manage or treat endometriosis: a cross-sectional study

BACKGROUND

There is a lack of evidence that pregnancy reduces endometriotic lesions or symptoms, however studies indicate that people with endometriosis are commonly advised to get pregnant to manage or treat endometriosis. This study sought to examine the impact of this advice on patients with endometriosis when the advice was provided by healthcare professionals.

METHODS

The Endometriosis Patient Experience Survey was a self-reported, community-based, cross-sectional online survey of people who had been medically diagnosed with endometriosis. Descriptive statistics were used to analyse the quantitative survey data and thematic analysis was undertaken for the qualitative survey data.

RESULTS

1892 participants had received the advice to get pregnant or have a baby to manage or treat their endometriosis, with 89.4% of participants receiving this advice from healthcare professionals. In exploring the qualitative data, seven themes were contextualised relating to the impact of this advice in terms of health literacy, accepting the advice, rejecting the advice, major life decisions, healthcare interactions, mental health and relationships.

CONCLUSIONS

This study demonstrates profound and often negative patient impacts of the advice from healthcare professionals to get pregnant to manage or treat endometriosis. Impacts ranged from planning for pregnancy, hastening the making of major life decisions, eroding trust with healthcare professionals, worsening mental health and straining relationships. Providing evidence-based information on the treatment and management of endometriosis is essential. Pregnancy or having a baby should not be suggested as a treatment for endometriosis and the provision of this advice by healthcare professionals can have negative impacts on those who receive it.

Endometriosis, Oocyte, and Embryo Quality

Endometriosis is a common finding among women with infertility, and women who are diagnosed with endometriosis are almost twice as likely to experience infertility. Mechanisms by which endometriosis causes infertility remain poorly understood. In this review, we evaluate the current literature on the impact of endometriosis on oocyte and embryo quality. The presence of endometriosis evidently reduces ovarian reserve, oocyte quality, and embryo quality; however, this does not appear to translate to a clear clinical impact. Analysis of data from large assisted reproduction technology registries has shown that women with endometriosis have a lower oocyte yield but no reduction in reproductive outcomes. There is a need for future studies in the form of well-designed randomized controlled trials to further evaluate the role of surgical and medical treatment options in women with endometriosis undergoing assisted conception.

Current Understanding of and Future Directions for Endometriosis-Related Infertility Research with a Focus on Ferroptosis

BACKGROUND

To date, the development of therapy for endometriosis and disease-related infertility remains a major challenge. Iron overload caused by periodic bleeding is a hallmark of endometriosis. Ferroptosis is an iron- and lipid-reactive oxygen species-dependent type of programmed cell death that is distinct from apoptosis, necrosis, and autophagy. This review summarizes the current understanding of and future directions for the research and treatment of endometriosis and disease-related infertility, with the main focus on the molecular basis of ferroptosis in endometriotic and granulosa cells.

METHODS

Papers published between 2000 and 2022 in the PubMed and Google Scholar databases were included in this review.

RESULTS

Emerging evidence suggests that ferroptosis is closely linked to the pathophysiology of endometriosis. Endometriotic cells are characterized by ferroptosis resistance, whereas granulosa cells remain highly susceptible to ferroptosis, suggesting that the regulation of ferroptosis is utilized as an interventional target for research into the treatment of endometriosis and disease-related infertility. New therapeutic strategies are urgently needed to efficiently kill endometriotic cells while protecting granulosa cells.

CONCLUSIONS

An analysis of the ferroptosis pathway in in vitro, in vivo, and animal research enhances our understanding of the pathogenesis of this disease. Here, we discuss the role of ferroptosis modulators as a research approach and potential novel treatment for endometriosis and disease-related infertility.

Ovarian endometrioma increases the embryo aneuploid rate: an analysis of 7092 biopsied blastocysts from fertile monogenetic disease carriers

BACKGROUND

Endometriosis affects many reproductive aged patients with fertility decline and poor outcomes of assisted reproductive treatments, mainly by decreased ovarian reserve and lower fertilization and implantation rates. In recent decade, altered oocyte microenvironments and abnormal spindle organization have been reported to be critical to oocyte chromosomal segregation, organization and aneuploid formation. However, clinical evidences are still limited on whether endometriosis influences oocyte and embryo development. We aimed to figure out the impact of endometrioma on embryo aneuploid formation.

METHOD

This retrospective cohort study included 1,021 patients (7,092 biopsied embryos) from January 2012 to December 2020. Fertile patients without a history of miscarriage who underwent PGT-M treatment with aneuploid screening were included. Patients with ovarian endometrioma were defined as the study group, while patients without endometriosis were defined as the control group. All demographic, controlled ovarian stimulation treatment and aneuploid screening data were recorded and compared.

RESULTS

The incidence of endometrioma in our study population was 6.5%. There were 7,092 embryos biopsied in total, with 308 embryos in the study group and 6,784 embryos in the control groups. The demographic characteristics were comparable between the two groups except the basal FSH level (6.02 IU/L vs. 5.52 IU/L, p = 0.012). The euploid rate of the study group was significantly lower than that of the control group (52.6% vs. 61.8%, p = 0.012), while the oocyte maturation, fertilization, usable embryo and blastocyst formation rates were comparable. Adjusted for basal FSH level, starting stimulating gonadotropin dosage, total gonadotropin dosage and FSH level on hCG day, euploid rate was still negatively related to endometrioma status.

CONCLUSIONS

Endometrioma status disturbs oocyte and embryo development. For infertile patients with endometrioma who require assisted reproductive treatment, pre-treatment is necessary to improve treatment outcomes.

TRIAL REGISTRATION

Not applicable.

Endometriosis-associated infertility: From pathophysiology to tailored treatment

Despite the clinically recognized association between endometriosis and infertility, the mechanisms implicated in endometriosis-associated infertility are not fully understood. Endometriosis is a multifactorial and systemic disease that has pleiotropic direct and indirect effects on reproduction. A complex interaction between endometriosis subtype, pain, inflammation, altered pelvic anatomy, adhesions, disrupted ovarian reserve/function, and compromised endometrial receptivity as well as systemic effects of the disease define endometriosis-associated infertility. The population of infertile women with endometriosis is heterogeneous, and diverse patients' phenotypes can be observed in the clinical setting, thus making difficult to establish a precise diagnosis and a single mechanism of endometriosis related infertility. Moreover, clinical management of infertility associated with endometriosis can be challenging due to this heterogeneity. Innovative non-invasive diagnostic tools are on the horizon that may allow us to target the specific dysfunctional alteration in the reproduction process. Currently the treatment should be individualized according to the clinical situation and to the suspected level of impairment. Here we review the etiology of endometriosis related infertility as well as current treatment options, including the roles of surgery and assisted reproductive technologies.

Iron overload compromises preimplantation mouse embryo development

We and others have previously shown that abnormal pelvic environment plays an important role in the unexplained infertility of endometriosis. However, whether iron overload caused by ectopic periodic bleeding found in patients with endometriosis participates in endometriosis-associated reproductive failure is unknown. This study aimed to investigate effects of iron at level relevant to pelvic iron overload on the development of preimplantation mouse embryo. Two-cell embryos were collected, and cultured to blastocysts in G1/G2 medium supplemented with iron alone or in combination with iron chelator. The development rates, ATP level, mitochondrial membrane potential (MMP), reactive oxygen species level (ROS), and apoptotic and ferroptotic indices were compared between control and iron treatments across each specific developmental stage. Prolonged exposure to iron remarkably impaired early embryo development in vitro by hampering blastocyst formation (P < 0.001), which could be partly restored by iron chelator (P < 0.001). The arrest of embryo development was linked with iron-initiated mitochondrial dysfunction with reduction of ATP generation and MMP (P < 0.05 and P < 0.001, respectively). Impaired mitochondria altered ROS accumulation post-iron exposure at morula stage and blastocyst stage (P < 0.05). Moreover, Iron-exposed blastocyst stage embryos showed higher apoptotic and ferroptotic rates (P < 0.001 and P < 0.05, respectively). Our results highlight that pathologically relevant level of iron compromises preimplantation mouse embryo development by disrupting mitochondrial function and triggering both apoptosis and ferroptosis, which implicates that excess iron found in peritoneal fluid of women with endometriosis likely participates in endometriosis-associated reproductive failure.

Can Endometriosis-Related Oxidative Stress Pave the Way for New Treatment Targets?

Endometriosis is a disease of reproductive age characterized by chronic pelvic pain and infertility. Its pathogenesis is complex and still partially unexplained. However, there is increasing evidence of the role of chronic inflammation, immune system dysregulation, and oxidative stress in its development and progression. The latter appears to be involved in multiple aspects of the disease. Indeed, disease progression sustained by a hyperproliferative phenotype can be related to reactive oxygen species (ROS) imbalance, as numerous experiments using drugs to counteract hyperproliferation have shown in recent years. Chronic pelvic pain is also associated with cell function dysregulation favoring chronic inflammation and oxidative stress, specifically involving macrophages and mast cell activation. Moreover, there is increasing evidence of a role for ROS and impaired mitochondrial function not only as deleterious effectors of the ovarian reserve in patients with endometriomas but also in terms of oocyte quality and, hence, embryo development impairment. Targeting oxidative stress looks to be a promising strategy to both curb endometriotic lesion progression and alleviate endometriosis-associated symptoms of chronic pain and infertility. More investigations are nevertheless needed to develop effective therapeutic strategies for clinical application.

The rate of oocytes with granular cytoplasm is higher in women with endometrioma in ICSI cycles

The purpose of this study was to investigate the impact of endometrioma on oocyte morphology and fertility outcome in intracytoplasmic sperm injection (ICSI)cycles. The study material was obtained from 114 ICSI cycles of infertile women aged between 20 and 38 years with ovarian endometriomas and unexplained infertility. In total, 644 mature oocytes were included in the analysis. The rates of specific oocyte morphological abnormalities were similar between the two groups however the central granulation rate was significantly higher in the group with endometrioma (p < .05). Fertilisation rate were not significantly different between the groups (p ≥ .05) however the numbers of metaphase 2 (MII) oocytes and embryos were lower in the endometrioma group (p ≤ .05). Endometrioma was associated with a higher rate of oocytes with granular cytoplasm, despite the fertilisation rate the numbers of the MII oocytes and embryo were affected.IMPACT STATEMENTWhat is already known on this subject? The association between endometrioma and infertility is a well-known condition, but the possible mechanisms of the effects of endometrioma on women's fertility is still debated and controversial. There is limited data on the effect of endometrioma on oocyte morphology. Low oocyte quality and lower fertilisation rates might be the main cause of adverse pregnancy outcomes during in vitro fertilisation/intracytoplasmic sperm injection cycles.What do the results of this study add? Endometrioma was associated with a higher rate of oocytes with granular cytoplasm, and lower metaphase 2 oocytes and embryos.What are the implications of these findings for clinical practice and/or further research? Future studies using further oocyte quality assessment methods and prospective observational studies including live-birth rate should be designed to better understand how endometrioma affects fertility outcomes.

Novel therapeutic targets to improve IVF outcomes in endometriosis patients: a review and future prospects

BACKGROUND

Patients with endometriosis often experience infertility and have poor IVF outcomes, with low fertilization and pregnancy rates. Although many theories have tried to explain the mechanisms underlying infertility in these patients, none of them is conclusive.

OBJECTIVE AND RATIONALE

In this review, we discuss the pathologic mechanisms through which endometriosis likely leads to infertility along with the therapeutic options used to date to treat endometriosis-related infertility and, thereby, to improve IVF outcomes in patients with endometriosis.

SEARCH METHODS

We performed a comprehensive literature search of clinical outcomes in endometriosis and the molecular mechanisms contributing to oocyte quality using the PubMed database to identify human and animal studies published from 1992 until September 2020. In total, 123 manuscripts were included.

OUTCOMES

While some theories propose that endometriosis patients may have fertility problems as a result of decreased endometrial receptivity, others reinforce the idea that infertility could be associated with oocyte alterations and lower implantation rates. Single-cell RNA sequencing of oocytes from patients with endometriosis has identified dysregulated mechanisms involved in steroid metabolism and biosynthesis, response to oxidative stress and cell cycle regulation. Dysregulation of these mechanisms could result in the poor IVF outcomes observed in patients with endometriosis. Further, impaired steroidogenesis may directly affect oocyte and embryo quality. Increased oxidative stress in patients with endometriosis also has a detrimental effect on the follicular microenvironment, inducing cell cycle dysregulation in oocytes, poor oocyte quality, and infertility. Moreover, granulosa cells in the context of endometriosis undergo increased apoptosis and have an altered cell cycle that could adversely affect folliculogenesis, oocyte and embryo quality, and IVF outcomes. Endometriosis is also associated with inflammatory damage and impaired angiogenesis, which could be directly correlated with poor IVF outcomes. While therapeutic options using GnRH analogues, progestins and aromatase inhibitors do not improve endometriosis-related infertility, anti-inflammatory agents and antioxidant supplementation could improve oocyte quality as well as implantation and clinical pregnancy rates in patients with endometriosis.

WIDER IMPLICATIONS

Endometriosis is a heterogeneous disease whose pathogenesis is complex and could affect fertility by altering a collection of molecular mechanisms in oocytes. Thus, a single model is not sufficient to describe endometriosis-related infertility. Dysregulation of steroidogenesis, oxidative stress, cell cycle progression, inflammation and angiogenesis in the follicular environment and oocytes in individuals with endometriosis are all possible contributors to endometriosis-related infertility. Therefore, treatments targeting these mechanisms could be therapeutic alternatives to improve IVF outcomes for these patients.

Getting to Know Endometriosis-Related Infertility Better: A Review on How Endometriosis Affects Oocyte Quality and Embryo Development

Endometriosis-related infertility describes a case of deteriorated fecundity when endometriosis is diagnosed. Numerous mechanisms have been proposed in an effort to delineate the multifaceted pathophysiology that induces impairment of reproductive dynamics in patients with endometriosis. In this critical analysis, authors present the plethora of molecular events that are entailed and elaborate on how they potentially impair the oocyte's and embryo's competence in patients with endometriosis. Reactive oxygen species, dysregulation of the immune system and cellular architectural disruption constitute the crucial mechanisms that detrimentally affect oocyte and embryo developmental potential. The molecular level impairment of the reproductive tissue is discussed, since differentiation, proliferation and apoptosis constitute focal regulatory cellular functions that appear severely compromised in cases of endometriosis. Mapping the precise molecular mechanisms entailed in endometriosis-related infertility may help delineate the complex nature of the disorder and bring us a step closer to a more personalized approach in understanding, diagnosing and managing endometriosis-related infertility.

Analysis of IVF/ICSI Outcomes in Endometriosis Patients With Recurrent Implantation Failure: Influence on Cumulative Live Birth Rate

OBJECTIVE

To study the influence of endometriosis activity on the pregnancy outcomes of patients with recurrent implantation failure (RIF) in in-vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) cycles. The pregnancy outcomes were compared between RIF patients with endometriosis who received treatment at different occasions to explore the appropriate treatment plan for these patients and to optimize the pregnancy-support strategies.

DESIGN

Ambispective cohort study.

METHODS

A total of 330 patients with endometriosis were enrolled from 2008 to 2018 and included 1043 IVF/ICSI cycles. All patients were diagnosed with RIF after IVF/ICSI. Patients were assigned to three subtypes according to different control states of endometriosis, including the untreated, early-treatment, and late-treatment groups. The clinical pregnancy rate, live birth rate, and cumulative live birth rate of endometriosis patients with RIF were the main outcomes; additionally, the fertilization rate, available embryonic rate, and high-quality embryonic rate were also compared.

RESULTS

The early-treatment and late-treatment groups showed higher cumulative live birth rate than the untreated group (early-treated 43.6% vs. late-treated 46.3% vs. untreated 27.7%, P<0.001), though patients in the two treatment groups had higher rates of adenomyosis and ovarian surgery. The two treatment group showed a better laboratory result than the untreated and especially, the early-treatment group. The untreated group (46.24%) had a lower IVF fertilization rate than the treated group (early-treated [64.40%] and late-treated [60.27%] (P<0.001). In addition, the rates of available embryos and high-quality embryos in the early-treated group were much higher those that in the untreated group (90.30% vs. 85.20%, 76.50% vs. 64.47%). Kaplan-Meier curve showed that patients in the untreated group needed a mean of 23.126 months to achieve one live birth; whereas those in the treated group needed a comparatively shorter duration (early-treated: 18.479 ± 0.882 months and late-treated: 14.183 ± 1.102 months, respectively).

CONCLUSION

Endometriosis has a negative influence on IVF/ICSI outcome. The control of endometriosis activity can result in a higher cumulative live birth rate in patients. It is necessary for endometriosis patients to receive medical treatment to achieve a better prognosis especially for those with RIF.

The Significance of Planned Fertility Preservation for Women With Endometrioma Before an Expected Ovarian Cystectomy

Endometrioma is known to reduce the ovarian reserve and the extent of the decrease is more severe when ovarian surgery is performed. Therefore, to prevent this decline in fertility, patients with endometrioma are considered candidates for preoperative fertility preservation (FP). In this study, we evaluate the efficacy of FP in women with endometrioma before planned ovarian surgery. A total of 95 cycles in 62 patients with endometrioma, undergoing controlled ovarian stimulation (COS) for FP using a gonadotropin-releasing hormone (GnRH) antagonist protocol before an expected ovarian surgery, were enrolled retrospectively. COS outcomes were compared according to endometrioma laterality. Additionally, first COS cycle outcomes in patients with endometrioma were compared with those in infertile patients, or in patients with a benign ovarian cyst using propensity score matching. When multiple COS cycles were performed, the results of cumulative cycles were analyzed. Embryo quality was worse in the bilateral endometrioma group. Compared with the infertile patient group, the patients with endometrioma had significantly lower Anti-Müllerian Hormone (AMH) and fewer numbers of oocytes retrieved (median, 3.3 vs. 1.2, p<0.001; 7.0 vs. 4.0, p=0.009, respectively). Compared with mature oocytes in infertile patients or patients with a benign cyst, mature oocytes were fewer in patients with endometrioma, but this was not statistically significant (median, 4.0 vs. 3.0, p=0.085; 5.5 vs. 3.0, p=0.052, respectively). The median value of the cumulative number of cryopreserved oocytes or embryos was 14.5 up to the fourth cycle compared to 3 up to the first cycle, with cumulative effect. Women with endometrioma should be counseled for FP before planned ovarian cystectomy. The number of cryopreserved oocytes or embryos can be increased by repeated cycles.

Endometriosis shows no impact on the euploid blastocyst rate per cohort of inseminated metaphase-II oocytes: A case-control study

OBJECTIVE

To evaluate the true impact of endometriosis on oocytes' competence defined as blastulation, euploidy and implantation rates.

DESIGN

Retrospective multicenter case-control study involving infertile couples undergoing ICSI with qPCR and trophectoderm biopsy-based PGT-A. Patients affected from endometriosis (n = 210) were diagnosed through transvaginal sonography or surgical history with histological confirmation. Each case was matched to two controls (n = 420) according to IVF clinic, maternal age at retrieval (38.6 ± 2.7 yr), number of previous failed IVF treatments (0.5 ± 0.8) and number of metaphase-II oocytes retrieved (6.1 ± 3.7 per patient). The primary outcome was the mean euploid blastocyst rate per cohort of inseminated metaphase-II oocytes. Other embryological, clinical, obstetric and neonatal outcomes were also evaluated.

RESULTS

The mean euploid blastocyst rate per cohort of inseminated metaphase-II oocytes was identical in the two groups (18 %±22 %) independently of maternal age. No difference was shown for all embryological outcomes investigated. The live birth rates per vitrified-warmed single euploid blastocyst transfer were also similar (67/158, 42 % in patients affected from endometriosis versus 132/327, 40 % in matched-controls). No difference was reported in the gestational and neonatal outcomes. The cumulative live birth delivery rates among completed cycles were also identical (61/201, 30 % versus 117/391, 30 % in endometriosis and matched-control groups, respectively) independently of maternal age.

CONCLUSIONS

Endometriosis might not impair oocyte developmental and reproductive competence, although its potential impact on the number of metaphase-II oocytes retrieved cannot be ignored. This information is critical for clinicians during counseling to outline an effective strategy to treat infertile patients affected from this condition. Future prospective studies are needed to evaluate the impact of endometriosis stage on euploidy rates.

Single-cell RNA sequencing of oocytes from ovarian endometriosis patients reveals a differential transcriptomic profile associated with lower quality

STUDY QUESTION

Do oocytes from women with ovarian endometriosis (OE) have a different transcriptomic profile than those from healthy women?

SUMMARY ANSWER

Oocytes from endometriosis patients, independently of whether they came from the affected ovary, exhibited a differential transcriptomic profile compared to oocytes from healthy egg donors.

WHAT IS KNOWN ALREADY

Studies of endometriosis have sought to determine whether OE affects oocyte quality. While many reports indicate that oocytes recovered from endometriotic ovaries may be affected by the disease, other studies have found no significant differences among oocyte/embryo quality and fertilization, implantation and pregnancy rates in women with endometriosis.

STUDY DESIGN, SIZE, DURATION

This prospective study compared metaphase II (MII) oocytes (n = 16) from endometriosis patients (n = 7) to oocytes (n = 16) from healthy egg donors (n = 5) by single-cell RNA sequencing (scRNA-seq). Participants were recruited between December 2016 and February 2018 at IVI-RMA Valencia and Vigo clinics.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Human MII oocytes were collected from healthy egg donors and OE patients aged 18-34 years, with a body mass index of <30 and >6 pre-antral follicles. RNA was extracted, cDNA was generated and libraries were constructed and sequenced. scRNA-seq data libraries were processed and statistically analysed. Selected genes were validated by quantitative real-time PCR.

MAIN RESULTS AND THE ROLE OF CHANCE

Our scRNA-seq results revealed an effect of endometriosis on global transcriptome behaviour in oocytes from endometriotic ovaries. The highest number of differentially expressed genes (DEGs) was found when oocytes from women with OE were compared to oocytes from healthy donors [520 DEGs (394 upregulated and 126 downregulated)], independently of whether oocytes came from an affected or unaffected ovary. Among the top 20 significant DEGs in this comparison, most were upregulated, including APOE, DUSP1, G0S2, H2AFZ, ID4, MGST1 and WEE1. PXK was the only downregulated gene. Subsequently, functional analysis showed 31 enriched functions deregulated in endometriosis patients (Benjamini P < 0.1), being 16 significant enriched functions considering Benjamini P < 0.05, which involved in biological processes and molecular functions, such as steroid metabolism, response to oxidative stress and cell growth regulation. In addition, our functional analysis showed enrichment for mitochondria, which are an important cellular component in oocyte development. Other functions important in embryo development, such as angiogenesis and methylation, were also significantly enriched.

LARGE SCALE DATA

All raw sequencing data are submitted in Gene Expression Omnibus (GEO) under accession number (PRJNA514416).

LIMITATIONS, REASONS FOR CAUTION

This study was restricted only to OE and thereby other anatomical entities, such as peritoneal and deep infiltrating endometriosis, were not considered. This is a descriptive study with a limited number of samples reflecting the difficulty to recruit human oocytes, especially from women with endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

This study suggests that OE exhibits a global transcriptomic effect on oocytes of patients in OE, independently if they come from an affected or unaffected ovary and alters key biological processes and molecular functions related to steroid metabolism, response to oxidative stress and cell growth regulation, which reduce oocyte quality.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by IVI Foundation, the Spanish Ministry of Economy and Competitiveness through the Miguel Servet programme (CPII018/00002 to F.D.), the Sara Borrell Program (CD15/00057 to H.F.) and the VALi+d Programe (Generalitat Valenciana); ACIF/2016/444 to A.C.). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

None.

FACTORS OF ENDOMETRIAL RECEPTIVITY DOWN-REGULATION IN GENITAL ENDOMETRIOSIS

Endometriosis, or endometrioid disease, is a chronic estrogen-dependent gynecological disease caused by ectopic localization of endometrial tissue, mainly in the pelvis and ovaries. However, at the present stage of development of reproductive medicine, the classical topographic definition of endometriosis should be expanded with new significant characteristics established using the achievements of cell and molecular biology, which allowed a more detailed study of the pathogenesis of this disease. In addition, the introduction of personalized approaches to the treatment of patients with endometriosis and infertility, more attention should be paid to the search for disease predictors and the formation of risk groups with the observation of patients from puberty to menopause. In this review, we have analyzed the literature data and our own studies with an emphasis on factors and markers of decreased receptivity of eutopic endometrium in women with endometriosis, as well as pain, the manifestations of which can contribute to the exact diagnosis of external genital endometriosis.

Clinical management of endometriosis

Endometriosis is a disease of reproductive age women that is commonly characterized by symptoms that often negatively impact quality of life. The clinical management of endometriosis remains highly variable and mostly influenced by geographic location, practice patterns, and breadth of clinician experience. This variability in treatment has inspired a trend towards multidisciplinary and specialized care of patients suffering from this disease. Surgical sampling, followed by histologic confirmation of endometrial-like tissue, remains the standard for the definitive diagnosis of endometriosis. However, the high sensitivity and specificity of MRI and ultrasound has shed light on the path towards non-surgical diagnosis of deep infiltrating endometriosis. Molecular variability and intricacy of this disease has limited the development of biologic markers to target for non-invasive diagnosis and pharmacologic therapies. Surgical management of advanced-stage endometriosis can be difficult, mostly secondary to the invasive nature of the disease, and anatomical distortion requiring advanced surgical skills to manage. The high prevalence of chronic pelvic pain and other complex pain syndromes in patients with endometriosis also requires knowledge in the management of these types of issues in order to provide comprehensive care. Menopausal endometriosis, extrapelvic presentation, and potential malignant transformation of lesions are infrequent, requiring a high index of suspicion for timely diagnosis and treatment.

Ethiopathogenic mechanisms of endometriosis-related infertility

Endometriosis is a highly prevalent disease among women of reproductive age and is frequently associated to infertility. However, the mechanisms underlying endometriosis-related infertility are still not completely known. Several studies have been conducted in order to elucidate this question. Besides anatomical changes that may impair gametes and embryo transport along the tubes; a smaller ovarian reserve due to advanced endometriosis and endometriomas; and a dysregulated hypothalamic-pituitary-ovarian axis, there are pieces of evidence suggesting that the peritoneal ectopic endometrial foci may induce a local inflammatory response, with the recruitment of macrophages, cytokine release, and reactive oxygen species generation, leading to a pro-oxidant peritoneal microenvironment. These alterations may be systemically reflected and also affect the follicular microenvironment. A harmful follicular fluid may disrupt cumulus cells functions and, consequently, compromise oocyte competence. There is also evidence suggesting that the peritoneal fluid of women with endometriosis may alter sperm function. Reduced endometrial receptivity is also pointed as a possible mechanism involved in endometriosis-related infertility, which needs further investigation.

Clinical Management of Endometriosis

Endometriosis is a common and challenging condition of reproductive-aged women that carries a high individual and societal cost. The many molecular dissimilarities between endometriosis lesions and eutopic endometrium create difficulties in the development of new drug therapies and treatments. Surgery remains the gold standard for definitive diagnosis, but it must be weighed against the risks of surgical morbidity and potential decreases in ovarian reserve, especially in the case of endometriomas. Safe and effective surgical techniques are discussed within this article for various presentations of endometriosis. Medical therapy is suppressive rather than curative, and regimens that are long-term and affordable with minimal side effects are recommended. Recurrences are common and often rapid when medical therapy is discontinued. Endometriosis in the setting of infertility is reviewed and appropriate management is discussed, including when and whether surgery is warranted in this at-risk population. In patients with chronic pain, central sensitization and myofascial pain are integral components of a multidisciplinary approach. Endometriosis is associated with an increased risk of epithelial ovarian cancer; however, the risk is low and currently no preventive screening is recommended. Hormone therapy for symptomatic women with postsurgical menopause should not be delayed as a result of concerns for malignancy or recurrence of endometriosis.

The Effect of Imbalanced Progesterone Receptor-A/-B Ratio on Gelatinase Expressions in Endometriosis

Background

Gelatinases degrade extracellular matrix (ECM) components to allow for physiological remodeling and contribute to pathological tissue destruction in endometriosis. It is known that the function of gelatinases is resistant to suppression by progesterone in endometriosis. The ability of progesterone to impact gene expression depends on the progesterone receptor-A/-B(PR-A/PR-B) ratio. An imbalanced PR-A/PR-B ratio in endometriotic tissue may be the result of the differential expression of MMP-2 and MMP-9, which could be important in the etiology and pathogenesis of the disease. Hence, we decided to study the association of PR-A/PR-B ratio and gelatinases expression in endometriosis.

Materials and Methods

In this prospective case-control study, we enrolled 40 women, 20 in the case group who were diagnosed with stage III/IV endometriosis and 20 normal subjects without endometriosis (controls) who referred to Royan Institute, Tehran, Iran during 2013-2014. We obtained 60 tissue samples [ectopic (n=20), eutopic (n=20), and normal endometrium (n=20)]. RNA was extracted from the tissue samples in order to analyze PR-A, PR-B, MMP-2, and MMP-9 mRNA levels through real-time polymerase chain reaction (PCR).

Results

There was significantly lower expression of the PR-B isoform in ectopic tissues compared to the control (P=0.002) and eutopic endometrium (P=0.006) tissues. PR-A expression was higher, but not significantly so, in the same ectopic and eutopic endometrium tissues compared to the control tissues (P=0.643). There was significant overexpression of MMP-9 in ectopic samples compared to control (P=0.014) and eutopic endometrium (P=0.012) samples. The PR-A/PR-B ratio was not significantly higher in either eutopic or ectopic samples compared to the control samples (P=0.305).

Conclusion

Our findings support an altered PR-B expression in endometriosis, which may be associated with MMP-9 overexpression. This finding can be important for disease pathogenesis.

Elevated peritoneal fluid ceramides in human endometriosis-associated infertility and their effects on mouse oocyte maturation

OBJECTIVE

To characterize the peritoneal fluid (PF) sphingolipid profile in endometriosis-associated infertility (EAI), and to assess the plausible functional role(s) of ceramides in oocyte maturation potential.

DESIGN

Retrospective case-control study and in vitro mouse oocyte study.

SETTING

University-affiliated hospital and university laboratory.

SUBJECTS

Twenty-seven infertile patients diagnosed with endometriosis and 20 infertile patients who did not have endometriosis; BALB/c female mice.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

PF sphingolipid concentrations. Number of metaphase II (MII) mouse oocytes.

RESULT(S)

Liquid chromatography-tandem mass spectrometry revealed 11 significantly elevated PF sphingolipids in infertile women with severe endometriosis compared with infertile women without endometriosis (change >50%, false discovery rate ≤10%). Logistic regression analysis identified three very-long-chain ceramides potentially associated with EAI. Functional studies revealed that very-long-chain ceramides may compromise or induce murine MII oocyte maturation. The oocyte maturation effects induced by the very long-chain ceramides were triggered by alterations in mitochondrial superoxide production in a concentration-dependent manner. Scavenging of mitochondrial superoxide reversed the maturation effects of C_24:0 ceramide.

CONCLUSION(S)

EAI is associated with accumulation of PF very-long-chain ceramides. Mouse studies demonstrated how ceramides affect MII oocyte maturation, mediating through mitochondrial superoxide. These results provide an opportunity for direct functional readout of pathophysiology in EAI, and future therapies targeted at this sphingolipid metabolism may be harnessed for improved oocyte maturation.

Effects of cisplatin on surgically induced endometriosis in a rat model

Research has strongly suggested that the features of endometriosis serve as a precursor lesion of ovarian cancer. Cisplatin (CDDP) is the preferred drug against these cancer types. The present study investigated the effects of CDDP on surgically induced endometriosis in a rat model. Endometriosis was surgically induced by the autologous transplantation of endometrial tissue. A total of 36 model rats were randomly divided into three groups. The rats in Group 1 (control group, n=12) received no medication. The rats in Group 2 (n=12) and Group 3 (n=12) were administered 35 mg/m² CDDP and 70 mg/m² CDDP, respectively, every four days. All rats were treated for a total of 24 days. The growth and histologic scores of the implants were calculated. The expression of protein markers, including vascular endothelial growth factor (VEGF), aromatase P450 (P450arom), transforming growth factor-β (TGF-β) and matrix metalloproteinase (MMP)-2, were assessed using immunohistochemistry, an enzyme-linked immunosorbent assay and western blot analysis. Following CDDP treatment, the mean implant sizes were significantly reduced in Groups 2 and 3 compared with the control group (P=0.01). The mean histologic scores were also significantly lower in Groups 2 and 3. Furthermore, the protein expression of VEGF, P450arom, TGF-β and MMP-2 was significantly lower in Groups 2 and 3 when compared with the control group. A loss of hair was observed in 4 rats, which only occurred in Group 3. A dose-dependent effect was observed in the two CDDP-treated groups. In conclusion, the expression of proliferation- and angiogenesis-associated proteins was significantly lower following treatment with CDDP. CDDP caused a significant regression in the size of the endometriotic implants and induced atrophy of these lesions in rats.

Detrimental effects of endometriosis on oocyte morphology in intracytoplasmic sperm injection cycles: a retrospective cohort study

While an association can be addressed among endometriosis and subfertility, the causal relationship has not been elucidated yet. Impaired oocyte quality in endometriosis patients has been accused for the unsuccessful outcomes of assisted reproductive techniques. There are limited studies in literature evaluated association between endometriosis and oocyte morphology. We conducted this retrospective study to evaluate whether morphological abnormalities of oocytes are more common in women with endometriosis than women with diagnosis of male factor infertility as a source of healthy oocytes. Totally 1568 oocytes, 775 (49.4%) in endometriosis groups and 793 (50.6%) in control group were evaluated for morphological parameters before ICSI cycles. Abnormal oocyte morphology was detected in 352 (22.4%) of 1568 oocytes. Of the abnormal oocytes, 208 (59.1%) were in endometriosis group and 144 (40.9%) in control group (p < .001). The following dysmorphisms were significantly higher in oocytes retrieved from endometriosis group: dark cytoplasm; dark, large or thin zona pellucida; and flat or fragmented polar body (p <  .05 for all). When morphological parameters for oocytes of endometriosis patients evaluated, the oocyte defects has increased significantly in endometriosis patients. These findings are thought to be useful to clarify the subfertility in endometriosis patient, which needs to be confirmed with further studies.

Endometriosis Is a Cause of Infertility. Does Reactive Oxygen Damage to Gametes and Embryos Play a Key Role in the Pathogenesis of Infertility Caused by Endometriosis?

Approximately, 10-15% of women of reproductive age are affected by endometriosis, which often leads to infertility. Endometriosis often has an inherited component, and several causative predisposing factors are hypothesized to underlie the pathogenesis of endometriosis. One working hypothesis is the theory of retrograde menstruation. According to the theory of retrograde menstruation, components of refluxed blood, including apoptotic endometrial tissue, desquamated menstrual cells, lysed erythrocytes, and released iron, induce inflammation in the peritoneal cavity. This in turn activates macrophage release of reactive oxygen species (ROS), leading to oxidative stress via the respiratory burst. Refluxed blood promotes the Fenton reaction, terminating in the production of hydroxyl radical, the most potently destructive ROS. In this article, we review the papers that demonstrate decreased quantity and quality of oocytes and embryos retrieved from IVF/ICSI patients with endometriosis. We discuss literature data demonstrating that ROS are generated in endometriotic tissues that have physical proximity to gametes and embryos, and demonstrating adverse impacts on oocyte, sperm and embryo microtubule apparatus, chromosomes, and DNA. Data that addresses the notions that endometriosis causes oocyte and fetal aneuploidy and that these events are mediated by ROS species are also discussed. Literature data are also discussed that employ use of anti-oxidant molecules to evaluate the importance of ROS-mediated oxidative damage in the pathogenesis of endometriosis. Studies are discussed that have employed anti-oxidants compounds as therapeutics to improve oocyte and embryo quality in infertile subjects, and improve fertility in patients with endometriosis.

Endometriosis, especially mild disease: a risk factor for miscarriages

OBJECTIVE

To investigate the prevalence of miscarriage in women with endometriosis (WwE) compared with disease-free control women (CW).

DESIGN

Cross-sectional analysis nested in a retrospective observational study (n = 940).

SETTING

Hospitals and associated private practices.

PATIENT(S)

Previously pregnant women (n = 268) within reproductive age in matched pairs.

INTERVENTION(S)

Retrospective analysis of surgical reports and self-administered questionnaires.

MAIN OUTCOME MEASURE(S)

Rate of miscarriage, subanalysis for fertility status (≤12 vs. >12 months' time to conception), endometriosis stages (revised American Society of Reproductive Medicine classification [rASRM] I/II vs. III/IV) and phenotypic localizations (superficial peritoneal, ovarian, and deep infiltrating endometriosis).

RESULT(S)

The miscarriage rate was higher in WwE (35.8% [95% confidence interval 29.6%-42.0%]) compared with CW (22.0% [16.7%-27.0%]); adjusted incidence risk ratio of 1.97 (95% CI 1.41-2.75). This remained significant in subfertile WwE (50.0% [40.7%-59.4%]) vs. CW (25.8% [8.5%-41.2%]) but not in fertile WwE (24.5% [16.3%-31.6%]) vs. CW (21.5% [15.9%-26.8%]). The miscarriage rate was higher in women with milder forms (rASRM I/II 42.1% [32.6%-51.4%] vs. rASRM III/IV 30.8% [22.6%-38.7%], compared with 22.0% [16.7%-27.0%] in CW), and in women with superficial peritoneal endometriosis (42.0% [32.0%-53.9%]) compared with ovarian endometriosis (28.6% [17.7%-38.7%]) and deep infiltrating endometriosis (33.9% [21.2%-46.0%]) compared with CW (22.0% [16.7%-27.0%]).

CONCLUSION(S)

Mild endometriosis, as in superficial lesions, is related to a great extent of inflammatory disorder, possibly leading to defective folliculogenesis, fertilization, and/or implantation, presenting as increased risk of miscarriage.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02511626.

Advanced oxidation protein products from the follicular microenvironment and their role in infertile women with endometriosis

Endometriosis (EM) is associated with oxidative stress. Advanced oxidation protein products (AOPPs) are novel markers of oxidative stress, which serve an important role as an inflammatory mediator in various chronic diseases. In order to examine the role of AOPPs in infertile women with EM, the present study analyzed the levels of AOPPs, estradiol (E₂) and progesterone (P₄) in the follicular fluid (FF) of 89 women with or without EM undergoing in vitro fertilization (IVF). The AOPP concentration in the FF of the EM group was significantly higher when compared with that of the control group (51.5±22.4 vs. 41.8±18.3 µmol/l; P<0.05). However, the FF P₄ levels and blastocyst rate were significantly lower in the EM group compared with the control group (P₄:1,249.6±465.4 vs. 1,752.7±565.4 ng/ml, P<0.05; blastocyst rate: 0.511±0.322 vs. 0.662±0.278; P<0.05). The AOPP concentration and P₄ level in the FF presented a significant negative correlation in the EM and control groups, as well as in the total cohort of patients (EM group: r=-0.406, P=0.006; control group: r=-0.315, P=0.035; total: r=-0.421, P<0.001). In addition, there was a significant negative correlation between the FF AOPP concentrations and blastocyst rate in the EM group and in the total cohort (EM group: r=-0.376, P=0.012; total: r=-0.367, P<0.001). In conclusion, these results suggested that AOPPs may be a potentially effective marker for predicting the oocyte quality and outcomes of IVF in infertile women with EM.

Is the oocyte quality affected by endometriosis? A review of the literature

Endometriosis is an estrogen-dependent chronic inflammatory condition that affects women in their reproductive period causing infertility and pelvic pain. The disease, especially at the ovarian site has been shown to have a detrimental impact on ovarian physiology. Indeed, sonographic and histologic data tend to support the idea that ovarian follicles of endometriosis patients are decreased in number and more atretic. Moreover, the local intrafollicular environment of patients affected is characterized by alterations of the granulosa cell compartment including reduced P450 aromatase expression and increased intracellular reactive oxygen species generation. However, no comprehensive evaluation of the literature addressing the effect of endometriosis on oocyte quality from both a clinical and a biological perspective has so far been conducted. Based on this systematic review of the literature, oocytes retrieved from women affected by endometriosis are more likely to fail in vitro maturation and to show altered morphology and lower cytoplasmic mitochondrial content compared to women with other causes of infertility. Results from meta-analyses addressing IVF outcomes in women affected would indicate that a reduction in the number of mature oocytes retrieved is associated with endometriosis while a reduction in fertilization rates is more likely to be associated with minimal/mild rather than with moderate/severe disease. However, evidence in this field is still far to be conclusive, especially with regards to the effects of different stages of the disease and to the impact of patients’ previous medical/surgical treatment(s).

Patients with endometriosis have aneuploidy rates equivalent to their age-matched peers in the in vitro fertilization population

OBJECTIVE

To determine whether endometriosis ultimately results in an increased risk of embryonic aneuploidy.

DESIGN

Retrospective cohort.

SETTING

Infertility clinic.

PATIENT(S)

Patients participating in an in vitro fertilization (IVF) cycle from 2009-2015 using preimplantation genetic screening (PGS) who had endometriosis identified by surgical diagnosis or by ultrasound findings consistent with a persistent space-occupying disease whose sonographic appearance was consistent with endometriosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Rate of aneuploidy in endometriosis patients undergoing IVF compared to controls without endometriosis undergoing IVF.

RESULT(S)

There were 305 patients with endometriosis who produced 1,880 blastocysts that met the criteria for inclusion in the endometriosis group. The mean age of the patients with endometriosis was 36.1 ± 3.9 years. When the aneuploidy rates in patients with endometriosis and aneuploidy rates in patients without endometriosis were stratified by Society for Assisted Reproductive Technology age groups and compared, there were no statistically significant differences in the rate of aneuploidy (odds ratio 0.85; 95% confidence interval, 0.84-0.85).

CONCLUSION(S)

Patients with endometriosis undergoing IVF have aneuploidy rates equivalent to their age-matched peers in IVF population who do not have endometriosis.

Research Priorities for Endometriosis

The 3rd International Consensus Workshop on Research Priorities in Endometriosis was held in São Paulo on May 4, 2014, following the 12th World Congress on Endometriosis. The workshop was attended by 60 participants from 19 countries and was divided into 5 main sessions covering pathogenesis/pathophysiology, symptoms, diagnosis/classification/prognosis, disease/symptom management, and research policy. This research priorities consensus statement builds on earlier efforts to develop research directions for endometriosis. Of the 56 research recommendations from the 2011 meeting in Montpellier, a total of 41 remained unchanged, 13 were updated, and 2 were deemed to be completed. Fifty-three new research recommendations were made at the 2014 meeting in Sao Paulo, which in addition to the 13 updated recommendations resulted in a total of 66 new recommendations for research. The research recommendations published herein, as well as those from the 2 previous papers from international consensus workshops, are an attempt to promote high-quality research in endometriosis by identifying and agreeing on key issues that require investigation. New areas included in the 2014 recommendations include infertility, patient stratification, and research in emerging nations, in addition to an increased focus on translational research. A revised and updated set of research priorities that builds on this document will be developed at the 13th World Congress on Endometriosis to be held on May 17-20, 2017, in Vancouver, British Columbia, Canada.

Modern Management of Endometrioma-Associated Infertility: in Favor of ART

Introduction

Endometrioma is present in 17% to 40% of women with endometriosis. Since it has been traditionally believed that the presence of an endometrioma adversely affects the outcome of assisted reproductive technology (ART), surgery has been suggested by many practitioners before advancing to ART, in the hope of improving results.

Scientific Evidence

In the present article, we outline the impact of an endometrioma on the ovarian reserve and describe how surgical resection of an endometriotic cyst affects ovarian reserve, ovarian response after stimulation and ART outcome. Several studies suggest that the sole presence of an endometrioma may have a negative impact on ovarian reserve of the affected ovary, and surgery (particularly cystectomy) has been the choice of treatment in ovarian endometriosis for many years. However, detrimental effects of laparoscopic surgical removal on ovarian reserve and responsiveness to hyperstimulation has made that ART practices are shifting towards a more conservative approach: experimental and clinical data supporting this shift are thoroughly reviewed here.

Clinical Implications

Opposed to the conventional criteria of performing cystectomy when ovarian endometrioma is observed, careful consideration of patient symptoms as well as her age and ovarian reserve will help to select the patients that require surgery prior to ART, whereas the majority will not need surgery prior to ART; even more, surgery may compromise ovarian reserve in most cases even if performed by careful surgeons.

Conclusions

Individualization of the treatment is imperative. Each case should be thoroughly assessed, looking at both the advantages and complications of cyst removal prior to ART. Surgery should be approached with caution in women with endometriomas, especially if the woman has had previous ovarian surgery. In the presence of infertility, we recommend generally sparing surgical treatment and proceeding directly to ART. This reduces the time to achieve a pregnancy, avoids potential surgical risks and limits patient costs.

EFFECT OF PELVIC ENDOMETRIOSIS, ENDOMETRIOMAS AND RECURRENT ENDOMETRIOMAS ON IVF-ET/ICSI OUTCOMES

Introduction:

Endometriosis, the most common gynecological disorder, is a challenging disease observed in 20% - 40% of subfertile women.

Material and Methods:

380 women were divided into four groups. Group A consisted of 176 women with pelvic endometriosis. Group B consisted of 125 women who had previously undergone a laparoscopic endometrioma cystectomy. Group C consisted of 38 women with recurrent endometriomas without aspiration before IVF-ET/ICSI. Group D consisted of 41 women with recurrent endometriomas undergone aspiration before IVF-ET/ICSI.

Results:

Baseline FSH level (8.61 ± 3.42 mIU/mL) and total dose of Gn (2337.15 ± 853.00 IU) in Group A were the lowest (p < 0.05). The number of retrieved oocytes in Group B (7.98 ± 5.05) was significantly fewer than those in Group A and D (p < 0.05). The numbers of MII oocytes in Groups A, C and D were significantly larger than that in Group B. The number of retrieved oocytes, high-quality embryos, implantation and pregnancy rates were similar in Groups C and D.

Conclusions:

Pelvic endometriosis had a less adverse effect on ovarian reserve than endometrioma. No advantage was found in transvaginal aspiration for recurrent endometriomas before IVF-ET/ICSI.

Effect of Endometriosis on IVF Outcomes in Cases of Single Embryo Transfer for first IVF Attempt in Patients under 35

Background

Implantation disorders are regarded differently in different groups undergoing in vitro fertilization (IVF) because of heterogeneous patient populations. To avoid this problem, this study was based solely on the first attempts of a single embryo transfer in patients under the age of 35.

Methods

This was a retrospective comparative study with 2 groups of patients: a group with endometriosis (n = 288) and a group without endometriosis (n = 1,368), registered from January 2010 to December 2013 in the IVF center of the University Hospital of Clermont-Ferrand. This study compared the 2 groups and subgroups according to ovarian response and embryo quality, and analyzed oocyte number, embryo number, transfer rate, implantation rate and delivery rate per ovum pick-up and per transfer.

Results

In the cases of endometriosis, the number of collected oocytes (8.37 ± 7.01 vs. 10.13 ± 6.53 p<0.001), the transfer rate (81.4% vs. 86.1%, p = 0. 045) and the rate of cycles with a frozen embryo (48.9% vs. 57.3%, p<0.01) were lower. The probability of a satisfactory response to stimulation (70.7% vs. 81.0%, p<0.001) and of a good quality embryo cohort (45% vs. 52%, p = 0.003) was lower. However, the implantation and delivery rates per transfer were not distorted in the cases of endometriosis, either in the total group or in any subgroup. The cumulative live birth rate per attempt was similar (29.2% vs. 29.5%).

Conclusions

Endometriosis has no impact on the embryo transfer in IVF, particularly when the embryo quality is satisfactory.

Arginine methyltransferases mediate an epigenetic ovarian response to endometriosis

Endometriosis is associated with infertility and debilitating chronic pain. Abnormal epigenetic modifications in the human endometrium have recently been implicated in the pathogenesis of this condition. However, whether an altered epigenetic landscape contributes to pathological changes in the ovary is unknown. Using an established baboon endometriosis model, early-, and late-stage epigenetic changes in the ovary were investigated. Transcript profiling of key chromatin-modifying enzymes using pathway-focused PCR arrays on ovarian tissue from healthy control animals and at 3 and 15 months of endometriosis revealed dramatic changes in gene expression in a disease duration-dependent manner. Ingenuity Pathway Analysis indicated that transcripts for chromatin-remodeling enzymes associated with reproductive system disease and cancer development were abnormally regulated, most prominently the arginine methyltransferases CARM1, PRMT2, and PRMT8. Downregulation of CARM1 protein expression was also detected in the ovary, fully-grown oocytes and eutopic endometrium following 15 months of endometriosis. Sodium bisulfite sequencing revealed DNA hypermethylation within the PRMT8 promoter, suggesting that deregulated CpG methylation may play a role in transcriptional repression of this gene. These results demonstrate that endometriosis is associated with changes of epigenetic profiles in the primate ovary and suggest that arginine methyltransferases play a prominent role in mediating the ovarian response to endometriosis. Owing to the critical role of CARM1 in nuclear receptor-mediated transcription and maintenance of pluripotency in the cleavage stage embryo, our results suggest that epigenetic alterations in the ovary may have functional consequences for oocyte quality and the etiology of infertility associated with endometriosis.

N-Acetyl-Cysteine and l-Carnitine Prevent Meiotic Oocyte Damage Induced by Follicular Fluid From Infertile Women With Mild Endometriosis

This study evaluated the potential protective effect of the antioxidants, l-carnitine (LC) and N-acetyl-cysteine (NAC), in preventing meiotic oocyte damage induced by follicular fluid (FF) from infertile women with mild endometriosis (ME). We performed an experimental study. The FF samples were obtained from 22 infertile women undergoing stimulated cycles for intracytoplasmic sperm injection (11 with ME and 11 without endometriosis). Immature bovine oocytes were submitted to in vitro maturation (IVM) divided into 9 groups: no-FF (No-FF); with FF from control (CFF) or ME (EFF) groups; and with LC (C + LC and E + LC), NAC (C + NAC and E + NAC), or both antioxidants (C + 2Ao and E + 2Ao). After IVM, oocytes were immunostained for visualization of microtubules and chromatin by confocal microscopy. The percentage of meiotically normal metaphase II (MII) oocytes was significantly lower in the EFF group (51.35%) compared to No-FF (86.36%) and CFF (83.52%) groups. The E + NAC (62.22%), E + LC (80.61%), and E + 2Ao (61.40%) groups showed higher percentage of normal MII than EFF group. The E + LC group showed higher percentage of normal MII than E + NAC and E + 2Ao groups and a similar percentage to No-FF and CFF groups. Therefore, FF from infertile women with ME causes meiotic abnormalities in bovine oocytes, and, for the first time, we demonstrated that the use of NAC and LC prevents these damages. Our findings elucidate part of the pathogenic mechanisms involved in infertility associated with ME and open perspectives for further studies investigating whether the use of LC could improve the natural fertility and/or the results of in vitro fertilization of women with ME.

Oocyte quality is decreased in women with minimal or mild endometriosis

Endometriosis, a pathological condition in which the endometrium grows outside the uterus, is one of the most common causes of female infertility; it is diagnosed in 25–40% of infertile women. The mechanism by which endometriosis affects the fertility of females remains largely unknown. We examined the ultrastructure of oocytes from patients with minimal or mild endometriosis and control females undergoing in vitro fertilization (IVF) treatment by transmission electron microscopy (TEM) to investigate the physiological significance of oocyte quality for patients with minimal or mild endometriosis. The TEM results revealed that the oocytes from women with minimal or mild endometriosis exhibited abnormal mitochondrial structure and decreased mitochondria mass. Quantitative real time PCR analysis revealed that the mitochondrial DNA copy number was significantly reduced in the oocytes from women with minimal or mild endometriosis compared with those of the control subjects. Our results suggest that decreased oocyte quality because of impaired mitochondrial structure and functions probably an important factor affecting the fertility of endometriosis patients.

Effect of induced peritoneal endometriosis on oocyte and embryo quality in a mouse model

PURPOSE

To assess the impact of peritoneal endometriosis on oocyte and embryo quality in a mouse model.

METHODS

Peritoneal endometriosis was surgically induced in 33 B6CBA/F1 female mice (endometriosis group, N = 17) and sham-operated were used as control (sham group, N = 16). Mice were superovulated 4 weeks after surgery and mated or not, to collect E0.5-embryos or MII-oocytes. Evaluation of oocyte and zygote quality was done by immunofluorescence under spinning disk confocal microscopy.

RESULTS

Endometriosis-like lesions were observed in all mice of endometriosis group. In both groups, a similar mean number of MII oocytes per mouse was observed in non-mated mice (30.2 vs 32.6), with a lower proportion of normal oocytes in the endometriosis group (61 vs 83 %, p < 0.0001). Abnormalities were incomplete extrusion or division of the first polar body and spindle abnormalities. The mean number of zygotes per mouse was lower in the endometriosis group (21 vs 35.5, p = 0.02) without difference in embryo quality.

CONCLUSIONS

Our results support that induced peritoneal endometriosis in a mouse model is associated with a decrease in oocyte quality and embryo number. This experimental model allows further studies to understand mechanisms of endometriosis-associated infertility.

Effect of endometriosis on implantation rates when compared to tubal factor in fresh non donor in vitro fertilization cycles

OBJECTIVE:

The objective of the following study is to compare the outcome of in vitro fertilization and embryo transfer (IVF-ET) in women with endometriosis and tubal-factor infertility.

DESIGN:

Retrospective study.

SETTING:

Tertiary referral hospital, assisted reproductive technologies unit.

MATERIALS AND METHOD:

The study group consisted of 78 women diagnosed with advanced stage endometriosis. The control group included 100 women with tubal-factor infertility. These groups were retrospectively analyzed regarding stimulation, fertilization, embryo development, implantation and pregnancy outcome.

INTERVENTION (S):

Controlled ovarian hyperstimulation and IVF-ET.

RESULTS:

Lower oocyte yield with lower fertilization rate were found in women with endometriosis compared with tubal-factor control subjects. However, no differences were found in cleavage, implantation and clinical pregnancy rates between the endometriosis and tubal-factor groups.

CONCLUSIONS:

Our results showed that women with endometriosis have a lower oocyte yield and lower fertilization rate compared with women with tubal-factor infertility. However, once the oocyte is fertilized, it seems that the embryo has a normal chance of implantation, leading to similar pregnancy rates and adequately treated women with endometriosis have equal chances of conception as seen with tubal-factor infertility.

Role of pigment epithelium-derived factor in the reproductive system

The physiological function of the female reproductive organs is hormonally controlled. In each cycle, the reproductive organs undergo tissue modifications that are accompanied by formation and destruction of blood vessels. Proper angiogenesis requires an accurate balance between stimulatory and inhibitory signals, provided by pro- and anti-angiogenic factors. As with many other tissues, vascular endothelial growth factor (VEGF) appears to be one of the major pro-angiogenic factors in the female reproductive organs. Pigment epithelium-derived factor (PEDF) is a non-inhibitory member of the serine protease inhibitors (serpin) superfamily, possessing potent physiologic anti-angiogenic activity that negates VEGF activity. The role of PEDF in decreasing abnormal neovascularization by exerting its anti-angiogenic effect that inhibits pro-angiogenic factors, including VEGF, has been investigated mainly in the eye and in cancer. This review summarizes the function of PEDF in the reproductive system, showing its hormonal regulation and its anti-angiogenic activity. Furthermore, some pathologies of the female reproductive organs, including endometriosis, ovarian hyperstimulation syndrome, polycystic ovary syndrome, and others, are associated with a faulty angiogenic process. This review illuminates the role of PEDF in their pathogenesis and treatment. Collectively, we can conclude that although PEDF seems to play an essential role in the physiology and pathophysiology of the reproductive system, its full role and mechanism of action still need to be elucidated.

The effect of peritoneal fluid from patients with endometriosis on mitochondrial function and development of early mouse embryos

Background

Peritoneal fluid (PF) from patients with endometriosis can inhibit early embryo development via probable functional changes of embryo mitochondria in the early stage of embryo development. The purpose of this study was to determine the effect of PF from patients with endometriosis on mitochondrial function and development of early mouse embryos.

Methodology/Principal Findings

PF was collected from patients with infertility and endometriosis, infertility due to tubal factors, and normal control subjects, and the level of NO was measured. Early murine embryos were then cultured with PF from normal control subjects, those with endometriosis, and with human tubal fluid (HTF), respectively. Cleavage and blastulation rates, mitochondrial DNA (mtDNA) copy numbers, adenosine triphosphate (ATP) level, and mitochondrial membrane potential (ΔΨm) of the different groups were compared. The NO level in the PF of patients with endometriosis was significantly greater than in those without endometriosis and control patients. The embryos cultures with PF from patients with endometriosis had a lower cleavage rate and blastulation rate, and higher ATP and ΔΨm level at the 2- and 4-cell stages. No significant difference was found in mtDNA copies among the 3 groups.

Conclusions/Significance

PF from patients with endometriosis can inhibit early embryo development via probable functional changes of embryo mitochondria in the early stage of embryo development. Understanding the effects of PF on embryo development may assist in developing new methods of treatment for infertility.

Follicular fluid from infertile women with mild endometriosis may compromise the meiotic spindles of bovine metaphase II oocytes

STUDY QUESTION

What is the potential impact of follicular fluid (FF) from infertile women with mild endometriosis (ME) on oocyte quality, especially on nuclear maturation and the meiotic spindle?

SUMMARY ANSWER

FF from infertile women with ME may compromise nuclear maturation and the meiotic spindles of in vitro matured bovine oocytes.

WHAT IS KNOWN ALREADY

Controversial studies have suggested that impaired oocyte quality may be involved in the pathogenesis of endometriosis-related infertility. Moreover, some studies have demonstrated alterations in the composition of FF from infertile women with endometriosis. However, to date no study has evaluated the effect of FF from infertile women with ME on the genesis of meiotic oocyte anomalies.

STUDY DESIGN, SIZE, DURATION

We performed an experimental study. Samples of FF were obtained from February 2009 to February 2011 from 22 infertile women, 11 with ME and 11 with tubal or male factors of infertility (control group), who underwent ovarian stimulation for ICSI at our university IVF Unit. From March 2011 to February 2012 we performed in vitro maturation (IVM) experiments using immature bovine oocytes as described below.

PARTICIPANTS/MATERIALS, SETTING, METHODS

FF free of blood and containing a mature oocyte was obtained from 22 infertile women during oocyte retrieval for ICSI. Immature bovine oocytes underwent IVM in the absence of FF (No-FF) and in the presence of four concentrations (1, 5, 10 and 15%) of FF from infertile women without endometriosis (C-FF) and with ME (ME-FF). Eleven replicates were performed, each one using FF from a control patient and a patient with ME. Each FF sample was used in only one experiment. After 22-24 h of IVM, oocytes were denuded, fixed and immunostained for morphological visualization of microtubules and chromatin by confocal microscopy.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1324 cumulus-oocyte complexes were matured in vitro. Of these, 1128 were fixed and 1048 were analyzed by confocal microscopy. The percentage of meiotically normal oocytes was significantly higher for oocytes that underwent IVM in the absence of FF (No-FF; 76.5%) and in the presence of 1% (80.9%), 5% (76.6%), 10% (75%) and 15% (76.2%) C-FF than in oocytes that underwent IVM in the presence of 1% (44.4%), 5% (36.7%), 10% (45.5%) and 15% (51.2%) ME-FF (P < 0.01). No differences were observed among FF concentrations within each group. When the four concentrations from each group were pooled, the number of oocytes in metaphase I stage was significantly higher in the ME-FF (50 oocytes) than in the C-FF (29 oocytes) group and the percentage of meiotic abnormalities was significantly higher when oocytes were matured with ME-FF (55.8%) than with C-FF (23.1%), P < 0.01.

LIMITATIONS, REASONS FOR CAUTION

Owing to the strict selection criteria for FF donors, this study had a small sample size (11 cases and 11 controls), and thus further investigations using a large cohort of patients are needed to confirm these results. In addition, data obtained from studies using animal models may not necessarily be extrapolated to humans and studies evaluating in vivo matured oocytes from infertile women with ME are important to confirm our results.

WIDER IMPLICATIONS OF THE FINDINGS

Our results open new insights into the pathogenic mechanisms of infertility related to mild endometriosis, suggesting that FF from infertile women with mild endometriosis may be involved in the worsening of oocyte quality of these women.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Council for Scientific and Technological Development (CNPq), Brazil. The authors declare no conflicts of interest.

Developmental exposure of fetal ovaries and fetal germ cells to endometriosis in an endometriosis model causes differential gene expression in the preimplantation embryos of the first-generation and second-generation embryos

OBJECTIVE

To characterize multigenerational gene expression anomalies in eight-cell stage embryos associated with developmental exposure to endometriosis.

DESIGN

Using an endometriosis model in rats (F0 founder generation) to evaluate gene expression in F1 (fetal exposure) and F2 (fetal germ cell exposure) generation eight-cell stage embryos.

SETTING

Laboratory.

ANIMAL(S)

Endometriosis model in rats (Endo) and controls (Sham).

INTERVENTION(S)

F0 Endo and Sham rats were bred; half the pregnant rats were killed on gestational day 3 to collect F1 eight-cell stage embryos and the others gestated to term (F1 females). Adult F1 females bred; F2 eight-cell embryos collected.

MAIN OUTCOME MEASURE(S)

Maintenance of differential gene expression in F1 and F2 generation eight-cell embryos in endometriosis.

RESULT(S)

Developmental exposure to endometriosis altered the gene signaling pathways, with changes found in apoptosis, the cell cycle process, the response to oxidative stress, negative regulation of molecular function, and RNA processing. The apoptotic genes Diablo, Casp3, Parp1, Cad, and Dnaja3 were increased and the Nfkbia transcripts were decreased in F1 Endo versus F1 Sham embryos. In F2 Endo versus Sham embryos, Casp3 and Cad were statistically significantly increased, and Parp1 and Nfkbia tended to be elevated.

CONCLUSION(S)

Fetal and germ cell exposure to endometriosis alters apoptotic gene expression in first- and second-generation eight-cell stage embryos, supporting the hypothesis of multigenerational inheritance resulting from exposure to endometriosis in utero.

Altered circulating levels of matrix metalloproteinases 2 and 9 and their inhibitors and effect of progesterone supplementation in women with endometriosis undergoing in vitro fertilization

OBJECTIVE

To investigate differences in the activity of matrix metalloproteinases (MMPs) 2 and 9 and their respective tissue inhibitors (TIMPs) in follicular fluid of women with endometriosis, to correlate the findings with IVF outcome, and to examine the therapeutic potential of progesterone supplementation in restoring the fine balance between MMPs and TIMPs.

DESIGN

Prospective case-control clinical study.

SETTING

Infertility clinic and reproductive health research unit.

PATIENT(S)

A total of 340 infertile women undergoing IVF.

INTERVENTION(S)

Natural micronized progesterone capsules were administered for luteal support.

MAIN OUTCOME MEASURE(S)

Association of MMPs 2 and 9 and TIMP-1 with oocyte maturity and embryo development.

RESULT(S)

An abnormal expression of MMP-2, MMP-9, and TIMP-1 with extensive MMP-9/TIMP-1 imbalance in women with endometriosis undergoing IVF was observed. Transforming growth factor β1 plays an important role in these women with possible involvement of Smad-2 and -3 proteins. Progesterone supplementation improves the imbalance in MMP-9/TIMP-1 ratio significantly in women with endometriosis who conceive after IVF.

CONCLUSION(S)

Increase in MMP-2 and -9 and decrease in TIMP-1 expression was associated with poor oocyte and embryo development in women with endometriosis undergoing IVF. MMP-9/TIMP-1 balance was highly affected in these women, and progesterone supplementation appeared to restore this imbalance to a considerable degree.