Endometriosis is associated with a lowered cumulative live birth rate: A retrospective matched cohort study including 3071 in vitro fertilization cycles

Effects of various controlled ovarian hyperstimulation protocols and surgery on pregnancy outcomes in women with endometriosis

Endometriosis is a common gynecological condition in women of childbearing age that causes symptoms such as menstrual changes and dysmenorrhea, and is also a major cause of infertility. Therefore, women with endometriosis usually need to use assisted reproductive technology (ART), such as in vitro fertilization or intracytoplasmic sperm injection, to increase their chances of conceiving. Numerous clinical observations and studies have indicated that endometriosis can affect the success of ART, such that women with endometriosis who use ART have a lower live-birth rate than those without endometriosis who use ART. Therefore, this article reviews the impact of various controlled ovarian hyperstimulation protocols and surgery on the pregnancy outcomes of women with endometriosis using ART to explore the selection of individualized treatment.

[Research Progress in the Role of Mitochondrial Dysfunction in Endometriosis-Associated Infertility]

Endometriosis (EMT), a common benign gynecological disease, is a leading cause of infertility in women. EMT affects female fertility in various aspects. However, the underlying mechanisms have not been fully elucidated. Mitochondria are known as the "powerhouse" of a cell. They play pivotal roles in the physiological processes of cellular energy metabolism, calcium homeostasis, oxidative stress, autophagy, the regulation of cell cycle, and cell death, and are involved in the pathophysiology of many diseases. Cellular mitochondria are highly dynamic, continuously undergoing cyclic fission and fusion to meet the demands of cellular activities. Balanced mitochondrial dynamics are critical for maintaining normal reproductive function in women. In addition, mitochondria are the major source of reactive oxygen species (ROS). Cell damage, cell death, and fibrosis mediated by the imbalance in the oxidative-antioxidant system in EMT patients lead to decreased oocyte quality and ovarian reserve. Currently, the treatment of EMT-associated infertility remains a challenging and controversial topic. We herein reviewed the latest findings on the role of mitochondrial dysfunction in EMT-associated infertility and the potential therapeutic targets.

Impact of endometriosis on the ovarian follicles

A significant body of evidence has supported a negative impact of endometriosis on ovarian follicles; however, the origin and relevance of this ovarian impairment in endometriosis is still a matter of debate. The ovarian damage can be caused by endometriosis itself or by surgeries aiming to remove endometriotic lesions. In this review, we summarized the existing knowledge on the mechanisms by which endometriosis can impact the ovarian follicles, from molecular to clinical points of view. From a molecular standpoint, the presence of endometriosis or its consequences can induce oxidative stress, inflammation, aberrant mitochondrial energy metabolism and inappropriate steroid production in granulosa cells, phenomena that may impair the quality of oocytes to variable degrees. These alterations may have clinical relevance on the accelerated exhaustion of the ovarian reserve, on the ovarian response to gonadotrophin stimulation in IVF cycles and on the competence of the oocytes. Critical points to be considered in current clinical practices related to fertility issues in endometriosis are discussed.

Endometrial receptivity in women with endometriosis

As endometriosis is recognized as a contributing factor to infertility, prompting couples to embark on Assisted Reproductive Technology (ART) treatments, it becomes crucial to comprehend the extent and way this condition can affect success rates. Natural conception data reveal lower success rates for women with endometriosis, yet the same cannot be extrapolated to the outcomes of in vitro fertilization (IVF). In recent years, advancements in the ART process, particularly the distinct stages of the IVF pathway and investigations into embryo quality have shown a comparable rate of embryonic quality and chromosomal normalcy (euploidy) between embryos obtained from individuals with or without endometriosis. Thus, the primary question that lingers relates to the functionality of the endometrium. This review addresses whether endometriosis can influence endometrial receptivity and implantation rates.

Is endometrial receptivity affected in women with endometriosis? Results from a matched pair case-control study of assisted reproductive technology treatments

RESEARCH QUESTION

Is endometriosis detrimental to embryo implantation?

DESIGN

A retrospective matched case-control study of women with a surgical or ultrasound diagnosis of endometriosis at Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico di Milano between 2015 and 2021. Women with endometriosis who underwent a 'freeze-all' cycle during an IVF treatment were eligible to be included. They were matched to patients without the disease, who also underwent cryopreserved blastocyst transfer cycles, in a 1:1 ratio by age (±1 year), and number (=) and quality (±1 top versus low) of cryopreserved blastocysts. All women underwent single frozen embryo transfer, and assisted reproductive technology outcomes suggested by the Core Outcome Measure for Infertility Trials initiative were evaluated. The main outcome was the cumulative live birth rate per cycle.

RESULTS

One hundred and one women with endometriosis and 101 matched unaffected women were included. Cumulative live birth rate per cycle did not vary between women with and without endometriosis (50% versus 58%, respectively; P = 0.32). On the basis of the Kaplan-Meier analysis, the predicted success rates over four embryos transferred were also similar (74% versus 82%, respectively; P = 0.67).

CONCLUSION

In women with moderate or severe endometriosis, these retrospective results seem to indicate no or a limited effect of the disease on endometrial receptivity.

Endometriosis and IVF treatment outcomes: unpacking the process

Advanced endometriosis is associated with a reduction of IVF success. Surgical damage to the ovarian reserve following the excision of endometriomas has been claimed as a critical factor in the explanation of this detrimental effect. However, it is generally inferred that other mechanisms might also hamper IVF success in affected women. They include diminished responsiveness to ovarian stimulation, altered steroidogenesis, a decline in oocyte quality, reduced fertilization and embryo development, and impaired implantation. To navigate these limitations, we scrutinized available literature for studies specifically designed to address distinct phases of the IVF process. Utmost consideration was given to intra-patient ovarian response comparisons in women with unilateral endometriomas and to studies applying a meticulous matching to control confounders. The following observations have been drawn: 1) endometriosis has a negligible impact on ovarian response. A slight reduction in stimulation response can only be observed for endometriomas larger than 4 cm. Follicular steroidogenesis is unaffected; 2) oocyte quality is not hampered. Fertilization rates are similar, and intracytoplasmic sperm injection (ICSI) is not justified. Embryonic development is uncompromised, with no increase in aneuploidy rate; 3) endometrial receptivity is either unaffected or only slightly impacted. In conclusion, our study suggests that, aside from the well-known negative effect on ovarian reserve from excisional endometrioma surgeries, endometriosis does not significantly affect IVF outcomes.

Decreased oocyte quality in patients with endometriosis is closely related to abnormal granulosa cells

Infertility and menstrual abnormalities in endometriosis patients are frequently caused by aberrant follicular growth or a reduced ovarian reserve. Endometriosis typically does not directly harm the oocyte, but rather inhibits the function of granulosa cells, resulting in a decrease in oocyte quality. Granulosa cells, as oocyte nanny cells, can regulate meiosis, provide the most basic resources required for oocyte development, and influence ovulation. Endometriosis affects oocyte development and quality by causing granulosa cells apoptosis, inflammation, oxidative stress, steroid synthesis obstacle, and aberrant mitochondrial energy metabolism. These aberrant states frequently interact with one another, however there is currently relatively little research in this field to understand the mechanism of linkage between abnormal states.

Controlled ovarian stimulation for endometriosis patients with ultra-long GnRH-agonist or GnRH-antagonist protocols: A retrospective study by propensity score matching

OBJECTIVES

Although in vitro fertilization with embryo transfer is the most effective treatment for infertile patients with endometriosis, ovarian stimulation protocols are controversial.

STUDY DESIGN

We recruited 639 patients with endometriosis from January 2016 to June 2020; 111 and 528 patients were treated with the gonadotropin-releasing hormone (GnRH) antagonist and ultra-long GnRH agonist protocols, respectively. Potential baseline differences between the regimens were adjusted by propensity score matching. Clinical and laboratory data, including the cumulative clinical pregnancy rate (CCPR) and cumulative live birth rate (CLBR), were compared.

RESULTS

Ovulation induction required significantly longer use of gonadotropins in the GnRH agonist group. However, the GnRH agonist group had a lower starting dose of gonadotropin (all p < 0.05). Furthermore, significantly lower clinical pregnancy, implantation, and live birth rates were observed in the GnRH antagonist group receiving fresh assisted reproductive technology cycles (all p < 0.05); however, pregnancy outcomes using the subsequent freeze-thaw cycles for the same oocyte retrieval were not significantly different. CCPR and CLBR for the oocyte retrieval cycles of the antagonist and ultra-long agonist protocols were similar. The ultra-long agonist protocol resulted in more favorable implantation of fresh embryos and improved clinical outcomes of the fresh cycle.

CONCLUSIONS

This novel strategy could be appropriate for endometriosis patients who are temporarily unsuitable for fresh embryo transfer. The GnRH antagonist protocol can be combined with the whole embryo freezing strategy to achieve CCPR and CLBR similar to the ultra-long agonist regimen, thus simultaneously avoiding the long pre-treatment duration of GnRH agonists during the ultra-long agonist protocol.

IGF2BP2 promotes the progression of ovarian endometriosis by regulating m6A-modified MEIS2 and GATA6

BACKGROUND

m6A-RNA modification mediated by the N6-methyladenosine RNA methylation-related molecule methyltransferase-like 3 has been implicated in the progression of endometriosis. However, the functions of other m6A regulators, especially in ovarian endometriosis, remain unknown.

METHODS

Three datasets (GSE7305, GSE7307, and GSE37837) with diagnosed ovarian endometriosis were extracted from the Gene Expression Omnibus database. Using bioinformatics methods such as Weighted Gene Co-expression Network Analysis, Gene Ontology analysis, protein-protein interaction, and correlation, hub genes were identified. Using dot blot and N6-methyladenosine-IP-qPCR, the total and individual N6-methyladenosine gene levels were quantified. On clinical ovarian ectopic and eutopic endometrium tissues, N6-methyladenosine RNA methylation sequencing was performed. To authenticate protein localization and expression level, immunohistochemical staining and western blot were conducted, respectively. The database Connectivity Map was used to predict small molecules with potential therapeutic effects.

RESULTS

In ovarian endometriosis, the N6-methyladenosine "reader" molecule IGF2BP2 and related target genes MEIS2 and GATA6 were highly expressed. IGF2BP2 promoted the proliferation, migration, and invasion of ectopic endometrial stromal cells by stabilizing the mRNA of MEIS2 and GATA6. Synergistically, METTL3 and IGF2BP2 increased the N6-methyladenosine methylation of MEIS2 and GATA6. We developed five molecules (Mercaptopurine, MK-886, CP-863187, Canadine, and Securinine) that could be used to treat ovarian endometriosis based on IGF2BP2.

CONCLUSION

Our findings provided additional support for a systematized understanding of the role of N6-methyladenosine RNA methylation in endometriosis and confirmed for the first time the mechanism of IGF2BP2 in promoting ovarian endometriosis. This provides the molecular foundation for potential future therapies for ovarian endometriosis.

DATA AVAILABILITY

The data used to support the findings of this study are available from the corresponding author upon request.