Unexplained infertility and age-related infertility: indistinguishable diagnostic entities but different IVF prognosis.

STUDY QUESTION: Is IVF indicated for couples with age-related infertility? SUMMARY ANSWER: IVF may be of doubtful utility for age-related infertility. WHAT IS KNOWN ALREADY: A diagnosis of unexplained infertility is drawn when the diagnostic work-up fails to identify any patent cause. Although typically managed uniformly, unexplained infertility is likely to comprise a wide range of conditions, including age-related infertility (at least in older women). Unfortunately, no validated tests for the identification of age-related infertility exist and these women are typically treated as unexplained cases. However, homologous ART may be less effective for these women because these techniques may be unable to treat the detrimental effects of ageing on oocyte competence. STUDY DESIGN, SIZE, DURATION: Women aged 18-42 years who underwent IVF procedures between January 2014 and December 2021 were selected retrospectively. In the first part of the study, we aimed to assess whether the proportion of women with unexplained infertility (i.e. without patent causes of infertility) increased with age. In the second part of the study, women with unexplained infertility were matched 1:1 by age, study period, and duration of infertility, to those with a patent cause of infertility. If our hypothesis is valid, the first part of the study should highlight an increase in the proportion of unexplained infertility with age. Moreover, in the second part of the study, one should observe a sharper decrease in the rate of IVF success of the procedure with age in women with an unremarkable work-up compared to those with a definite cause of infertility. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women were included if: they had been trying to conceive for more than 2 years, they had retrieved more than three oocytes, and had not undergone previous IVF attempts. We exclude couples with severe male factor (criptozoospermia), chronic anovulation, untreated hydrosalpinx, or intracavitary diseases. The first part of the study aimed at investigating the relative proportion of unexplained infertility with age. The outcome of the second part was the distribution of the live births between unexplained versus explained infertility, in women younger or older than 35 years. Only the results of the first IVF cycle were considered (including both fresh and frozen cycles). The live birth rate corresponded to the cumulative chance of a live birth per oocyte retrieval. MAIN RESULTS AND THE ROLE OF CHANCE: One thousand five hundred and thirty-five women were selected for the first part of the study; 742 of them had unexplained infertility (48%). The frequency of this diagnosis was lower among women aged <35 years (40%) compared to those ≥35 years (52%) (P < 0.001). A clear gradient emerged when considering smaller intervals of age (P < 0.001). A total of 1134 women (567 unexplained cases and 567 explained cases) were selected for the second part of the study. Baseline variables were comparable between women with unexplained and explained infertility. Among women younger than 35 years (n = 229 unexplained cases and 229 explained cases), 108 live births were observed in women with unexplained infertility (47%) and 88 in those with explained infertility (38%). In comparison, among women older than 35 years, the live births occurred in 90 (27%) and 114 (34%) couples, respectively (P = 0.03). The adjusted odds ratio (OR) for a live birth in older women with unexplained infertility was 0.63 (95% CI: 0.43-0.94). In other words, the effectiveness of IVF in older women with unexplained infertility is reduced by an additional 37% when compared to women of similar age with a patent cause of infertility. Moreover, when considering smaller intervals of age, a gradient of the adverse effect of age on the distribution of live births between unexplained and explained infertility emerged (P = 0.003). Overall, these results support the hypothesis that IVF may be of modest benefit in women with age-related infertility. The decline in IVF success is sharper in women with unexplained infertility compared to those with explained infertility, indirectly suggesting that IVF cannot effectively treat age-related infertility. LIMITATIONS, REASONS FOR CAUTION: We postulated that the greater decline in IVF success with age in the unexplained group could be related to the concomitant increase in the proportion of women with age-related infertility. However, even if this is theoretically logical, the unavailability of validated tools to diagnose age-related infertility makes our inference speculative. We cannot exclude that the prevalence of other unknown causes of infertility that cannot also be effectively overcome with IVF could increase with age. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that IVF may be of modest utility for treating age-related infertility. Offering this procedure to older women with an unremarkable infertility work-up may be questioned. However, the diagnosis of age-related infertility remains challenging and identifying a biomarker that could reliably diagnose age-related infertility is a priority. STUDY FUNDING/COMPETING INTEREST(S): The study was partially funded by the Italian Ministry of Health-current research IRCCS and by a specific grant supported by Ferring. ES declares receiving honoraria for lectures at meetings from IBSA and Gedeon-Richter and he also handles private grants of research from Ferring, IBSA, Theramex, and Gedeon-Richter. All the other authors do not have any conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Effect of prematurely elevated late follicular progesterone on pregnancy outcomes following ovarian stimulation-intrauterine insemination for unexplained infertility: secondary analysis of the AMIGOS trial.

STUDY QUESTION: What is the relationship between late follicular phase progesterone levels and clinic pregnancy and live birth rates in couples with unexplained infertility undergoing ovarian stimulation with IUI (OS-IUI)? SUMMARY ANSWER: Late follicular progesterone levels between 1.0 and <1.5 ng/ml were associated with higher live birth and clinical pregnancy rates while the outcomes in groups with higher progesterone levels did not differ appreciably from the <1.0 ng/ml reference group. WHAT IS KNOWN ALREADY: Elevated late follicular progesterone levels have been associated with lower live birth rates after fresh embryo transfer following controlled ovarian stimulation and egg retrieval, but less is known about whether an association exists with outcomes in OS-IUI cycles. Existing studies are few and have been limited to ovarian stimulation with gonadotrophins, but the use of oral agents, such as clomiphene citrate and letrozole, is common with these treatments and has not been well studied. STUDY DESIGN, SIZE, DURATION: The study was a prospective cohort analysis of the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) randomized controlled trial. Frozen serum was available for evaluation from 2121 cycles in 828 AMIGOS participants. The primary pregnancy outcome was live birth per cycle, and the secondary pregnancy outcome was clinical pregnancy rate per cycle. PARTICIPANTS/MATERIALS, SETTING, METHODS: Couples with unexplained infertility in the AMIGOS trial, for whom female serum from day of trigger with hCG was available in at least one cycle of treatment, were included. Stored frozen serum samples from day of hCG trigger during treatment with OS-IUI were evaluated for serum progesterone level. Progesterone level <1.0 ng/ml was the reference group for comparison with progesterone categorized in increments of 0.5 ng/ml up to ≥3.0 ng/ml. Unadjusted and adjusted risk ratios (RR) and 95% CI were estimated using cluster-weighted generalized estimating equations to estimate modified Poisson regression models with robust standard errors. MAIN RESULTS AND THE ROLE OF CHANCE: Compared to the reference group with 110/1363 live births (8.07%), live birth rates were significantly increased in cycles with progesterone 1.0 to <1.5 ng/ml (49/401 live births, 12.22%) in both the unadjusted (RR 1.56, 95% CI 1.14, 2.13) and treatment-adjusted models (RR 1.51, 95% CI 1.10, 2.06). Clinical pregnancy rates were also higher in this group (55/401 clinical pregnancies, 13.72%) compared to reference group with 130/1363 (9.54%) (unadjusted RR 1.46, 95% CI 1.10, 1.94 and adjusted RR 1.42, 95% CI 1.07, 1.89). In cycles with progesterone 1.5 ng/ml and above, there was no evidence of a difference in clinical pregnancy or live birth rates relative to the reference group. This pattern remained when stratified by ovarian stimulation treatment group but was only statistically significant in letrozole cycles. LIMITATIONS, REASONS FOR CAUTION: The AMIGOS trial was not designed to answer this clinical question, and with small numbers in some progesterone categories our analyses were underpowered to detect differences between some groups. Inclusion of cycles with progesterone values above 3.0 ng/ml may have included those wherein ovulation had already occurred at the time the IUI was performed. These cycles would be expected to experience a lower success rate but pregnancy may have occurred with intercourse in the same cycle. WIDER IMPLICATIONS OF THE FINDINGS: Compared to previous literature focusing primarily on OS-IUI cycles using gonadotrophins, these data include patients using oral agents and therefore may be generalizable to the wider population of infertility patients undergoing IUI treatments. Because live births were significantly higher when progesterone ranged from 1.0 to <1.5 ng/ml, further study is needed to clarify whether this progesterone range may truly represent a prognostic indicator in OS-IUI cycles. STUDY FUNDING/COMPETING INTEREST(S): Oklahoma Shared Clinical and Translational Resources (U54GM104938) National Institute of General Medical Sciences (NIGMS). AMIGOS was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development: U10 HD077680, U10 HD39005, U10 HD38992, U10 HD27049, U10 HD38998, U10 HD055942, HD055944, U10 HD055936, and U10HD055925. Research made possible by the funding by American Recovery and Reinvestment Act. Dr Burks has disclosed that she is a member of the Board of Directors of the Pacific Coast Reproductive Society. Dr Hansen has disclosed that he is the recipient of NIH grants unrelated to the present work, and contracts with Ferring International Pharmascience Center US and with May Health unrelated to the present work, as well as consulting fees with May Health also unrelated to the present work. Dr Diamond has disclosed that he is a stockholder and a member of the Board of Directors of Advanced Reproductive Care, Inc., and that he has a patent pending for the administration of progesterone to trigger ovulation. Dr Anderson, Dr Gavrizi, and Dr Peck do not have conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.

An unbiased approach of molecular characterization of the endometrium: toward defining endometrial-based infertility.

Infertility is a complex condition affecting millions of couples worldwide. The current definition of infertility, based on clinical criteria, fails to account for the molecular and cellular changes that may occur during the development of infertility. Recent advancements in sequencing technology and single-cell analysis offer new opportunities to gain a deeper understanding of these changes. The endometrium has a potential role in infertility and has been extensively studied to identify gene expression profiles associated with (impaired) endometrial receptivity. However, limited overlap among studies hampers the identification of relevant downstream pathways that could play a role in the development of endometrial-related infertility. To address these challenges, we propose sequencing the endometrial transcriptome of healthy and infertile women at the single-cell level to consistently identify molecular signatures. Establishing consensus on physiological patterns in endometrial samples can aid in identifying deviations in infertile patients. A similar strategy has been used with great success in cancer research. However, large collaborative initiatives, international uniform protocols of sample collection and processing are crucial to ensure reliability and reproducibility. Overall, the proposed approach holds promise for an objective and accurate classification of endometrial-based infertility and has the potential to improve diagnosis and treatment outcomes.

Cytokine and chemokine profiles in women with endometriosis, polycystic ovary syndrome, and unexplained infertility.

Numerous factors (including immunological, congenital, hormonal, and morphological disorders) can lead to infertility. In this regard, 3 specific diseases associated with infertility are discussed in this review study (i.e., polycystic ovary syndrome [PCOS], endometriosis [EMS], and unexplained infertility [UI]). PCOS is a common endocrine disorder characterized by chronic low-grade inflammation, and EMS is a benign disease characterized by the presence of ectopic endometrial tissue. UI refers to couples who are unable to conceive for no known reason. Conception and pregnancy are significantly affected by the immune system; in this regard, chemokines and cytokines play important roles in the regulation of immune responses. Patients with PCOS, EMS, and UI have altered cytokine and chemokine profiles, suggesting that dysregulation of these molecules may contribute to infertility in these conditions. Accordingly, the issue of infertility is addressed in this review study, a condition that affects approximately 16% of couples worldwide.

The prevalence of endometriosis in unexplained infertility: a systematic review.

In 15-30% of couples with infertility, no abnormalities are found after the initial diagnostic work-up. The aim of this study was to investigate the prevalence of endometriosis in patients with unexplained infertility undergoing diagnostic laparoscopy in the current era of improved imaging and assisted reproductive technology. A systematic search of PubMed, Embase and Cochrane Central was conducted to identify all studies reporting on pelvic pathologies found by laparoscopy in couples diagnosed with unexplained infertility. Normal ovulatory cycles, normal semen analysis and an infertility period of ≥12 months were the minimum requirements for a study population to be included. The prevalence of endometriosis was 44%, and most lesions were classified as minimal or mild (74%). The prevalence rates of tubal factors and adhesions were 20% and 16%, respectively. The detection rate for pelvic abnormalities was higher in women with prior fertility treatment (75%) compared with women without prior fertility treatment (53%). Despite the significant improvements in imaging for the diagnosis of endometriosis and tubal factors over the last decades, the prevalence rates of endometriosis and tubal abnormalities remain high in patients with unexplained infertility. The high prevalence of endometriosis in this population is important for decision-making in patients who also suffer from pain symptoms suggestive of endometriosis.

Modelling and comparing the use of IVF and ICSI in Australia.

PURPOSE: This study estimates the need of IVF/ICSI in Australia as compared to its actual uptake. METHODS: We created a model estimating for the annual demand for IVF/ICSI in a hypothetical infertile population, using demographic data from medical literature and Australian government databases. For each category of infertility (tubal, severe male, endometriosis, anovulation and unexplained), our estimated need for IVF/ICSI was compared to the actual IVF/ICSI uptake (ANZARD 2019). The model consisted of three categories depending on couples' cause of infertility, i.e. couples with absolute indications for IVF/ICSI (couples with severe male factor infertility and tubal obstruction); couples with anovulatory infertility (couples with ovulation disorders) and couples with ovulatory infertility (couples suffering from unexplained infertility and endometriosis). The model was applied to each of these categories to determine the number of couples that would require IVF/ICSI treatment after failing to conceive naturally or after following alternative treatment plans. The main outcomes of this study were the estimate of IVF/ICSI cycles and the difference between the estimate and the reported number of IVF/ICSI cycles (2019 ANZARD report). RESULTS: We estimated that approximately 35,300 couples required IVF/ICSI treatment in Australia in 2019, while in 2019 according to ANZARD, 46,000 couples underwent IVF/ICSI. A higher uptake of IVF/ICSI cycles than expected was specifically reported in couples with unexplained infertility, ovulation disorders and endometriosis, while for tubal and severe male infertility uptake seemed adequate. CONCLUSION: In Australia, there seems to be overservicing of IVF/ICSI, specifically for unexplained, ovulatory and endometriosis-related infertility.

Sperm DNA Fragmentation: Unraveling Its Imperative Impact on Male Infertility Based on Recent Evidence.

Male factors may be present in up to 50-70% of infertile couples and the prevalence of male infertility accounts for 20-30% of infertility cases. Understanding the mechanisms and causes behind male infertility remains a challenge, but new diagnostic tools such as DNA fragmentation might aid in cases where the routine semen analysis is insufficient. DNA fragmentation, which refers to damages or breaks of the genetic material of the spermatozoa, is considered one of the main causes of male infertility due to impaired functional capability of sperm. The aim of the present narrative review is to investigate and enlighten the potential correlation between DNA fragmentation and male infertility parameters such as the seminal profile and the reproductive outcomes. Comprehensive research in PubMed/Medline and Scopus databases was conducted and 28 studies were included in the present review. Fourteen studies provided data regarding the impact of DNA fragmentation and seminal parameters and showed a correlation of significantly lower sperm count, lower concentration, motility, and abnormal morphology with an increased DNA fragmentation index (DFI). Similarly, 15 studies provided data regarding the impact of DFI on reproductive outcomes. Two studies showed higher aneuploidy rates with higher DFI values, and seven studies showed significantly lower pregnancy rates and live birth rates with higher DFI values. Ultimately, the studies included in this review highlight, collectively, the importance of measuring sperm DFI in the assessment of male infertility. Further studies are needed to explore the effectiveness of interventions aiming to reduce DFI levels.

Evidence-based guideline: unexplained infertility†.

STUDY QUESTION: What is the recommended management for couples presenting with unexplained infertility (UI), based on the best available evidence in the literature? SUMMARY ANSWER: The evidence-based guideline on UI makes 52 recommendations on the definition, diagnosis, and treatment of UI. WHAT IS KNOWN ALREADY: UI is diagnosed in the absence of any abnormalities of the female and male reproductive systems after 'standard' investigations. However, a consensual standardization of the diagnostic work-up is still lacking. The management of UI is traditionally empirical. The efficacy, safety, costs, and risks of treatment options have not been subjected to robust evaluation. STUDY DESIGN, SIZE, DURATION: The guideline was developed according to the structured methodology for ESHRE guidelines. Following formulation of key questions by a group of experts, literature searches, and assessments were undertaken. Papers written in English and published up to 24 October 2022 were evaluated. PARTICIPANTS/MATERIALS, SETTING, METHODS: Based on the available evidence, recommendations were formulated and discussed until consensus was reached within the guideline development group (GDG). Following stakeholder review of an initial draft, the final version was approved by the GDG and the ESHRE Executive Committee. MAIN RESULTS AND THE ROLE OF CHANCE: This guideline aims to help clinicians provide the best care for couples with UI. As UI is a diagnosis of exclusion, the guideline outlined the basic diagnostic procedures that couples should/could undergo during an infertility work-up, and explored the need for additional tests. The first-line treatment for couples with UI was deemed to be IUI in combination with ovarian stimulation. The place of additional and alternative options for treatment of UI was also evaluated. The GDG made 52 recommendations on diagnosis and treatment for couples with UI. The GDG formulated 40 evidence-based recommendations-of which 29 were formulated as strong recommendations and 11 as weak-10 good practice points and two research only recommendations. Of the evidence-based recommendations, none were supported by high-quality evidence, one by moderate-quality evidence, nine by low-quality evidence, and 31 by very low-quality evidence. To support future research in UI, a list of research recommendations was provided. LIMITATIONS, REASONS FOR CAUTION: Most additional diagnostic tests and interventions in couples with UI have not been subjected to robust evaluation. For a large proportion of these tests and treatments, evidence was very limited and of very low quality. More evidence is required, and the results of future studies may result in the current recommendations being revised. WIDER IMPLICATIONS OF THE FINDINGS: The guideline provides clinicians with clear advice on best practice in the care of couples with UI, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in the field. The full guideline and a patient leaflet are available in www.eshre.eu/guideline/UI. STUDY FUNDING/COMPETING INTEREST(S): The guideline was developed by ESHRE, who funded the guideline meetings, literature searches, and dissemination of the guideline in collaboration with the Monash University led Australian NHMRC Centre of Research Excellence in Women's Health in Reproductive Life (CREWHIRL). The guideline group members did not receive any financial incentives; all work was provided voluntarily. D.R. reports honoraria from IBSA and Novo Nordisk. B.A. reports speakers' fees from Merck, Gedeon Richter, Organon and Intas Pharma; is part of the advisory board for Organon Turkey and president of the Turkish Society of Reproductive Medicine. S.B. reports speakers' fees from Merck, Organon, Ferring, the Ostetric and Gynaecological Society of Singapore and the Taiwanese Society for Reproductive Medicine; editor and contributing author, Reproductive Medicine for the MRCOG, Cambridge University Press; is part of the METAFOR and CAPE trials data monitoring committee. E.B. reports research grants from Roche diagnostics, Gedeon Richter and IBSA; speaker's fees from Merck, Ferring, MSD, Roche Diagnostics, Gedeon Richter, IBSA; E.B. is also a part of an Advisory Board of Ferring Pharmaceuticals, MSD, Roche Diagnostics, IBSA, Merck, Abbott and Gedeon Richter. M.M. reports consulting fees from Mojo Fertility Ltd. R.J.N. reports research grant from Australian National Health and Medical Research Council (NHMRC); consulting fees from Flinders Fertility Adelaide, VinMec Hospital Hanoi Vietnam; speaker's fees from Merck Australia, Cadilla Pharma India, Ferring Australia; chair clinical advisory committee Westmead Fertility and research institute MyDuc Hospital Vietnam. T.P. is a part of the Research Council of Finland and reports research grants from Roche Diagnostics, Novo Nordics and Sigrid Juselius foundation; consulting fees from Roche Diagnostics and organon; speaker's fees from Gedeon Richter, Roche, Exeltis, Organon, Ferring and Korento patient organization; is a part of NFOG, AE-PCOS society and several Finnish associations. S.S.R. reports research grants from Roche Diagnostics, Organon, Theramex; consulting fees from Ferring Pharmaceuticals, MSD and Organon; speaker's fees from Ferring Pharmaceuticals, MSD/Organon, Besins, Theramex, Gedeon Richter; travel support from Gedeon Richter; S.S.R. is part of the Data Safety Monitoring Board of TTRANSPORT and deputy of the ESHRE Special Interest Group on Safety and Quality in ART; stock or stock options from IVI Lisboa, Clínica de Reprodução assistida Lda; equipment/medical writing/gifts from Roche Diagnostics and Ferring Pharmaceuticals. S.K.S. reports speakers' fees from Merck, Ferring, MSD, Pharmasure. HRV reports consulting and travel fees from Ferring Pharmaceuticals. The other authors have nothing to disclose. DISCLAIMER: This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available at www.eshre.eu/guidelines.).

An interplay of Progesterone, Leukemia Inhibitor Factor and Interleukin-6 in the window of implantation; Impact on fertility.

BACKGROUND: The process of implantation is crucial for the initiation of conception and hence fertility. In addition to a number of factors, it is regulated by a cross talk of gonadotrophins [Luteinizing Hormone (LH), Follicle Stimulatory Hormone (FSH)], ovarian steroids [Estrogen (Et), Progesterone (Pt)] and cytokines [Leukemia inhibitory factor (LIF) and Interleukin 6 (IL6)]. These biomarkers are chief players of implantation. OBJECTIVE: We aimed to explore the role of gonadotrophins (LH, FSH, LH/FSH ratio), ovarian steroids (Et, Pt) and cytokines (LIF, IL6) in the implantation process. This aim was achieved by comparing these hormones and cytokines in the fertile and infertile groups [Polycystic ovaries (PCOs), endometriosis, unexplained infertility (Uex-IF)] and finding their association in all study groups. METHODS: A case control study conducted from October 2020-March 2023. A total of 135 infertile women (with PCOs, Uex-IF, and endometriosis) and 177 fertile women (matched for age and BMI) were selected. Levels of 'Et', 'Pt', 'LIF' and, 'IL6' were estimated using Enzyme Linked Immunosorbent Assay (ELISA). LH and FSH values were obtained from hospital desk records. The Independent Student'st-test was used to compare fertile and infertile groups. One-way ANOVA test was used to compare more than two groups, and Pearson's chi-square (χ2) test was employed to compare percentages of variables. Pearson correlation analysis was performed to assess the associations and correlations. A p value < 0.05 was considered statistically significant. RESULTS: Significantly higher levels of LIF and IL6 were observed in fertile women compared to infertile women. Pt levels were significantly greater in the fertile group than in the infertile group. The FSH/LH ratio was significantly higher in the fertile group. Among infertile women, PCOs (71%) and Uex-IF (91%) exhibited lower Pt levels than the fertile controls (p < 0.01), but these levels remained within the reference range (RR). Among the fertile group (81%), levels of LIF within the RR were significantly higher compared to those with Uex-IF (49%) and females with endometriosis (37%). Moreover, the highest number of participants (57%) with Uex-IF exhibited IL6 levels significantly below the RR in comparison to the fertile group and infertile groups (PCOS and endometriosis). However, lower levels of IL6 were observed in women with Uex-IF. In the control group, LIF exhibited a significant positive correlation with IL6 (r = 0.370), Pt (r = 0.496), Et (r = 0.403), and LH (r = 0.428). Among women with PCOs, LIF showed a significant positive correlation with IL6 (r = 0.443), Pt (r = 0.607), and LH (r = 0.472). In cases of Uex-IF, LIF demonstrated a significant positive correlation with IL6 (r = 0.727). Females with endometriosis displayed a significant positive correlation between LIF and IL6 (r = 0.535) as well as Pt (r = 0.605). In fertile women, a positive correlation was observed between LH and IL6 (r = 0.197, p = 0.009), LIF (r = 0.428, p = 0.000), Pt (r = 0.238, p = 0.001), and Et (r = 0.356, p = 0.000). Furthermore, a positive correlation was found between LH and LIF (r = 0.472, p = 0.000) in women with PCOs. CONCLUSION: Elevated levels of Pt were found to increase the production of LIF in fertile females. However, infertile females with PCOs and Uex-IF exhibited deficient levels of Pt, supporting its role as a biomarker for successful implantation in infertile women. These females showed decreased levels of gonadotropins as well as reduced LH/FSH ratio and diminished secretion of receptivity marker LIF, in addition to reduced Pt secretion. This suggests that reduced gonadotropin levels contribute to a lower LH/FSH ratio, resulting in decreased Pt secretion and ultimately leading to low levels of LIF, thereby causing impaired implantation in women with PCOs and Uex-IF. The exploration of low levels of LIF in patients with endometriosis requires further investigation. The significantly low levels of IL6 in the Uex-IF group elucidate the role of this cytokine in association with decreased Pt and LIF synthesis within this group.

The definition of unexplained infertility: A systematic review.

BACKGROUND: There is no consensus on tests required to either diagnose unexplained infertility or use for research inclusion criteria. This leads to heterogeneity and bias affecting meta-analysis and best practice advice. OBJECTIVES: This systematic review analyses the variability of inclusion criteria applied to couples with unexplained infertility. We propose standardised criteria for use both in future research studies and clinical diagnosis. SEARCH STRATEGY: CINAHL and MEDLINE online databases were searched up to November 2022 for all published studies recruiting couples with unexplained infertility, available in full text in the English language. DATA COLLECTION AND ANALYSIS: Data were collected in an Excel spreadsheet. Results were analysed per category and methodology or reference range. MAIN RESULTS: Of 375 relevant studies, only 258 defined their inclusion criteria. The most commonly applied inclusion criteria were semen analysis, tubal patency and assessment of ovulation in 220 (85%), 232 (90%), 205 (79.5%) respectively. Only 87/220 (39.5%) studies reporting semen analysis used the World Health Organization (WHO) limits. Tubal patency was accepted if bilateral in 145/232 (62.5%) and if unilateral in 24/232 (10.3%). Ovulation was assessed using mid-luteal serum progesterone in 115/205 (56.1%) and by a history of regular cycles in 87/205 (42.4%). Other criteria, including uterine cavity assessment and hormone profile, were applied in less than 50% of included studies. CONCLUSIONS: This review highlights the heterogeneity among studied populations with unexplained infertility. Development and application of internationally accepted criteria will improve the quality of research and future clinical care.

The effect of chronic endometritis and treatment on patients with unexplained infertility.

PURPOSE: This paper was mainly conducted to investigate the effect of chronic endometritis (CE) on the clinical outcome of patients with unexplained infertility. MATERIALS AND METHODS: 145 patients with unexplained infertility from the Reproductive Center of our hospital from January 2018 to December 2021 were selected as the unexplained infertility group. 42 patients with definite infertility causes were selected as the control group during the same period. Both groups of patients underwent hysteroscopy and immunohistochemical tests for CD38 and CD138. According to the results of hysteroscopy and immunohistochemistry, the incidence of CE between the two groups was analyzed. Patients with CE as CE group accepted oral antibiotic therapy for 14 days. Another 58 patients with unexplained infertility who did not undergo hysteroscopy and immunohistochemical tests for CD38 and CD138 were selected as the unexamined group. Both groups of patients were expected natural pregnancy. Follow-up lasted for 1 year, and the pregnant patients were followed up until delivery.The clinical pregnancy rate, spontaneous abortion rate and baby-carrying home rate of the two groups were compared. RESULTS: There were 75 patients with CE in the unexplained infertility group, and the prevalence rate was 51.7% (75/145). Compared with the control group (28.6%), the incidence of CE was significantly higher (P < 0.05). After treated with antibiotic treatment, the patients' clinical pregnancy rate was 61.3% (46/75) and baby-carrying home rate was 60% (45/75) in the CE group, which were higher than those in the unexamined group(43.1% & 36.2%) (P < 0.05), while the spontaneous abortion rate was 2.2% (1/46),which was lower than that in the unexamined group (16.0%) (P < 0.05). CONCLUSIONS: For patients with unexplained infertility, hysteroscopy combined with endometrial immunohistochemical detection of CD38 and CD138 should be performed in time to exclude CE. The clinical pregnancy outcome of CE patients can be significantly improved by antibiotic treatment.

Should IUI replace IVF as first-line treatment for unexplained infertility? A literature review.

BACKGROUND: Unexplained infertility accounts for 25% of infertility causes in the UK. Active intervention methods, such as intrauterine insemination (IUI) or in vitro fertilisation (IVF), are often sought. Despite the National Institute for Health and Care Excellence (NICE) recommending IVF for unexplained infertility, this recommendation has generated an ongoing debate, with few fertility clinics discontinuing the use of IUI as the first-line management of choice. In contrast to NICE, recent guidance released from the European Society for Human Reproduction and Embryology (ESHRE) in August 2023 supports the use of IUI as first-line. High-quality evidence behind such interventions is lacking, with current literature providing conflicting results. AIMS: This review aims to provide a literature overview exploring whether IUI or IVF should be used as first-line treatment for couples with unexplained infertility, in the context of current guidelines. METHODS: The primary outcome used to assess efficacy of both treatment methods is live birth (LB) rates. Secondary outcomes used are clinical pregnancy (CP) and ongoing pregnancy (OP) rates. A comprehensive literature search of 4 databases: Ovid MEDLINE, EMBASE, Maternity & Infant Care and the Cochrane Library were searched in January 2022. Upon removal of duplications, abstract screening, and full-text screening, a total of 34 papers were selected. DISCUSSION/CONCLUSION: This review highlights a large discrepancy in the literature when examining pregnancy outcomes of IUI and IVF treatments. Evidence shows IUI increases LB and CP rates 3-fold compared to expectant management. Literature comparing IUI to IVF is less certain. The review finds the literature implies IVF should be used for first-line management but the paucity of high-quality randomised controlled trials (RCTs), coupled with heterogeneity of the identified studies and a lack of research amongst women > 40 years warrants the need for further large RCTs. The decision to offer IUI with ovarian stimulation (IUI-OS) or IVF should be based upon patient prognostic factors. We suggest that IUI-OS could be offered as first-line treatment for unexplained infertility for women < 38 years, with good prognosis, and IVF could be offered first to those > 38 years. Patients should be appropriately counselled to enable informed decision making.

Association of endometrial polyps with STC-1 and STC-2 in infertile patients.

OBJECTIVE: The present study aimed to evaluate the impact of endometrial polyps (EPs) on the endometrium of patients with unexplained infertility using stanniocalcin-1 and -2 proteins (STC), whose effects on endometrial receptivity have been reported recently. MATERIALS AND METHODS: A case-control study was performed, consisting of 26 patients who underwent endometrial sampling for diagnosis and/or treatment and diagnosed with EP on biopsy and/or excision material, and 23 patients with normal endometrial findings in the pathology, for a total of 49 patients with unexplained infertility. An immunohistochemistry examination was performed on paraffin-embedded tissue samples from both groups to understand whether there was a relationship between EP and STC. Staining results of the polyp and control groups for STC-1 and STC-2 were compared, and it was investigated whether STCs were predictive for EP. RESULTS: In the comparison performed between the H-score evaluation results of the control and polyp groups after the immunohistochemical staining method, the staining in the polyp group was significantly higher for both STC-1 (p < 0.001) and STC-2 (p < 0.001). There was more staining with STC-1 than STC-2 in all groups (STC-1: 15.08; STC-2: 8.27; p < 0.05). In the logistic regression analysis established with STC-1, STC-2, and age, the predictive effect of STC-1 for EP was statistically significant (p = 0.040; odds ratio: 1.66; 95% confidence interval: 1.02-2.68). In EP, according to receiver operating characteristic curve analysis, area under the curve was 0.980 (likelihood ratio: 20.35; p < 0.05), and the cut-off value was 18 for STC-1. CONCLUSION: In infertile patients, since STC-1, which affects endometrial receptivity, is found to be significantly higher in polyps and has a predictive effect on polyps, in patients with unexplained infertility, routine uterine cavity evaluation and routine excision of polypoid lesions detected during this period may have a positive effect on endometrial receptivity.

Comparing the prognosis of in vitro fertilization/intracytoplasmic sperm injection and embryo transfer between unexplained primary infertility patients with repeated artificial insemination with homologous semen failure and tubal infertility patients.

BACKGROUND: Both in vitro fertilization and embryo transfer (IVF-ET) and intracytoplasmic sperm injection and embryo transfer (ICSI-ET) have been recommended for unexplained primary infertility after recurrent artificial insemination with homologous semen failure (UAIHF), but few studies focused on the safety and efficiency of the IVF/ICSI-ET technique for these patients. In this study, we compared the IVF/ICSI-ET outcomes and perinatal and postnatal complications between UAIHF patients and tubal infertility (TI) patients. METHODS: We conducted a retrospective study of UAIHF and TI patients who underwent IVF/ICSI-ET at Guangxi Reproductive Medical Center, the First Affiliated Hospital of Guangxi Medical University from January 2012 to March 2021. After propensity score matching (PSM), we analyzed the IVF/ICSI-ET outcomes and rates of perinatal and postnatal complications. RESULTS: PSM analysis revealed that the baselines of age, infertility duration, and body mass index were comparable. The fertilization method was significantly different between the two groups. Through IVF/ICSI-ET, UAIHF patients had a similar clinical outcome compared to TI patients. Regarding perinatal and postnatal complications, the incidence of premature rupture of membranes (PROM) (7.54% vs. 3.17%, p = 0.030) was significantly higher in UAIHF patients. CONCLUSIONS: UAIHF patients could achieve satisfying pregnancy outcomes by IVF/ICSI-ET. ICSI-ET did not seem to improve the clinical outcomes of UAIHF patients compared to those of TI patients who underwent IVF-ET, which might be related to possible underlying diseases in these patients. In addition, the incidence of PROM was significantly higher in UAIHF patients, which might be related to the ICSI technique used and uncertain potential idiopathic diseases associated with unexplained infertility patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200057572. Registered 15 March 2022.

Endogenous progesterone in unexplained infertility: a systematic review and meta-analysis.

PURPOSE: To investigate the possibility that altered actions of endogenous progesterone affect receptivity and contribute to unexplained infertility (UI). METHODS: Two authors electronically searched MEDLINE, CINAHL and Embase databases from inception to 6 July 2022 and hand-searched according to Cochrane methodology. We included all published primary research reporting outcomes related to endogenous progesterone in natural cycles in women with UI. Studies were assessed for risk of bias using a modified Newcastle-Ottawa Score or NHLBI Score. We pooled results where appropriate using a random-effects model. Findings were reported as odds ratios or mean differences. RESULTS: We included 41 studies (n = 4023). No difference was found between the mid-luteal serum progesterone levels of women with UI compared to fertile controls (MD 0.74, - 0.31-1.79, I2 36%). Women with UI had significantly higher rates of 'out-of-phase' endometrium than controls. Nine out of 10 progesterone-mediated markers of endometrial receptivity were significantly reduced in women with UI compared to fertile controls (the remaining 1 had conflicting results). Resistance in pelvic vessels was increased and perfusion of the endometrium and sub-endometrium reduced in UI compared to fertile controls in all included studies. Progesterone receptor expression and progesterone uptake were also reduced in women with unexplained infertility. CONCLUSIONS: End-organ measures of endogenous progesterone activity are reduced in women with UI compared to fertile controls. This apparently receptor-mediated reduction in response affects endometrial receptivity and is implicated as the cause of the infertility. Further research is required to confirm whether intervention could overcome this issue, offering a new option for treating unexplained infertility. TRIAL REGISTRATION: PROSPERO registration: CRD42020141041 06/08/2020.

Impact of tubal patency test selection on the live birth rate following intrauterine insemination in couples with unexplained infertility: a retrospective cohort study.

OBJECTIVE: We planned a study to evaluate the impact of selecting hysterosalpingography (HSG) over diagnostic laparoscopy during initial fertility evaluation on IUI treatment outcomes in couples diagnosed with unexplained infertility. METHODS: The study comprised a retrospective cohort and included couples evaluated for infertility at our tertiary level hospital between January 2008 and December 2019. Couples diagnosed with unexplained infertility based on tubal patency tests (either HSG or diagnostic laparoscopy) were included. We compared outcomes following ovarian stimulation (OS) and intrauterine insemination (IUI) between women who underwent HSG versus laparoscopy for up to three treatment cycles. RESULTS: A total of 7413 women were screened, out of which 1002 women were diagnosed with unexplained infertility. We did not find a significant statistical difference in the clinical pregnancy (16.7% vs. 11.7%; OR (odds ratio) 1.51; 95% CI (confidence interval) 0.90-2.5) or live birth rate per IUI cycle (15.1% vs. 10.7%; OR 1.51, 95% CI 0.9-2.6) in women who underwent HSG for tubal evaluation as compared to laparoscopy. After adjustment for potential confounders through multivariate analysis, we found that outcomes were comparable between the HSG and laparoscopy. CONCLUSION: The current study did not find any significant difference in treatment outcomes following OS and IUI in women with unexplained infertility who underwent HSG compared to laparoscopy for the assessment of the tubal patency during the initial fertility workup. The finding suggests minimal or no impact of selecting HSG over diagnostic laparoscopy as a tubal patency test on the subsequent IUI outcomes.

SUMO1 and Defective Spermatozoa Correlate with Endogenous Hydrogen Peroxide and Live Birth Outcome in Intrauterine Insemination Cycles for Unexplained Infertility.

This study aimed to investigate the correlation between hydrogen peroxide (H2O2), small ubiquitin-like modifier molecules (SUMO), and pregnancy outcomes in couples with unexplained infertility (UI) undergoing intrauterine insemination (IUI) treatment. We prospectively collected semen samples from 56 couples with UI and divided the spermatozoa into motile and immotile fractions by density gradient centrifugation (DSC). Immunofluorescence staining was used to examine the immunostaining and localization of nuclear pore complex (NPC), SUMO1, and SUMO2/3 in spermatozoa. We detected H2O2 levels by chemiluminescence methods. We found that H2O2 levels correlated with NPC (neck) (r = 0.400) and NPC (tail) (r = 0.473) in motile sperm fractions. In immotile fractions, H2O2 positively correlated with NPC (tail) (r = 0.431) and SUMO1 (neck) (r = 0.282). Furthermore, the positive NPC (tail) group had a significantly lower live birth rate than the negative NPC group (17.9% = 5/28 vs. 42.9% = 12/28). In conclusion, H2O2 positively correlated with SUMO1 (neck) and NPC (tail) in human spermatozoa. The DSC may partially eliminate defective spermatozoa (positive NPC staining); however, if defective spermatozoa remain in the motile fraction, this scenario is associated with a low live birth rate following IUI treatment.

Oxidative Stress as a Potential Underlying Cause of Minimal and Mild Endometriosis-Related Infertility.

Oxidative stress (OS) plays an important role in a variety of physiological and pathological processes of the female reproductive system. In recent years the relationship between OS and endometriosis has been of particular interest, and a theory has been suggested that OS may be a cause of endometriosis development. While the link between endometriosis and infertility is well established, minimal or mild stages of endometriosis are not considered to cause infertility. Increasing evidence of OS as a leading agent in the development of endometriosis has brought up a theory of minimal/mild endometriosis itself being one of the manifestations of high OS rather than a separate disease which directly causes infertility. Moreover, further development of the disease is thought to contribute to an increased production of reactive oxygen species (ROS) thus leading to the progression of endometriosis itself as well as to other pathological processes in the female reproductive system. Therefore, in case of minimal or mild endometriosis, the less invasive treatment could be offered in order to stop the ongoing cycle of endometriosis-reinforced excess ROS production and to reduce their harmful effects. In this article the existing connection between OS, endometriosis, and infertility is explored.

Serum copper, zinc and selenium levels in women with unexplained infertility in Ibadan Nigeria: A cross-sectional analytical study.

Background: Infertility is a global public health issue affecting couples. Trace metals have been implicated in effective reproductive functions in males but less studied in females. Objective: To compare the serum levels of copper (Cu), zinc (Zn), selenium (Se) and copper/zinc ratio in women with unexplained infertility and fertile women. Subjects and Methods: This was a cross-sectional analytical study that compared 75 consenting women who had unexplained infertility with 74 fertile women that were controls. Both groups were seen within 1 year of delivery and were recruited from the family planning unit, at the University College Hospital, Ibadan. Data were obtained through a semi-structured questionnaire, after which 10 mL of venous blood was collected. Analysis of selected trace elements were done by atomic absorption spectrophotometry. IBM SPSS version 23 was utilized for data analysis and the levels of statistical significance was set at <0.05. Results: The mean (± SD) serum concentrations of Cu (93.11 ± 16.55 µg/dL), Zn (72.04 ± 15.03 µg/dL) and Se (28.28 ± 8.33 µg/dL) amongst the women with unexplained infertility were lower when compared to the control group (all with P < 0.001). The serum Cu/Zn ratio was higher among the fertile women, though not statistically significant (P < 0.62). Age of <35 years was associated with normal serum levels of Cu (P < 0.01), while women with normal body mass index had low serum concentrations of Cu (P = 0.04), amongst the fertile group. Conclusion: Serum copper, zinc and selenium concentrations are significantly lower in women with unexplained infertility, therefore diets or supplements containing these trace elements may be helpful in their management.

IUI is a better alternative than IVF as the first-line treatment of unexplained infertility.

The treatment of a condition with no known cause, such as unexplained infertility is, unsurprisingly, controversial. The alternatives that have been suggested for the first-line treatment are expectant management, ovarian stimulation, intrauterine insemination (IUI) with or without ovarian stimulation, or IVF. As far as live births are concerned, the choice has realistically been narrowed down to IUI with ovarian stimulation by low-dose gonadotrophins using strict cancellation criteria versus IVF. In several well-designed studies, three cycles of the former have proved as successful as one cycle of IVF. As IUI is less invasive, more comfortable for the patient, markedly less expensive and safe with a high compliance rate, it should be recommended for the first-line treatment of unexplained infertility for couples in whom the woman's age is not more than 38 years.