Unexplained infertility: an update and review of practice

A Key regulatory protein QRICH2 governing sperm function with profound antioxidant properties, enhancing sperm viability

Infertility poses a global health and social challenge, affecting approximately 15% of couples at childbearing age, with half of the cases attributed to male factors, wherein genetic factors exert a substantial role. In our prior investigation, we identified loss-of-function variants within the gene encoding glutamine-rich protein 2 (QRICH2) in two consanguineous families, leading to various morphological abnormalities in sperm flagella and male infertility. Moreover, our observations in Qrich2 knockout mice revealed a pronounced reduction in spermatozoa count. However, the underlying mechanism remains elusive, prompting further investigation in the current study. By conducting experiments such as Hematoxylin-eosin (HE) staining, immunofluorescence staining, flow cytometry, and single sperm metabolism analysis on the testes and spermatozoa of Qrich2 knockout mice, we found a strong antioxidant capacity mediated by QRICH2 both in vivo and in vitro. Qrich2 knockout led to elevated levels of ROS, consequently inducing DNA damage in spermatids, which in turn triggered increased autophagy and apoptosis, ultimately causing a significant decrease in spermatozoa count. Incubation with the N-terminal purified protein of QRICH2 exhibited potent strong antioxidant activity at the cell and spermatozoa levels in vitro, thereby enhancing spermatozoa viability and motility. Therefore, QRICH2 plays a crucial role in safeguarding spermatids from excessive ROS-induced damage by augmenting antioxidant capacity, thereby promoting spermatozoa survival and improving motility. Furthermore, the N-terminal purified protein of QRICH2 shows promise as an additive for protecting spermatozoa during preservation and cryopreservation.

Identification novel mutations and phenotypic spectrum expanding in PATL2 in infertile women with IVF/ICSI failure

AIM

Abnormalities in oocyte maturation, fertilization, and early embryonic development are major causes of primary infertility in women who are undergoing IVF/ICSI attempts. Although many genetic factors responsible for these abnormal phenotypes have been identified, there are more additional pathogenic genes and variants yet to be discovered. Previous studies confirmed that bi-allelic PATL2 deficiency is an important factor for female infertility. In this study, 935 infertile patients with IVF/ICSI failure were selected for whole-exome sequencing, and 18 probands carrying PATL2 variants with a recessive inheritance pattern were identified.

METHODS

We estimated that the prevalence contributed by PATL2 was 1.93% (18/935) in our study cohort.

RESULTS

15 novel variants were found in those families, including c.1093C > T, c.1609dupA, c.1204C > T, c.643dupG, c.877-2A > G, c.1228C > G, c.925G > A, c.958G > A, c.4A > G, c.1258T > C, c.1337G > A, c.1264dupA, c.88G > T, c.1065-2A > G, and c.1271T > C. The amino acids altered by the corresponding variants were highly conserved in mammals, and in silico analysis and 3D molecular modeling suggested that the PATL2 mutants impaired the physiologic function of the resulting proteins. Diverse clinical phenotypes, including oocyte maturation defect, fertilization failure, and early embryonic arrest might result from different variants of PATL2.

CONCLUSIONS

These results expand the spectrum of PATL2 variants and provide an important reference for genetic counseling for female infertility, and they increase our understanding of the mechanisms of oocyte maturation arrest caused by PATL2 deficiency.

Metabolic profiling identifies Qrich2 as a novel glutamine sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm

In our prior investigation, we discerned loss-of-function variants within the gene encoding glutamine-rich protein 2 (QRICH2) in two consanguineous families, leading to various morphological abnormalities in sperm flagella and male infertility. The Qrich2 knockout (KO) in mice also exhibits multiple morphological abnormalities of the flagella (MMAF) phenotype with a significantly decreased sperm motility. However, how ORICH2 regulates the formation of sperm flagella remains unclear. Abnormal glutamylation levels of tubulin cause dysplastic microtubules and flagella, eventually resulting in the decline of sperm motility and male infertility. In the current study, by further analyzing the Qrich2 KO mouse sperm, we found a reduced glutamylation level and instability of tubulin in Qrich2 KO mouse sperm flagella. In addition, we found that the amino acid metabolism was dysregulated in both testes and sperm, leading to the accumulated glutamine (Gln) and reduced glutamate (Glu) concentrations, and disorderly expressed genes responsible for Gln/Glu metabolism. Interestingly, mice fed with diets devoid of Gln/Glu phenocopied the Qrich2 KO mice. Furthermore, we identified several mitochondrial marker proteins that could not be correctly localized in sperm flagella, which might be responsible for the reduced mitochondrial function contributing to the reduced sperm motility in Qrich2 KO mice. Our study reveals a crucial role of a normal Gln/Glu metabolism in maintaining the structural stability of the microtubules in sperm flagella by regulating the glutamylation levels of the tubulin and identifies Qrich2 as a possible novel Gln sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm.

Evaluating the Use of Selective Serotonin Reuptake Inhibitors (SSRIs) and Male Infertility: A Critical Retrospective Study

Background: The use of selective serotonin reuptake inhibitors (SSRIs) has been associated with potential effects on male fertility, although the exact mechanisms are not fully understood. The aim of this study was to understand the relationship between SSRIs and male infertility; Methods: A retrospective chart review of Saudi males who were treated with SSRIs and attended an infertility clinic in KSMC was undertaken. The medical records of men from an infertility clinic were reviewed to screen the quality of the sperm parameters in patients taking SSRIs; Results: In total, 299 men were identified, of whom 29 (9.6%) were exposed to SSRIs, while 270 (90.4%) did not receive SSRIs, defined as the control infertile group. When comparing the mean ages, a notable disparity was observed between the control group of infertile men (34.2 ± 6.9 years) and the infertile group using SSRIs (41.5 ± 3.2 years) (p < 0.001). Regarding the sperm analysis and the use of SSRIs, the impact of SSRIs use showed no significant differences in sperm liquefaction (p = 0.1), motility (p = 0.17), viscosity (p = 0.16), or count (p = 0.069) with escitalopram, fluoxetine, or paroxetine use; Conclusions: Our study showed no significant difference in the sperm analysis between the SSRI and non-SSRI cohorts. However, the relationship between SSRI use and sperm count warrants further investigation and consideration in clinical practice.

Prevalence of impaired renal function among childless men as compared to fathers: a population-based study

Male reproductive impairment has been linked with an increased risk of numerous non-communicable diseases. Yet, epidemiological data on renal disease among subfertile men is scarce. Therefore, by using male childlessness as a proxy for male infertility, we aimed to investigate its association with renal function. Data was sourced from a population-based cohort including 22,444 men. After exclusion of men aged < 45 years (n = 10,842), the remaining men were divided into two groups: these being childless (n = 5494) and fathers (n = 6108). Logistic regression was applied to explore the association between male childlessness and renal impairment. Childless men as compared to fathers, were more likely to have an estimated-glomerular filtration rate < 60 ml/min/1.73m2 (OR 1.36, 95 CI 1.08-1.70; p = 0.008). After adjustment for age, marital status, smoking habits, diabetes, hypertension and other components of metabolic syndrome, childless men were also more likely to have dipstick proteinuria (OR 1.85, 95 CI 1.16-2.95; p = 0.01). With the growing panorama of disease associated with male reproductive impairment, men with fertility issues may constitute a target population with potential benefit from closer follow-up of their renal function.

The Prevalence of Endometriosis in Patients with Unexplained Infertility

Endometriosis, a systemic ailment, profoundly affects various aspects of life, often eluding detection for over a decade. This leads to enduring issues such as chronic pain, infertility, emotional strain, and potential organ dysfunction. The prolonged absence of diagnosis can contribute to unexplained obstetric challenges and fertility issues, necessitating costly and emotionally taxing treatments. While biopsy remains the gold standard for diagnosis, emerging noninvasive screening methods are gaining prominence. These tests can indicate endometriosis in cases of unexplained infertility, offering valuable insights to patients and physicians managing both obstetric and non-obstetric conditions. In a retrospective cross-sectional study involving 215 patients aged 25 to 45 with unexplained infertility, diagnostic laparoscopy was performed after unsuccessful reproductive technology attempts. Pathology results revealed tissue abnormalities in 98.6% of patients, with 90.7% showing endometriosis, confirmed by the presence of endometrial-like glands and stroma. The study underscores the potential role of endometriosis in unexplained infertility cases. Although the study acknowledges selection bias, a higher than previously reported prevalence suggests evaluating endometriosis in patients who have not responded to previous reproductive interventions may be justified. Early detection holds significance due to associations with ovarian cancer, prolonged fertility drug use, pregnancy complications, and elevated post-delivery stroke risk.

Unexplained subfertility: active or conservative management?

OBJECTIVES

Unexplained subfertility (UEI) describes a couple whose standard subfertility workout consider acceptable but unable to conceived.

METHODS

This retrospective study was conducted in the Advanced Reproductive Centre, UKM Hospital, Kuala Lumpur, from January 2016 to December 2019. The data of 268 UEI couples were obtained from the clinical database. Women aged 21-45 years old was included and further divided into four groups according to the female partner's age and subfertility duration: group A (age <35 years and subfertility <2 years), group B (age <35 years and subfertility >2 years), group C (age >35 years and subfertility <2 years), and group D (age >35 years and subfertility <2 years). All statistical analyses were performed using SPSS 22.0 for Windows.

RESULTS

A total of 255 cases were included in this study. The mean age of the women was 32.9 ± 4.04 years, and the mean subfertility duration was 5.04 ± 2.9 years. A total of 51 (20 %) cases underwent timed sexual intercourse, 147 (57.6 %) cases had intrauterine insemination (IUI), whereas 57 (22.4 %) cases opted for in vitro fertilization (IVF). A total of 204 cases underwent active management (IUI/IVF), which showed a significant difference (p<0.05). Out of eight clinical pregnancies, half of them were from group B.

CONCLUSIONS

Active management in younger women with a shorter subfertility duration revealed a better pregnancy outcome. Otherwise, individualized treatment should be considered in selecting a suitable treatment plan.

Abnormal centriolar biomarker ratios correlate with unexplained bull artificial insemination subfertility: a pilot study

The mechanisms underlying male infertility are poorly understood. Most mammalian spermatozoa have two centrioles: the typical barrel-shaped proximal centriole (PC) and the atypical fan-like distal centriole (DC) connected to the axoneme (Ax). These structures are essential for fertility. However, the relationship between centriole quality and subfertility (reduced fertility) is not well established. Here, we tested the hypothesis that assessing sperm centriole quality can identify cattle subfertility. By comparing sperm from 25 fertile and 6 subfertile bulls, all with normal semen analyses, we found that unexplained subfertility and lower sire conception rates (pregnancy rate from artificial insemination in cattle) correlate with abnormal centriolar biomarker distribution. Fluorescence-based Ratiometric Analysis of Sperm Centrioles (FRAC) found only four fertile bulls (4/25, 16%) had positive FRAC tests (having one or more mean FRAC ratios outside of the distribution range in a group's high-quality sperm population), whereas all of the subfertile bulls (6/6, 100%) had positive FRAC tests (P = 0.00008). The most sensitive biomarker was acetylated tubulin, which had a novel labeling pattern between the DC and Ax. These data suggest that FRAC and acetylated tubulin labeling can identify bull subfertility that remains undetected by current methods and may provide insight into a novel mechanism of subfertility.

Characterization and risk factors for unexplained female infertility in Sudan: A case-control study

BACKGROUND

Female infertility with unknown causes (unexplained) remains one of the mysteries in the reproductive health field, where the diagnostic evidence is still weak and the proposed treatments still work with unknown methods. However, several studies have proposed some possible causes and risk factors for unexplained female infertility.

AIM

To characterize and identify factors associated with unexplained infertility in Sudanese women.

METHODS

A matched (age and body mass index) case-control study was conducted from March 2021 to February 2022. The study samples were 210 women with unexplained infertility (UI) and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum, Sudan. The risk factors of unexplained infertility were identified using a structured, pre-tested questionnaire containing information on socio-demographic variables, anthropometrics, clinical diagnosis of infertility, behavioral factors, physical activity assessment, diversity, and consumption of different food groups by the study participants.

RESULTS

The results showed a higher proportion of women diagnosed with UI were residents of rural areas than controls (21.4% vs 11.1%, P < 0.05), and previous miscarriages and/or abortions were more common in fertile women compared with infertile women (13.16% vs 5.71%, P < 0.05). Additionally, infertile women had a significantly (P < 0.05) higher proportion of family history of infertility (explained and unexplained) compared with controls. Finally, after controlling for the effects of potentially confounding variables using multivariable logistic regression analysis, only marital status, family history of infertility, use of modern contraceptives, smoking, caffeine consumption, physical activity level, meals consumed, other vitamin-A-rich fruits and vegetables, and other vegetables were found to be significant (P < 0.05) factors associated with unexplained infertility among Sudanese women.

CONCLUSION

Married women with a family history of infertility who smoke and consume a high amount of caffeine, who live a sedentary lifestyle, and who consume more than two meals free of vitamin-A-rich fruits and/or vegetables and/or other vegetables per day are at the highest risk of developing unexplained infertility.

Comparative metabolomic profiling of women undergoing in vitro fertilization procedures reveals potential infertility-related biomarkers in follicular fluid

Infertility is a worldwide concern, affecting one in six couples throughout their reproductive period. Therefore, enhancing the clinical tools available to identify the causes of infertility may save time, money, and emotional distress for the involved parties. This study aims to annotate potential biomarkers in follicular fluid that are negatively affecting pregnancy outcomes in women suffering infertility-related diseases such as endometriosis, tuboperitoneal factor, uterine factor, and unexplained infertility, using a metabolomics approach through high-resolution mass spectrometry. Follicular fluid samples collected from women who have the abovementioned diseases and managed to become pregnant after in vitro fertilization procedures [control group (CT)] were metabolically compared with those from women who suffer from the same diseases and could not get pregnant after the same treatment [infertile group (IF)]. Mass spectrometry analysis indicated 10 statistically relevant differential metabolites in the IF group, including phosphatidic acids, phosphatidylethanolamines, phosphatidylcholines, phosphatidylinositol, glucosylceramides, and 1-hydroxyvitamin D3 3-D-glucopyranoside. These metabolites are associated with cell signaling, cell proliferation, inflammation, oncogenesis, and apoptosis, and linked to infertility problems. Our results indicate that understanding the IF's metabolic profile may result in a faster and more assertive female infertility diagnosis, lowering the costs, and increasing the probability of a positive pregnancy outcome.

Serum leptin level in Sudanese women with unexplained infertility and its relationship with some reproductive hormones

BACKGROUND

The excessive concentration of leptin has negative effects on all aspects of female reproduction. Despite this established relationship, the exact role of leptin in women’s fertility is not clear enough and needs more clarification.

AIM

To evaluate the serum leptin levels in Sudanese women and to ascertain the relationship between serum leptin levels and unexplained infertility (UI).

METHODS

A matched (age and body mass index) case-control study was conducted from March 2021 to February 2022. The study samples were 210 women with UI and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum state Sudan. The serum concentration of leptin and other serum biomarkers were determined using enzyme-linked immunosorbent assays.

RESULTS

The results showed that there was a highly statistically significant difference between the two groups (P < 0.001) for all examined eight biomarkers. Whereby, leptin, luteinizing hormone (LH)/follicular stimulating hormone (FSH) ratio, prolactin hormone (PRL) and testosterone (T) were significantly higher in the UI group compared with the control group. In contrast, FSH and estradiol (E2)/T ratio were significantly lower in the UI group than in the control group and the effect size test for the difference between the two groups was very large (effect size > 0.80), for leptin level, LH/FSH ratio, PRL level, and E2/T ratio, and large (effect size 0.50- ≤ 0.80) for FSH and T.

CONCLUSION

This study reveals that leptin could be a potential biomarker for UI in Sudanese women and it may be useful for identifying women with a high risk of infertility.

Should we adopt a prognosis-based approach to unexplained infertility?

The treatment of unexplained infertility is a contentious topic that continues to attract a great deal of interest amongst clinicians, patients and policy makers. The inability to identify an underlying pathology makes it difficult to devise effective treatments for this condition. Couples with unexplained infertility can conceive on their own and any proposed intervention needs to offer a better chance of having a baby. Over the years, several prognostic and prediction models based on routinely collected clinical data have been developed, but these are not widely used by clinicians and patients. In this opinion paper, we propose a prognosis-based approach such that a decision to access treatment is based on the estimated chances of natural and treatment-related conception, which, in the same couple, can change over time. This approach avoids treating all couples as a homogeneous group and minimizes unnecessary treatment whilst ensuring access to those who need it early.

Association of Phthalate Exposure with Endometriosis and Idiopathic Infertility in Egyptian Women

BACKGROUND: Phthalates are compounds found in medical supplies, cellophane wraps, beverage containers, metal can linings, and other products. They have the potential to be significant endocrine disruptors. In experimental animals, thereby affecting their reproductive capacity. Endometriosis is a gynecological condition defined by ectopic endometrial glands and stromal development. Exposure to phthalates has been linked to the development of endometriosis in numerous studies. The dangers of phthalates to women’s reproductive health and fertility have been widely reported. AIM: So far, the relationship between phthalates and infertility is not proven so we decided to see if there was a link between the urine phthalate metabolite levels and endometriosis or idiopathic infertility in Egyptian women. METHODS: Our research was carried out at the infertility outpatient clinic of the Faculty of Medicine of Cairo University. It included 100 female subjects aged 18−40-years-old. Group A (idiopathic infertility; n = 40), Group B (endometriosis; n = 40), and Group C (control; n = 20) were the three age-matched groups that were studied. Using high-performance liquid chromatography (HPLC), the urine levels of mono-2-ethylhexyl phthalate (MEHP) were quantified. RESULTS: The comparison between the study groups has revealed statistically significant differences regarding the urine MEHP levels between Groups A and B. An analysis of the urine MEHP levels in the study Groups A and B has also revealed that the significantly higher urinary MEHP levels are correlated with the use of dietary plastic containers, the use of cosmetics, and the patients’ estrogen levels. Moreover, the urinary MEHP levels of Group A were associated with a history of abortions. CONCLUSIONS: Higher levels of urinary MEHP are positively associated with female reproductive disorders, specifically endometriosis, idiopathic infertility, and abortion.

Determination of idiopathic female infertility from infrared spectra of follicle fluid combined with gonadotrophin levels, multivariate analysis and machine learning methods

By in vitro fertilization, oocytes can be removed and the embryo can be cultured, and then trans cervically replaced when they reach cleavage or when the blastocyst stage. The characterization of the follicular fluid is important for the treatment process. Women who applied to the Academic Hospital in vitro fertilization (IVF) Center diagnosed with idiopathic female infertility (IFI) were sought in the patient group. Demographics and clinical gonadotropin measurements of the study population were recorded. Of the 116 follicular fluid samples (n=58 male-induced infertility; n=58 control) were analyzed using the FTIR system. To identify FTIR spectral characteristics of follicular fluids associated with an ovarian reserve and reproductive hormone levels from control and IFI, six machine learning methods and multivariate analysis were used. To assess the quantitative information about the total biochemical composition of a follicular fluid across various diagnoses. FTIR spectra showed a higher level of vibrations corresponding to lipids and a lower level of amide vibrations in the IFI group. Furthermore, the T square plot from Partial Last Square (PLS) analysis showed, that these vibrations can be used to distinguish IFI from the control group which was obtained by principal component analysis (PCA). Proteins and lipids play an important role in the development of IFI. The absorption dynamics of FTIR spectra showed wavenumbers with around 100% discrimination probability, which means, that the presented wavenumbers can be used as a spectroscopic marker of IFI. Also, six machine learning methods showed, that classification accuracy for the original set was from 93.75% to 100% depending on the learning algorithm used. These results can inform about IFI women's follicular fluid has biomacromolecular differentiation in their follicular fluid. By using a safe and effective tool for the characterization of changes in follicular fluid during in vitro fertilization, this study builds upon a comprehensive examination of the idiopathic female infertility remodeling process in human studies. We anticipate that this technology will be a valuable adjunct for clinical studies.

Sperm Physiological Response to Female Serum-Potential New Insights into the Reproductive Incompatibility Diagnostics

Infertility is assumed to arise exclusively from male- and female-dependent pathological factors. However, recent studies have indicated that reproductive failure may also result from the reproductive incompatibility of the partners. Selection against such incompatibilities likely occurs via female-derived reproductive secretions, including follicular fluid (FF), that mediate gamete-level mate choice towards the sperm of specific males. To facilitate potential development of diagnostic tests for human reproductive incompatibility, we examined whether sperm physiological response to female serum indicate male–female compatibility in the presence of FF. We performed a full-factorial experiment, in which the sperm of 10 males were treated with the FF and serum of 6 healthy females. We found that sperm motility and viability in both biofluids were highly similar and that in 70% of the males, sperm serum treatment predicted male–female compatibility. We also identified male human leucocyte antigen (HLA) alleles and female (FF and serum) anti-HLA antibodies and tested whether the number of allele–antibody matches predict sperm physiological response to female fluids. However, no association was found between measured sperm traits and the number of allele–antibody matches. Overall, the present results may open novel possibilities for the future development of reproductive incompatibility tests and may pave the way towards more accurate infertility diagnostics and treatments.

Metabolic risk factors and fertility disorders: A narrative review of the female perspective

Metabolic risk factors such as obesity are considered major obstacles to female fertility. Chronic infertility imposes psychological and social burdens on women because infertility violates societal gender roles. Although the prevalence of obesity among women is expected to increase in the future, the relevance of metabolic status for fertility is still underestimated. However, the assessment of metabolic risk factors is highly relevant for understanding fertility disorders and improving infertility treatment. This narrative review discusses the associations of metabolic risk factors (e.g. obesity, female athlete triad, oxidative stress) with significant infertility. An electronic search was conducted for studies published between 2006 and 2020 in Cumulative Index to Nursing and Allied Health Literature, ScienceDirect, PubMed, Scopus, Google Scholar and related databases. In total, this search identified 19,309 results for polycystic ovary syndrome, 28,969 results for endometriosis, and only 1611 results for idiopathic and/or unknown infertility. For the present narrative review, 50 relevant studies were included: 19 studies were on obesity, 24 studies investigated the female athlete triad, and seven studies addressed other risk factors, including reactive oxygen species. This narrative review confirms the direct impact of obesity on female infertility, while the effect of other risk factors needs to be confirmed by large-scale population studies.

Assisted Reproductive Technology Treatment, the Catalyst to Amplify the Effect of Maternal Infertility on Preterm Birth

OBJECTIVE

To identify the influence of different infertility causes and assisted reproductive technology (ART) treatment on perinatal outcomes and clarify the relationship between the maternal pathophysiological changes and artificial interventions.

METHODS

A total of 1,629 fertile women and 27,112 infertile women with sole infertility causes were prospectively recruited from July 2014 to December 2017, and 9,894 singletons were finally enrolled into the study. Pregnancies with more than one cause of infertility and/or multiple births were excluded. According to the causes of infertility and the exposure of ART treatment, the participants were divided into four groups, namely, fertile naturally conceived (NC) group, infertile NC group, female factor ART group, and male factor ART group. Perinatal outcomes, including gestational age of delivery (GA), birth weight (BW), preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA), and large for gestational age (LGA), were compared among groups. Logistic regression was performed for the adjustment of several covariates.

RESULTS

The birth outcomes of the infertile NC group and fertile NC group, female factor ART group, and infertile NC group were comparable. Compared to the fertile NC group, the female factor ART group had a shorter GA (39.0 ± 1.6 vs. 39.3 ± 1.5 weeks, BW: P < 0.05). An interaction test showed that ART treatment had an interaction on the effect of female infertility on GA (P = 0.023). The female factor ART group also had a higher risk of PTB (OR 1.56, 95% CI 1.18-2.07) and LGA (OR 1.27, 95% CI 1.10-1.47) compared to the fertile NC group. The risk of PTB was increased for tubal factor ART (OR 1.49, 95% CI 1.12-2.00), ovulatory dysfunction ART (OR 1.87, 95% CI 1.29-2.72), and unexplained infertility ART (OR 1.88, 95% CI 1.11-3.17). The risk of LGA was increased for tubal factor ART (OR 1.28, 95% CI 1.11-1.48) and ovulatory dysfunction ART (OR 1.27, 95% CI 1.03-1.57).

CONCLUSIONS

Our findings indicated that ART treatment could amplify the adverse effect of female infertility on neonates. Women with tubal factor infertility, ovulatory dysfunction, and unexplained infertility have a higher risk of PTB after ART treatment. Thus, clinicians should be vigilant in such patients and provide corresponding prevention strategies before and during pregnancy.

OUP accepted manuscript

BACKGROUND

Oocyte activation deficiency (OAD) is attributed to the majority of cases underlying failure of ICSI cycles, the standard treatment for male factor infertility. Oocyte activation encompasses a series of concerted events, triggered by sperm-specific phospholipase C zeta (PLCζ), which elicits increases in free cytoplasmic calcium (Ca²⁺) in spatially and temporally specific oscillations. Defects in this specific pattern of Ca²⁺ release are directly attributable to most cases of OAD. Ca²⁺ release can be clinically mediated via assisted oocyte activation (AOA), a combination of mechanical, electrical and/or chemical stimuli which artificially promote an increase in the levels of intra-cytoplasmic Ca²⁺. However, concerns regarding safety and efficacy underlie potential risks that must be addressed before such methods can be safely widely used.

OBJECTIVE AND RATIONALE

Recent advances in current AOA techniques warrant a review of the safety and efficacy of these practices, to determine the extent to which AOA may be implemented in the clinic. Importantly, the primary challenges to obtaining data on the safety and efficacy of AOA must be determined. Such questions require urgent attention before widespread clinical utilization of such protocols can be advocated.

SEARCH METHODS

A literature review was performed using databases including PubMed, Web of Science, Medline, etc. using AOA, OAD, calcium ionophores, ICSI, PLCζ, oocyte activation, failed fertilization and fertilization failure as keywords. Relevant articles published until June 2019 were analysed and included in the review, with an emphasis on studies assessing large-scale efficacy and safety.

OUTCOMES

Contradictory studies on the safety and efficacy of AOA do not yet allow for the establishment of AOA as standard practice in the clinic. Heterogeneity in study methodology, inconsistent sample inclusion criteria, non-standardized outcome assessments, restricted sample size and animal model limitations render AOA strictly experimental. The main scientific concern impeding AOA utilization in the clinic is the non-physiological method of Ca²⁺ release mediated by most AOA agents, coupled with a lack of holistic understanding regarding the physiological mechanism(s) underlying Ca²⁺ release at oocyte activation.

LIMITATIONS, REASONS FOR CAUTION

The number of studies with clinical relevance using AOA remains significantly low. A much wider range of studies examining outcomes using multiple AOA agents are required.

WIDER IMPLICATIONS

In addition to addressing the five main challenges of studies assessing AOA safety and efficacy, more standardized, large-scale, multi-centre studies of AOA, as well as long-term follow-up studies of children born from AOA, would provide evidence for establishing AOA as a treatment for infertility. The delivery of an activating agent that can more accurately recapitulate physiological fertilization, such as recombinant PLCζ, is a promising prospect for the future of AOA. Further to PLCζ, many other avenues of physiological oocyte activation also require urgent investigation to assess other potential physiological avenues of AOA.

STUDY FUNDING/COMPETING INTERESTS

D.G. was supported by Stanford University’s Bing Overseas Study Program. J.K. was supported by a Healthcare Research Fellowship Award (HF-14-16) made by Health and Care Research Wales (HCRW), alongside a National Science, Technology, and Innovation plan (NSTIP) project grant (15-MED4186-20) awarded by the King Abdulaziz City for Science and Technology (KACST). The authors have no competing interests to declare.

The step-up protocol increases clinical pregnancy rates compared with the step-down in patients with unexplained infertility. A randomized controlled trial

OBJECTIVE

Unexplained infertility is a relevant indication for controlled ovarian stimulation associated to intrauterine insemination. The "step-up" and "step-down" gonadotropin-based protocols were designed to reduce multiple pregnancy and ovarian hyperstimulation syndrome in polycystic ovary syndrome patients, but there is no related evidence in normoovulatory women undergoing intrauterine insemination. Our aim was to compare the efficacy and safety of both protocols with intrauterine insemination in unexplained infertility patients.

METHODS

Randomized clinical trial including 145 women with unexplained infertility randomly following the step-up (n=73) or step-down (n=72) protocol. In the step-up group, patients started on day 3 of a spontaneous cycle administrating recombinant FSH 75IU sc/day, increasing it to 150IU if no response after 7 days. In the step-down, patients started administrating 150IU sc/day, constantly decreasing it to 75IU after 5 days. Recombinant hCG was administered when a follicle reached ≥18mm diameter.

RESULTS

Clinical pregnancy rate was higher in the step-up group than in the step-down (20.5% vs . 8.3%; p =0.037). Significant differences between step-up and step-down protocols were found regarding days of rFSH administration (8.83±4.01% vs . 7.42±2.18%; p =0.001) and cancellation rate due to hyper response (8.21% vs . 25%; p =0.05). No differences were detected in miscarriage rates, multiple pregnancy rates/cycle and hyper stimulation syndrome incidence.

CONCLUSIONS

The step-up protocol is longer-lasting but more effective obtaining pregnancies than the step-down in patients with unexplained infertility undergoing intrauterine insemination. This effect could be explained by lower cancellation rates due to ovarian hyper response than the step-down protocol, with no differences in ovarian hyper stimulation syndrome incidence.

Unexplained infertility: A French national survey of clinical practices

INTRODUCTION

The aim of our study was to carry out a national survey of French practitioners to evaluate (i) their diagnostic criteria for making a diagnosis of unexplained infertility (UEI) and (ii) their management strategy when facing UEI.

MATERIALS AND METHOD

An online questionnaire comprising ten multiple-choice questions was sent by mail to French reproductive practitioners in 80 fertility centres.

RESULTS

The response rate was 59.6% (195/327). Post coital testing was always or often prescribed by 14.8% of respondents (n=36). Chlamydia trachomatis testing was never prescribed by 31.7% (n=59) of them, 30.2% prescribed a pelvic MRI in cases of UEI and 18.4% (n=33) always or often performed laparoscopy. For 87.6% (n=169), advanced maternal age was always or often an indication of first-line IVF, with an average threshold of 37.4 years. For 68.6% (n=129), diminished AMH was an indication for first-line IVF, with an average AMH threshold of 1.2 ng/ml. With respect to the management of UEI, we did not observe a consensus between the strategies of 2 to 6 intrauterine insemination cycles before IVF or IVF as the first-line treatment.

CONCLUSION

There is no consensus in France on what tests should or should not be carried out to conclude UEI, and there is also no consensus on the management of UEI. UEI is one of the top 10 priorities for future infertility research. The diagnostic criteria must be standardized to enable the comparison of studies on this topic as well as to improve the translation of research into clinical practice.

Proof of concept and development of a couple-based machine learning model to stratify infertile patients with idiopathic infertility

We aimed to develop and evaluate a machine learning model that can stratify infertile/fertile couples on the basis of their bioclinical signature helping the management of couples with unexplained infertility. Fertile and infertile couples were recruited in the ALIFERT cross-sectional case-control multicentric study between September 2009 and December 2013 (NCT01093378). The study group consisted of 97 infertile couples presenting a primary idiopathic infertility (> 12 months) from 4 French infertility centers compared with 100 fertile couples (with a spontaneously conceived child (< 2 years of age) and with time to pregnancy < 12 months) recruited from the healthy population of the areas around the infertility centers. The study group is comprised of 2 independent sets: a development set (n = 136 from 3 centers) serving to train the model and a test set (n = 61 from 1 center) used to provide an unbiased validation of the model. Our results have shown that: (i) a couple-modeling approach was more discriminant than models in which men's and women's parameters are considered separately; (ii) the most discriminating variables were anthropometric, or related to the metabolic and oxidative status; (iii) a refined model capable to stratify fertile vs. infertile couples with accuracy 73.8% was proposed after the variables selection (from 80 to 13). These influential factors (anthropometric, antioxidative, and metabolic signatures) are all modifiable by the couple lifestyle. The model proposed takes place in the management of couples with idiopathic infertility, for whom the decision-making tools are scarce. Prospective interventional studies are now needed to validate the model clinical use.Trial registration: NCT01093378 ALIFERT https://clinicaltrials.gov/ct2/show/NCT01093378?term=ALIFERT&rank=1 . Registered: March 25, 2010.

Genetic incompatibility of the reproductive partners: an evolutionary perspective on infertility

In natural fertilisation, the female reproductive tract allows only a strictly selected sperm subpopulation to proceed in the vicinity of an unfertilised oocyte. Female-mediated sperm selection (also known as cryptic female choice (CFC)) is far from a random process, which frequently biases paternity towards particular males over others. Earlier studies have shown that CFC is a ubiquitous phenomenon in the animal kingdom and often promotes assortative fertilisation between genetically compatible mates. Here, I demonstrate that CFC for genetic compatibility likely also occurs in humans and is mediated by a complex network of interacting male and female genes. I also show that the relative contribution of genetic compatibility (i.e. the male-female interaction effect) to reproductive success is generally high and frequently outweighs the effects of individual males and females. Together, these facts indicate that, along with male- and female-dependent pathological factors, reproductive failure can also result from gamete-level incompatibility of the reproductive partners. Therefore, I argue that a deeper understanding of these evolutionary mechanisms of sperm selection can pave the way towards a more inclusive view of infertility and open novel possibilities for the development of more personalised infertility diagnostics and treatments.

Dispensing of clomiphene citrate to treat infertility: medication supplied and population prevalence of assisted pregnancies and multiple births

OBJECTIVE

To determine the proportion of pregnancies resulting in birth that were conceived with the use of clomiphene citrate (CC) and the frequency of multiple pregnancy.

DESIGN

Whole-of-population cohort study, constructed through data linkage. Comprehensive Australian Government records of dispensed medications were linked to state Perinatal Registry records for all births of at least 20 weeks' gestation.

SETTING

The state of South Australia.

PATIENT(S)

Women who maintained pregnancy for at least 20 weeks and gave birth between July 2003 and December 2015, a total of 150,713 women with 241,561 pregnancies.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy occurring in proximity to CC, defined as dispensing from 90 days before to the end of a conception window derived from newborn date of birth and gestational age.

RESULT(S)

Linkage to dispensed prescription records was achieved for 97.9% of women. Women who conceived with CC tended to be older and socioeconomically advantaged and more likely than other women to have a history of miscarriage. Ongoing pregnancies associated with CC comprised 1.6% of the total; 5.7% were multiple births (mostly twins, 94.6%) compared with 1.5% in the remainder (98.5% twins).

CONCLUSION(S)

In South Australia, 1.6% of pregnancies (1 in 60) of at least 20 weeks' gestation were conceived proximal to CC dispensing. Of these, 5.7% were multiple pregnancies. This takes the proportion of women who achieved an ongoing pregnancy with medical assistance from 4.4%, based on reports from assisted reproductive technology clinics, to 6% in total.

Endometrial Factor in Unexplained Infertility and Recurrent Implantation Failure

Unexplained infertility (UI) and recurrent implantation failure (RIF) are diagnoses based on failed pregnancy attempts within current infertility treatment models. Both diagnoses are made when fertility is unexplained based on current diagnostic methods and has no clear cause; UI is diagnosed when testing is inconclusive, and RIF is diagnosed after three failed in vitro fertilization cycles. In both cases, interventions are often introduced without an understanding of the cause of the infertility, frequently leading to frustration for patients and caregivers. Here, we review evidence to support an influence of endometrial factor in patients given these poorly defined diagnoses and possible treatments targeting the endometrium to improve outcomes in these patients.

Eating disorders and sexuality: A quantitative study in a French medically assisted procreation course

OBJECTIVE

Among medically assisted procreation (MAP) patients, the prevalence of eating disorders (ED), clinical or subclinical, current or past, is considerable. In addition to metabolic repercussions, the literature suggests that these patients present with more sexual dysfunction, leading to anxiety. This quantitative research on a population of women consulting a MAP department for unexplained or ovulatory infertility proposed to study the sexuality of this population by comparing the sexuality of patients suffering from or having suffered from an ED to the sexuality of the non-ED group.

METHOD

Patients (n = 61) filled out the Eating Disorder Examination Questionnaire (EDE-Q), the Brief Index of Sexual Functioning for Women (BISF-W), the ED Whole Life Research Questionnaire, the Hospital Anxiety and Depression Scale (HADS) and the Kansas Marital Satisfaction Scale (KMSS).

RESULTS

We found a prevalence of 54% of ED, current or past. Even though these patients reported the same prevalence of sexual intercourse, they had significantly more physical problems (e.g., anorgasmia, vaginismus, headache) affecting their sexuality (p = .01) than the non-ED group, after adjusting for depression. Approximately 10% of the study population reported no intravaginal intercourse during the last month.

DISCUSSION

This study provides evidence for the existence of more sexual dysfunction in patients who have a fertility disorder and have ED or a history of ED. Future research should evaluate the results of psychological or sexological care that may be more suitable for the infertility of these patients.

Effectiveness and safety of Korean medicine for treating women with unexplained infertility: A multi-center observational study

Background

This study was conducted to demonstrate the effectiveness and safety of herbal medicine and acupuncture treatment in unexplained infertile females.

Methods

One hundred patients were recruited from 3 Korean Medicine hospitals in Korea and they voluntarily signed informed consent agreements. Participants took the Onkyeong-tang (120cc) twice daily between menstrual cycle day (MCD) 3 and 12, and herbal medicine for ovulation and implantation (120cc) twice daily between MCD 13 and 28. They also received acupuncture and moxibustion treatment during 4 menstrual cycles. After the 4 menstrual cycle treatment period, there were 3 menstrual cycle observation periods. The primary outcome is signified by clinical pregnancy rates (CPR) and the secondary outcomes were implantation rates (IR), ongoing pregnancy rates (OPR), and live birth rates.

Results

90 patients completed the study. 13 of the 90 subjects became pregnant. The CPR and IR was 14.44%. 7 of 13 pregnant subjects had continuing pregnancy for over 12 weeks, so that the OPR was 53.85%. The birth rate was 7.78%. All 7 pregnant patients gave birth to their babies and all the babies were live singletons and healthy. There were no serious adverse events.

Conclusions

The findings of this study may provide the possibility of effectiveness and safety of Korea medicine treatment for unexplained infertile women. Further study is required due to lack of control and small sample size in this study.

Protective effects of caffeic acid phenethyl ester on cadmium-induced testicular injury: A crucial role of antioxidant enzymes in male mice infertility

Infertility in men is referred to inability to achieve pregnancy in fertile females after at least one year of regular intercourse. The lack of oxygen in the environment may lead to an imbalance of testes production. Swiss mice were alienated into four groups 10 mice/each. This included one negative normal control group I. The induction of infertility was achieved with injection of cadmium chloride at dose 3 mg/kg body weight for four consecutive days for the rest groups. Group III received vehicle (saline) from the second day of induction for the similar period during the experiment. Infertile mice determined depending on alterations in morphology, motility, and reduced sperm count. Group IV was treated with 3 mg/kg of caffeic acid phenethyl ester (CAPE) per day, for 6 days from the second day of cadmium intoxication. Data showed effectiveness of CAPE significantly through improving the antioxidant enzymes SOD, GST and GSH in testes homogenate and GSH-Px in mice serum that were treated compared to those in the untreated group II (P˂0.001). The histopathology, DNA analysis showed marked improvement in spermatogenesis and DNA intact pattern in treated mice testis. Overall, the results demonstrated the ability of CAPE to improve spermatogenic cells. The data analysis indicated the possibility for the future use of CAPE as an inhibitory agent of infertility. Clinical trials and further studies are required to evaluate the definite medical effects of CAPE based on abundant experimental studies, with predictive future applications in human clinical trials.

Antioxidant-Based Therapies in Male Infertility: Do We Have Sufficient Evidence Supporting Their Effectiveness?

Under physiological conditions, reactive oxygen species (ROS) play pivotal roles in various processes of human spermatozoa. Indeed, semen requires the intervention of ROS to accomplish different stages of its maturation. However, ROS overproduction is a well-documented phenomenon occurring in the semen of infertile males, potentially causing permanent oxidative damages to a vast number of biological molecules (proteins, nucleic acids, polyunsaturated fatty acids of biological membrane lipids), negatively affecting the functionality and vitality of spermatozoa. ROS overproduction may concomitantly occur to the excess generation of reactive nitrogen species (RNS), leading to oxidative/nitrosative stress and frequently encountered in various human pathologies. Under different conditions of male infertility, very frequently accompanied by morpho-functional anomalies in the sperm analysis, several studies have provided evidence for clear biochemical signs of damages to biomolecules caused by oxidative/nitrosative stress. In the last decades, various studies aimed to verify whether antioxidant-based therapies may be beneficial to treat male infertility have been carried out. This review analyzed the results of the studies published during the last ten years on the administration of low-molecular-weight antioxidants to treat male infertility in order to establish whether there is a sufficient number of data to justify antioxidant administration to infertile males. An analysis of the literature showed that only 30 clinical studies tested the effects of the administration of low-molecular-weight antioxidants (administered as a single antioxidant or as a combination of different antioxidants with the addition of vitamins and/or micronutrients) to infertile males. Of these studies, only 33.3% included pregnancy and/or live birth rates as an outcome measure to determine the effects of the therapy. Of these studies, only 4 were case–control studies, and only 2 of them found improvement of the pregnancy rate in the group of antioxidant-treated patients. Additionally, of the 30 studies considered in this review, only 43.3% were case–control studies, 66.7% enrolled a number of patients higher than 40, and 40% carried out the administration of a single antioxidant. Therefore, it appears that further studies are needed to clearly define the usefulness of antioxidant-based therapies to treat male infertility.

Current opportunities and new horizons into the genetic study of infertility

INTRODUCTION

An estimated 12.5% of couples experiencing fertility problems and almost 12% of reproductive age women have turned to health services at least once due to infertility. First trimester miscarriage is the most common clinical manifestation of infertility associated with a genetic cause.

PATIENTS, MATERIALS AND METHODS

The scientific research was conducted at A.S. Medical Center in Bucharest, Romania, between January 2016 and December 2018, on a representative group of 1264 Caucasian patients diagnosed with infertility, from which the study group was selected, consisting of 273 patients who were further genetically investigated.

RESULTS

Chromosomal instability, identified in 14% of patients, has been encountered most frequently in women (7%), and least often in fetuses (2%), unlike other chromosomal anomalies, identified in 55% of patients, which were more common in fetuses (27%) and least frequently in men (9%). Recurrent pregnancy loss due to genetic causes was identified in 53% of cases, being determined by chromosomal instability in 16% of cases and by other chromosomal anomalies in 37% of cases. Infertility due to a genetic cause was identified in 83% of cases, being determined by chromosomal instability in 17% of cases and by other chromosomal anomalies encountered in 66% of cases. In genetic risk pregnancies in evolution, fetal chromosomal anomalies were detected in 94% of cases, the most frequent being aneuploidy and polyploidy. Cytogenetic studies carried out on tissue fragments taken from aborted products of conception revealed the presence of a genetic cause in 57% of cases, an abnormal chromosome number being the most common (36%). The analysis of microdeletions of the long arm of the Y chromosome indicated that 5.5% of men with infertility are affected by this condition.

CONCLUSIONS

Although genetic tests are considered complex and expensive laboratory investigations, they are crucial in identifying the etiology of over 40% of infertility cases associated with genetic factors, as well as in the correct and effective management of infertility.

Metabolomics Analysis Discovers Estrogen Altering Cell Proliferation via the Pentose Phosphate Pathway in Infertility Patient Endometria

Estrogen therapy is widely used as a supplementary treatment after hysteroscopy for female infertility patients owing to its protective function that improves endometrial regeneration and menstruation, inhibits recurrent adhesions, and improves subsequent conception rate. The endometrial protective function of such estrogen administration pre-surgery is still controversial. In the current study, 12 infertility patients were enrolled, who were treated with estrogen before hysteroscopy surgery. Using cutting-edge metabolomic analysis, we observed alterations in the pentose phosphate pathway (PPP) intermediates of the patient's endometrial tissues. Furthermore, using Ishikawa endometrial cells, we validated our clinical discovery and identified estrogen-ESR-G6PD-PPP axial function, which promotes estrogen-induced cell proliferation.

Thoughts on the popularity of ICSI

Purpose

Intracytoplasmic sperm injection (ICSI) is the most widely utilized assisted reproductive technique (ART) worldwide. In this feature, we review the early assisted fertilization attempts that eventually led to the development of ICSI, and discuss its current utilization in cases of male and non-male factor infertility.

Methods

We researched the literature related to the development, indications, and current use of ICSI, such as sperm structural abnormalities, male genetic indications, surgically retrieved sperm, high sperm chromatin fragmentation, oocyte dysmorphism, and preimplantation genetic testing (PGT). We also describe the potential future applications of ICSI.

Results

This review summarizes the early micromanipulation techniques that led to the inception of ICSI. We also explore its current indications, including non-male factor infertility, where its use is more controversial. Finally, we consider the benefits of future advancements in reproductive biology that may incorporate ICSI, such as in vitro spermatogenesis, neogametogenesis, and heritable genome editing.

Conclusion

The versatility, consistency, and reliability of ICSI have made it the most prevalently utilized ART procedure worldwide.

Is Intracytoplasmic Sperm Injection the Solution for all in Unexplained Infertility?

Intracytoplasmic sperm injection (ICSI) was first introduced as a supplemental method to conventional in vitro fertilization (c-IVF) for couples with severe male factor infertility to overcome the poor fertilization rate, while its indications expanded in current clinical practice and gained worldwide popularity. However, ICSI is invasive and crosses all natural barriers, raising several unresolved concerns regarding procedure-dependent and procedure-independent risks, as well as the characteristic of being labor-intensive and more expensive than c-IVF. This review is aimed to draw readers' attention, to the widespread use of ICSI worldwide, with its effectiveness in different indications of infertility, especially in those with unexplained infertility, as well as the cost-effectiveness of the ICSI-for-all strategy. Also, we covered current evidence on the short- and long-term safety of children born thanks to ICSI-aided conception. Further well-designed, adequately powered, and randomized controlled clinical trials are absolutely needed to arrive at a consensus on the use of ICSI over c-IVF in different populations.

Molecular genetics of infertility: loss-of-function mutations in humans and corresponding knockout/mutated mice

BACKGROUND

Infertility is a major issue in human reproductive health, affecting an estimated 15% of couples worldwide. Infertility can result from disorders of sex development (DSD) or from reproductive endocrine disorders (REDs) with onset in infancy, early childhood or adolescence. Male infertility, accounting for roughly half of all infertility cases, generally manifests as decreased sperm count (azoospermia or oligozoospermia), attenuated sperm motility (asthenozoospermia) or a higher proportion of morphologically abnormal sperm (teratozoospermia). Female infertility can be divided into several classical types, including, but not limited to, oocyte maturation arrest, premature ovarian insufficiency (POI), fertilization failure and early embryonic arrest. An estimated one half of infertility cases have a genetic component; however, most genetic causes of human infertility are currently uncharacterized. The advent of high-throughput sequencing technologies has greatly facilitated the identification of infertility-associated gene mutations in patients over the past 20 years.

OBJECTIVE AND RATIONALE

This review aims to conduct a narrative review of the genetic causes of human infertility. Loss-of-function mutation discoveries related to human infertility are summarized and further illustrated in tables. Corresponding knockout/mutated animal models of causative genes for infertility are also introduced.

SEARCH METHODS

A search of the PubMed database was performed to identify relevant studies published in English. The term 'mutation' was combined with a range of search terms related to the core focus of the review: infertility, DSD, REDs, azoospermia or oligozoospermia, asthenozoospermia, multiple morphological abnormalities of the sperm flagella (MMAF), primary ciliary dyskinesia (PCD), acephalic spermatozoa syndrome (ASS), globozoospermia, teratozoospermia, acrosome, oocyte maturation arrest, POI, zona pellucida, fertilization defects and early embryonic arrest.

OUTCOMES

Our search generated ∼2000 records. Overall, 350 articles were included in the final review. For genetic investigation of human infertility, the traditional candidate gene approach is proceeding slowly, whereas high-throughput sequencing technologies in larger cohorts of individuals is identifying an increasing number of causative genes linked to human infertility. This review provides a wide panel of gene mutations in several typical forms of human infertility, including DSD, REDs, male infertility (oligozoospermia, MMAF, PCD, ASS and globozoospermia) and female infertility (oocyte maturation arrest, POI, fertilization failure and early embryonic arrest). The causative genes, their identified mutations, mutation rate, studied population and their corresponding knockout/mutated mice of non-obstructive azoospermia, MMAF, ASS, globozoospermia, oocyte maturation arrest, POI, fertilization failure and early embryonic arrest are further illustrated by tables. In this review, we suggest that (i) our current knowledge of infertility is largely obtained from knockout mouse models; (ii) larger cohorts of clinical cases with distinct clinical characteristics need to be recruited in future studies; (iii) the whole picture of genetic causes of human infertility relies on both the identification of more mutations for distinct types of infertility and the integration of known mutation information; (iv) knockout/mutated animal models are needed to show whether the phenotypes of genetically altered animals are consistent with findings in human infertile patients carrying a deleterious mutation of the homologous gene; and (v) the molecular mechanisms underlying human infertility caused by pathogenic mutations are largely unclear in most current studies.

WILDER IMPLICATIONS

It is important to use our current understanding to identify avenues and priorities for future research in the field of genetic causes of infertility as well as to apply mutation knowledge to risk prediction, genetic diagnosis and potential treatment for human infertility.

Does Laparoscopy and Hysteroscopy Have a Place in the Diagnosis of Unexplained Infertility?

The standard fertility workup includes assessment of ovulation, semen analysis, and evaluation of tubal patency. If the fertility workup is found to be normal, a diagnosis of unexplained infertility is made. The role of laparoscopy in fertility workup has been a matter of debate. The current review presents the evidence for and against laparoscopy and hysteroscopy during fertility workup and subsequently prior to fertility treatment. After appraising the literature, we found the role of diagnostic laparoscopy in fertility workup is limited and is dependent on factors like prevalence of pelvic infection, setting, and availability of expertise. Moreover, whenever a laparoscopy is planned as a part of the fertility workup, the preparation should include ability to carry out simultaneous therapeutic intervention to maximize the benefit. Similarly, the routine use of hysteroscopy in women with unexplained infertility cannot be recommended. There is a need to investigate the impact of choice of tubal test on chances of spontaneous conception and treatment outcomes in women with unexplained infertility. Our future research agenda should also include high-quality multicenter randomized trials assessing the cost-effectiveness of screening and operative hysteroscopy prior to intrauterine insemination or in vitro fertilization.

How and Why to Define Unexplained Infertility?

Unexplained infertility represents up to 30% of all cases of infertility. It is a diagnosis of exclusion, where no cause for infertility may be identified in the investigation of the couple, be it anovulation, fallopian tube blockage, or severe male factor. Unexplained infertility therefore cannot be considered a diagnosis to which a specific treatment is directed, rather that it indicates a failure to reach a diagnosis of the true cause of infertility. In this review, we explore the evidence base and potential limitations of the current routine infertility assessment. We also aim to highlight the importance of considering the prognosis of each individual couple through the process of assessment and propose a reconsidered approach to treatment, targeted to the prognosis rather than the diagnosis. Ultimately, a better understanding of the mechanisms of infertility will reduce the number of couples diagnosed with "unexplained" infertility.

Post-copulatory genetic matchmaking: HLA-dependent effects of cervical mucus on human sperm function

Several studies have demonstrated that women show pre-copulatory mating preferences for human leucocyte antigen (HLA)-dissimilar men. A fascinating, yet unexplored, possibility is that the ultimate mating bias towards HLA-dissimilar partners could occur after copulation, at the gamete level. Here, we explored this possibility by investigating whether the selection towards HLA-dissimilar partners occurs in the cervical mucus. After combining sperm and cervical mucus from multiple males and females (full factorial design), we found that sperm performance (swimming velocity, hyperactivation, and viability) was strongly influenced by the male–female combination. This indicates that sperm fertilization capability may be dependent on the compatibility between cervical mucus (female) and sperm (male). We also found that sperm viability was associated with partners' HLA dissimilarity, indicating that cervical mucus may selectively facilitate later gamete fusion between immunogenetically compatible partners. Together, these results provide novel insights into the female-mediated sperm selection (cryptic female choice) in humans and indicate that processes occurring after copulation may contribute to the mating bias towards HLA-dissimilar partners. Finally, by showing that sperm performance in cervical mucus is influenced by partners' genetic compatibility, the present findings may promote a deeper understanding of infertility.

Gamete-level immunogenetic incompatibility in humans-towards deeper understanding of fertilization and infertility?

Human leukocyte antigen (HLA) immune genes play an important role in partner selection, but it has remained unclear if nonrandom pairing with respect to parental HLA genes could occur at the level of the gametes. We tested this possibility by investigating whether the sperm fertilization competence in humans is dependent on HLA genotype combination of the partners. We conducted a full-factorial experiment, in which the sperm physiological preparation for fertilization among multiple males was studied in the presence of follicular fluid (oocyte surrounding bioactive liquid) of several females. All the studied sperm pre-fertilization physiological parameters (motility, hyperactivation, acrosome reaction, and viability) were strongly dependent on male-female combination. In other words, follicular fluids (women) that induce strong sperm physiological response in some males often induce much weaker response in the other(s). Sperm physiological responses were stronger in HLA-dissimilar male-female pairs than in HLA-similar combinations, but none of the measured sperm traits were associated with genome-wide similarity. Together, these findings shed new light on the evolutionary and immunological mechanisms of fertilization. Furthermore, our results raise an intriguing possibility that against currently prevailing WHO's definition, infertility may not represent exclusively a pathological condition, but may also result from immunogenetic incompatibility of the gametes.

Special characteristics, reproductive, and clinical profile of women with unexplained infertility versus other causes of infertility: a comparative study

PURPOSE

To investigate whether women with unexplained infertility (UI) demonstrate different demographic and IVF characteristics compared to those with other causes of infertility.

METHODS

Data on 245 couples that underwent a total of 413 IVF/ICSI cycles were analyzed (UI 114 cycles, 73 women; anovulation (PCO/PCOS) 83 cycles, 51 women; tubal factor 85 cycles, 47 women; male factor 131 cycles, 74 women). Features of UI were compared versus other infertility groups, after adjustment for multiple comparisons. Generalized least squares (GLS) and random-effects logistic regression analysis were also performed.

RESULTS

Live birth rates, consisting of the primary outcome, were similar in all compared infertility groups. Compared to male infertility, UI was associated with woman's older age at cycle, lower body mass index (BMI), and higher follicle-stimulating hormone (FSH). Compared to tubal infertility, UI was linked to lower endometrial thickness at oocyte retrieval and lower BMI; compared to anovulatory infertility related to PCO/PCOS, UI was linked to woman's older age, more frequent smoking, and poorer ovarian reserve tests (FSH and antral follicle count). After adjustment for other types of infertility, woman's age, age at menarche, and FSH levels, anovulatory infertility presented with higher odds of clinical pregnancy compared to UI (adjusted OR = 2.13, 95% C: 1.01-4.52).

CONCLUSIONS

Infertile women with UI undergoing assisted reproduction demonstrate different demographic and clinical characteristics compared to those of other causes of infertility, albeit live birth rates are similar.

Women Undergoing Hormonal Treatments for Infertility: A Systematic Review on Psychopathology and Newly Diagnosed Mood and Psychotic Disorders

BACKGROUND

The association between infertility treatments and mental disorders has been poorly addressed. This work aims to review current evidence on the psychopathological effects of hormonal treatments used for infertility on women and the occurrence of newly diagnosed mood and psychotic disorders.

METHODS

A systematic review was performed by searching PubMed and clinicaltrials.gov databases from inception until September 2019. Clinical trials on hormone treatments for infertility in patients with mood or psychotic disorders, as well as those evaluating the onset of symptoms, were included. Selected studies were published in English, Spanish, and Dutch language peer-reviewed journals. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Observational studies and case reports were excluded. Effect sizes for changes in depressive symptoms were calculated with Hedges'g and Cohen's d confidence intervals. A meta-analysis was not performed due to the heterogeneity of hormonal compounds in protocols.

RESULTS

From 1,281 retrieved records, nine trials were included; all of them were conducted in non-clinical populations. Four trials compared Gonadotropin-releasing hormone (GnRH) agonists and GnRH antagonists, showing a better mood profile for hormonal protocols including antagonists in one trial. Two trials compared protocols using GnRH agonists/antagonists versus natural cycle protocols (without gonadotropin stimulation), with a better mood profile (less depressive symptoms) in those protocols without gonadotropin stimulation. Other studies compared long and short protocols of GnRH agonists (no differences); two GnRH agonists, buserelin, and goserelin (no differences); and two patterns of clomiphene vs placebo administration (no differences). None of the selected studies investigated the risk of relapse in women with a previous diagnosis of depressive or psychotic disorders. When exploring pre-post changes in depressive symptoms, effect sizes suggested mild mood worsenings for most protocols (effect sizes ≤ -0.4), with the following pattern (worse to better): GnRH agonist > GnRH antagonist > no gonadotropin stimulation.

CONCLUSIONS

This is the first systematic review exploring the psychopathological effects of hormonal infertility treatments. Our study suggests that protocols without gonadotropin stimulation show a better mood profile when compared to those using GnRH antagonists or GnRH agonists. Future studies need to include patients with major mood and psychotic disorders.

Seminal plasma and CD4+ T-cell cytokine profiles in the in vitro fertilization success

Background:

Abnormal female immune response is one of the potential causes of unexplained infertility (UI). Seminal plasma (SP) is an important regulator of female immune responses during pregnancy. This study investigated a SP effect on the expression of CD4⁺ T-cell-related cytokines in a group of UI woman candidates for in vitro fertilization (IVF) and healthy fertile women.

Materials and Methods:

This was a semi-experimental study that performed on 20 UI couples (ten unsuccessful and ten successful IVF outcomes) and 10 fertile couples as the healthy group. CD4⁺ T-cells were separated from peripheral blood mononuclear cells of women by magnetic-activated cell sorting technique and incubated with (stimulated condition) or without (unstimulated condition) SP of their husbands. After incubation, real-time polymerase chain reaction method was used to investigate interleukin (IL)-23, IL-17, IL-4, IL-10, transforming growth factor (TGF)-β, and interferon (IFN)-γ gene expression. Mann–Whitney U-test, Kruskal–Wallis test, and Wilcoxon signed-rank test were used for statistical analysis.

Results:

Baseline TCD4⁺ mRNA levels of IL-23 (P = 0.03) and TGF-β (P = 0.01) were different between healthy and infertile groups. However, IL-17, IL-4, IFN-γ, and IL-10 were expressed similarly regardless of fertility status. Comparing mRNA expression before and after SP exposure, our results have shown that relative expression of IL-23 significantly increased in successful (P = 0.04) and unsuccessful IVF groups (P = 0.01), whereas IL-10 expression increased only in the IVF failure group (P = 0.01).

Conclusion:

SP can make a positive effect on IVF outcome through alteration in CD4 + T-cell-related cytokines expression, especially IL-10 and IL-23.

Couples with mild male factor infertility and at least 3 failed previous IVF attempts may benefit from laparoscopic investigation regarding assisted reproduction outcome

The aim of this study is to assess the value of laparoscopy for couples diagnosed with mild male factor infertility and at least three previous failed In-Vitro Fertilization (IVF) attempts. A total of 169 couples were included in this prospective cohort study. Patients were presented with the option of being subjected to laparoscopic investigation for correction of previously unidentified endometriosis or pelvic adhesions. The outcome measures were Live Birth/Ongoing Pregnancy, clinical pregnancy and positive hCG rate. One-hundred and one of them opted for, whereas 68 opted against laparoscopic investigation. All patients proceeded with a single ICSI cycle. Following laparoscopic investigation, 43 patients were diagnosed with endometriosis, 22 with adhesions, while for 36 patients laparoscopic investigation provided no further diagnosis. No statistically significant differences were observed regarding baseline hormonal levels and other characteristics between the two groups and the three subgroups. When compared to the no-laparoscopy group, women subjected to laparoscopy presented with a higher clinical pregnancy and ongoing pregnancy/live birth rate. Following endometriosis correction, a marginally non-statistically significant trend was observed regarding a decrease in poor-quality blastocysts (p = 0.056). A statistically significant higher clinical pregnancy (p = 0.03) and ongoing pregnancy/live birth rate was observed in the endometriosis group when compared to male factor infertility only (p = 0.04). Laparoscopic identification and correction of undiagnosed endometriosis in couples initially diagnosed with male infertility and at least 3 failed previous IVF attempts, appears to be a promising approach efficiently addressing infertility for these patients while avoiding IVF overuse.

Association of Soluble HLA-G Plasma Level and HLA-G Genetic Polymorphism With Pregnancy Outcome of Patients Undergoing in vitro Fertilization Embryo Transfer

Infertility is currently a growing problem observed around the world and is estimated to affect between 8 and 12% of reproductive-aged couples worldwide. Artificial reproductive techniques are the last chance for couples seeking their own child. Human leukocyte antigen (HLA)-G expression has been suggested as an immunomodulatory molecule that influences pregnancy outcome. The HLA-G gene encodes either membrane-bound or/and soluble proteins. The aim of this study was the evaluation of the role of soluble HLA-G (sHLA-G) and its gene polymorphism in successful implantation after in vitro fertilization embryo transfers (IVF-ETs) in different clinical protocols. We tested the HLA-G polymorphism in three positions: rs1632947: c.-964G>A; rs1233334: c.-725G>C/T in promoter region; rs371194629: c.^*65_^*66insATTTGTTCATGCCT in 3′ untranslated region of exon 8, in 389 patients who underwent IVF-ETs and 320 women with healthy children born after natural conception. Among the patient group, 239 women were with recurrent implantation failure and 117 women had an ongoing pregnancy or a child born after IVF-ET. We found that certain rs1632947-rs1233334-rs371194629 HLA-G haplotypes and diplotypes were associated with infertility, while others were protective. The lowest secretors of sHLA-G were G-C-ins haplotype carriers (37.21 IU/ml), while the highest -G-C-del carriers (73.80 IU/ml). Other haplotype carriers were intermediate secretors. In our study, regardless of possessed haplotype by the patient, 59.73 IU/ml sHLA-G was the threshold value with the best sensitivity (58.82%) and specificity (66.10%) to discriminate patients who achieved and maintained pregnancy from those who did not conceive or they had miscarriage (p = 0.0085; likelihood ratio, 1.74; 95% CI = 0.55–0.78). However, we do not exclude that factors other than sHLA-G may also contribute to complications in pregnancy. In addition, we found that IVF patients in cycles when frozen/thawed embryo was transferred secreted higher soluble HLA-G levels than patients with fresh embryo transferred (p = 0.021). Moreover, correlation analysis of sHLA-G concentration measured before and after embryo transfer for particular patients indicated short ovarian stimulation with gonadotropin-releasing hormone antagonist as more beneficial than long protocol with gonadotropin-releasing hormone agonist. Our study confirms a role of HLA-G polymorphism in infertility and soluble HLA-G in the early stages of pregnancy.

Predictive serum markers for unexplained infertility in child-bearing aged women

PROBLEM

Unexplained infertility (UI) represents about 25%-40% of all infertility and is a formidable obstacle for successful pregnancy for child-bearing aged women. However, up to now, there is no reliable method to predict this condition with high accuracy, thereby hindering early management of this condition.

METHOD OF STUDY

Our prospective study consists of 84 child-bearing aged women that were clinically diagnosed UI. Forty-four matched healthy fertility (HF) women were served as controls. We examined the profiles of 25 hormones and cytokines that were likely related to pathogeneses and molecular pathways involved in UI with the technique of protein array. The samples were randomly stratified 7:3 into a training set and a testing set. We used the SMOTEboost model with 10 serum proteins in a clinical verification study to identify UI cases.

RESULTS

The predictor had an area under the receiver operating characteristic curve (AUC) of 0.788 with 24 serum protein features. The predictive performance in terms of AUC of the model with the top 10 important serum proteins in the clinical verification study to classify UI cases was 0.809. Three most significantly differentially expressed proteins (DEPs) were prolactin, monocyte chemotactic protein-1 (MCP-1), and leptin.

CONCLUSION

Examination of serum-based protein profile changes could help to identify child-bearing aged women at risk of UI. This would enable early detection and facilitate development of clinical strategies to treat UI and guide their planned parenthood. It may also give clues to pathogeneses of the condition of test subjects.

Effect of the anterior uterocervical angle in unexplained infertility: a prospective cohort study

Objective

The present study aimed to evaluate an anatomical region, the anterior uterocervical angle (UCA), to determine whether it plays a role in unexplained infertility.

Methods

In this prospective, cross-sectional study, unexplained infertile and healthy fertile (controls) women were compared. The longitudinal and transverse axes of the uterine cervix and uterine corpus were measured by transvaginal ultrasonography. The UCA was determined as the angle between two lines. One line was drawn between the internal and the external os, and the other was drawn through the internal cervical os and was parallel to the lower side of the front part of the uterine wall in the internal os. Demographic characteristics and uterocervical ultrasonographic measurements were compared between the two groups.

Results

Eighty participants, aged from 20 to 35 years, were enrolled (unexplained infertile [n = 30] and healthy fertile women [n = 50)]. The mean lengths of the uterine corpus longitudinal axis, uterine corpus transverse axis, and uterine cervix longitudinal axis were similar between the groups. The mean UCA was significantly higher in healthy fertile women (131.9 ± 22.9 degrees) than in women with unexplained infertility (114.2 ± 17.3 degrees).

Conclusion

The present study shows that a narrow anterior UCA is associated with unexplained infertility.

From "Every Day" Hormonal to Oxidative Stress Biomarkers in Blood and Follicular Fluid, to Embryo Quality and Pregnancy Success?

BACKGROUND

Oxidative stress appears to be involved in oocyte growth and maturation that when impaired results in poor embryo quality and lower potential to implant. The biochemical microenvironment of the oocyte (follicular fluid (FF)) consists of hormones and other various substances regulating the balance between oxidants and antioxidants.

AIM

The aim of this study was to examine the possible impact of selected biomarkers ("every day," hormonal biomarkers, enzymatic and nonenzymatic antioxidants, and also oxidative stress markers) in serum and FF, on embryo quality and pregnancy success in infertile women undergoing infertility treatment.

METHODS

All 53 patients, mean age 34.7 ± 4.1 years, with serum AMH level ≥ 0.7 ng/mL, were diagnosed with idiopathic infertility. They were stimulated in short antagonist protocol, followed by in vitro fertilization (IVF-ICSI intracytoplasmatic sperm injection) and a single embryo transfer. Follicular fluid was aspirated from the first mature follicle. In statistical analyses the R software was used, then all data was assessed with the Shapiro-Wilk test, logistic regression, and later the receiver operating characteristic (ROC) curve was applied using "pROC" R package.

RESULTS

We did not observe any correlation between AMH and embryo quality and pregnancy rate. Statistically significant results were only found for biomarkers examined in follicular fluid. Greater levels of GPX in FF were associated with the increased chance of producing a high quality embryo (the optimal cut-off concentration was established at over 450 lU/L.) Regarding pregnancy success, increasing levels of GR (cut-off at 21 IU/L), CuZnSOD (cut-off at 9NU/mL), and GST (cut-off at 2.5 IU/L) resulted in lower chances of a successful pregnancy.

CONCLUSION

Our results indicate that FF markers may have some advantages in predicting embryo quality and pregnancy over AMH. The GPX system seems to be mostly related to embryo quality and pregnancy.

Sexual Activity of Patients Undergoing Testicular Sperm Extraction

Introduction

For couples who wish for a baby, sexual activity (through intercourse) is the only way to conceive naturally. However, the sexual activity of men undergoing testicular sperm extraction (TESE) and factors that influence it among affected couples are not clearly understood.

Aim

To examine sexual activity among infertile men undergoing TESE and to identify factors that influenced it.

Methods

Married Japanese male patients undergoing TESE were included. Sexual activity during the previous month was surveyed using a questionnaire, and potential predictive factors influencing sexual activity were examined.

Main Outcome Measures

Two hundred twenty-six married men who answered a questionnaire regarding sexual frequency were reviewed retrospectively.

Results

The patient mean age was 35.8 ± 7.5 years (range 23–67) and the mean age of their partners was 32.9 ± 4.5 years (range 23–44). Most couples (n = 193) were in their first marriage, and 33 were remarried. The mean marriage duration was 52.6 ± 42.2 months (range 1–192). Microdissection TESE and conventional TESE were performed for 152 and 74 patients, respectively. Overall, the mean sexual activity during the last month was 3.6 ± 2.6 times (range 0–15). Marriage duration was negatively correlated with the frequency of sexual activity (r = −0.23; P < .01). There were no correlations between sexual activity and patient age, partner age, marriage type (first marriage or remarried), testicular volume, or serum total testosterone concentration. Regression analysis showed that marriage duration (odds ratio = 1.01; 95% CI, 1.003–1.019; P = .009) and testicular volume (odds ratio = 0.94; 95% CI, 0.88–0.99; P = .033) were significant predictors of low sexual activity (0–1 times/month).

Conclusion

The sexual activity of patients undergoing TESE was almost the same as reported previously. Patient age, partner age, testicular volume, and serum total testosterone concentration had no correlation with the reported frequency of sexual activity.

Taniguchi H, Matsuda T, Nakaoka Y, et al. Sexual Activity of Patients Undergoing Testicular Sperm Extraction. Sex Med 2019;8:30–35.

Pharmacotherapy of infertility in Ghana: retrospective study at the cape coast teaching hospital

Background

Infertility is a major challenge for couples globally. Due to low income levels and the high cost of other assisted reproductive techniques, pharmacotherapy remain the major first line treatment option for infertility in Sub-Saharan Africa.

Objective

The aim of this study was to assess the prevalence of infertility as well as the effectiveness and success achieved following infertility pharmacotherapy at the Cape Coast Teaching Hospital in Ghana.

Methods

This study was a retrospective observational study of 825 couples attending infertility clinic at the hospital.

Results

Prevalence of infertility at the study center was estimated to be 12.3%. Treatment mainly involved the use of clomiphene citrate, antioxidants, herbo-mineral drugs (Ayurveda), multivitamin and antibiotics. Pharmacotherapy resulted in successful conception in one out of every five couples (19.4%; n = 160). Secondary infertility, although more prevalent in the study population (44.8%; n = 370), had lower conception rates during pharmacotherapy than primary infertility (15% vs 26.2%). Age, kind of infertility, employment status but not educational level were significantly associated with pharmacotherapy success. In ovulation induction, clomiphene citrate plus folic acid and vitamin E adjuncts improved ovulation rates during cycle treatments compared to clomiphene citrate alone. Pharmacotherapy of idiopathic infertility (39%, n = 323) was a major challenge with very limited success rates. Interestingly, it was noted that treating couples or female partners only for idiopathic infertility resulted in higher success rates than treating the male partner only. Again, 90-day treatment regimen doubled conception rates when compared with corresponding 30-day treatment regimen. However, zinc sulfate even in short term treatment regimens (30 days) enhanced conception rates in idiopathic infertility.

Conclusions

Prevalence of infertility was estimated to be about 12.3%. One out of every five infertile couples achieved success with pharmacotherapy. Factors such as age, type of infertility, employment status, but not education were significantly associated with treatment success.