Female Unexplained Infertility: A Disease with Imbalanced Adaptive Immunity

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.

Regulatory T Cell and T Helper 17 Cell Imbalance in Patients with Unexplained Infertility

Purpose

Female infertility is a global health concern. The aim of this study was to investigate the relationship between regulatory T (Treg) cells and helper T cells 17 (Th17) in peripheral blood and unexplained infertility (UI). In addition, we explored potential valuable diagnostic biomarkers for patients with UI and ascertained whether Treg and Th17 cells are associated with primary and secondary UI.

Patients and Methods

The patients underwent standard fertility evaluation test, including blood tests, ultrasound examination, fallopian tube tests, ovulation assessment, and male partner's semen analysis. According to the inclusion and exclusion criteria, this study enrolled 37 patients with UI (30 with primary UI and 7 with secondary UI) and 26 age-matched healthy volunteers as the control group. Flow cytometry was used to detect the frequency of Treg and Th17 cells. The area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI) was used to assess the diagnostic performance. An AUC > 0.800 indicated good diagnostic performance.

Results

The percentage of Treg decreased significantly, whereas the percentage and absolute count of Th17 cells increased. Moreover, the Th17/Treg ratio in patients with UI increased significantly. As a diagnostic biomarker for UI, the Th17/Treg ratio exhibited remarkable diagnostic performance (AUC: 0.813 (95% CI = 0.709-0.917)). However, the percentages and absolute counts of Treg and Th17 cells in the peripheral blood of women with primary and secondary UI, as well as their Th17/Treg ratios, did not differ significantly.

Conclusion

The distribution of Treg and Th17 cells is imbalanced in patients with UI. Therefore, the Th17/Treg ratio may be a promising indicator of UI. However, there were no significant differences in the distribution of Treg and Th17 cells between women with primary and secondary UI.

Innate and adaptive immune dysregulation in women with recurrent implantation failure

Recurrent implantation failure (RIF) is a condition where a woman fails to obtain pregnancy after multiple embryo transfer cycles, even with superior-quality blastocysts. There are various factors that can contribute to RIF, including immunologic disturbances. The immune system is extremely important during pregnancy. Immune cells such as T cells, B cells, natural killer (NK) cells, and macrophages (MQ) are present in the female reproductive tract and are accountable for regulating the immune response to invading pathogens and maintaining tissue homeostasis. Dysregulation of these immune cells can lead to inflammation, which can impair fertility. One of the most common immunological disturbances observed in RIF is an altered Th1/Th2 ratio, along with changes in NK cell and macrophage numbers. In addition, the presence of some antibodies, such as anti-ovarian antibodies, can also contribute to RIF. Interleukins have been implicated in the development of an inflammatory response that can interfere with successful embryo implantation. As a result, a comprehensive understanding of immunological compartments in RIF women could assist us in determining the immunological origins of this disease. We will discuss immunological factors that might contribute to RIF etiology, including cellular and molecular components.

High Dietary Inflammatory Index increases the risk of female infertility: An analysis of NHANES 2013-2018

Diet-related inflammation, which can be evaluated using the dietary inflammatory index (DII), is increasingly related to female infertility. However, studies on the association between DII and infertility are limited. In this study, we aim to explore the association between DII and infertility and its dose-effect relationship among women aged 20 to 45 years through a cross-sectional analysis of the National Health and Nutrition Examination Survey 2013-2018. A total of 2613 women aged 20 to 45 years were included and analyzed. The DII was calculated using the first 24-hour dietary recall interview data and divided into quartiles. Weighted multivariable logistic regression and restricted cubic spline analysis were used to explore the relationship between DII and infertility. The odds ratio (OR) (95% confidence interval [CI]) for the association between DII and infertility was 1.06 (0.96-1.19) after multivariable adjustment. Compared with the first quartile (anti-inflammatory diet), the fourth quartile of DII (pro-inflammatory diet) was more strongly associated with an increased risk of infertility, with an OR of 1.61 (95% CI, 1.05-2.47). Restricted cubic splines showed a J-shaped nonlinear association between DII and infertility (P for nonlinear = .003), with a cutoff point of 2.45. When DII was higher than 2.45, the OR for infertility was 1.95 (95% CI, 1.49-2.54). Similar results were observed among the subgroup analyses. In conclusion, this study found high DII (pro-inflammatory diet) increases the risk of female infertility. DII had a J-shaped nonlinear relationship with female infertility, whose cut point is 2.45. Controlling the intake of pro-inflammatory food may be beneficial for female infertility.

Molecular Mechanism of Resveratrol and Its Therapeutic Potential on Female Infertility

Resveratrol is a polyphenol present in various plant sources. Studies have reported numerous potential health benefits of resveratrol, exhibiting anti-aging, anti-inflammatory, anti-microbial, and anti-carcinogenic activity. Due to the reported effects, resveratrol is also being tested in reproductive disorders, including female infertility. Numerous cellular, animal, and even human studies were performed with a focus on the effect of resveratrol on female infertility. In this review, we reviewed some of its molecular mechanisms of action and summarized animal and human studies regarding resveratrol and female infertility, with a focus on age-related infertility, polycystic ovary syndrome, and endometriosis.

Perceptions and Experiences With Healthcare Providers Among People Navigating Reproductive and Fertility Decisions

OBJECTIVES

Primary healthcare providers have an important role in helping people manage their reproductive health and fertility by assessing pregnancy intentions to inform the provision of contraception and/or preconception care. This study explores how women navigating fertility decisions perceived and experienced interactions with their healthcare providers around their fertility.

METHODS

We conducted in-depth interviews (N = 17) and focus groups (N = 17 groups) with 65 women aged 18 to 35 years about fertility, infertility, and reproductive planning. Two researchers coded 2 transcripts using thematic and inductive methods and met to develop a structured codebook. We then applied the codebook to the remaining transcripts.

RESULTS

In all interviews and focus groups, participants discussed their interactions with healthcare providers around fertility. Three central themes emerged in the data, including a desire for more information from healthcare providers about fertility; experiences of having fertility concerns dismissed by healthcare providers (eg, ability to become pregnant when desired); and, feelings that healthcare providers lacked sensitivity in discussing fertility related issues. Notably, these themes were present, even among participants who were not trying to become pregnant or who did not wish to become pregnant.

CONCLUSION

Participants wanted information about fertility from their primary healthcare providers that they felt was lacking. Moreover, participants wanted their healthcare providers to engage with them as multifaceted individuals with current needs as well as future plans regarding fertility. While healthcare providers regularly assess pregnancy intentions, they may need to make a concerted effort to address fertility concerns among both those who want to pursue pregnancy and those who do not wish to become pregnant immediately.

Immunological Aspects of Infertility-The Role of KIR Receptors and HLA-C Antigen

The mechanisms of immune tolerance of a mother against an antigenically foreign fetus without a concomitant loss of defense capabilities against pathogens are the factors underlying the success of a pregnancy. A significant role in human defense is played by killer immunoglobulin-like receptor (KIR) receptors, which regulate the function of the natural killer (NK) cells capable of destroying antigenically foreign cells, virus-infected cells, or tumor-lesioned cells. A special subpopulation of NK cells called uterine NK cells (uNK) is found in the uterus. Disruption of the tolerance process or overactivity of immune-competent cells can lead to immune infertility, a situation in which a woman's immune system attacks her own reproductive cells, making it impossible to conceive or maintain a pregnancy. Since the prominent role of the inflammatory response in infertility, including KIR receptors and NK cells, has been postulated, the process of antigen presentation involving major histocompatibility complex (MHC) molecules (HLA) appears to be crucial for a successful pregnancy. Proper interactions between KIR receptors on female uNK cells and HLA class I molecules, with a predominant role for HLA-C, found on the surface of germ cells, are strategically important during embryo implantation. In addition, maintaining a functional balance between activating and inhibitory KIR receptors is essential for proper placenta formation and embryo implantation in the uterus. A disruption of this balance can lead to complications during pregnancy. The discovery of links between KIR and HLA-C has provided valuable information about the complexity of maternal-fetal immune interactions that determine the success of a pregnancy. The great diversity of maternal KIR and fetal HLA-C ligands is associated with the occurrence of KIR/HLA-C combinations that are more or less favorable for reproductive success.

Gene pathway analysis of the endometrium at the start of the window of implantation in women with unexplained infertility and unexplained recurrent pregnancy loss: is unexplained recurrent pregnancy loss a subset of unexplained infertility?

This study aims to understand differences/similarities in the genetic profile of the endometrium at the start of window of implantation (WOI) in women with unexplained infertility (UI) and unexplained recurrent pregnancy loss (uRPL). Differentially expressed genes (DEGs) from the endometrium were evaluated using gene expression array and pathway enrichment analysis was performed to analyse gene expression pathways involved in both conditions. We found 2,171 genes arranged in 117 pathways and 730 genes arranged in 33 pathways differentially expressed in endometrium of patients in UI and uRPL, respectively. Complement-coagulation cascades, morphine addiction pathway, and PI3K-Akt signalling pathway were predominantly differentially expressed in UI. Cancer pathways, NF-κB signalling pathway, and actin cytoskeleton regulation pathway showed significant changes in uRPL. Forty-eight percent of DEGs and 84% of differentially expressed pathways in uRPL were found in the endometrium of UI patients. Unexpected close association in gene expression pathways between UI and uRPL is observed supporting the hypothesis 'uRPL is a clinical subset of UI'. Yet 100% DEGs overlap wasn't found suggesting the endometrium has still some different gene expression patterns at start of WOI in UI and uRPL. Lastly, diagnostic tools may be developed for uRPL because more specific genes-pathways are involved compared with UI, which shows broader genetic expression profile.

Poor ovarian response in assisted reproductive technology cycles is associated with anti-ovarian antibody and pro-inflammatory immune responses

Anti-ovarian antibody (AOA) could be considered an independent marker for autoimmune ovarian disease and predicting future premature ovarian failure (POF). This study aims to investigate if AOA is associated with poor ovarian response (POR) and pro-inflammatory immune responses in women undergoing assisted reproductive technology (ART) cycles. Two hundred forty-eight women undergoing ART cycles were divided into four groups based on AOA test results and the presence of POR: POR(-)/AOA(-) group (N = 148), POR(+)/AOA(-) group (N = 34), POR (-)/AOA(+) group (N = 44), POR(+)/AOA(+) group (N = 22). The POR patients have a significantly higher prevalence of AOA than non-POR patients (P < 0.05). Peripheral blood CD56 + natural killer (NK) cell level (%), NK cytotoxicity, CD19 +CD5 + B-1 cell level (%), and IFN-γ/IL-10 producing T helper (Th) 1/Th2 cell ratios were significantly higher in POR(+)/AOA(+) group than those of other groups (P < 0.001, P < 0.005, P < 0.01, P < 0.05, respectively). TNF-α/IL-10 producing Th1/Th2 cell ratio of POR(+)/AOA(+) group was significantly higher than those of POR(+)/AOA(-) and POR(-)/AOA(-) groups (P < 0.05, respectively). Homocysteine and vitamin D levels of the POR(+)/AOA(+) group were significantly lower than those of other groups (P < 0.005, respectively). Plasminogen activator inhibiter-1 (PAI-1) level of POR(+)/AOA(+) group was significantly higher than that of POR(-)/AOA(-) group (P < 0.05). In the POR(+)/AOA(+) group, the prevalence of antiphospholipid antibodies was significantly higher than that of the POR(+)/AOA(-) group (P = 0.005). Women with autoimmune POR (POR(+)/AOA(+)) have dysregulated pro-inflammatory immune responses and metabolic factors. The diagnostic and therapeutic approaches for autoimmune POR should be differentiated from those for non-autoimmune POR.

Inflammatory Markers in Women with Infertility: A Cross-Sectional Study

Purpose

Infertility is highly correlated with inflammation. We sought to evaluate the independent relationships between each inflammatory marker in women with infertility.

Patients and Methods

This cross-sectional study included 1028 infertile patients who were hospitalized at Jining Medical University between January 2016 and December 2022. NLR and PLR were the independent and dependent variables measured at baseline, respectively. Age, body mass index (BMI), and menstrual status were covariates. Based on BMI, the study population was split into two groups: Low-BMI and High-BMI.

Results

A stratified analysis revealed that the overweight group had significantly higher levels of WBC, platelet count, lymphocyte count, neutrophil count and NLR. Comparing the overweight group to the normal weight group, the levels were noticeably higher in the overweight group. Significantly positive correlations between NLR and PLR were found in both univariate and multiple regression analyses.

Conclusion

There was a significant positive correlation between NLR and PLR in infertility patients. These results will help in the search for biomarkers of infertility and in the development of infertility prediction models.

Decreased ratio of FOXP3+/FOXP3-CD45RA+CD4+ T cells in peripheral blood is associated with unexplained infertility and ART failure

Unexplained infertility has a huge social impact and is a significant challenge for both clinicians and researchers. Previous studies have shown the involvement of multiple factors in infertility. Among these, the subset of regulatory T cells is of particular interest for the maternal tolerance towards the semi-allogenic fetus. We investigated circulating CD45RA⁺ regulatory and non-regulatory CD4⁺ T cells in healthy women and patients with unexplained infertility in the context of thymic output and peripheral proliferation. The proportion of FOXP3⁺ and FOXP3^-CD45RA⁺CD4⁺ T cells in peripheral blood was studied in control groups of healthy parous and nulliparous (never-pregnant) women and in patients with unexplained infertility. In the same groups thymic output and peripheral proliferation were defined by the sj/βTREC ratio, and signal joint T-cell receptor excision circles (sjTREC) and Ki67 expression, respectively. In parous women a decrease in sjTREC/10⁵ cells and CD45RA⁺ T lymphocytes, compared to nulliparous group was found. At the same time, the proportion of FOXP3^-CD45RA⁺CD4⁺ cells, but not FOXP3⁺CD45RA⁺ Tregs was reduced. In contrast, in patients with unsuccessful pregnancy, proportions of both regulatory and non-regulatory T cell counterparts were lower. Taken together, our results provide evidence for group-specific properties in the CD45RA⁺ T cell compartment between healthy parous, nulliparous and women with unexplained infertility.

The association of decreased HLA-G+ immune cell frequencies with critical COVID-19 patients

INTRODUCTION

COVID-19 (coronavirus disease-2019) is an infectious disease caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Immune dysregulation causes inflammation and massive production of inflammatory mediators that worsen the patients' status. Here, regulatory immune cells may ameliorate inflammation and improve the severity of the disease.

MATERIALS AND METHODS

A total of 76 participants were enrolled in this study and divided into 3 groups as follows: patients with moderate/severe COVID-19 (n = 25), patients with critical COVID-19 (n = 26), and healthy controls (n = 25). After blood collection, peripheral blood mononuclear cells (PBMCs) were isolated and stained by FITC-conjugated anti-CD4 monoclonal antibodies (mABs), PE-conjugated anti-HLA-G mABs, PerCPCy5.5-conjugated anti-CD14 mABs, and APC-conjugated anti-CD8 mABs.

RESULTS

Critical COVID-19 patients had a significantly lower frequency of CD4⁺ HLA-G⁺ T lymphocytes compared with moderate/severe COVID-19 patients (p value < 0.001; SMD, -1.27; 95% CI [-1.86, -0.66]) and healthy controls (p value < 0.05; SMD, -0.69; 95% CI [-1.25, -0.12]). Critical COVID-19 patients had a significantly lower frequency of CD14⁺ HLA-G⁺ monocytes compared with moderate/severe COVID-19 patients (p value < 0.001; SMD, -2.09; 95% CI [-2.77, -1.41]) and healthy controls (p value < 0.05; SMD, -0.83; 95% CI [-1.40, -0.25]). However, there was no difference between the groups regarding the frequency of CD8⁺ HLA-G⁺ T lymphocytes.

CONCLUSION

The increased amount of immunomodulatory HLA-G⁺ cells may reduce the severity of the disease in moderate/severe COVID-19 patients compared with critical COVID-19 patients.

Personalized Nutrition in the Management of Female Infertility: New Insights on Chronic Low-Grade Inflammation

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting a mutual association between nutrition and female fertility. Different “fertile” dietary patterns have been studied; however, in humans, conflicting results or weak correlations are often reported, probably because of the individual variations in genome, proteome, metabolome, and microbiome and the extent of exposure to different environmental conditions. In this scenario, “precision nutrition”, namely personalized dietary patterns based on deep phenotyping and on metabolomics, microbiome, and nutrigenetics of each case, might be more efficient for infertile patients than applying a generic nutritional approach. In this review, we report on new insights into the nutritional management of infertile patients, discussing the main nutrigenetic, nutrigenomic, and microbiomic aspects that should be investigated to achieve effective personalized nutritional interventions. Specifically, we will focus on the management of low-grade chronic inflammation, which is associated with several infertility-related diseases.

Leptin levels in women with unexplained infertility: A systematic review and meta-analysis

BACKGROUND

Unexplained infertility (UI) is usually used for any heterosexual couple who failed to have a successful clinical pregnancy without identifying clear causes after they undergo all standard fertility tests. Evidence shows that leptin is one of the most accurate biomarkers for UI. Nevertheless, conflicting results regarding leptin levels in women with UI have been reported.

AIM

To find the serum leptin levels in women with UI.

METHODS

All studies written in English and conducted before April 30, 2021 from PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Google Scholar, OpenGrey, OATD, and the infertility conference abstract were included. Studies were found eligible if they provided the mean and standard deviation of leptin for the case group and control group. The quality assessment of individual studies was evaluated using the Joanna Briggs Institute Quality Assessment Tool. Data synthesis and statistical analysis were done using STATA software version 16.

RESULTS

A total of 378 studies were reviewed, and just six studies that fulfilled the eligibility criteria were included in this meta-analysis. The pooled result showed that leptin levels were significantly higher in women with UI compared to fertile women, with a standardized mean difference of 0.97 (95% confidence interval: -0.49-2.43). However, heterogeneity across studies was highly significant (P < 0.00001; I² = 98.8%).

CONCLUSION

The results of this study suggest that leptin levels are elevated in women with UI compared with fertile women; hence, leptin could be a potential biomarker for UI in women, and it may be useful for identifying women with a high risk of infertility.

Human Immune System Diseasome Networks and Female Oviductal Microenvironment: New Horizons to be Discovered

Human hypofertility and infertility are two worldwide conditions experiencing nowadays an alarming increase due to a complex ensemble of events. The immune system has been suggested as one of the responsible for some of the etiopathogenic mechanisms involved in these conditions. To shed some light into the strong correlation between the reproductive and immune system, as can be inferred by the several and valuable manuscripts published to date, here we built a network using a useful bioinformatic tool (DisGeNET), in which the key genes involved in the sperm-oviduct interaction were linked. This constitutes an important event related with Human fertility since this interaction, and specially the spermatozoa, represents a not-self entity immunotolerated by the female. As a result, we discovered that some proteins involved in the sperm-oviduct interaction are implicated in several immune system diseases while, at the same time, some immune system diseases could interfere by using different pathways with the reproduction process. The data presented here could be of great importance to understand the involvement of the immune system in fertility reduction in Humans, setting the basis for potential immune therapeutic tools in the near future.

The association between miscarriage and fecundability: the Norwegian Mother, Father and Child Cohort Study

STUDY QUESTION

Is fecundability associated with miscarriage history and future miscarriage risk?

SUMMARY ANSWER

Prior miscarriage was associated with lower fecundability, and participants with a history of subfertility (time-to-pregnancy (TTP) ≥12 months) were at a higher risk of subsequent miscarriage.

WHAT IS KNOWN ALREADY

Although miscarriage and low fecundability share common risk factors, prior studies have reported both lower and higher fecundability after miscarriage.

STUDY DESIGN, SIZE, DURATION

In this study, we examined two related associations: one, between miscarriage history and subsequent fecundability and, two, between fecundability and miscarriage risk in the subsequent pregnancy. The study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). In addition, the outcome of the pregnancy after the MoBa index pregnancy was obtained by linking information from three national health registries: the Medical Birth Registry of Norway, the Norwegian Patient Registry and the general practice database.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We examined the association between number of prior miscarriages and fecundability in 48 537 naturally conceived, planned pregnancies in participants with at least one prior pregnancy. We estimated fecundability ratios (FRs) and 95% CIs using proportional probability regression. We further estimated the relative risk (RR) of miscarriage in the subsequent pregnancy as a function of TTP in the MoBa index pregnancy for 7889 pregnancies using log-binomial regression. Multivariable analyses adjusted for maternal age, pre-pregnancy maternal BMI, smoking status, cycle regularity, income level and highest completed or ongoing education.

MAIN RESULTS AND THE ROLE OF CHANCE

Fecundability decreased as the number of prior miscarriages increased. The adjusted FRs among women with one, two and three or more prior miscarriages were 0.83 (95% CI: 0.80–0.85), 0.79 (95% CI: 0.74–0.83) and 0.74 (95% CI: 0.67–0.82), respectively, compared with women with no prior miscarriages. Compared to women with a TTP of <3 months, the adjusted RR of miscarriage in the subsequent pregnancy was 1.16 (0.99–1.35) with TTP of 3–6 months, 1.18 (0.93–1.49) with TTP of 7–11 months and 1.43 (1.13–1.81) with TTP of 12 or more months.

LIMITATIONS, REASONS FOR CAUTION

Information on TTP and prior miscarriages was obtained retrospectively, and TTP was self-reported. MoBa is a pregnancy cohort, and findings may not be generalizable to all women. We were unable to examine the effect of changing partners between pregnancies, as well as other paternal factors such as seminal parameters. We also did not know what proportion of our participants had changed partners between their prior pregnancies and the index pregnancy. Furthermore, it is likely that many early miscarriages are not recognized.

WIDER IMPLICATIONS OF THE FINDINGS

The association between miscarriage and fecundability may reflect a contribution of occult pregnancy losses to TTP, as well as shared underlying causes for reduced fecundability and miscarriage.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Research Council of Norway through its Medical Student Research Program funding scheme (project number 271555/F20), its Centres of Excellence funding scheme (project number 262700) and through the project ‘Women's fertility – an essential component of health and well-being’ (project number 320656). M.C.M. has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement number 947684). A.J.W. is supported by the Intramural Program of the National Institute of Environmental Health Sciences at the National Institutes of Health, USA. The authors report no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Risk Factors for Atonic Postpartum Hemorrhage: A Systematic Review and Meta-analysis

OBJECTIVE

To identify and quantify risk factors for atonic postpartum hemorrhage.

DATA SOURCES

PubMed, CINAHL, EMBASE, Web of Science, and and ClinicalTrials.gov databases were searched for English language studies with no restrictions on date or location. Studies included randomized trials, prospective or retrospective cohort studies, and case-control studies of pregnant patients who developed atonic postpartum hemorrhage and reported at least one risk factor.

METHODS OF STUDY SELECTION

Title, abstract, and full-text screening were performed using the Raayan web application. Of 1,239 records screened, 27 studies were included in this review. Adjusted or unadjusted odds ratios (ORs), relative risks, or rate ratios were recorded or calculated. For each risk factor, a qualitative synthesis of low and moderate risk of bias studies classifies the risk factor as definite, likely, unclear, or not a risk factor. For risk factors with sufficiently homogeneous definitions and reference ranges, a quantitative meta-analysis of low and moderate risk of bias studies was implemented to estimate a combined OR.

TABULATION, INTEGRATION, AND RESULTS

Forty-seven potential risk factors for atonic postpartum hemorrhage were identified in this review, of which 15 were judged definite or likely risk factors. The remaining 32 assessed risk factors showed no association with atonic postpartum hemorrhage or had conflicting or unclear evidence.

CONCLUSION

A substantial proportion of postpartum hemorrhage occurs in the absence of recognized risk factors. Many risk factors for atonic hemorrhage included in current risk-assessment tools were confirmed, with the greatest risk conferred by prior postpartum hemorrhage of any etiology, placenta previa, placental abruption, uterine rupture, and multiple gestation. Novel risk factors not currently included in risk-assessment tools included hypertension, diabetes, and ethnicity. Obesity and magnesium were not associated with atonic postpartum hemorrhage in this review.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020157521.

Decreased Frequency of CD8+HLA-G+ T Cell in the Peripheral Blood of Primary Unexplained Infertile Females

Most of the findings have focused on the importance of CD4⁺HLA-G⁺ and CD8⁺HLA-G⁺ regulatory T cells (Treg) during pregnancy. It has been demonstrated that these HLA-G⁺ T cell subsets could induce maternal immune tolerance against semi-allogenic conceptus during pregnancy. There are only a few experiments regarding the Treg cells in the context of unexplained infertility (UI). Thirty-five participants including 18 primary unexplained infertile and 17 fertile females were enrolled in this study. A total of 3-5 ml blood samples were taken, and peripheral blood mononuclear cells (PBMCs) were separated by using Ficoll. Using a flow cytometer, the frequency of CD4⁺HLA-G⁺ and CD8⁺ HLA-G⁺ T cells was assessed in the peripheral blood samples of primary unexplained infertile and fertile females. Our results showed that the frequency of CD8⁺HLA-G⁺ Treg cells was significantly lower in primary unexplained infertile females than fertile females (P = 0.048). Although the frequency of CD4⁺HLA-G⁺ Treg cells in the primary unexplained infertile females was lower than fertile females, the difference was not statistically significant (P = 0.25). Regarding the important role of CD8⁺HLA-G⁺ Treg cells during pregnancy and its decrease in females with primary UI, it seems that reduced CD8⁺ HLA-G⁺ Treg cells could be a leading immunological factor in the context of infertility. Nevertheless, more researches are needed in this field.

Periodontal and caries status in unexplained female infertility: A case-control study

BACKGROUND

The aim of this study was to investigate the possible association between maternal periodontal disease and dental caries that affect oral health and unexplained infertility.

METHODS

This cross-sectional case-control study included 50 fertile women and 50 women with unexplained infertility aged 21 to 39 years. Dental and periodontal parameters were examined to evaluate the oral health of the participants. According to the new periodontal disease classification, periodontitis severity was determined.

RESULTS

In infertile women, the number of advanced caries lesions, the percentage of bleeding on probing (BOP), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were higher (P < 0.05). The DMFT and mean plaque index (PI) were not statistically different between the two groups. The PISA and PESA values were higher in women with unexplained infertility than in fertile women (P = 0.005 and P = 0.002, respectively). In multivariate analysis showed that association of DMFT and BOP variables with periodontitis was found to be significant for all women included in the study and for infertile women only (P = 0.000 and P = 0.012 for DMFT, respectively; P = 0.000 and P = 0.016 for BOP, respectively).

CONCLUSION

The chronic inflammatory environment caused by periodontitis and advanced carious lesions in women with unexplained infertility should be of great concern as it may have a role in the etiology of infertility.