The role of infection in miscarriage

Influenza Activity and Preterm Birth in the Atlanta Metropolitan Area: A Time-Series Analysis from 2010 to 2017

BACKGROUND

Annual influenza epidemics lead to a substantial public health burden, and pregnant people are vulnerable to severe outcomes. Influenza during pregnancy is hypothesized to increase the risk of adverse birth outcomes, but population-based epidemiologic evidence remains limited and inconsistent.

METHODS

We conducted a time-series analysis to estimate short-term associations between community-level seasonal influenza activity and daily counts of preterm births in Atlanta, United States from October 17, 2010 to July 10, 2017. We defined weekly influenza exposures four ways: (1) percent test-positive from virologic surveillance, (2) percent of patients with symptoms of influenza-like illness (ILI) in outpatient settings, (3) a composite measure of percent test-positive and ILI, and (4) influenza hospitalization rates. We used Poisson log-linear models to estimate associations, adjusting for time-varying confounders and ongoing at-risk pregnancies. We further examined associations by influenza type and exposure lags and effect modification by maternal characteristics.

RESULTS

We studied a total of 316,253 births. We found consistent positive associations between influenza activity and preterm birth across different exposure measures and exposure lags. An interquartile range increase in a composite measure of ILI activity and percent test-positive was associated with a 1.014 (95% confidence interval: 1.001-1.027) increase in preterm birth during the same week. In stratified analyses, associations were more pronounced among married, non-Black, and Hispanic pregnant people.

CONCLUSION

Periods of high influenza activity were associated with an increased risk of preterm birth.

The numbers of biopsied cells in routine clinical process of preimplantation genetic testing (PGT) do not affect the pregnancy outcomes of embryos

STUDY QUESTION

Does the number of biopsied trophectoderm cells sampled for preimplantation genetic testing for monogenic disease (PGT-M) affect subsequent clinical outcomes for those selected embryos?

SUMMARY ANSWER

The number of biopsied cells does not affect the pregnancy outcome of preimplantation genetically tested embryos.

WHAT IS KNOWN ALREADY

The successful execution of PGT relies on the availability of a certain number of high-quality biopsied cells. Evidence in the literature has reported that blastocyst biopsies may have a negative impact on clinical outcomes.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study including 850 single-blastocyst transfer cycles from 605 couples between May 2014 and August 2024 was conducted at Peking University Third Hospital. The primary clinical outcome measure was the biochemical pregnancy rate, while other indicators such as the live birth rate, the clinical pregnancy rate, and the miscarriage rate were also recorded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study included 850 blastocysts obtained from routine PGT-M cycles. Based on biopsied cell numbers, data were categorized into four groups: Group 1 (1-5 cells) (n = 234), Group 2 (6-10 cells) (n = 328), Group 3 (11-15 cells) (n = 192), and Group 4 (>15 cells) (n = 96).

MAIN RESULTS AND THE ROLE OF CHANCE

The number of cells biopsied from the embryo did not significantly affect either the biochemical pregnancy rate or the live birth rate in the routine PGT process (P > 0.05). There were 129 of 234 embryos (55.1%) in the 1-5 biopsied cell group, 183 of the 328 embryos (55.8%) with 6-10 biopsied cells, 92 of 192 embryos (47.9%) with 11-15 biopsied cells, and 48 of 96 (50.0%) embryos with more than 15 biopsied cells which achieved successful pregnancies. The live birth rates were 42.7%, 49.7%, 43.2%, and 43.8% for each of the biopsy groups, respectively.

LIMITATIONS, REASONS FOR CAUTION

Data for this study were collected from one center only, therefore multicenter, large-scale cohort studies are essential to confirm the accuracy and the reliability of this study.

WIDER IMPLICATIONS OF THE FINDINGS

The number of biopsied cells in a blastocyst is associated with the embryo quality and hatching status. The conclusion of this study emphasizes that routine procedures during the biopsy process do not affect pregnancy outcomes. It is crucial to strike a balance between minimizing damage to the blastocyst's developmental potential and achieving the highest possible detection efficiency for PGT-M.

STUDY FUNDING/COMPETING INTEREST(S)

This project is funded by the National Key Research and Development Program of China (2019YFA0801401, 2019YFA0110001) and the National Natural Science Foundation of China (82125013). The authors declare that they have no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Role of SAA1 in Endometrial Extracellular Matrix Remodeling in Polycystic Ovary Syndrome: Implication for Pregnancy Loss

CONTEXT

Abnormal endometrial extracellular matrix (ECM) remodeling compromises endometrial receptivity and diminishes the probability of a successful live birth. Serum amyloid A1 (SAA1), a modulator of inflammation, is elevated in the circulation of polycystic ovary syndrome (PCOS) patients and involved in ECM remodeling during tissue repair. However, the specific role of SAA1 in endometrial ECM remodeling and subsequent risk of pregnancy loss in PCOS patients remains unclear.

OBJECTIVE

To examine the role and underlying mechanism of SAA1 in ECM remodeling in the endometrium of PCOS patients.

DESIGN

Serum samples from PCOS and control patients were utilized to investigate the relationship between the abundance of SAA1 and pregnancy loss. Human endometrial tissues and primary human endometrial stromal cells were used to examine the role and underlying mechanism of SAA1 in ECM remodeling.

RESULTS

Serum SAA1 concentration was elevated and could serve as an independent risk of pregnancy loss in PCOS patients. Increased SAA1 abundance was also observed in endometrium obtained from these patients. Further mechanistic studies showed that SAA1 stimulated collagen I chains synthesis (COL1A1 and COL1A2) in endometrial stromal cells, suggesting excessive SAA1 may contribute to endometrial ECM remodeling, resulting in a nonsupportive environment for ongoing pregnancy. This effect was abolished by either a toll-like receptor 2/4 antagonist or a nuclear factor κB inhibitor.

CONCLUSION

The locally elevated levels of SAA1 in endometrium contribute to ECM overdeposition by inducing collagen I synthesis in PCOS patients, which may hamper embryo implantation and increase the risk of pregnancy loss. These observations highlight the crucial role of heightened SAA1 in orchestrating endometrial dysfunction and shed light on potential therapeutic avenues for improving reproductive outcomes in PCOS patients.

Uterine Microbiota and Bisphenols: Novel Influencers in Reproductive Health

Infertility affects 8-12% of couples worldwide, and 30-75% of preclinical pregnancy losses are due to a failure during the implantation process. Exposure to endocrine disruptors, like bisphenols, among others, has been associated with the increase in infertility observed in the past decades. An increase in infertility has correlated with exposure to endocrine disruptors like bisphenols. The uterus harbors its own microbiota, and changes in this microbiota have been linked to several gynecological conditions, including reproductive failure. There are no studies on the effects of bisphenols on the uterine-microbiota composition, but some inferences can be gleaned by looking at the gut. Bisphenols can alter the gut microbiota, and the molecular mechanism by which gut microbiota regulates intestinal permeability involves Toll-like receptors (TLRs) and tight junction (TJ) proteins. TJs participate in embryo implantation in the uterus, but bisphenol exposure disrupts the expression and localization of TJ proteins. The aim of this review is to summarize the current knowledge on the microbiota of the female reproductive tract (FRT), its association with different reproductive diseases-particularly reproductive failure-the effects of bisphenols on microbiota composition and reproductive health, and the molecular mechanisms regulating uterine-microbiota interactions crucial for embryo implantation. This review also highlights existing knowledge gaps and outlines research needs for future risk assessments regarding the effects of bisphenols on reproduction.

Infection by Tickborne Bacterium Candidatus Midichloria Associated with First Trimester Pregnancy Loss, Tennessee, USA

A previously healthy 26-year-old woman in middle Tennessee, USA, experienced a first trimester pregnancy loss after multiple tick bites. Histopathology, 16S rRNA sequencing, and electron microscopy examination of the products of conception revealed an infection by a bacterium within the Candidatus Midichloria genus.

Association between alkali and alkaline earth elements in chorionic villus and risk for spontaneous abortion

Exposure to specific alkali and alkaline earth elements(AEs/AEEs) has been reported that are linked to an increased risk of spontaneous abortion. However, the direct evidence of exposure in the uterus are absent. Therefore, we collected chorionic villi after spontaneous abortion or induced abortion in Peking University Third Hospital. The concentrations of six alkali and alkaline earth elements in chorionic villi were measured using inductively coupled plasma mass spectrometry (ICP-MS). Through using logistic regression, Bayesian kernel machine regression (BKMR) and Weighted quantile sum regression (WQS) model, we assessed single and mixed exposure effects of alkali and alkaline earth elements on spontaneous abortion. In terms of the individual effect, high concentration group of barium (Ba) increased the risk of spontaneous abortion by 150 % (95 % CI: 1.38-4.51), whereas rubidium (Rb), cesium (Cs) and Magnesium (Mg) all clearly demonstrated dose dependency in reducing the incidence of spontaneous abortion. The BKMR model demonstrated that as the mixed exposure percentile increased, the likelihood of spontaneous abortion decreased almost linearly. For every quartile increasing in the WQS index, the risk of spontaneous abortion decreased (OR: 0.21, 95 % CI: 0.13-0.33), with Mg and Rb having the highest weights at 0.587 and 0.367, respectively. According to our findings, there were negative dose-response relationships between Mg and Rb levels and risk for spontaneous abortion, but exposure to higher concentration of Ba in the chorionic villi was positively associated with the risk of it.

Capacity Planning (Capital, Staff and Costs) of Inpatient Maternity Services: Pitfalls for the Unwary

This study investigates the process of planning for future inpatient resources (beds, staff and costs) for maternity (pregnancy and childbirth) services. The process of planning is approached from a patient-centered philosophy; hence, how do we discharge a suitably rested healthy mother who is fully capable of caring for the newborn baby back into the community? This demonstrates some of the difficulties in predicting future births and investigates trends in the average length of stay. While it is relatively easy to document longer-term (past) trends in births and the conditions relating to pregnancy and birth, it is exceedingly difficult to predict the future nature of such trends. The issue of optimum average bed occupancy is addressed via the Erlang B equation which links number of beds, average bed occupancy and turn-away. Turn-away is the proportion of times that there is not an immediately available bed for the next arriving inpatient. Data for maternity units show extreme and unexplained variation in turn-away. Economy of scale implied by queuing theory (and the implied role of population density) explains why many well intended community-based schemes fail to gain traction. The paper also addresses some of the erroneous ideas around the dogma that reducing length of stay 'saves' money. Maternity departments are encouraged to understand how their costs are calculated to avoid the trap where it is suggested by others that in reducing the length of stay, they will reduce costs and increase 'efficiency'. Indeed, up to 60% of calculated maternity 'costs' are apportioned from (shared) hospital overheads from supporting departments such as finance, personnel, buildings and grounds, IT, information, etc., along with depreciation charges on the hospital-wide buildings and equipment. These costs, known as 'the fixed costs dilemma', are totally beyond the control of the maternity department and will vary by hospital depending on how these costs are apportioned to the maternity unit. Premature discharge, one of the unfortunate outcomes of turn-away, is demonstrated to shift maternity costs into the pediatric and neonatal departments as 'boomerang babies', and then require the cost of avoidable inpatient care. Examples are given from the English NHS of how misdirected government policy can create unforeseen problems.

Comparative Safety of Antipsychotic Medications and Mood Stabilizers During Pregnancy: A Systematic Review and Network Meta-analysis of Congenital Malformations and Prenatal Outcomes

BACKGROUND

A network meta-analysis was performed to evaluate the risk of congenital malformations and other prenatal outcomes in fetuses after exposure to antipsychotic medications and mood stabilizers during pregnancy.

METHODS

We searched the PubMed, EMBASE, and Cochrane CENTRAL databases up to 15 December 2023, to identify experimental and observational studies comparing antipsychotic and mood stabilizer treatments with control treatments (no exposure). The primary outcome of the study was the incidence of congenital malformations and the secondary outcomes were preterm birth and spontaneous abortion. Additionally, two authors independently assessed the risk of bias in each domain of the included studies using the ROBINS-I tool and evaluated the quality of evidence using the CINeMA rating tool.

RESULTS

The literature search identified 18,334 potential records, and 22 studies involving 3,042,997 pregnant women were ultimately included. Compared with the unexposed group, quetiapine [odds ratio (OR), 1.19; 95% credible interval (CrI), 1.01-1.39], aripiprazole (OR, 1.30; 95% CrI 1.10-1.65), olanzapine (OR, 1.33; 95% CrI 1.11-1.64), risperidone (OR, 1.43; 95% CrI 1.18-1.77), and lithium (OR, 1.61; 95% CrI 1.07-2.30) were associated with a slightly increased risk of congenital malformations. In contrast, lamotrigine (OR, 1.21; 95% CrI 0.86-1.64), ziprasidone (OR, 1.14; 95% CrI 0.73-1.72), and haloperidol (OR, 1.26; 95% CrI 0.90-1.75) did not show significant differences compared with the unexposed group, with narrower credible intervals.

CONCLUSIONS

The evidence from this analysis suggests that, overall, quetiapine has the lowest teratogenic risk when used during pregnancy, making it the safer option for pregnant women. Lamotrigine and haloperidol follow closely behind. At the same time, the use of lurasidone and ziprasidone should be approached with caution, and further clinical studies are necessary to better assess their safety.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD4201811373.

Differential mRNA and lncRNA Expression Profiles Associated with Early Pregnancy Loss in ART Patients

Early pregnancy loss (EPL) is the most common complication in assisted reproductive technology (ART). However, the precise causes for nearly 50% patients remain unexplained. In the current study, we aimed to discover the differentially expressed profiling of mRNAs and lncRNAs by RNA sequencing (RNA-seq). Human chorionic villi tissues were collected from patients with EPL and natural control (NC) group. RNA sequencing (RNA-seq) of these specimens was performed for transcriptome analysis. As a result, we identified a total of 141 mRNAs and 137 lncRNAs that were significantly differentially expressed between villi tissues from EPL and NC. Functional enrichment analyses indicated enrichment of differentially expressed genes involved in pathways were associated with growth hormone receptor binding, PI3K-Akt signaling pathway, Jak-STAT signaling pathway, transcriptional misregulation in cancer, metabolic pathways and Rap1 signaling pathway. Additionally, the co-expression networks (lncRNA-miRNA-mRNA) was constructed based on the correlation analysis between the differentially expressed RNAs.7 mRNAs and 6 lncRNAs were successfully technically validated with RT-PCR. In conclusion, our results suggest a direction for the further study of EPL-related mRNAs and lncRNAs and may ultimately assist in understanding the pathogenesis of EPL.

Risk of invasive pneumococcal disease during pregnancy and postpartum and association with adverse maternal and foetal outcomes: A prospective cohort study, England, 2014-19

BACKGROUND

Pneumococcal infections are associated with significant morbidity and mortality, especially at the extremes of age and in those with underlying conditions. Little is known about the risks, presentations or outcomes of invasive pneumococcal disease (IPD) during pregnancy or the postpartum period.

METHODS

The UK Health Security Agency conducts enhanced national surveillance of IPD in England. We used national surveillance data to calculate IPD risk and outcomes in pregnant, postpartum and non-pregnant women of childbearing age with IPD over a five-year period in England.

FINDINGS

There were 1701 IPD cases in women aged 15-44 years between 1 July 2014 and 30 June 2019, including 123 (7.2%) pregnant, 38 (2.2%) postpartum and 1540 (90.5%) non-pregnant women. IPD incidence in pregnant women (0.048/1000 woman-years) was not significantly different compared to non-pregnant women (0.041/1000 woman-years; Incidence Rate Ratio [IRR]: 1.17; 95%CI 0.96-1.40; p=0.11). When stratified by trimester, however, women in their third trimester had a 2.27-fold (95%CI 1.80-2.85, p<0.001) increased risk of IPD, compared to non-pregnant women (IRR 2.27, 95%CI 1.78-2.85, p<0.001), while those in the first (IRR 0.49, 95%CI 0.28-0.80) and second trimester (IRR 0.71, 95%CI 0.47-1.04) had a lower risk, albeit only statistically significant for the first trimester. Postpartum women (0.144 per 1000 woman-years), on the other hand, had a 3.49-fold (95%CI 2.46-4.81, p<0.001) higher IPD risk than non-pregnant women. Most pregnant women developed IPD during their third trimester (80/123, 65.0%), with all but one pregnancy resulting in a live birth. IPD in the second trimester was associated with live birth in 77.8% of cases (21/27), while 22.2% experienced a miscarriage (5/27, 18.5%) or stillbirth (1/27, 3.7%). IPD in the first trimester was associated with live birth in 41.7% of cases (5/12), miscarriages in 41.7% (5/12), and termination in 16.7% (2/12) cases. Only three neonates (3/142) had confirmed IPD. There were no deaths in pregnant women with IPD compared to 5.5% (85/1540) in non-pregnant women.

INTERPRETATION

While pregnant women overall did not appear to have an increased risk of IPD compared to non-pregnant women, those infected in third trimester or postpartum appeared to have more than twice the incidence. Most pregnant and postpartum women had a live birth, and subsequent neonatal infection was rare, occurring in 2% of live births.

Preconception Chlamydia trachomatis seropositivity and fecundability, live birth, and adverse pregnancy outcomes

OBJECTIVE

To study the impact of preconception Chlamydia trachomatis seropositivity on fecundability, live birth, and pregnancy loss and to assess the effect of low-dose aspirin therapy (81 mg/day) on live birth and pregnancy loss.

DESIGN

Preconception cohort study conducted using data and specimens from the Effects of Aspirin in Gestation and Reproduction study-a randomized placebo-controlled trial.

PATIENTS

A total of 1,228 individuals with proven fecundity and a history of 1-2 pregnancy losses.

EXPOSURE

Preconception C. trachomatis seropositivity determined using an enzyme-linked immunoabsorbent assay-based synthetic peptide assay at baseline.

MAIN OUTCOME MEASURES

Time-to pregnancy (fecundability) was defined as number of menstrual cycles to beta human chorionic gonadrotropin-detected pregnancy; live birth status was determined from medical record abstraction; pregnancy loss was defined as any loss post positive beta human chorionic gonadrotropin test.

RESULTS

After adjusting for confounders (baseline demographic and reproductive history variables), C. trachomatis seropositivity (n = 134/1228, 11%) was associated with a reduced live birth likelihood (relative risk [RR]: 0.77, 95% confidence interval [CI]: 0.59, 0.99) and an increased risk of pregnancy loss (RR: 1.16, 95% CI: 1.04, 1.29), but was not associated with fecundability (fecundability odds ratio: 0.92, 95% CI: 0.71, 1.20). Among a subset of C. trachomatis seropositive individuals with chronic inflammation indicated by increased C-reactive protein levels ≥1.95 but ≤10 mg/L (n = 50/134, 37.3%), low-dose aspirin therapy improved live birth rates (RR: 1.68, 95% CI: 0.96, 2.92) and reduced the risk of pregnancy loss (RR: 0.83, 95% CI: 0.65, 1.10). However, the sample size reduced precision.

CONCLUSIONS

Prior exposure to C. trachomatis among women with a history of pregnancy loss may impact risk of pregnancy loss. Our results indicate the need for future studies exploring mechanisms by which C. trachomatis may influence long-term reproductive function, because this may identify treatments to improve outcomes among those with a history of infection.

Parvovirus B19 in Pregnancy-Do We Screen for Fifth Disease or Not?

Parvovirus B19 (B19V) infection is the cause of erythema infectiosum, or the "fifth disease", a widespread infection, potentially affecting 1-5% of pregnant women, in most cases without significant damage to the pregnancy or fetus. It follows a seasonal variation, with a higher prevalence in temperate climates, mainly in late winter and early spring. Women at increased risk include mothers of preschool and school-age children, and those working in nurseries, kindergartens, and schools. Vertical transmission occurs in 33% to 51% of cases of maternal infection. Parvovirus infection is an important cause of fetal perinatal infection resulting in increased morbidity through the development of fetal anemia, heart failure, and non-immune hydrops. A comprehensive literature review was conducted using PubMed, Cochrane Library, and Google Scholar, focusing on publications from the last 10 years and prioritizing studies related to parvovirus B19 infection in pregnancy. We summarized the existing data in the literature on the effects of parvovirus B19 infection during pregnancy and weighed if there is a need for screening in pregnant patients. Routine screening for parvovirus B19 infection can be considered in communities where infection is common, there is occupational exposure, or during endemic periods, with the reason being that accurate identification and treatment of fetuses affected by congenital B19V infection have been shown to improve perinatal outcomes.

Elevated IL-10 serum levels are associated with slower serological response following syphilis treatment during pregnancy

BACKGROUND

Approximately 50% of pregnant individuals treated for syphilis do not achieve a decline in non-treponemal titers by delivery. The serological response in pregnant persons is significantly slower compared to non-pregnant individuals, with unclear pathogenesis and clinical significance. This study aimed to determine the association between the host immune response and serological outcome in pregnant individuals with syphilis.

METHODS

Twenty-four females with early syphilis, including 14 pregnant individuals, were included. Pro-inflammatory and regulatory cytokines (IFN-γ, TNF-α, IL-4, IL-1β, IL-10, TGF-β) were measured before treatment and 6 months after penicillin injection.

RESULTS

The median time to serological cure was 5 months for pregnant individuals and 2 months for non-pregnant females. Pregnant individuals had significantly higher serum levels of IL-10 and TGF-β at baseline and at 6 months post-treatment compared to non-pregnant individuals (p < .05).

CONCLUSIONS

A robust regulatory immune response to syphilis may be associated with a slower serological response to therapy during pregnancy.

The positive impact of targeted modulating food intolerance on immune-related recurrent pregnancy loss

BACKGROUND

It has been proven that immune disorders are one of the vital risk factors of recurrent pregnancy loss (RPL), and the presence of food intolerance seems to play an essential role in this. However, the impact of immune status induced by food intolerance on RPL has not been reported. This study utilized a targeted diet avoiding food intolerance as much as possible for each participant to investigate their effects on pregnancy outcomes in RPL patients with positive autoimmune markers.

METHODS

From January 2020 to May 2021, fifty-eight patients with RPL were enrolled. They were divided into two groups based on the presence of autoantibodies: the autoantibody-positive group (AP, n = 29) and the autoantibody-negative group (AN, n = 29). Their food-specific immunoglobulin (Ig) G antibodies for 90 foods were tested using enzyme-linked immunosorbent assay (ELISA). The levels of immune parameters and the presence of gastrointestinal discomforts (diarrhea or constipation, eczema, and mouth ulcers) were recorded before and after dietary conditioning, followed by the analysis of pregnancy outcomes.

RESULTS

Compared to the AN group, the patients in the AP group showed immune disorders at baseline, such as reduced levels of IL-4 and complement C3, and increased levels of IL-2 and total B cells. These parameters within the AP group were significantly improved after dietary conditioning that avoided food intolerance, while no significant changes were observed in the AN group. Patients in the AP group had significantly higher food-specific IgG antibodies for cow's milk (89.66% vs. 48.28%, p < .001), yolk (86.21% vs. 27.59%, p < .001), bamboo shoots (86.21% vs. 44.83%, p < .001) compared to those in the AN group. Additionally, gastrointestinal discomforts including diarrhea or constipation, eczema, and mouth ulcers were more common in the AP group than in the AN group. After 3-month dietary conditioning, these significantly improved characteristics were only observed in the AP group (p < .001). Finally, the baby-holding rate was higher in the AP group compared to the AN group (p < .05).

CONCLUSIONS

The RPL patients in the AN group did not exhibit immune disorders, whereas those in the AP group experienced immune disorders and gastrointestinal discomforts. For patient with positive autoantibodies, dietary intervention may mitigate immune disorders and gastrointestinal discomforts, presenting a promising approach to enhance pregnancy outcomes.

Unveiling the truth: Pathogen infections linked to miscarriage: A STROBE-Compliant Mendelian randomization study

Miscarriage represents a prevalent yet insufficiently studied adverse pregnancy outcome. The definitive causal links between various pathogens and miscarriage remain to be established. To investigate the causal connections between pathogen infections and miscarriage, we utilized a two-sample bidirectional Mendelian randomization (MR) analysis. We sourced genome-wide association studies data on pathogen infections from the UK Biobank, which included serological markers for infectious diseases and comprehensive whole-genome genetic information from approximately 10,000 individuals. Additionally, genome-wide association studies data on miscarriages were collected from 3 distinct European populations for our analysis. The MR analysis was primarily conducted using the inverse variance weighted method, complemented by Bayesian weighted MR and the weighted median method for robustness. To ensure the reliability of our findings, we performed heterogeneity and pleiotropy tests, leave-one-out sensitivity analyses, and a meta-analysis. Our extensive research has identified a causal association between miscarriage and infections by several human herpesviruses (HHV-1, HHV-3, HHV-4, HHV-6, and HHV-7), polyomaviruses (BK, JC, and Merkel cell polyomaviruses), and Chlamydia trachomatis (inverse variance weighted, P < .05). Notably, a meta-analysis of the integrated data highlighted the particularly high accuracy and consistency of the association with Merkel cell polyomavirus. Our MR analysis has clarified the causal relationships between specific pathogen infections and miscarriage, providing a critical foundation for the prevention and treatment of this adverse pregnancy outcome.

Inhibition of BCAT1 expression improves recurrent miscarriage by regulating cellular dysfunction and inflammation of trophoblasts

Sustained or chronic inflammation in the placenta can result in placental insufficiency, leading to adverse reproductive outcomes such as pregnancy loss. Branched-chain amino acid transaminase 1 (BCAT1) expresses in the placenta and is involved in the pathological inflammatory response, but its role in recurrent miscarriage (RM) has not been fully investigated. In the present study, we delved into the effects of BCAT1 on trophoblast inflammation induced by lipopolysaccharide (LPS) and a mouse model of pregnancy loss induced by LPS. In vitro, after the HTR-8/SVneo cells were treated with LPS and BCATc inhibitor 2 (a selective BCAT inhibitor), the cell apoptosis was verified by TUNEL assay, and the activity of caspase-3 and caspase-9 was detected. Real-time PCR, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence (IF) were used to determine the expression of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and inflammasomes (NLRP3 and ASC) in LPS-treated trophoblast cells. Western blot analysis was performed to verify the expression of phospho-IκBα (p-IκBα) in cells and NF-κB p65 in the nuclei. IF staining was used to detect the nuclear translocation of NF-κB p65. The DNA binding activity of NF-κB was detected by an electrophoretic mobility shift assay (EMSA). The results demonstrated that inhibition of BCAT1 reduced trophoblast apoptosis, suppressed the release of proinflammatory cytokines, and prevented NLRP3 inflammasome activation in response to LPS. Additionally, BCAT1 inhibition blocked the activation of the NF-κB pathway in trophoblasts. This study highlights the potential therapeutic role of targeting BCAT1 in preventing adverse reproductive outcomes associated with chronic placental inflammation.

Short term air pollution exposure during pregnancy and associations with maternal immune markers

BACKGROUND

Air pollution exposure during pregnancy has been associated with numerous adverse pregnancy, birth, and child health outcomes. One proposed mechanism underlying these associations is maternal immune activation and dysregulation. We examined associations between PM2.5 and NO2 exposure during pregnancy and immune markers within immune function groups (TH1, TH2, TH17, Innate/Early Activation, Regulatory, Homeostatic, and Proinflammatory), and examined whether those associations changed across pregnancy.

METHODS

In a pregnancy cohort study (n = 290) in Rochester, New York, we measured immune markers (using Luminex) in maternal plasma up to 3 times during pregnancy. We estimated ambient PM2.5 and NO2 concentrations at participants' home addresses using a spatial-temporal model. Using mixed effects models, we estimated changes in immune marker concentrations associated with interquartile range increases in PM2.5 (2.88 μg/m3) and NO2 (7.82 ppb) 0-6 days before blood collection, and assessed whether associations were different in early, mid, and late pregnancy.

RESULTS

Increased NO2 concentrations were associated with higher maternal immune markers, with associations observed across TH1, TH2, TH17, Regulatory, and Homeostatic groups of immune markers. Furthermore, the largest increases in immune markers associated with each 7.82 ppb increase in NO2 concentration were in late pregnancy (e.g., IL-23 = 0.26 pg/ml, 95% CI = 0.07, 0.46) compared to early pregnancy (e.g., IL-23 = 0.08 pg/ml, 95% CI = -0.11, 0.26).

CONCLUSIONS

Results were suggestive of NO2-related immune activation. Increases in effect sizes from early to mid to late pregnancy may be due to changes in immune function over the course of pregnancy. These findings provide a basis for immune activation as a mechanism for previously observed associations between air pollution exposure during pregnancy and reduced birthweight, fetal growth restriction, and pregnancy complications.

Serological and molecular survey of Toxoplasma Gondii in aborted livestock fetuses from Northeast Iran

BACKGROUND

Toxoplasmosis not only leads to abortion in humans but also in herbivores, which causes significant financial and quality-adjusted life-year losses. The present study aimed to determine the prevalence of toxoplasmosis in aborted fetuses via serological and molecular assays. Moreover, the genotypes of the obtained isolates were detected.

METHODS

Serological and molecular methods were used to study aborted fetuses from Bojnourd City, North Khorasan Province, Iran, which included 52 ovines and 16 bovines. Nested PCR of the B1 gene was used to detect parasite DNA in brain tissues. The PCR-RFLP method for the GRA6 gene was used to determine the genotype of T. gondii.

RESULTS

Out of 68 aborted fetuses, 16.1% showed the presence of anti-T. gondii IgG. Among these, 11.7% were identified in bovine fetuses and 4.4% in ovine fetuses. Additionally, two (2.94%) samples of ovine tested positive for anti-T. gondii IgM. Our PCR analysis detected parasite DNA in two cases (2.94%) among 11 IgG-positive samples. All obtained isolates belong to type I of T. gondii.

CONCLUSION

Infection with Type I of T. gondii during the neonatal period may partly be responsible for abortion and economic losses in livestock farming in our studied region. To understand the molecular epidemiology and genotypes of T. gondii associated with abortion, further evaluation of aborted samples from different geographical locations is necessary.

A Cross-Sectional Comparative Study of Vaginal Microbiota and Spontaneous Abortion at a Tertiary Care Hospital in North Karnataka, India

OBJECTIVE

To compare the vaginal microbiome in women who have undergone spontaneous abortion with a gestational age of less than 20 weeks to that of women who have a continued pregnancy of the same gestational age.

DESIGN

Cross-sectional comparative research design.

SETTING

The study was conducted in a tertiary care hospital of North Karnataka, India. In this rural area, many women lack awareness of prenatal care and women's health information. Given rising rates of spontaneous abortion, studying the impact of the vaginal microbiome on pregnancy outcomes is crucial for raising local awareness.

PARTICIPANTS

Two hundred women; 100 experienced spontaneous abortion within 20 weeks' gestation, and 100 maintained pregnancy with the same gestational age.

MEASURES

Vaginal swab was used to detect participants' vaginal microbiota. DNA was extracted from the vaginal samples; the 16S ribosomal RNA sequencing method was used to identify the organisms present.

RESULTS

A pathogen detection rate of 13.15% (n = 200 women) was found in vaginal cultures. The percentages of bacterial detection in women who had spontaneous abortion and those whose pregnancies continued were 19.9% and 7.9%, respectively (p < .05). Compared to women who sustained their pregnancy, women who experienced spontaneous abortion had five common species: Escherichia coli (48%), Enterococcus faecalis (28%), Enterococcus faecium (12%), Pseudomonas fluorescens (7%), and Pseudomonas cedrina (5%); the most prevalent species among those with sustained pregnancy were Lactobacillus iners (58%), Lactobacillus crispatus (32 %), and E. coli (10%; p < .05).

CONCLUSION

The vaginal microbiomes of women with spontaneous abortion were more varied and irregularly distributed with bacteria. The bacteria identified could affect a woman's pregnancy outcome and perhaps be associated with spontaneous abortion. It is vital for nurses to provide education to women who are in the fertile period regarding prenatal screening, sexually transmitted infections, and perineal care.

NLRP3 Inflammasome in the Pathogenesis of Miscarriages

Despite significant advances in prenatal medicine, spontaneous miscarriage remains one of the most common and serious pregnancy complications, affecting an increasing number of women. Since many aspects of the pathogenesis of spontaneous miscarriage remain unexplained, the aim of this study has been to assess the involvement of the NLRP3 inflammasome as a potential causative factor. The concentrations of NLRP3, IL-1β, IL-18, and cytochrome C in the serum of patients after miscarriage were measured by means of the immunoenzymatic method. In the placental tissue, the expression of NLRP3, IL-1β, IL-18, and Caspase-1 as well as that of the classical apoptosis biomarkers Fas, FasL, Bcl-2, and Ca was evaluated by means of immunohistochemistry techniques. Additionally, in whole blood, the concentrations of elements crucial for pregnancy progression, such as Ca, K, Mg, and Na, were examined by means of the ICP-OES method. Significantly higher concentrations of NLRP3 and IL-18 were demonstrated in the serum of patients with miscarriage as compared to the control group. In the placental tissue samples, a higher expression of IL-1β, IL-18, and Caspase-1 proteins was noted in women who had experienced miscarriage as compared to the control group. At the same time, a significantly lower expression of FasL and Bcl-2 proteins as well as Ca deposits was observed in women after miscarriage as compared to those with a normal pregnancy outcome. Significantly lower concentrations of Ca and K were recorded in the blood of patients with spontaneous miscarriage as compared to pregnant women. The analysis of the results x indicated a greater involvement of the inflammasome in women with spontaneous miscarriage associated with oxidative-antioxidative imbalance than in the case of miscarriage related to NET formation. Our research has provided evidence for the involvement of the inflammasome in the process of spontaneous miscarriage and identifies a new direction for diagnostics that includes NLRP3 as a preventive element in prenatal care, particularly in light of the steadily declining number of pregnancies and the increasing number of reproductive failures.

The Impact of Human Papillomavirus Infections on Recurrent Pregnancy Loss: A Review of the Literature

Human papillomavirus (HPV) infections are significantly associated with multiple adverse reproductive outcomes such as miscarriages. Pregnant women are more susceptible to an HPV infection and its prevalence increases as pregnancy progresses. In this present review, we summarize the existing evidence indicating the potential impact of an HPV infection on the occurrence of recurrent pregnancy loss (RPL). Comprehensive research of the literature was performed in the Medline/PubMed and Scopus databases. A total of 185 articles were identified and 40 full-text articles were assessed. Four studies were eligible to be included in this literature review. To our knowledge, this is the first review aiming to summarize the current state of evidence regarding the possible association of HPV infections and RPL. Recurrent pregnancy loss constitutes a distressing reproductive event and scientific research has made significant efforts to determine the causes and mechanisms that could lead to RPL. It is still unclear whether the papillomavirus infection is associated with an increased risk for recurrent miscarriages. Research in the field revealed conflicting results and their deductions are limited by methodological limitations. Given the high prevalence of HPV infections and their potential role in the occurrence of adverse outcomes during pregnancy, further research is required to clarify the possibility of an HPV infection being a potential risk factor for recurrent miscarriages.

Fetal Zika virus inoculation in macaques revealed control of the fetal viral load during pregnancy

BACKGROUND

Early pregnancy Zika virus (ZIKV) infection is associated with major brain damage in fetuses, leading to microcephaly in 0.6-5.0% of cases, but the underlying mechanisms remain largely unknown.

METHODS

To understand the kinetics of ZIKV infection during fetal development in a nonhuman primate model, four cynomolgus macaque fetuses were exposed in utero through echo-guided intramuscular inoculation with 103 PFU of ZIKV at 70-80 days of gestation, 2 controls were mock inoculated. Clinical, immuno-virological and ultrasound imaging follow-ups of the mother/fetus pairs were performed until autopsy after cesarean section 1 or 2 months after exposure (n = 3 per group).

RESULTS

ZIKV was transmitted from the fetus to the mother and then replicate in the peripheral blood of the mother from week 1 to 4 postexposure. Infected fetal brains tended to be smaller than those of controls, but not the femur lengths. High level of viral RNA ws found after the first month in brain tissues and placenta. Thereafter, there was partial control of the virus in the fetus, resulting in a decreased number of infected tissue sections and a decreased viral load. Immune cellular and humoral responses were effectively induced.

CONCLUSIONS

ZIKV infection during the second trimester of gestation induces short-term brain injury, and although viral genomes persist in tissues, most of the virus is cleared before delivery.

Antepartum Intimate Partner Violence: Development of a Risk Prediction Model

Objectives: To explore socio-behavioral, clinical, and imaging findings associated with antepartum intimate partner violence (IPV) and aid in risk stratification of at-risk individuals. Methods: We analyzed electronic medical records during indexed pregnancies for 108 pregnant patients who self-reported antepartum IPV (cases) and 106 age-matched pregnant patients who did not self-report antepartum IPV (controls). Sociodemographic, clinical, and radiology data were analyzed via chi-squared and Fisher's exact tests with p < 0.05 as the threshold for significance. Stepwise logistic regression was applied to derive a risk prediction model. Results: The proportion of cases reporting emotional IPV (76% vs. 52%) and/or physical IPV (45% vs. 31%) during pregnancy significantly increased from prior to pregnancy. Cases were significantly more likely to report prepregnancy substance use (odds ratio [OR] = 2.60; 95% confidence interval [CI]: 1.13-5.98), sexually transmitted infections (OR = 3.48; 95%CI: 1.64-7.37), abortion (OR = 3.17; 95%CI: 1.79, 5.59), and preterm birth (OR = 5.97; 95%CI: 1.69-21.15). During pregnancy, cases were more likely to report unstable housing (OR = 5.26; 95%CI: 2.67-10.36), multigravidity (OR = 2.83; 95%CI: 1.44-5.58), multiparity (OR = 3.75; 95%CI: 1.72-8.20), anxiety (OR = 3.35; 95%CI: 1.85-6.08), depression (OR = 5.58; 95%CI: 3.07-10.16), substance use (OR = 2.92; 95%CI: 1.28-6.65), urinary tract infection (UTI) (OR = 3.26; 95%CI: 1.14-9.32), intrauterine growth restriction (OR = 10.71; 95%CI: 1.35-85.25), and cesarean delivery (OR = 2.25; 95%CI: 1.26-4.02). Cases had significantly more OBGYN abnormalities on imaging and canceled more radiological studies (OR = 5.31). Logistic regression found housing status, sexually transmitted infection history, preterm delivery history, abortion history, depression, and antepartum UTI predictive of antepartum IPV. The risk prediction model achieved good calibration with an area under the curve of 0.79. Conclusions: This study identifies significant disparities among patients experiencing antepartum IPV, and our proposed risk prediction model can inform risk assessment in this setting.

Validation of the Revised Impact of Miscarriage Scale in the Republic of Burundi: A cross-sectional multicenter study

OBJECTIVE

The objective of this study was to translate and validate the Revised Impact of Miscarriage Scale (RIMS) into Kirundi for use among women and men in Burundi. Additionally, the study aimed to compare the experience and personal meaning of miscarriage between women and men.

METHODS

This is a cross-sectional multicentered study. The RIMS was translated into Kirundi. Cronbach coefficient alpha and its internal consistency were measured for both genders. An exploratory factor analysis (EFA) was used to determine the underlying factors and the shared variance. Both women and men completed the RIMS questionnaire, while women completed sociodemographic, reproductive and mental health questions.

RESULTS

In all, 79 couples completed the RIMS. The original factor structure was retained after the EFA, with 68% of the shared variance explained in the three-factor solution with 16 questions. Isolation/guilt, Loss of baby, and Devastating event. The internal consistency for women and men combined was α = 0.928. Although women scored higher on the factors of Isolation/guilt and Loss of baby, there were no significant differences in the Devastating event factor between women and men. Couples scores were positively correlated. Women who had experienced a previous miscarriage were more significantly impacted by all three factors compared to women experiencing their first miscarriage.

CONCLUSIONS

The Kirundi translation of the RIMS retained the original factor structure and demonstrated excellent internal consistency α = 0.928 in women and men combined. The RIMS could be a tool for caregivers to identify individuals who require additional support after a miscarriage.

Primary cilia abnormalities participate in the occurrence of spontaneous abortion through TGF-β/SMAD2/3 signaling pathway

Spontaneous abortion is the most common complication in early pregnancy, the exact etiology of most cases cannot be determined. Emerging studies suggest that mutations in ciliary genes may be associated with progression of pregnancy loss. However, the involvement of primary cilia on spontaneous abortion and the underlying molecular mechanisms remains poorly understood. We observed the number and length of primary cilia were significantly decreased in decidua of spontaneous abortion in human and lipopolysaccharide (LPS)-induced abortion mice model, accompanied with increased expression of proinflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. The length of primary cilia in human endometrial stromal cell (hESC) was significantly shortened after TNF-α treatment. Knocking down intraflagellar transport 88 (IFT88), involved in cilia formation and maintenance, promoted the expression of TNF-α. There was a reverse regulatory relationship between cilia shortening and TNF-α expression. Further research found that shortened cilia impair decidualization in hESC through transforming growth factor (TGF)-β/SMAD2/3 signaling. Primary cilia were impaired in decidua tissue of spontaneous abortion, which might be mainly caused by inflammatory injury. Primary cilia abnormalities resulted in dysregulation of TGF-β/SMAD2/3 signaling transduction and decidualization impairment, which led to spontaneous abortion.

Prevalence of and Factors Associated With Adverse Maternal Obstetrical Events Among Teenage Mothers Delivering in a Tertiary Referral Hospital in Southwestern Uganda

INTRODUCTION

Many female teenagers in low-resource settings conceive, of which half are unplanned and end in many deaths in sub-Saharan Africa, accounting for the majority of the cases. Teenage pregnancy is associated sometimes with poor maternal, newborn, and child deaths.

OBJECTIVES

 The aim of the study was to determine the prevalence, maternal obstetric outcomes, and factors associated with poor maternal obstetric outcomes among teenage mothers delivering at Mbarara Regional Referral Hospital.

METHODS

 This was a cross-sectional study carried out in a maternity ward at Mbarara Regional Referral Hospital, where 9,200 mothers deliver annually. All the women coming in for the delivery of their babies were consecutively approached for inclusion in the study. The women were enrolled in the post-delivery ward after delivery and interviewed with pretested questionnaires to capture the sociodemographic, obstetric, and medical profiles of the mothers. Factors were significant if the p-value was <0.05.  Results: Out of the 327 participants, the majority were rural dwellers (68.5%), married (75.8%), attained primary education (69.4%), had not used contraception (89%), and had had a planned pregnancy (63.3%). The prevalence of adverse maternal obstetrical events was 59.9%. The HIV-positive rate was 4.9%, and about half of the participants had delivered by cesarean section (41.6%). The participants' mean age was 18.4 years and SD 1.1. The mean number of antenatal care contacts attended was 4.59 and SD 1.9. The adverse maternal outcomes included episiotomy (30.9%), perineal tear (18.7%), premature rupture of membranes (10.1%), placenta abruption (5.2%), and pre-eclampsia/eclampsia (4%). Having a cesarean delivery was found to significantly reduce the occurrence of adverse maternal obstetric events among the participants by 97% (adjusted odds ratio (aOR) (95% CI) of 0.03 (0.02-0.06), p-value<0.001). Having a prior history of a miscarriage was significantly associated with the occurrence of adverse maternal obstetrical events among the participants (aOR (95% CI) of 6.55 (1.46-29.42), p-value0.014).

CONCLUSIONS

 Slightly more than half of the teenage mothers had adverse maternal obstetrical outcomes, and a history of a miscarriage in previous pregnancies was significantly associated with adverse maternal obstetrical outcomes. Having a cesarean delivery was found to significantly reduce the occurrence of adverse maternal obstetric events among the participants. Teenage mothers are at a high risk of adverse maternal obstetrical outcomes, and close antepartum and intrapartum surveillance is recommended.

COVID-19 and menstrual-related disturbances: a Spanish retrospective observational study in formerly menstruating women

Introduction

Four years after the start of the pandemic, there is limited evidence on the impact of COVID-19 on the women's health regardless of their reproductive status.

Objective

The aim was to analyze the prevalence and associated factors of menstrual-related disturbances in formerly menstruating women following SARS-CoV-2 infection.

Study design

A retrospective observational study of adult women in Spain was conducted during the month of December 2021 using an online survey (N = 17,512). The present analysis includes a subpopulation of SARS-CoV-2-infected and formerly menstruating women (n = 72). The collected data included general characteristics, medical history, and specific information on COVID-19. Chi-square and Mann-Whitney U-tests were performed. Bivariate logistic regression analysis was then performed to investigate possible associations between the occurrence of menstrual-related disturbances after SARS-CoV-2 infection.

Results

38.8% of participants experienced menstrual-related disturbances following COVID-19. Among these, unexpected vaginal bleeding (20.8%) was the most common event, followed by spotting (11.1%) ( Table 1). Other reported changes were in the length (shorter = 12.5%) and flow (heavier = 30.3%) of menstrual bleeding in comparison to their previous experience. Regression analysis revealed that being a perimenopausal woman [adjusted odds ratio (AOR) 4.721, CI 95%, 1.022-21.796, p = 0.047] and having a previous diagnosis of menorrhagia (AOR 5.824 CI 95%, 1.521-22.310, p = 0.010) were factors associated with the event.

Conclusion

These findings could help health professionals provide their patients with up-to-date scientific information to empower them to actively manage their reproductive health, especially in societies where menstrual health is still taboo.

Association between Abortion and All-Cause and Cause-Specific Premature Mortality: A Prospective Cohort Study from the UK Biobank

Background: Concerns have been raised about the increasing prevalence of both spontaneous and induced abortions worldwide, yet their effect on premature mortality remains poorly understood. We aimed to examine the associations between abortion and all-cause and cause-specific premature mortality, and the potential effect modification by maternal characteristics. Methods: Women aged 39 to 71 years at baseline (2006 to 2010) with prior pregnancies were derived from the UK Biobank and categorized as no abortion history, spontaneous abortion alone, induced abortion alone, and both spontaneous and induced abortions. All-cause and cause-specific mortality were ascertained through linkage to death certificate data, with premature death defined as occurring before the age of 70. Results: Of the 225,049 ever gravid women, 43,418 (19.3%) reported spontaneous abortion alone, 27,135 (12.1%) reported induced abortion alone, and 10,448 (4.6%) reported both spontaneous and induced abortions. During a median of 14.4 years of follow-up, 5,353 deaths were recorded, including 3,314 cancer-related and 1,444 cardiovascular deaths. Compared with no abortion history, spontaneous abortion alone was associated with an increased risk of all-cause premature mortality (adjusted hazard ratio [aHR] 1.10, 95% confidence interval [CI] 1.02 to 1.17), and induced abortion alone was associated with increased risks of all-cause (aHR 1.12, 95% CI 1.04 to 1.22) and cardiovascular mortality (aHR 1.27, 95% CI 1.09 to 1.48). The aHRs for all-cause and cardiovascular mortality were higher for recurrent abortions, whether spontaneous or induced (P trend < 0.05). The increased risk of all-cause mortality associated with induced abortion was higher in women with hypertensive disorders of pregnancy than in those without (40% vs. 9%, P interaction = 0.045). Conclusions: Either spontaneous or induced abortion alone was associated with an increased risk of premature mortality, with induced abortion alone particularly linked to cardiovascular death. Future studies are encouraged to explore the underlying mechanisms.

Re-examining the adaptive function of nausea and vomiting in pregnancy

Nausea and vomiting in pregnancy (NVP) have been proposed to have a prophylactic function. In this review, I re-examine NVP from an evolutionary perspective in light of new research on NVP. First, current evidence suggests that the observed characteristics of NVP does not align well with a prophylactic function. Further, NVP is typically associated with high costs for pregnant women, while moderate-to-severe NVP is associated with increased risks of poorer foetal/birth outcomes. In contrast, mild NVP limited to early pregnancy may associate with improved foetal outcomes-indicating a potential evolutionary benefit. Second, researchers have recently identified growth differentiation factor 15 (GDF15) to cause NVP, with implications that low-levels of pre-conception GDF15 (associated with lower cellular stress/inflammation) may increase risks/symptoms of NVP. If so, NVP in contemporary post-industrialized populations may be more severe due to environmental mismatch, and the current symptomology of NVP in such populations should not be viewed as a typical experience of pregnancy.

Consensus Statements for Assessment and Management of Threatened Miscarriage in the First Trimester in Pakistan: A Three-Step Modified Delphi Approach

BACKGROUND AND OBJECTIVE

It aimed to develop an expert consensus regarding the risk assessment, diagnosis, and threatened miscarriage management during the first trimester in Pakistan.

METHODS

A three-step modified Delphi method was applied to develop the consensus. Eleven specialized obstetricians and gynecologists participated in its development. If 75% or higher agreement level was attained on each assertion, it was declared as a consensus.

RESULTS

Age of 35 or above, previous history of two or more previous miscarriages, and direct strong trauma were considered to be threatened miscarriage risk factors. Infection was discussed and specified to include specific infectious diseases, like malaria, and COVID-19 as a risk factor. The experts agreed from the first time on considering endocrinological disorders, thrombophilia, and lifestyle variables as threatened miscarriage risk factors. They proposed adding a statement concerning acquired thrombophilia which was accepted unanimously. Finally, experts agreed on the importance of educating pregnant women about factors whose risk can be modified by modifying their behavior. As for diagnosis statements, it was agreed to be trifold: physical examination, imaging, and laboratory testing. Physical examination included abdominal and pelvic exams but focused more on vaginal examination with speculum to identify bleeding severity and etiology. The statements regarding the imaging approaches to diagnose threatened miscarriage in the first trimester achieved a consensus in most statements. TVS was recommended to check on uterine structural abnormalities, fetus viability focusing on heartbeat and crown-to-rump length, gestation sac size and emptiness, subchorionic hematoma, and ectopic pregnancy. Each was defined on how to identify and diagnose in separate statements. Statements about laboratory tests indicated the need for human chorionic gonadotropin hormone assessment whether serial or once is dependent on the ultrasound. Recommended hematologic investigations include complete blood count for anemia, Rh factor for potential bleeding risk and in special cases, thrombophilia assessment is undertaken. The first and foremost management aspect was follow-up while most management statements were controversial, and some were altogether removed with only some reaching agreement after discussion.

CONCLUSION

These consensus statements aggregated the best available evidence and experts' opinion-supported statements to improve patient education, risk assessment, diagnosis, and evaluation as well as management of threatened miscarriage during the first trimester in Pakistan.

Mammalian placental explants: A tool for studying host-parasite interactions and placental biology

The placenta plays a critical role in host-pathogen interactions. Thus, ex vivo infection of mammalian placental explants is an excellent and simple method to study the mechanisms of cellular and tissue invasion by different pathogens in different mammalian species. These explants can be maintained in culture for several days, preserving the tissue architecture and resembling in-utero conditions under more physiological conditions than their isolated counterparts in isolated cell culture models. In addition, placental explants not only allow us to study how the placenta responds and defends itself against various infections but also provide a versatile platform for advancing our understanding of placental biology and the immune response. Furthermore, they serve as powerful tools for drug discovery, facilitating the screening of potential therapeutics for placental infections and for the identification of diagnostic markers. This review highlights the utility of mammalian placental explants in studying the host-pathogen interaction of two relevant protozoan parasites, Trypanosoma cruzi, the causative agent of Chagas disease, and Toxoplasma gondii, the etiological agent of Toxoplasmosis. Here, we discuss the different methodologies and technical aspects of the model, as well as the effect of both parasites on placental responses in human, canine, and ovine explants.

Mechanisms of YAP1-mediated trophoblast ferroptosis in recurrent pregnancy loss

PURPOSE

The purpose of our study is to investigate the function of YAP1 in the trophoblast ferroptosis and maternal-fetal interface communication of RPL.

METHODS

We collected 25 villous tissues and detected the expression of YAP1. Cell counting kit-8 assay, scratch wound-healing assay, and Matrigel invasion assay were performed to observe the proliferation, migration, and invasion of HTR-8/SVneo and JAR cells. Subsequently, measured the levels of reactive oxygen species (ROS), malondialdehyde (MDA), reduced glutathione (GSH), SLC7A11, SOD2, and GPX4. Ultimately, the use of ferroptosis activator (erastin) and inhibitor (Ferrostatin-1, fer-1) further confirmed the regulation by YAP1. In addition, established an in vitro-induced cell model to study the effect of YAP1 on the decidualization process. Finally, animal models were implemented for further confirmation.

RESULTS

We found that YAP1 was downregulated in RPL patients. Overexpression of YAP1 could significantly enhance the proliferation, migration, and invasion of trophoblasts, and inhibit ferroptosis. Knocking down YAP1 exhibited the opposite effect. Rescue experiments have shown that YAP1 could upregulate the expression of SLC7A11 and GPX4, which are key molecules in the classic pathway of ferroptosis. In addition, the decidualization was impaired when hESCs were treated with conditioned medium of YAP1 knockdown trophoblasts. Moreover, we found that Yap1, Slc7a11, and Gpx4 were downregulated in the RPL mice, along with increased MDA and decreased GSH.

CONCLUSION

Downregulation of YAP1 induces ferroptosis, thereby damaging the trophoblast invasion processes, which also disturbs the communication at the maternal-fetal interface. Our study identified YAP1 as a potential key molecule in the pathogenesis of RPL.

Miscarriage and stillbirth in relation to risk of cardiovascular diseases: A systematic review and meta-analysis

INTRODUCTION

The relationship between pregnancy loss and the risk of cardiovascular diseases (CVDs) remains a matter of debate. Our intention in conducting this meta-analysis was to analyze the relationship between miscarriage and stillbirth and risk of CVDs.

METHODS

PubMed, Embase, and Web of Science were systematically searched up to May 30, 2023 for all relevant studies. The random-effects model was applied to estimate the pooled relative risks (RRs) and 95% confidence intervals (95% CIs). We evaluated RR estimates for the risk of CVDs with each additional miscarriage and stillbirth through generalized least squares regression.

RESULTS

Twenty-three articles were incorporated into the meta-analysis. For women with a history of miscarriage, the pooled RRs for the risk of total CVDs, coronary heart disease (CHD), stroke, and total CVD deaths were 1.16 (95 % CI 1.10-1.22), 1.26 (1.12-1.41), 1.13 (1.03-1.24), and 1.20 (1.01-1.42), respectively. For women with a history of stillbirth, the pooled RRs for the risk of total CVDs, CHD, stroke, and total CVD deaths were 1.60 (1.34-1.89), 1.30 (1.12-1.50), 1.37 (1.06-1.78), and 1.95 (1.05-3.63), respectively. With each additional miscarriage, the risk increased for total CVDs (1.08, 1.04-1.13), CHD (1.08, 1.04-1.13), and stroke (1.05, 1.00-1.10). With each additional stillbirth, the risk increased for total CVDs (1.11, 1.03-1.21) and CHD (1.13, 1.07-1.19).

CONCLUSION

This meta-analysis indicates that both miscarriages and stillbirths are related to a higher risk of total CVDs, CHD, stroke, and total CVD deaths. The risk of total CVDs and CHD increased with the number of miscarriages or stillbirths.

Aberrant CD8+T cells drive reproductive dysfunction in female mice with elevated IFN-γ levels

Introduction

Interferon-gamma (IFN-γ) is pivotal in orchestrating immune responses during healthy pregnancy. However, its dysregulation, often due to autoimmunity, infections, or chronic inflammatory conditions, is implicated in adverse reproductive outcomes such as pregnancy failure or infertility. Additionally, the underlying immunological mechanisms remain elusive.

Methods

Here, we explore the impact of systemic IFN-γ elevation on cytotoxic T cell responses in female reproduction utilizing a systemic lupus-prone mouse model with impaired IFN-γ degradation.

Results

Our findings reveal that heightened IFN-γ levels triggered the infiltration of CD8+T cells in the pituitary gland and female reproductive tract (FRT), resulting in prolactin deficiency and subsequent infertility. Furthermore, we demonstrate that chronic IFN-γ elevation increases effector memory CD8+T cells in the murine ovary and uterus.

Discussion

These insights broaden our understanding of the role of elevated IFN-γ in female reproductive dysfunction and suggest CD8+T cells as potential immunotherapeutic targets in female reproductive disorders associated with chronic systemic IFN-γ elevation.

The Association between Histidine-Rich Glycoprotein rs10770 Genotype and Recurrent Miscarriage in Iranian Women

Purpose

Recurrent miscarriage (RM) is a significant reproductive concern affecting numerous women globally. Genetic factors are believed to play a crucial role in RM, making the histidine-rich glycoprotein (HRG) gene, a topic of interest due to its potential involvement in angiogenesis. This study is aimed at investigating the association between the HRG rs10770 genotype and RM.

Method

Blood samples were collected from a total of 200 women at the beginning of the study. Subsequently, a comparative analysis was conducted between the blood samples of 100 women with a history of RM (case group) and the blood samples of another 100 healthy women (control group). HRG rs10770 genotyping was performed through polymerase chain reaction restriction-fragment length polymorphism (PCR-RFLP), followed by statistical analysis to evaluate the relationship between HRG rs10770 genotype and RM.

Results

The results indicated a significant statistical difference between the C/C genotype (OR = 3.32, CI: 1.22-9.04, p = 0.01) and the C/T genotype (OR = 1.24, CI: 0.67-2.30, p = 0.47) in both the case and control groups. Additionally, a significant correlation was observed in the C allelic frequency among RM participants compared to the control group (OR = 1.65, CI: 1.06-2.58, p = 0.02).

Conclusion

The study highlights the importance of HRG rs10770 in understanding RM, shedding light on its implications for reproductive health. Furthermore, it became evident that women carrying the homozygous C/C genotype exhibited increased susceptibility to the risk of RM.

Collateral Damage in the Placenta during Viral Infection in Pregnancy: A Possible Mechanism for Vertical Transmission and an Adverse Pregnancy Outcome

In mammals, the placenta is a connection between a mother and a new developing organism. This tissue has a protective function against some microorganisms, transports nutrients, and exchanges gases and excretory substances between the mother and the fetus. Placental tissue is mainly composed of chorionic villi functional units called trophoblasts (cytotrophoblasts, the syncytiotrophoblast, and extravillous trophoblasts). However, some viruses have developed mechanisms that help them invade the placenta, causing various conditions such as necrosis, poor perfusion, and membrane rupture which, in turn, can impact the development of the fetus and put the mother's health at risk. In this study, we collected the most relevant information about viral infection during pregnancy which can affect both the mother and the fetus, leading to an increase in the probability of vertical transmission. Knowing these mechanisms could be relevant for new research in the maternal-fetal context and may provide options for new therapeutic targets and biomarkers in fetal prognosis.

Higher Cumulative Live Birth Rate but Also Higher Late Miscarriage Risk in Non-Obese Women with Polycystic Ovary Syndrome Undergoing the First IVF/ICSI Cycle

Purpose

To determine the impact of polycystic ovary syndrome on in vitro fertilization/intracytoplasmic sperm injection and embryo transfer outcomes while analyzing the influencing factors.

Patients and Methods

A retrospective cohort study comprised 4839 patients who underwent their first cycle of IVF/ICSI treatment from January 2016 to December 2021. Cumulative pregnancy rates, cumulative live birth rates, and late miscarriage rates compared between the PCOS group and control group. Subgroup analysis and binary regression were used to analyze the influence of BMI on clinical outcomes among individuals diagnosed with PCOS.

Results

Non-obese PCOS patients exhibited higher cumulative pregnancy rates, cumulative live birth rates, and late miscarriage rates compared to the control group with the normal BMI population (84.7% vs71.2%, P < 0.001; 74.1% vs 61.6%, P < 0.001; 4.1% vs 2.0%, P = 0.002), but there was no significant difference in early miscarriage rates between the two groups.

Conclusion

Non-obese PCOS patients demonstrated a notably higher cumulative live birth rate but also a higher risk of late miscarriage compared to non-PCOS females with a normal BMI.

Expression and clinical significance of miR-141-5p as a biomarker in the serum of patients with early spontaneous abortion

AIM

miR-141-5p expression in patients with Early Spontaneous Abortion (ESA) and its correlation with hormone levels during pregnancy were investigated.

METHODS

A total of 70 pregnant women with ESA were selected as the research group, and 70 normal pregnant women who chose abortion for non-medical reasons were selected as the Con group. Serum β-HCG, Progesterone (P), and Estrogen (E2) were detected by enzyme-linked immunosorbent assay. Differentially expressed miRNAs were screened by miRNA microarray analysis. miR-141-5p expression was detected by RT-qPCR, and its correlation with serum β-HCG, P, and E2 levels was analyzed. The diagnostic value of miR-141-5p for ESA was evaluated by the ROC curve.

RESULTS

Serum β-HCG, P, and E2 were decreased and serum miR-141-5p was increased in patients with ESA. Pearson correlation analysis showed that serum β-HCG, P, and E2 levels were negatively correlated with miR-141-5p expression levels. ROC curve showed that miR-141-5p had a diagnostic value for ESA.

CONCLUSIONS

miR-141-5p is related to hormone levels during pregnancy and is expected to become a new candidate diagnostic marker for ESA.

Molecular examination for Coxiella burnetii and Brucella spp. infections in Iranian women experiencing spontaneous miscarriage

BACKGROUND

Spontaneous miscarriage, a leading health concern globally, often occurs due to various factors, including infections. Among these, Coxiella burnetii and Brucella spp. may have adverse effects on pregnancy outcomes. While previous research has established a link between infections and spontaneous miscarriage, our study aimed specifically to investigate the presence of these two pathogens in abortion samples from women who experienced spontaneous miscarriages in Iran. Our study can add to the existing knowledge by focusing on Iran, a region with a high prevalence of C. burnetii and Brucella spp. As a result, it could provide a better understanding and unique insights into the relationship of these pathogens with spontaneous miscarriages in endemic regions.

METHODS

From March 2021 to March 2022, a total of 728 abortion samples (including placenta and cotyledon) were collected from 409 women who had experienced spontaneous miscarriages in the provinces of Tehran, Fars, and West Azerbaijan in Iran. The specimens included 467 Formalin-Fixed Paraffin-Embedded (FFPE) and 261 fresh frozen samples. After DNA extraction from abortion samples, the quantitative real-time PCR (qPCR) assay targeted a specific fragment of the IS1111 and IS711 elements for molecular identification of C. burnetii and Brucella spp., respectively. Furthermore, the qPCR assay employing specific primers for different species was used to determine the species of Brucella.

RESULTS

Among the studied women, 1 out of 409 (0.24%) samples tested positive for Brucella spp., specifically Brucella melitensis. There were no positive specimens for C. burnetii.

CONCLUSIONS

Our study contributes to understanding the potential involvement of Brucella species in spontaneous infectious abortion within endemic regions. The identification of B. melitensis in this study highlights the need for further research in this area. However, while our results suggest a relatively low or zero identification of these pathogens in our sample population, this does not rule out the possibility of undetected infections. Therefore, it is critical to acknowledge the limitations of the molecular techniques used (qPCR), which may have potential limitations such as sensitivity and specificity. Moreover, because 64.15% of our samples were FFPE, the sensitivity of the qPCR test may be reduced. These raise concerns about the accuracy of the reported prevalence rates and the potential for false positives or negatives.

Melatonin: the placental antioxidant and anti-inflammatory

Melatonin (N-acetyl-5-methoxytryptamine) is an indolamine hormone with many physiological and biological roles. Melatonin is an antioxidant, anti-inflammatory, free radical scavenger, circadian rhythm regulator, and sleep hormone. However, its most popular role is the ability to regulate sleep through the circadian rhythm. Interestingly, recent studies have shown that melatonin is an important and essential hormone during pregnancy, specifically in the placenta. This is primarily due to the placenta's ability to synthesize its own melatonin rather than depending on the pineal gland. During pregnancy, melatonin acts as an antioxidant and anti-inflammatory, which is necessary to ensure a stable environment for both the mother and the fetus. It is an essential antioxidant in the placenta because it reduces oxidative stress by constantly scavenging for free radicals, i.e., maintain the placenta's integrity. In a healthy pregnancy, the maternal immune system is constantly altered to accommodate the needs of the growing fetus, and melatonin acts as a key anti-inflammatory by regulating immune homeostasis during early and late gestation. This literature review aims to identify and summarize melatonin's role as a powerful antioxidant and anti-inflammatory that reduces oxidative stress and inflammation to maintain a favorable homeostatic environment in the placenta throughout gestation.

Assisted reproduction after SARS-CoV-2-infection: results of a single-center cohort-study

PURPOSE

The effects of SARS-CoV-2 infections on the outcome of assisted reproduction techniques (ART) were studied in a retrospective cohort study.

METHODS

The outcome of 1581 treatment cycles with embryo transfer at a university fertility center in Germany was compared in years before and during the COVID-19 pandemic. For 335 treatment cycles in 2022 a detailed analysis was carried out depending on infection and immunization status of both partners.

RESULTS

ART cycles did not differ in most of the parameters examined between 2018-2022. In spite of comparable clinical pregnancy rates, there was a significantly higher miscarriage rate at 34.6% (27/78) in 2022, compared to 19.7% (29/147) in the pre-pandemic years of 2018-2019 (p = 0.014). In 37.0% of the treatment cycles (124/335) 2022 at least one partner reported a SARS-CoV-2-Infection 6 months before ART, mostly with the virus variant Omicron. Clinical pregnancy rates were lower in cycles without infection. Comparing women with confirmed infection to no infection, a significantly higher risk of miscarriage was seen (62.5% vs. 26.2%, p = 0.009). In treatment cycles of partners with basic immunization against SARS-CoV-2 a statistically significant increase of pregnancy rates was seen comparing to cycles with both unvaccinated partners (p = 0.011).

CONCLUSION

The results indicate a negative impact of SARS-CoV-2-infections up to 6 months on ART treatment, in particular an increased risk of miscarriage. Vaccination was associated with a better outcome of ART treatment.

Association Between Herpes Simplex Virus II Infection and Rheumatoid Arthritis in US Adults: A Population-Based Propensity Score-Matching Study

BACKGROUND/OBJECTIVE

The potential correlation between herpes simplex virus (HSV) and human papillomavirus (HPV) infections and rheumatoid arthritis (RA) has not been definitively established. Further research is needed to determine the relationship between the development of RA and the presence of these viral infections.

METHODS

A case-control study was conducted with data from the National Health and Nutrition Examination Survey between 2009 and 2014. Our analysis examined the association between HSV I, HSV II, HPV oral polymerase chain reaction (PCR), HPV vaginal PCR, and RA. We identified adults aged 20 to 49 years with a primary diagnosis of RA using the National Health and Nutrition Examination Survey database codes (MCQ191 = 1 [years 2009-2010]; MCQ195 = 2 [years 2011-2014]) and excluded patients with incomplete data on key variables and primary outcomes.

RESULTS

The study included 8620 patients, with 150 patients diagnosed with RA and 1500 patients without RA. Patients with RA had a significantly higher prevalence of HSV II infection compared with those without RA (36.34% vs. 24.72%, p = 0.015) after propensity score matching. No significant differences were observed for HSV I, HPV oral PCR, and HPV vaginal PCR between the 2 groups. Patients with RA were older; were more likely to be female, obese, and non-Hispanic White; and had a higher prevalence of comorbidities than those without RA.

CONCLUSIONS

This population-based propensity score-matching study provides evidence of an association between HSV II infection and RA in US adults. Further research is needed to fully elucidate the relationship between viral infections and RA, with the aim of developing effective risk reduction strategies and innovative treatments for RA.

Maternal and neonatal complications after IVF/ICSI-fresh embryo transfer in low-prognosis women under the POSEIDON criteria: a retrospective cohort study

BACKGROUND

Several studies on pregnancy complications of poor ovarian response (POR) patients did not draw a consistent conclusion. The POSEIDON criteria introduces the concept of "low prognosis" and divides POR patients into four groups based on age, AFC and AMH for individualized management. We analyzed low-prognosis population and patients with regular ovarian response, compared maternal and neonatal complications and discussed the relevant risk factors.

METHODS

A retrospective cohort study was conducted of females who achieved a singleton clinical pregnancy after IVF / ICSI-fresh embryo transfer in a single center from January 2014 to March 2019. Participants with low prognosis, as defined by the POSEIDON criteria, were enrolled in the study groups. The controls were defined as AFC ≥ five and number of retrieved oocytes > nine. Maternal and neonatal complications were compared among those groups.

RESULTS

There were 2554 cycles in POSEIDON group 1, 971 in POSEIDON group 2, 141 in POSEIDON group 3, 142 in POSEIDON group 4, and 3820 in Control. Univariate analysis roughly showed that Groups 2 and 4 had an increased tendency of pregnancy complications. Multi-variable generalized estimating equations (GEE) analysis showed that the risks of GDM, total pregnancy loss, and first-trimester pregnancy loss in Groups 2 and 4 were significantly higher than in Control. The risk of hypertensive disorders of pregnancy (HDP) in Groups 2 and 3 increased, and Group 4 had an increased tendency without statistical significance. After classification by age, GEE analysis showed no significant difference in risks of all complications among groups ≥ 35 years. In patients < 35 years, the risk of HDP in POSEIDON group 3 was significantly higher than in controls (< 35 years), and there was no significant increase in the risk of other complications.

CONCLUSION

Compared to patients with regular ovarian response, low-prognosis population have increased tendency of maternal and neonatal complications. In low-prognosis patients, advanced age (≥ 35 years) might be the predominant risk factor for pregnancy complications. In those < 35 years, poor ovarian reserve could contribute to HDP.

No Baby to Bring Home: Perinatal Loss, Infertility, and Mental Illness-Overview and Recommendations for Care

PURPOSE OF REVIEW

Update readers on the state of the research on mental health, perinatal loss, and infertility with a focus on providing a comprehensive overview to empower clinicians in treating this population.

RECENT FINDINGS

Rates of psychiatric illness are increased in people that experience perinatal loss and infertility. The research remains largely below the clear need for focused screening, prevention, and treatment. Clinicians and researchers need to remain attuned to the impact of perinatal loss and infertility on the mental health of patients and families. Screening, referral, and expanded therapeutic and psychiatric resources are imperative to improving the well-being of these patients and families.

Association of serum levels of vascular endothelial growth factor and placental growth factor in early threatened abortion and premature delivery: A case‑control study

Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) serve key roles in the regulation of vascular development, revascularization and vasopermeability in the endometrium, decidua and trophoblasts. Furthermore, both VEGF and PlGF are modulators of embryonic vascular development. Thus, the present study aimed to investigate the serum levels of VEGF and PlGF in female patients with early threatened abortion (TA) who experienced preterm delivery. The present case-control study included 130 pregnant patients with or without TA that were admitted to The Maternal and Childcare Hospital of Nantong University from January 2019 to January 2022. Patients were divided into two groups: i) Group A, which included 55 patients diagnosed with TA with slight vaginal bleeding and closed cervical internal os within the first 6-12 weeks of pregnancy; and ii) group B, which included 75 patients with healthy asymptomatic pregnancy. Blood samples were obtained from all patients and VEGF and PlGF levels were examined prior to treatment, and the chi-squared, Student's t-test and two-way ANOVA followed by Bonferroni's post hoc analysis were used to analyze statistical differences between the two patient groups. Results of the present study demonstrated that patients with TA had significantly lower levels of VEGF and PlGF, compared with the controls. In patients with or without TA, the levels of serum PlGF in the preterm delivery group were significantly decreased compared with patients that did not experience preterm delivery. However, there was no significant difference in the levels of VEGF between patients with or without preterm delivery. In addition, lower levels of PlGF, compared with those in patients without TA, may be associated with an increased risk of preterm delivery in patients without early TA.

Role of infections in miscarriage

Infections with certain pathogens can lead to perinatal complications. Several infections have been also associated with an increased likelihood of miscarriage. This manuscript discusses these infections, their modes of transmission, the evidence linking them to an increased risk of miscarriage, and whether prevention or treatment strategies are available.

Prevalence and risk factors of Toxoplasma gondii infection among women with miscarriage and their aborted fetuses in the northwest of Iran

Toxoplasmosis is a worldwide disease of various animals and human and results from infection with the Toxoplasma gondii parasite. Abortion and congenital defects are important consequences of the T. gondii infection. The aim of this study was to determine the Toxoplasma-induced abortions among women with miscarriage and the presence of T. gondii in their aborted fetuses in Urmia, the northwest of Iran. This cross-sectional study was conducted with 215 women with abortion and their aborted fetuses, from 2020 to 2021. Seroprevalence of anti-Toxoplasma IgG and IgM were determined using the sera of the aforesaid women. Nested PCR was carried out using RE-529 gene sequences, and sequencing was performed using the T. gondii GRA6 gene on the remnant of pregnancy after abortion. The tissue positive samples were then subjected to another PCR on GRA6 gene and sequenced for genotyping. Among 215 serum samples of women with abortion, 70 (32.6%) were positive for anti-Toxoplasma IgG, and three (1.4%) were positive for IgM. The RE-529 sequence of T. gondii was positive in three (1.4%) of the aborted fetuses. The analysis of GRA6 gene indicated that all three positive samples carried a GRA6 allele (GRA6I) of T. gondii type I genotype. Our findings suggest that T. gondii is one of the causative agents of spontaneous abortion in West Azerbijan Province, the northwest of Iran.

Role of the vaginal microbiome in miscarriage: exploring the relationship

Miscarriage is a devastating pregnancy loss that affects many women worldwide. It is characterized as a spontaneous miscarriage that occurs before 20 weeks of gestation which affects more than 25% of pregnancies. While the causes of miscarriage are complex and multifactorial, recent research has suggested a potential role of the vaginal microbiota. The vaginal microbiome is a dynamic ecosystem of microbes that are essential for preserving vaginal health and avoiding infections. Vaginal dysbiosis has been accompanied with numerous adverse pregnancy complications, such as preterm birth. However, the effect of the vaginal microbiome in miscarriage is not fully understood. This review aims to investigate the link between vaginal microbiota and miscarriage. Also, we investigate the various mechanisms through which the vaginal microbiota may affect miscarriage. Additionally, we examine the implications of these research findings, specifically the possibility of vaginal microbiome screening and targeted interventions to prevent miscarriage.

Endometrial responses to bacterial and viral infection: a scoping review

BACKGROUND

The endometrium is a highly dynamic tissue that undergoes dramatic proliferation and differentiation monthly in order to prepare the uterus for implantation and pregnancy. Intrauterine infection and inflammation are being increasingly recognized as potential causes of implantation failure and miscarriage, as well as obstetric complications later in gestation. However, the mechanisms by which the cells of the endometrium respond to infection remain understudied and recent progress is slowed in part owing to similar overlapping studies being performed in different species.

OBJECTIVE AND RATIONALE

The aim of this scoping review is to systematically summarize all published studies in humans and laboratory animals that have investigated the innate immune sensing and response of the endometrium to bacteria and viruses, and the signaling mechanisms involved. This will enable gaps in our knowledge to be identified to inform future studies.

SEARCH METHODS

The Cochrane Library, Ovid Embase/Medline, PubMed, Scopus, Google Scholar, and Web of Science databases were searched using a combination of controlled and free text terms for uterus/endometrium, infections, and fertility to March 2022. All primary research papers that have reported on endometrial responses to bacterial and viral infections in the context of reproduction were included. To focus the scope of the current review, studies in domesticated animals, included bovine, porcine, caprine, feline, and canine species were excluded.

OUTCOMES

This search identified 42 728 studies for screening and 766 full-text studies were assessed for eligibility. Data was extracted from 76 studies. The majority of studies focused on endometrial responses to Escherichia coli and Chlamydia trachomatis, with some studies of Neisseria gonorrhea, Staphylococcus aureus, and the Streptococcus family. Endometrial responses have only been studied in response to three groups of viruses thus far: HIV, Zika virus, and the herpesvirus family. For most infections, both cellular and animal models have been utilized in vitro and in vivo, focusing on endometrial production of cytokines, chemokines, and antiviral/antimicrobial factors, and the expression of innate immune signaling pathway mediators after infection. This review has identified gaps for future research in the field as well as highlighted some recent developments in organoid systems and immune cell co-cultures that offer new avenues for studying endometrial responses to infection in more physiologically relevant models that could accelerate future findings in this area.

WIDER IMPLICATIONS

This scoping review provides an overarching summary and benchmark of the current state of research on endometrial innate immune responses to bacterial and viral infection. This review also highlights some exciting recent developments that enable future studies to be designed to deepen our understanding of the mechanisms utilized by the endometrium to respond to infection and their downstream effects on uterine function.

Decidualization dampens toll-like receptor mediated inflammatory responses in human endometrial stromal cells by upregulating IκBα

Endometrial stromal cells (EnSCs) are the major cell type of the human endometrium and they undergo dramatic differentiation, termed decidualization, every month that enables them to be receptive to implantation. Appropriate decidualization and EnSC function is key for a successful pregnancy. EnSC function may be affected when the uterus is exposed to bacterial and viral infection. However, how human EnSCs respond to viral and bacterial components have not been well-studied and it remains unclear whether uterine innate immune responses change during decidualization. This study demonstrated that viral double-stranded RNA [Poly(I:C)] and bacterial lipopolysaccharide (LPS) upregulated undecidualized human EnSC production of a large array of proinflammatory cytokines and chemokines, and revealed that these immune responses were significantly dampened during decidualization in vitro and in vivo. This dampened response was associated with increased NFKBIA transcription during decidualization that leads to the accumulation of this negative regulator in decidualizing EnSCs that can bind to NFκB p65 and prevents its nuclear translocation and downstream Toll-like receptor signaling. These findings highlight that endometrial responses to infection may vary at different stages of the menstrual cycle which may be important for preparing the endometrium to support the growth of the semi-allogenic blastocyst. This work emphasizes the need to consider menstrual cycle stage, sex hormone levels and the differentiation status of cells when examining inflammatory responses in the future.