Effectiveness and potential mechanisms of intralipid in treating unexplained recurrent spontaneous abortion

Decrease in peripheral natural killer cell level during early pregnancy predicts live birth among women with unexplained recurrent pregnancy loss: a prospective cohort study

BACKGROUND

Previous studies have suggested that trophoblast cells inhibit the proliferation of peripheral natural killer cells and that the level of peripheral natural killer cells decrease in the middle and late pregnancy stage among healthy women. The change in peripheral natural killer cell level during early pregnancy and the relationship between the change in peripheral natural killer cell level and pregnancy outcomes among women with unexplained recurrent pregnancy loss have not been sufficiently explored.

OBJECTIVE

This study aimed to characterize the level of prepregnancy peripheral natural killer cells in comparison with those in early pregnancy among women with unexplained recurrent pregnancy loss and to determine if the change in the level of peripheral natural killer cells from prepregnancy to early pregnancy can predict pregnancy outcomes.

STUDY DESIGN

In this prospective cohort study, 1758 women with recurrent pregnancy loss were recruited between January 2017 and December 2021 among whom 252 women with unexplained recurrent pregnancy loss had prepregnancy and early pregnancy (4-6 weeks gestation) peripheral natural killer cell measurements. These 252 women were divided into 2 groups, namely those with a lower gestational peripheral natural killer cell level (group 1) when compared with prepregnancy levels and those who did not (group 2). The respective outcomes of these groups in terms of live birth and pregnancy loss were comparatively analyzed using chi-square and Student's t tests. Candidate factors that could influence live birth were selected using the Akaike information criterion. The participates were then randomly divided into training and testing groups. A multivariable logistic regression analysis was performed and a nomogram was created to assess the possibility of live birth. The predictive accuracy was determined by the area under the receiver operating characteristic curve and validated by plotting the predicted probabilities and the observed probabilities. A Hosmer-Lemeshow test was used to assess the goodness of fit.

RESULTS

When early gestational peripheral natural killer cell levels were compared with prepregnancy peripheral natural killer cell levels, 61.5% (154) of women had a comparatively lower early-gestational peripheral natural killer cell level and 38.9% (98) of women had an increase or no change in the peripheral natural killer cell level. The live birth rate in group 1 was 89.0% (137/154), which was significantly higher than the rate of 49.0% (48/98) in group 2 (P<.001). A decrease in the peripheral natural killer cell level (odds ratio, 1.36; 95% confidence interval, 1.22-1.55; P<.001) and the anti-Muellerian hormone level (odds ratio, 1.41; 95% confidence interval, 1.14-1.81; P=.003) were important predicting factors for a higher live birth rate. Female body mass index (odds ratio, 0.97; 95% confidence interval, 0.82-1.15; P=.763) and parity (odds ratio, 1.61; 95% confidence interval, 0.71-4.12; P=.287) also were predicting factors. Furthermore, the area under the receiver operating characteristic curve of the model to diagnose of live birth was 0.853 with a sensitivity of 81.6% and a specificity of 78.0% using the training data set. And the Hosmer-Lemeshow test showed that the model was a good fit (p=6.068).

CONCLUSION

We report a comparative decrease in the peripheral natural killer cell levels in early gestation when compared with prepregnancy cell levels in more than 60% of women with unexplained recurrent pregnancy loss at 4 to 6 weeks of gestation. When compared with prepregnancy peripheral natural killer cell levels, a decrease in the peripheral natural killer cell level during early pregnancy might be a useful predictor of the live birth rate among women with unexplained recurrent pregnancy loss.

The use of immunomodulation therapy in women with recurrent implantation failure undergoing assisted conception: A multicentre cohort study

PROBLEM

Recurrent implantation failure (RIF) after multiple embryo transfers remains a vexing problem and immunomodulators have been used with conflicting results. This study aims to assess the effect of immunomodulation therapy on live birth rate (LBR) in women with RIF undergoing assisted reproduction treatment (ART).

METHOD OF STUDY DESIGN

This is a retrospective cohort study in multicentre network of private assisted conception units in the UK. The study included women who had at least two failed attempts of embryo transfers at CARE fertility network in the period from 1997 to 2018. Women in the treatment group had immunomodulator drugs in the form of corticosteroids, low molecular weight heparin (LMWH), and intravenous intralipid (IVIL) infusions, either separately or in combination, after immunological testing, in addition to standard ART whilst women in the control group had only ART without immunomodulators. The primary outcome was LBR per cycle. Secondary outcomes included the rates of clinical pregnancy (CPR), cumulative live birth (CLBR), and miscarriage.

RESULTS

A total of 27 163 ART cycles fulfilled the inclusion criteria, of which 5083 had immunomodulation treatment in addition to standard ART treatment, and 22 080 had standard ART treatment alone. Women in the treatment group were significantly older (mean age 38.5 vs. 37.1 years, p < .001), and had a higher number of previous failed ART cycles (mean 4.3 vs. 3.8, p < .01). There was a higher LBR in women who received immunomodulation therapy when compared with the control group (20.9% vs. 15.8%, odds ratio [OR] 1.4, 95% confidence interval [CI] 1.29-1.53, p < .001). Multivariate regression analysis showed that immunomodulation treatment was a significant independent predictor of live birth after adjusting for other confounders (adjusted OR [aOR] 1.33, 95% CI 1.15-1.54, p < .001). Survival analysis showed a higher CLBR in the treatment group (adjusted hazard ratio [aHR] 1.78, 95% CI 1.62-1.94, p < .001).

CONCLUSION(S)

This study provides evidence of a potential beneficial effect of immunomodulation therapy in women with RIF after immunological testing. There remains a need for high quality, adequately powered multicentre RCTs to robustly address the role of immunomodulation in women with RIF. There is also an urgent need for standardised screening tests for immune disorders that could preclude implantation.

Immunobiology of pregnancy: from basic science to translational medicine

Embryo implantation failure and spontaneous abortions represent the main causes of infertility in developed countries. Unfortunately, incomplete knowledge of the multiple factors involved in implantation and fetal development keeps the success rate of medically assisted procreation techniques relatively low. According to recent literature, cellular and molecular mechanisms of 'immunogenic tolerance' towards the embryo are crucial to establish an 'anti-inflammatory' state permissive of a healthy pregnancy. In this review we dissect the role played by the immune system in the endometrial-embryo crosstalk, with a particular emphasis towards the fork-head-box-p3 (Foxp3+) CD4+CD25+ regulatory T (Treg) cells and discuss the most recent therapeutic advances in the context of early immune-mediated pregnancy loss.

Peripheral blood natural killer cell cytotoxicity in recurrent miscarriage: a systematic review and meta-analysis

Dysregulated natural killer (NK) cells have been associated with recurrent miscarriages (RM). Studies have suggested that high peripheral blood NK cell cytotoxicities (pNKCs) are associated with an increased risk of RM. The aim of this systematic review (SR) and meta-analysis (MAs) is to investigate the difference in pNKC between nonpregnant and pregnant women with RM and controls and determine whether pNKC is reduced by immunotherapy. We searched the PubMed/Medline, Embase, and Web of Science databases. The MAs were conducted to compare pNKCs between women with and without RM before and during pregnancy as well as pre- and post-immunotherapy. Risk of bias in nonrandomized studies was assessed by the Newcastle-Ottawa Scale. Statistical analysis was performed using the Review Manager software. A total of 19 studies were included in the SR and 14 studies in the MAs. The MAs revealed higher pNKCs among nonpregnant women with RM compared to controls (MD, 7.99 95 %CI 6.40-9.58; p < 0.00001). pNKCs were also higher in pregnant women with RM than in pregnant controls (MD, 8.21 95 %CI 6.08-10.34; p < 0.00001). Women with RM showed significantly decreased pNKCs after the immunotherapy compared to before (MD, -8.20 95 %CI -10.20 - -6.19; p < 0, 00001). Additionally, there is an association between high pNKCs and the risk of pregnancy loss in women with RM. However, included studies showed substantial heterogeneities regarding the inclusion criteria of patients, techniques measuring pNKC, and types of immunotherapies. More studies are needed to evaluate the clinical efficiency of pNKCs in managing RM.

Investigation and Management of Recurrent Pregnancy Loss: A Comprehensive Review of Guidelines

Importance

Recurrent pregnancy loss (RPL) is one of the most frustrating clinical entities in reproductive medicine requiring not only diagnostic investigation and therapeutic intervention, but also evaluation of the risk for recurrence.

Objective

The aim of this study was to review and compare the most recently published major guidelines on investigation and management of RPL.

Evidence Acquisition

A descriptive review of guidelines from the Royal College of Obstetricians and Gynaecologists, the European Society of Human Reproduction and Embryology, the American Society for Reproductive Medicine, the French College of Gynecologists and Obstetricians, and the German, Austrian, and Swiss Society of Gynecology and Obstetrics on RPL was carried out.

Results

There is consensus among the reviewed guidelines that the mainstays of RPL investigation are a detailed personal history and screening for antiphospholipid syndrome and anatomical abnormalities of the uterus. In contrast, inherited thrombophilias, vaginal infections, and immunological and male factors of infertility are not recommended as part of a routine RPL investigation. Several differences exist regarding the necessity of the cytogenetic analysis of the products of conception, parental peripheral blood karyotyping, ovarian reserve testing, screening for thyroid disorders, diabetes or hyperhomocysteinemia, measurement of prolactin levels, and performing endometrial biopsy. Regarding the management of RPL, low-dose aspirin plus heparin is indicated for the treatment of antiphospholipid syndrome and levothyroxine for overt hypothyroidism. Genetic counseling is required in case of abnormal parental karyotype. The Royal College of Obstetricians and Gynaecologists, the European Society of Human Reproduction and Embryology, and the French College of Gynecologists and Obstetricians guidelines provide recommendations that are similar on the management of cervical insufficiency based on the previous reproductive history. However, there is no common pathway regarding the management of subclinical hypothyroidism and the surgical repair of congenital and acquired uterine anomalies. Use of heparin for inherited thrombophilias and immunotherapy and anticoagulants for unexplained RPL are not recommended, although progesterone supplementation is suggested by the American Society for Reproductive Medicine and the German, Austrian, and Swiss Society of Gynecology and Obstetrics.

Conclusions

Recurrent pregnancy loss is a devastating condition for couples. Thus, it seems of paramount importance to develop consistent international practice protocols for cost-effective investigation and management of this early pregnancy complication, with the aim to improve live birth rates.

Outcomes of Empirical Treatment With Intravenous Immunoglobulin G Combined With Low-Dose Aspirin in Women With Unexplained Recurrent Pregnancy Loss

BACKGROUND

To assess the clinical efficacy of intravenous immunoglobulin G (IVIG) administration combined with low-dose aspirin in women with unexplained recurrent pregnancy loss (RPL).

METHODS

We retrospectively analyzed the medical records of patients who had been diagnosed with unexplained RPL and treated with IVIG and low-dose aspirin between January 2000 and March 2020 at Asan Medical Center. We analyzed pregnancy outcomes and their association with the percentage of natural killer (NK) cells.

RESULTS

The study analyzed a total of 93 patients and 113 natural and assisted reproductive technology pregnancy cycles. The live birth rate per cycle was 73.5% (83/113), and the term delivery rate was 86.7% (72/83). The live birth rate was high regardless of the type of RPL, method of pregnancy, timing of IVIG treatment, and presence or absence of autoantibodies. In addition, the live birth rate was significantly higher in patients who received IVIG more than once, compared with patients who received IVIG only once (77.8% vs. 42.9%, P = 0.006). There was no significant association between the NK cell counts and live birth rate (65.5% in the group with NK cell < 12%, and 69.7% in that with NK cell ≥ 12%, P = 0.725). Among all patients, 87.6% had no complications, and there were no congenital malformation among newborn babies.

CONCLUSION

IVIG combined with low-dose aspirin treatment showed favorable pregnancy outcomes regardless of the patient's NK cell counts (%).

Recent Advances in Treatment of Recurrent Spontaneous Abortion

Importance

Recurrent spontaneous abortion (RSA) is a distressing condition experienced by approximately 1% of women trying to conceive. However, the treatment of RSA is a challenge both for clinicians and patients.

Objective

The aim of this review is to discuss the medical and surgical approach to the management of RSA, including those caused by anatomical, genetic, male, infectious, endocrine, and immune factors.

Evidence Acquisition

A literature search using MeSH terms for each topic was undertaken using PubMed, supplemented by hand searching for additional references. Retrieved articles were reviewed, synthesized, and summarized.

Results

Available treatments target hypothetical risk factors for RSA, although the effectiveness of many treatment options is controversial. Intervention should depend on the benefit-to-risk ratio of the proposed treatment.

Conclusions and Relevance

The etiology of RSA is heterogeneous, and patients often lack specific clinical manifestations, which has hindered the progress in predicting and preventing RSA to some extent. Despite intensive workup, at least 50% of couples do not have a clear underlying pathology. In addition, an evidence-based treatment is not available in most patients even if abnormal test results are present. Many new treatment directions are also still actively exploring; empirical and combined multiple treatments are still the main methods.

Target Audience

Obstetricians and gynecologists, family physicians.

Learning Objectives

After completing this activity, the learner should be better able to describe common risk factors for RSA; formulate individualized treatment plans to improve pregnancy outcomes; and propose supportive treatment recommendations for patients with unclear causes.

Correlation of TNF-α, IFN-γ and TGF-β Expression with In-vitro Fertilization Success Rates in Women with Recurrent Implantation Failure Undergoing Treatment with Intra-lipid Infusion

This study aimed at assessing the correlations between gene expression of TNF-a, IFN-g, TGF-β in peripheral lymphocytes from women suffering from repeated implantation failure before and after intravenous Intra-lipid (IL) therapy, and correlation between changes in gene expression with IL infusion and success rate of IVF cycles. Twenty-three women complaining of unexplained infertility without history of autoimmune disorders, or immunodeficient diseases were included. All women included aged <40 years, BMI <28 with history of recurrent IVF cycles failure, seeking medical advice for new IVF trial. All were average responders to induction of ovulation (≥5 oocytes in each cycle) with good quality embryos transferred to uterus at proper time. Included women received 200 ml of 10% IL slowly intravenous. Two venous blood samples were taken from all candidates, one before IL infusion and the second was at day of embryo transfer. The current study detected a significant reduction of expression in TNF-a and increased expression of TGF-β, while non-significant reduction in expression of IFN-g after treatment. Significant associations between reduction of TNF-α, IFN-g expression and positive clinical and ongoing pregnancy were observed, while increased TGF-β expression was associated with only positive ongoing pregnancy. In conclusion, IL therapy might have a positive impact on IVF pregnancy rates via alterations in peripheral cytokines expression mainly reduction of TNF-a mRNA expression and increased TGF-b mRNA expression.

Intralipid therapy and adverse reproductive outcome: is there any evidence?

Controversy exists regarding the benefits of intravenous intralipid therapy in patients with a poor reproductive history. It is frequently reported that there is no evidence to support the effectiveness, utility or safety for this treatment. While individual studies may be perceived as weak, a systematic review and meta-analysis were performed to determine if there is any advantage to patients. PubMed, Embase and Scopus searches were performed with the target populations being either recurrent pregnancy loss (RPL), or recurrent implantation failure (RIF) undergoing assisted reproductive technology (ART) and receiving intralipid infusions. These cohorts were compared with either placebo, no intervention or alternative treatments. The most relevant outcome measures were considered to be clinical pregnancy rate (CPR), live birth rate (LBR), implantation rate (IR) and miscarriage rate (MR). Twelve studies encompassing 2676 participants met the criteria for selection and were included and reviewed. Treatment of the target population with intralipid led to an improvement in IR (Odds Ratio (OR): 2.97, 2.05–4.29), pregnancy rate (OR: 1.64, 1.31–2.04), and LBR (OR: 2.36, 1.75–3.17), with a reduction in MR (OR: 0.2, 0.14–0.30). Although intravenous intralipid is not recommended as a routine treatment for recurrent miscarriage or implantation failure, there is enough data to suggest consideration in selected patients where routine testing is unremarkable, standard treatments have failed and immunological risk factors are present. The presence of abnormal uterine natural killer (uNK) cells needs more study as a target marker to determine those who could benefit.

Effects of intralipid infusions on anti-trophoblast antibody (ATAb)-activities in patients with recurrent pregnancy loss: An observational report

PROBLEM

Some studies suggest intravenous intralipid infusions (IVIL) to be effective in the treatment of immune-mediated pregnancy failure. To this date it remains to be established, how IVIL might protect pregnancy and therefore a specific subgroup of RPL patients that might benefit from IVIL has not been defined. Anti-trophoblast antibodies (ATAb) have been associated with RPL and appear to mediate immune pathology. We have shown, that ATAb in vitro decrease HCG- and progesterone production pointing to a mechanism how ATAb interfere with normal pregnancies. We have measured ATAb-activities in patients undergoing off label IVIL-treatment.

METHOD OF STUDY

Ten RPL-patients with positive ATAb, determined by using the choriocarcinoma cellline JEG-3 and flow cytometry as described before, and otherwise unexplained RPL, received off-label IVIL during pregnancy. Two ATAb-positive RPL patients preferred expectant management. In addition, ATAb-activity was studied in pregnancies of two healthy ATAb-negative volunteers without miscarriages.

RESULTS

In RPL patients receiving IVIL, relative ATAb-activity decreased from an average of 56.8±17.0% to 20.8±11.0% (P < .001). The two RPL-patients without IVIL, aborted at 6+3gw and 7+4gw and embryonic genetic testing revealed euploid karyotypes. During pregnancies of the two healthy ATAb-negative individuals, ATAb-activities remained negative (16±9.8%) without significant changes (P = .22). Nine of the 10 pregnancies receiving IVIL proceeded uneventful with healthy newborns ≥37gw. One patient receiving IVIL aborted at 7+6gw and embryonic genetic-testing revealed a trisomy 16. No specific side effects concerning IVIL were noted.

CONCLUSIONS

Intralipid preparations during pregnancies of ATAb-positive RPL-patients significantly reduce ATAb-activities and this may indicate a therapeutic mechanism of IVIL.

Efficacy of intralipid administration to improve in vitro fertilization outcomes: A systematic review and meta-analysis

We performed a systematic review and meta-analysis to evaluate whether intralipid administration improved the outcomes of in vitro fertilization. Online databases (PubMed, Cochrane Library, Medline, and Embase) were searched until March 2020. Only randomized controlled trials (RCTs) that assessed the role of intralipid administration during in vitro fertilization were considered. We analyzed the rates of clinical pregnancy and live birth as primary outcomes. Secondary outcomes included the rates of chemical pregnancy, ongoing pregnancy, and missed abortion. We reviewed and assessed the eligibility of 180 studies. Five RCTs including 840 patients (3 RCTs: women with repeated implantation failure, 1 RCT: women with recurrent spontaneous abortion, 1 RCT: women who had experienced implantation failure more than once) met the selection criteria. When compared with the control group, intralipid administration significantly improved the clinical pregnancy rate (risk ratio [RR], 1.48; 95% confidence interval [CI], 1.23-1.79), ongoing pregnancy rate (RR, 1.82; 95% CI, 1.31-2.53), and live birth rate (RR, 1.85; 95% CI, 1.44-2.38). However, intralipid administration had no beneficial effect on the miscarriage rate (RR, 0.75; 95% CI, 0.48-1.17). A funnel plot analysis revealed no publication bias. Our findings suggest that intralipid administration may benefit women undergoing in vitro fertilization, especially those who have experienced repeated implantation failure or recurrent spontaneous abortion. However, larger, well-designed studies are needed to confirm these findings.

Effect of Intralipid infusion on peripheral blood T cells and plasma cytokines in women undergoing assisted reproduction treatment

Objectives

Intravenous infusion of Intralipid is an adjunct therapy in assisted reproduction treatment (ART) when immune‐associated infertility is suspected. Here, we evaluated the effect of Intralipid infusion on regulatory T cells (Treg cells), effector T cells and plasma cytokines in peripheral blood of women undertaking IVF.

Methods

This prospective, observational pilot study assessed Intralipid infusion in 14 women exhibiting recurrent implantation failure, a clinical sign of immune‐associated infertility. Peripheral blood was collected immediately prior to and 7 days after intravenous administration of Intralipid. Plasma cytokines were measured by Luminex, and T‐cell subsets were analysed by flow cytometry.

Results

A small increase in conventional CD8⁺ T cells occurred after Intralipid infusion, but no change was seen in CD4⁺ Treg cells, or naïve, memory or effector memory T cells. Proliferation marker Ki67, transcription factors Tbet and RORγt, and markers of suppressive capacity CTLA4 and HLA‐DR were unchanged. Dimensionality‐reduction analysis using the tSNE algorithm confirmed no phenotype shift within Treg cells or other T cells. Intralipid infusion increased plasma CCL2, CCL3, CXCL8, GM‐CSF, G‐CSF, IL‐6, IL‐21, TNF and VEGF.

Conclusion

Intralipid infusion elicited elevated pro‐inflammatory cytokines, and a minor increase in CD8⁺ T cells, but no change in pro‐tolerogenic Treg cells. Notwithstanding the limitation of no placebo control, the results do not support Intralipid as a candidate intervention to attenuate the Treg cell response in women undergoing ART. Future placebo‐controlled studies are needed to confirm the potential efficacy and clinical significance of Intralipid in attenuating cytokine induction and circulating CD8⁺ T cells.

A Brief Analysis of Tissue-Resident NK Cells in Pregnancy and Endometrial Diseases: The Importance of Pharmacologic Modulation

NK cells are lymphocytes involved in the innate and adaptative immune response. These cells are located in peripheral blood and tissues with ample functions, from immune vigilant to tolerogenic reactions. In the endometrium, NK cell populations vary depending on age, hormones, and inflammation. When pregnancy occurs, tissue-resident NK cells and conventional NK cells are recruited to protect the fetus, a tolerogenic response. On the contrary, in the inflamed endometrium, various inflammatory cells down-regulate NK tolerance and impair embryo implantation. Therefore, NK cells’ pharmacological modulation is difficult to achieve. Several strategies have been used, from progesterone, lipid emulsions to steroids; the success has not been as expected. However, new therapeutic approaches have been proposed to decrease the endometrial inflammatory burden and increase pregnancy success based on understanding NK cell physiology.

Abnormal H3K27 histone methylation of RASA1 gene leads to unexplained recurrent spontaneous abortion by regulating Ras-MAPK pathway in trophoblast cells

Some studies suggest that the inactivation of the Ras-MAPK pathway in trophoblast cells can lead to recurrent abortion, but the molecular mechanism underlying the inactivation of this pathway in trophoblast cells is still unclear. This study aimed to explore the relationship between the mechanism of abnormal activation of RASA1, a regulatory protein of the Ras-MAPK pathway, and unexplained recurrent spontaneous abortion. RT-qPCR was used to detect the transcription levels of RASA1 gene. Immunohistochemistry and Western blot were used to detect the expression levels of the RASA1, Raf and MEK proteins. CCK-8, TUNEL and Transwell assays were used to detect the proliferative, apoptotic, and invasive capacities of HTR-8/SVneo cells. ChIP assays were used to detect the enrichment of H3K27me3 in RASA1 gene promoter. Abortion villi experiments showed that the enrichment of H3K27me3 in the RASA1 gene promoter was reduced, and that both RASA1 gene transcription and RASA1 protein expression were increased. Cell experiments confirmed that RASA1 could decrease the phosphorylated Raf and MEK proteins, inhibit the proliferation and invasion ability, and promote the apoptosis ability of HTR-8/SVneo cells. It was also found that the proliferation and invasion ability as well as the Ras-MAPK pathway activity of HTR-8/SVneo cells were inhibited when treated with histone methyltransferase inhibitor DZNep. RASA1 gene was abnormally activated in unexplained recurrent spontaneous abortion villi due to the decreased enrichment of H3K27me3 in the gene promoter. High expression of RASA1 could inhibit the activity of the Ras-MAPK pathway, and thus inhibit the proliferation and invasion ability of trophoblast cells.

Uterine natural killer cells: from foe to friend in reproduction

BACKGROUND

Recurrent miscarriage and pre-eclampsia are common reproductive disorders, but their causes are often unknown. Recent evidence has provided new insight into immune system influences in reproductive disorders. A subset of lymphocytes of the innate immune system known as uterine natural killer (uNK) cells are now recognized as fundamental to achieving embryo implantation and successful pregnancy, but were initially attributed a bad reputation. Indeed, immune therapies have been developed to treat the 'exaggerated' immune response from uNK cells. These treatments have been based on studies of peripheral blood natural killer (pbNK) cells. However, uNK cells and pbNK cells have different phenotypic and functional characteristics. The functions of uNK cells are closely related to their interactions with the extravillous trophoblast cells (EVTs) and spiral arteries, which underlie an essential role in regulating vascular function, controlling trophoblast invasion and promoting placental development. EVTs express MHC molecules of class I HLA-C/E/G/F, while uNK cells express, among other receptors, killer cell immunoglobulin-like receptors (KIRs) that bind to HLA-C or CD94/NKG2A inhibitory receptors, and then bind HLA-E. Associations of certain KIR/HLA-C combinations with recurrent miscarriage, pre-eclampsia, and foetal growth restriction and the interactions between uNK cells, trophoblasts and vascular cells have led to the hypothesis that uNK cells may play a role in embryo implantation.

OBJECTIVE AND RATIONALE

Our objective was to review the evolution of our understanding of uNK cells, their functions, and their increasingly relevant role in reproduction.

SEARCH METHODS

Relevant literature through June 2020 was retrieved using Google Scholar and PubMed. Search terms comprised uNK cells, human pregnancy, reproductive failure, maternal KIR and HLA-C, HLA-E/G/F in EVT cells, angiogenic cytokines, CD56+ NK cells, spiral artery, oestrogen and progesterone receptors, KIR haplotype and paternal HLA-C2.

OUTCOMES

This review provides key insights into the evolving conceptualization of uNK cells, from their not-so-promising beginnings to now, when they are considered allies in reproduction. We synthesized current knowledge about uNK cells, their involvement in reproduction and their main functions in placental vascular remodeling and trophoblast invasion. One of the issues that this review presents is the enormous complexity involved in studying the immune system in reproduction. The complexity in the immunology of the maternal-foetal interface lies in the great variety of participating molecules, the processes and interactions that occur at different levels (molecular, cellular, tissue, etc.) and the great diversity of genetic combinations that are translated into different types of responses.

WIDER IMPLICATIONS

Insights into uNK cells could offer an important breakthrough for ART outcomes, since each patient could be assessed based on the combination of HLA and its receptors in their uNK cells, evaluating the critical interactions at the materno-foetal interface. However, owing to the technical challenges in studying uNK cells in vivo, there is still much knowledge to gain, particularly regarding their exact origin and functions. New studies using novel molecular and genetic approaches can facilitate the identification of mechanisms by which uNK cells interact with other cells at the materno-foetal interface, perhaps translating this knowledge into clinical applicability.

The Impact of New Immunological Therapeutic Strategies on Recurrent Miscarriage and Recurrent Implantation Failure

Maternal-fetal immune dysregulation is one of the risk factors that increases the probability of embryo rejection and reproductive failure. The stimulation of immunological tolerance and suppression of immunological rejection are prerequisites for protecting embryos and preventing immunological attacks. Hence, it appears that immunomodulatory and immunosuppressive therapies can manage reproductive failures by controlling immune cells. The current medical literature has shown that immunotherapy approaches and cell therapy have promising results in improving pregnancy outcomes and live birth rates. These outcomes are obtained by regulating maternal immune responses, and exerting positive effects on human reproductive processes.

Alteration of vaginal microbiota in patients with recurrent miscarriage

The aim of this study was to characterise the structure of vaginal microbiota in unexplained recurrent miscarriage (RM). The vaginal bacterial communities of 16 patients with RM and 20 healthy volunteers were sampled. Then, the microbiomes of bacterial profiles of RM patients and healthy volunteers were compared by sequencing the V3-V4 regions of the bacterial 16S ribosomal RNA gene using the Illumina MiSeq platform (Illumina, San Diego, CA). Taxonomic analysis demonstrated that abundance of Lactobacillus and Gardnerella were significantly different between the RM and control groups. Furthermore, at the genus level, Lactobacillus was the most dominant genus in the two groups. Statistically significant differences were observed in three genera between RM and control groups. In the control group, two bacterial taxa were significantly more abundant (Lactobacillus and Gardnerella), while only one taxon was overrepresented in the RM group (Atopobium). These present findings provide experimental evidence supporting vaginal microbiota dysbiosis in women with RM.Impact statementWhat is already known on this subject? Currently, bacterial vaginosis is thought to be mainly due to the vaginal dysbacteriosis, which can induce unexplained recurrent miscarriage, premature rupture of membranes, low birth weight premature birth, premature birth, chorioamnionitis and series of diseases.What do the results of this study add? The current study demonstrated that Lactobacillus and Gardnerella were significantly decreased in RM patients compared to healthy control, while Atopobium was overrepresented in the RM group.What are the implications of these findings for clinical practice and/or further research? Clinically, women with RM might benefit from vaginal microbiota treatment, adjuvant therapy with Lactobacillus-based live biotherapeutics.

Intralipid infusion at time of embryo transfer in women with history of recurrent implantation failure: A systematic review and meta-analysis

AIM

Recurrent implantation failure (RIF) affects 10% of couples undergoing assisted conception, often due to poor endometrial receptivity. We conducted a systematic review and meta-analysis to evaluate the effectiveness of Intra-venous intralipid (IVI) in improving pregnancy rates in women with history of RIF using.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL for any randomized trials evaluating the use of IVI at the time of embryo transfer in women undergoing assisted conception until September 2020. We extracted data in duplicate and assessed risk of bias using the Cochrane Risk of Bias tools. We meta-analyzed data using a random effect model.

RESULTS

We included five randomized trials reporting on 843 women with an overall moderate risk of bias. All trials used 20% IVI solution at the time of embryo transfer compared to normal saline infusion or no intervention (routine care). The IVI group had a higher chance of clinical pregnancy (172 vs 119, risk ratio [RR] 1.55, 95% confidence interval [CI] 1.16-2.07, I² 44.2%) and live birth (132 vs 73, RR 1.83, 95% CI 1.42-2.35, I² 0%) post treatment compared to no intervention. Our findings are limited by the small sample size and the variations in treatment protocols and population characteristics.

CONCLUSION

There is limited evidence to support the use of IVI at the time of embryo transfer in women with the history of RIF. More research is needed before adopting it in clinical practice.

The impact of alfaxalone, propofol and ketamine on canine peripheral blood lymphocyte cytotoxicity in vitro

Anesthetics may worsen the outcome of patients undergoing oncologic surgery via immune suppression. This study examines the impact of propofol, ketamine, and alfaxalone on canine peripheral blood lymphocyte (PBL) cytotoxic function in vitro. PBLs isolated from healthy canine blood were cultured in the presence or absence of alfaxalone, propofol, ketamine, their carrier solutions or dexamethasone as a positive control for 20 h. There was a decrease in cytotoxicity in PBLs exposed to dexamethasone and propofol carrier compared to the control as assessed by means of a chromium-based cytotoxicity assay. The PBLs exposed to propofol carrier also showed lower cytotoxicity compared to propofol. No other significant differences were observed. Therefore, the documented effects of these anesthetics in vivo may be caused by an indirect mechanism. The lipid emulsion's significant decrease in PBL cytotoxicity may have implications for critically ill patients on total parenteral nutrition.

Immunological Risk Factors in Recurrent Pregnancy Loss: Guidelines Versus Current State of the Art

Around 1-5% of all couples experience recurrent pregnancy loss (RPL). Established risk factors include anatomical, genetic, endocrine, and hemostatic alterations. With around 50% of idiopathic cases, immunological risk factors are getting into the scientific focus, however international guidelines hardly take them into account. Within this review, the current state of immunological risk factors in RPL in international guidelines of the European Society of Reproduction and Embryology (ESHRE), American Society of Reproductive Medicine (ASRM), German/Austrian/Swiss Society of Obstetrics and Gynecology (DGGG/OEGGG/SGGG) and the Royal College of Obstetricians and Gynecologists (RCOG) are evaluated. Special attention was drawn to recommendations in the guidelines regarding diagnostic factors such as autoantibodies, natural killer cells, regulatory T cells, dendritic cells, plasma cells, and human leukocyte antigen system (HLA)-sharing as well as treatment options such as corticosteroids, intralipids, intravenous immunoglobulins, aspirin and heparin in RPL. Finally, the current state of the art focusing on both diagnostic and therapeutic options was summarized.

Enhancer RNA lnc-CES1-1 inhibits decidual cell migration by interacting with RNA-binding protein FUS and activating PPARγ in URPL

Unexplained recurrent pregnancy loss (URPL) is a significant reproductive health issue, affecting approximately 5% of pregnancies. Enhancer RNAs (eRNAs) have been reported to play important roles during embryo development and may be related to URPL. To investigate whether and how eRNAs are involved in URPL, we performed RNA sequencing in decidual tissue. Through comprehensive screening and validation, we identified a decidua-enriched eRNA long noncoding-CES1-1 (lnc-CES1-1) enriched in URPL patients and studied its function in decidua-associated cell lines (DACs). Higher expression of lnc-CES1-1 increased the level of inflammatory factors tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) and impaired the cell migration ability, which was attenuated by downregulating peroxisome proliferators-activated receptor γ (PPARγ). Upon activation by signal transduction and activation of transcription 4 (STAT4), lnc-CES1-1 interacted with the transcription factor fused in sarcoma (FUS) to upregulate the expression of PPARγ and affected cell migration. Taken together, these findings provide novel insights into the biological functions of decidua-associated lnc-CES1-1 and the molecular mechanisms underlying URPL. Our findings indicated that lnc-CES1-1 might be a potential candidate biomarker for URPL diagnosis and treatment.

Lipid emulsion therapy in women with recurrent pregnancy loss and repeated implantation failure: The role of abnormal natural killer cell activity

Altered immune and/or inflammatory response plays an important role in cases of recurrent pregnancy loss (RPL) and repeated implantation failure (RIF). Exacerbation of the maternal immune response through increased NK cell activity and inflammatory cytokines can cause embryo rejection leading to abortion or embryo implantation failure. Immunosuppressors or immunomodulators can help or prevent this condition. Currently, lipid emulsion therapy (LET) has emerged as a treatment for RPL and RIF in women with abnormal NK cell activity, by decreasing the exacerbated immune response of the maternal uterus and providing a more receptive environment for the embryo. However, the mechanisms by which the intralipid acts to reduce NK cell activity are still unclear. In this review, we focus on the studies that conducted LET to treat patients with RPL and RIF with abnormal NK cell activity. We find that although some authors recommend LET as an effective intervention, more studies are necessary to confirm its effectiveness in restoring NK cell activity to normal levels and to comprehend the underlying mechanisms of the lipids action in ameliorating the maternal environment and improving the pregnancy rate.

Natural killer cells in recurrent miscarriage: An overview

Recurrent Miscarriage is an early pregnancy complication which affects about 1-3 % of child-bearing couples. The mechanisms involved in the occurrence of recurrent miscarriages are not clearly understood. In the last decade Natural Killer cells have been studied in peripheral blood and uterus in order to determine if there are specific characteristics of Natural Killer cells associated with miscarriage. Different authors have described an increased number of uterine and peripheral blood Natural Killer cells in women with recurrent miscarriages compared to control women. However, its relationship with miscarriage has not been confirmed. In patients with recurrent miscarriage a lack of inhibition of decidua Natural Killer cells can be observed, which leads to a more activated state characterized by higher levels of proinflammatory cytokines. In peripheral blood, it has been also reported a dysfunctional cytokine production by Natural Killer cells, with an increase of interferon-γ levels and a decrease of Interleukin-4. Significant progress has been made in the last decade in understanding the biology of Natural Killer cells, including the identification of new receptors that also contribute to the activation and regulation of Natural Killer cells. In this review, we summarize the current progress in the study of Natural Killer cells in recurrent miscarriage.

Intralipid therapy for unexplained recurrent miscarriage and implantation failure: Case-series and literature review

INTRODUCTION

In retrospective cohort study of women with unexplained recurrent implantation failure (RIF) and miscarriage (RM), we analyzed the efficacy and safety of intralipid therapy to obtain a live birth.

PATIENTS AND METHODS

Women with unexplained RM and/or RIF were included from 2015 to 2018 from three French university hospitals.

RESULTS

Among 187 women treated for unexplained recurrent miscarriages and implantation failures, 26 women with median age of 36 years (29-43) received intralipid therapy. Among these 26 women, 10 women with a median age of 33 years (31-40) had a history of spontaneous recurrent miscarriages, with a median of 5 (4-8) previous miscarriages. Live births occurred in 7 (70 %) pregnancies under intralipids and were significantly more frequent than in women with recurrent miscarriages who did not receive intralipid therapy (n = 20, p = 0.02). Age, number of previous miscarriages, and additional therapies did not significantly differ between the two groups. Among the 26 included women, 16 had a history of recurrent implantation failures, with median age of 37 years (29-43) and median 9.5 (3-19) embryo transfers. Clinical pregnancy occurred in 9 (56 %) women receiving intralipids after embryo transfers under intralipids among which 5 (55 %) resulted in a live birth. Comparing successful pregnancies under intralipids with those with fetal loss, no significant differences have been noted.

CONCLUSION

Intralipids could be an effective and safe therapy in women with unexplained recurrent miscarriages and infertility.

Evaluation of T cell cytokines and their role in recurrent miscarriage

Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses that affect approximately 5% of conceived women worldwide. RM is a multi-factorial reproductive problem and has been associated with parental chromosomal abnormalities, embryonic chromosomal rearrangements, uterine anomalies, autoimmune disorders, endocrine dysfunction, thrombophilia, life style factors, and maternal infections. However, the exact cause is still undecided in remaining 50% of cases. Immunological rejection of the embryo due to exacerbated maternal immune reaction against paternal embryonic antigens has been set forth as one of the significant reason for RM. The accurate means that shield the embryo during normal pregnancy from the attack of maternal immune network and dismissal are inadequately implicit. However, it is suggested that the genetically irreconcilable embryo escapes maternal immune rejection due to communication among many vital cytokines exuded at maternal-embryonic interface both by maternal and embryonic cells. Previous investigations suggested the Th1/Th2 dominance in altered immunity of RM patients, according to which the allogenic embryo flees maternal T cell reaction by inclining the Th0 differentiation toward Th2 pathway resulting into diminished pro-inflammatory Th1 immunity. However, recently pro-inflammatory Th17 cells and immunoregulatory Treg cells have been discovered as essential immune players in RM besides Th1/Th2 components. Cytokines are believed to develop a complicated regulatory network so as to establish a state of homeostasis between the semi-allogenic embryo and the maternal immune system. However, an adverse imbalance among cytokines at maternal-embryonic interface perhaps due to their gene polymorphisms may render immunoregulatory means not enough to re-establish homeostasis and thus may collapse pregnancy.

Intralipid Immunotherapy for Repeated IVF Failure

The intravenous fat emulsion, intralipid, has been hypothesised to be an effective and safe treatment for repeated in vitro fertilisation (IVF), implantation failure and pregnancy loss. This exploratory, retrospective cohort study determined pregnancy outcomes and documented adverse events associated with intralipid use. Ninety-three women were identified as having received intralipid for a history of repeated unsuccessful IVF cycles and pre-viable pregnancy loss in two Australian IVF units that independently recruited between October 2014 and July 2016. Pregnancy outcomes and adverse events were recorded in fresh and frozen embryo transfer cycles in which the infusion was administered. The 93 women who received intralipid had a clinical pregnancy rate of 40.0%, compared with 35.0% in 651 age-matched controls undergoing IVF, which was not significantly different. The intralipid group had a livebirth rate of 35.7%. Apart from flushing, which was experienced by one individual, there were no adverse events associated with intralipid use. As a prelude to definitive evidence of benefit, we did not identify a safety concern or reduced pregnancy rates in intralipid users compared to controls. Indeed, these outcomes were better than expected in a poor prognosis group. This data supports an argument for large, randomised controlled trials to determine the benefit of intralipid in the treatment of recurrent implantation failure or miscarriage.

Gestational and perinatal outcomes in recurrent miscarriages couples treated with lymphocyte immunotherapy

Objective

This study aims to elucidate which types of recurrent miscarriage (RM) patients experienced a livebirth after paternal lymphocyte immunotherapy (LIT) and to evaluate the perinatal outcome.

Study design

Retrospective analysis of a multicenter, observational study which enrolled 1096 couples with a history of two or more spontaneous miscarriages without any intercalated delivery. We conducted an intention-to-treat analysis of couples with RM treated with or without LIT regarding to gestational and perinatal outcomes. We compared groups by using the Student’s t-test or Kruskal–Wallis test, Fisher’s exact-test and χ² test when appropriate.

Results

The success of gestation was significantly higher in the LIT group (60.1% vs. 33.1%; p <  0.001). A sub-analysis of four different immune disorder groups revealed a significantly higher success in the LIT group in all immune categories, except in patients who had autoantibodies positive. We observed no significant differences in perinatal outcomes such as gestational age at birth, preterm and extreme preterm birth, and birth weight in successful pregnancy in both groups. The success rate was significantly higher when LIT was administrated before and during pregnancy and only during pregnancy compared to only before pregnancy (p <  0.01).

Conclusions

Careful laboratory test phenotyping of RM patients may identify subgroups most likely to benefit and exclude those with little likelihood of benefit, and LIT during a pregnancy may significantly improve success rates.

Recombinant human granulocyte- colony stimulating factor in women with unexplained recurrent pregnancy losses: a randomized clinical trial

STUDY QUESTION

Does administration of recombinant human granulocyte colony stimulating factor (rhG-CSF) in the first trimester improve pregnancy outcomes, among women with a history of unexplained recurrent pregnancy loss?

SUMMARY ANSWER

rhG-CSF administered in the first trimester of pregnancy did not improve outcomes among women with a history of unexplained recurrent pregnancy loss.

WHAT IS KNOWN ALREADY

The only previous randomized controlled study of granulocyte colony stimulating factor in recurrent miscarriage in 68 women with unexplained primary recurrent miscarriage found a statistically significant reduction in miscarriage and improvement in live birth rates. A further four observational studies where G-CSF was used in a recurrent miscarriage population were identified in the literature, two of which confirmed statistically significant increase in clinical pregnancy and live birth rates.

STUDY DESIGN, SIZE, DURATION

A randomized, double-blind, placebo controlled clinical trial involving 150 women with a history of unexplained recurrent pregnancy loss was conducted at 21 sites with established recurrent miscarriage clinics in the United Kingdom between 23 June 2014 and 05 June 2016. The study was coordinated by University of Birmingham, UK.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One hundred and fifty women with a history of unexplained recurrent pregnancy loss: 76 were randomized to rhG-CSF and 74 to placebo. Daily subcutaneous injections of recombinant human granulocyte - colony stimulating factor 130 μg or identical appearing placebo from as early as three to five weeks of gestation for a maximum of 9 weeks. The trial used central randomization with allocation concealment. The primary outcome was clinical pregnancy at 20 weeks of gestation, as demonstrated by an ultrasound scan. Secondary outcomes included miscarriages, livebirth, adverse events, stillbirth, neonatal birth weight, changes in clinical laboratory variables following study drug exposure, major congenital anomalies, preterm births and incidence of anti-drug antibody formation. Analysis was by intention to treat.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 340 participants were screened for eligibility of which 150 women were randomized. 76 women (median age, 32[IQR, 29-34] years; mean BMI, 26.3[SD, 4.2]) and 74 women (median age, 31[IQR, 26-33] years; mean BMI, 25.8[SD, 4.2]) were randomized to placebo. All women were followed-up to primary outcome, and beyond to live birth. The clinical pregnancy rate at 20 weeks, as well as the live birth rate, was 59.2% (45/76) in the rhG-CSF group, and 64.9% (48/74) in the placebo group, giving a relative risk of 0.9 (95% CI: 0.7-1.2; P = 0.48). There was no evidence of a significant difference between the groups for any of the secondary outcomes. Adverse events (AEs) occurred in 52 (68.4%) participants in rhG-CSF group and 43 (58.1%) participants in the placebo group. Neonatal congenital anomalies were observed in 1/46 (2.1%) of babies in the rhG-CSF group versus 1/49 (2.0%) in the placebo group (RR of 0.9; 95% CI: 0.1-13.4; P = 0.93).

LIMITATIONS, REASONS FOR CAUTION

This trial was conducted in women diagnosed with unexplained recurrent pregnancy loss and therefore no screening tests (commercially available) were performed for immune dysfunction related pregnancy failure/s.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first multicentre study and largest randomized clinical trial to investigate the efficacy and safety of granulocyte human colony stimulating factor in women with recurrent miscarriages. Unlike the only available single center RCT, our trial showed no significant increase in clinical pregnancy or live births with the use of rhG-CSF in the first trimester of pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

This study was sponsored and supported by Nora Therapeutics, Inc., 530 Lytton Avenue, 2nd Floor, Palo Alto, CA 94301, USA. Darryl Carter was the co-founder and VP of research, Nora Therapeutics, Inc. and held shares in the company. He holds a patent for the use of recombinant human granulocyte colony stimulating factor to reduce unexplained recurrent pregnancy loss. Mark Joing, Paul Kwon and Jeff Tong were or are employees of Nora Therapeutics, Inc. No other potential conflict of interest relevant to this article was reported.

TRIAL REGISTRATION NUMBER

EUDRACT No: 2014-000084-40; ClinicalTrials.gov Identifier: NCT02156063.

TRIAL REGISTRATION DATE

31 Mar 2014.

DATE OF FIRST PATIENT’S ENROLMENT

23 Jun 2014.

Care prior to and during subsequent pregnancies following stillbirth for improving outcomes

BACKGROUND

Stillbirth affects at least 2.6 million families worldwide every year and has enduring consequences for parents and health services. Parents entering a subsequent pregnancy following stillbirth face a risk of stillbirth recurrence, alongside increased risks of other adverse pregnancy outcomes and psychosocial challenges. These parents may benefit from a range of interventions to optimise their short- and longer-term medical health and psychosocial well-being.

OBJECTIVES

To assess the effects of different interventions or models of care prior to and during subsequent pregnancies following stillbirth on maternal, fetal, neonatal and family health outcomes, and health service utilisation.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 June 2018), along with ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (18 June 2018).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-randomised controlled trials (qRCTs). Trials using a cluster-randomised design were eligible for inclusion, but we found no such reports. We included trials published as abstract only, provided sufficient information was available to allow assessment of trial eligibility and risk of bias. We excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and undertook data extraction and 'Risk of bias' assessments. We extracted data from published reports, or sourced data directly from trialists. We checked the data for accuracy and resolved discrepancies by discussion or correspondence with trialists, or both. We conducted an assessment of the quality of the evidence using the GRADE approach.

MAIN RESULTS

We included nine RCTs and one qRCT, and judged them to be at low to moderate risk of bias. Trials were carried out between the years 1964 and 2015 and took place predominantly in high-income countries in Europe. All trials assessed medical interventions; no trials assessed psychosocial interventions or incorporated psychosocial aspects of care. Trials evaluated the use of antiplatelet agents (low-dose aspirin (LDA) or low-molecular-weight heparin (LMWH), or both), third-party leukocyte immunisation, intravenous immunoglobulin, and progestogen. Trial participants were women who were either pregnant or attempting to conceive following a pregnancy loss, fetal death, or adverse outcome in a previous pregnancy.We extracted data for 222 women who had experienced a previous stillbirth of 20 weeks' gestation or more from the broader trial data sets, and included them in this review. Our GRADE assessments of the quality of evidence ranged from very low to low, due largely to serious imprecision in effect estimates as a result of small sample sizes, low numbers of events, and wide confidence intervals (CIs) crossing the line of no effect. Most of the analyses in this review were not sufficiently powered to detect differences in the outcomes assessed. The results presented are therefore largely uncertain.Main comparisonsLMWH versus no treatment/standard care (three RCTs, 123 women, depending on the outcome)It was uncertain whether LMWH reduced the risk of stillbirth (risk ratio (RR) 2.58, 95% CI 0.40 to 16.62; 3 trials; 122 participants; low-quality evidence), adverse perinatal outcome (RR 0.81, 95% CI 0.20 to 3.32; 2 trials; 77 participants; low-quality evidence), adverse maternal psychological effects (RR 1.00, 95% CI 0.07 to 14.90; 1 trial; 40 participants; very low-quality evidence), perinatal mortality (RR 2.58, 95% CI 0.40 to 16.62; 3 trials; 122 participants; low-quality evidence), or any preterm birth (< 37 weeks) (RR 1.01, 0.58 to 1.74; 3 trials; 114 participants; low-quality evidence). No neonatal deaths were reported in the trials assessed and no data were available for maternal-infant attachment. There was no clear evidence of a difference between the groups among the remaining secondary outcomes.LDA versus placebo (one RCT, 24 women)It was uncertain whether LDA reduced the risk of stillbirth (RR 0.85, 95% CI 0.06 to 12.01), neonatal death (RR 0.29, 95% CI 0.01 to 6.38), adverse perinatal outcome (RR 0.28, 95% CI 0.03 to 2.34), perinatal mortality, or any preterm birth (< 37 weeks) (both of the latter RR 0.42, 95% CI 0.04 to 4.06; all very low-quality evidence). No data were available for adverse maternal psychological effects or maternal-infant attachment. LDA appeared to be associated with an increase in birthweight (mean difference (MD) 790.00 g, 95% CI 295.03 to 1284.97 g) when compared to placebo, but this result was very unstable due to the extremely small sample size. Whether LDA has any effect on the remaining secondary outcomes was also uncertain.Other comparisonsLDA appeared to be associated with an increase in birthweight when compared to LDA + LMWH (MD -650.00 g, 95% CI -1210.33 to -89.67 g; 1 trial; 29 infants), as did third-party leukocyte immunisation when compared to placebo (MD 1195.00 g, 95% CI 273.35 to 2116.65 g; 1 trial, 4 infants), but these results were again very unstable due to extremely small sample sizes. The effects of the interventions on the remaining outcomes were also uncertain.

AUTHORS' CONCLUSIONS

There is insufficient evidence in this review to inform clinical practice about the effectiveness of interventions to improve care prior to and during subsequent pregnancies following a stillbirth. There is a clear and urgent need for well-designed trials addressing this research question. The evaluation of medical interventions such as LDA, in the specific context of stillbirth prevention (and recurrent stillbirth prevention), is warranted. However, appropriate methodologies to evaluate such therapies need to be determined, particularly where clinical equipoise may be lacking. Careful trial design and multicentre collaboration is necessary to carry out trials that would be sufficiently large to detect differences in statistically rare outcomes such as stillbirth and neonatal death. The evaluation of psychosocial interventions addressing maternal-fetal attachment and parental anxiety and depression is also an urgent priority. In a randomised-trial context, such trials may allocate parents to different forms of support, to determine which have the greatest benefit with the least financial cost. Importantly, consistency in nomenclature and in data collection across all future trials (randomised and non-randomised) may be facilitated by a core outcomes data set for stillbirth research. All future trials should assess short- and longer-term psychosocial outcomes for parents and families, alongside economic costs of interventions.

Intralipid® may represent a new hope for patients with reproductive failures and simultaneously an over-immune endometrial activation

PROBLEM

Continuous failures to achieve a pregnancy despite effective embryo transfers is extremely distressing for couples. In consequence, many adjuvant therapies to IVF have been proposed to achieve an "ideal" immune environment. We here focus on Intralipid® therapy (IL) reported to have immunosuppressive properties on NK cells.

METHOD OF STUDY

94 patients exhibited an immune profile of endometrial over-immune activation and an history of repeated implantation failures despite multiple embryos transfers (RIF). They received a slow perfusion of Intralipid®. We here report the live birth rate following the procedure at the next embryo transfer. To get new insight on its mechanism of action, a second immune profiling had been performed under Intralipid® before the embryo transfer.

RESULTS

The live birth rate of the RIF cohort treated with Intralipid® reached 54% (51/94) at the next embryo transfer. In patients successfully pregnant under Intralipid® who benefitted of a test of sensibility before the embryo transfer, we observed a significant decrease of the three biomarkers used to diagnose the over-immune endometrial activation (CD56 cells; IL-18/TWEAK, IL-14/FN-14).

CONCLUSIONS

Double blind placebo versus Intralipid® studies should be conducted. Intralipid® may be an option to explore in RIF patients who exhibit an over-immune activation of uNK cells.

A comparison of effectiveness among frequent treatments of recurrent spontaneous abortion: A Bayesian network meta-analysis

OBJECTIVE

A comprehensive network meta-analysis was designed to clarify contradictions and offer valuable clinical guidance in the treatment of recurrent spontaneous abortion (RSA).

METHOD

The included clinical trials were selected from the relevant medical journal databases and screened. Treatments were ranked by the surface under the cumulative ranking curve. Heat plots were constructed to analyze the inconsistency between direct data and network results, and adjusted funnel plots were constructed to assess publication bias.

RESULTS

Forty-nine randomized controlled trials involving a total of 8496 RSA patients were selected. With placebo as control, corticosteroid plus low dose aspirin (LDA) plus unfractionated heparin (UFH), granulocyte colony-stimulating factor (G-CSF) alone, and LDA plus low molecular weight heparin (LMWH) all demonstrated effectiveness in increasing successful live birth rates and reducing the incidences of miscarriage. However, no treatment was demonstrably superior to placebo in terms of pregnancy success. For all 3 endpoints (live birth, abortion and success pregnancy), the adjusted funnel plots were symmetric to zero and indicated no publication bias. In terms of live birth and abortion rates, no treatment outperformed placebo in patients with antiphospholipid syndrome.

CONCLUSION

In consideration of live birth and abortion rates, corticosteroid plus LDA plus UFH appeared to be the optimum treatment strategy; G-CSF was second, followed by LDA with LMWH, LDA plus LMWH plus intravenous immunoglobulin, corticosteroid with LDA and others. Subgroup analysis demonstrated no benefit of antithrombotic therapy in patients with antiphospholipid syndrome.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/050)

Purpose

Official guideline of the German Society of Gynecology and Obstetrics (DGGG), the Austrian Society of Gynecology and Obstetrics (ÖGGG) and the Swiss Society of Gynecology and Obstetrics (SGGG). The aim of this guideline was to standardize the diagnosis and treatment of couples with recurrent miscarriage (RM). Recommendations were based on the current literature and the views of the involved committee members.

Methods

Based on the current literature, the committee members developed the statements and recommendations of this guideline in a formalized process which included DELPHI rounds and a formal consensus meeting.

Recommendations

Recommendations for the diagnosis and treatment of patients with RM were compiled based on the international literature. Specific established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders were taken into consideration.

Recurrent pregnancy loss: current perspectives

Recurrent pregnancy loss is an important reproductive health issue, affecting 2%–5% of couples. Common established causes include uterine anomalies, antiphospholipid syndrome, hormonal and metabolic disorders, and cytogenetic abnormalities. Other etiologies have been proposed but are still considered controversial, such as chronic endometritis, inherited thrombophilias, luteal phase deficiency, and high sperm DNA fragmentation levels. Over the years, evidence-based treatments such as surgical correction of uterine anomalies or aspirin and heparin for antiphospholipid syndrome have improved the outcomes for couples with recurrent pregnancy loss. However, almost half of the cases remain unexplained and are empirically treated using progesterone supplementation, anticoagulation, and/or immunomodulatory treatments. Regardless of the cause, the long-term prognosis of couples with recurrent pregnancy loss is good, and most eventually achieve a healthy live birth. However, multiple pregnancy losses can have a significant psychological toll on affected couples, and many efforts are being made to improve treatments and decrease the time needed to achieve a successful pregnancy. This article reviews the established and controversial etiologies, and the recommended therapeutic strategies, with a special focus on unexplained recurrent pregnancy losses and the empiric treatments used nowadays. It also discusses the current role of preimplantation genetic testing in the management of recurrent pregnancy loss.

Pre-Pregnancy Levels of Peripheral Natural Killer Cells as Markers for Immunomodulatory Treatment in Patients with Recurrent Miscarriage

Immunological risk factors in patients with recurrent miscarriage (RM) are discussed controversially. Abnormalities of natural killer cells (NK) have been described in RM patients. Lipid infusions are known to modulate lymphocyte subsets. The aim of this study was to identify immune parameters that predict success of treatment with lipid infusions in RM patients with elevated NK. In sum, n = 341 couples with RM were screened for established risk factors and peripheral lymphocyte subpopulations as well as uterine NK cells. We identified n = 136 patients with ≥ 2 consecutive RM and elevated NK. So far, n = 40 RM patients with NK disorders were treated with lipid infusions starting at positive pregnancy test, every 2 weeks until 12 + 0 weeks of gestation (GW) or miscarriage. The pre-pregnancy immune diagnostics in idiopathic RM (iRM) patients with ongoing pregnancy were compared to the group with miscarriages and healthy controls (n = 15). Pre-pregnancy immune diagnostics differed significantly between the groups, with significant higher levels of peripheral NK (% and /µL) in iRM patients who miscarried again compared to controls (p = 0.0035 and p = 0.0019). Furthermore, iRM patients show lower percentages of CD3⁺ lymphocytes than healthy controls (p = 0.0049). In n = 22/40 (55%) patients, pregnancy is ongoing >12 + 0 GW. RM patients with very high pre-pregnancy peripheral NK (pNK) lymphocytes might not benefit from lipid infusions. Pre-pregnancy immunomodulatory treatment in RM patients might be helpful to lower pNK levels and establish an immune environment which is supportive for fetal development.