Treatment efficacy for idiopathic recurrent pregnancy loss - a systematic review and meta-analyses

The safety and efficacy of tumor necrosis factor-alpha inhibitor on pregnancy outcomes in patients with unexplained recurrent miscarriage

OBJECTIVES

Although tumor necrosis factor-alpha inhibitor (TNFi) treatment may improve pregnancy outcomes in unexplained recurrent miscarriage (URM) patients, evidence for its efficacy and safety is still insufficient. The goal of this study was to evaluate the efficacy and safety of TNFi on pregnancy outcomes in patients with URM.

METHODS

This retrospective study was conducted at a single institution in China, involving 121 patients treated with TNFi for URM from 2019 to 2022. Patients enrolled were divided into treatment group (receiving TNFi and heparin therapy) and control group (receiving heparin therapy). The outcome variables were the 24-week live birth rate, miscarriage rate, ectopic pregnancy rate, neonatal outcomes, and adverse events.

RESULTS

In our study, patients receiving TNFi treatment exhibited a significant increase in live birth rates, achieving 71.2 % compared to the 50.9 % observed in the control group (OR 2.507, 95 % CI: 1.127-5.579). Concurrently, there was a discernible reduction in the miscarriage rate within the TNFi-treated group, marking 24.2 %, in contrast to 43.6 % in the control group (OR 0.387, 95 % CI: 0.170-0.884). Subgroup analyses further illuminated that those under the age of 35 benefitted remarkably from TNFi treatment, with live birth rates soaring to 62.5 % (OR 2.525, 95 % CI: 1.041-6.125). For patients with a history of two miscarriages, the TNFi regimen significantly augmented the live birth rate to 58.9 % (OR 3.044, 95 % CI: 1.039-8.921). Patients with a normal weight range registered a 58.4 % live birth rate post-TNFi treatment (OR 4.261, 95 % CI: 1.539-11.397). Notably, an evident interaction between BMI and TNFi treatment was identified, suggesting a potential modulatory role of BMI on the therapeutic efficacy of TNFi. About safety assessments, neither the TNFi-treated group nor the control manifested any significant disparities in liver function abnormalities, platelet count anomalies, or other pregnancy-related complications.

CONCLUSIONS

TNFi, alongside basic therapy, notably enhances the live birth rate in URM patients under 35, with two prior miscarriages or a normal BMI, without increasing adverse event risk. Further prospective studies are essential to validate these observations.

Maternal-Fetal Compatibility in Recurrent Pregnancy Loss

Nowadays, recurrent pregnancy loss (RPL) is an undesirable condition suffered by many patients of reproductive age. In this scenario, certain immune cell populations and molecules, involved in maternal-fetal compatibility, have emerged as factors related with the pathogenesis of RPL. Among them, uterine Natural Killer cells (uNKs) appear to be of great relevance. These cells are involved in numerous processes during pregnancy, such as the remodeling of uterine spiral arteries or the control of trophoblast invasion. These functions are regulated by the interactions that these cells establish with the extravillous trophoblast, mainly through their Killer Immunoglobulin-like Receptors (KIRs) and the Human Leukocyte Antigen-C (HLA-C) molecules expressed by the embryo. A high level of polymorphism has been reported for both molecules involved in this interaction, with some of the possible KIR-HLA-C combinations being associated with an increased risk of RPL. However, the complexity of the maternal-fetal interface goes beyond this, as other HLA molecules also appear to be related to this reproductive pathology. In this review, we will discuss the role of uNKs in pregnancy, as well as the polymorphisms and clinical implications of KIR-HLA-C binding. We will also address the involvement of other, different HLA molecules in RPL, and the current advice on the appropriate management of patients with 'immunological mismatch', thus covering the main aspects regarding the involvement of maternal-fetal compatibility in RPL.

The use of immunotherapies for recurrent miscarriage: An overview of systematic reviews and meta-analysis

Immunotherapies have been a treatment proposed for recurrent miscarriages (RMs). The use of immunotherapies remains not recommended in the management of couples with RM. This overview of systematic reviews and meta-analysis (SRs-MAs) aims to identify and evaluate the quality of SRs-MAs that studied the effectiveness of immunotherapies in the treatment of RM patients. SRs-MAs were searched in PubMed/Medline, Embase, and Web of Science. SRs-MAs were analyzed using AMSTAR-2, PRISMA 2020, Risk of Bias in Systematic (ROBIS), and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tools to evaluate the methodological quality, reporting quality, risk of bias, and evidence quality of included SRs-MAs, respectively. This review included 20 SRs-MAs that evaluated the following immunotherapies: intravenous immunoglobulin (13 publications), lymphocyte immunotherapy (6 publications), corticosteroids (3 publications), and lipid emulsion (1 publication). SRs-MAs were rated as high methodological, moderate, and critically low quality in 14 (70 %), 1 (5 %), and 5 (25 %) SRs-MAs and high reporting, moderate, and low quality in 13 (65 %), 4 (20 %), and 3 (5 %) SRs-MAs, respectively. The overall risk of bias revealed a low risk of bias for three-quarters of the SRs-MAs. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) analysis resulted in 23 outcomes, of which 4, 3, 5, and 11 results were of high, moderate, low, and very low quality, respectively. An improvement has been observed over the past few years in the quality of systematic reviews (SR)-MAs that have investigated the efficacy of intravenous immunoglobulin, lymphocyte immunotherapy, lipid emulsion therapy, and corticosteroids as a therapy for RM.

Increased Live Birth Rate with Dydrogesterone among Patients with Recurrent Pregnancy Loss Regardless of Other Treatments

BACKGROUND

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies. Several treatment options are available, including progesterone, which is one of the few treatments that improve live birth rates in RPL patients.

OBJECTIVE

To compare the live birth rates, medical and obstetric characteristics, and RPL evaluation results of women with and without progesterone treatment. These women attended the RPL clinic at Soroka University Medical Center.

METHODS

A retrospective cohort study based on 866 patients was conducted. The patients were divided into two groups and examined: the dydrogesterone treatment group consisting of 509 women and a group of 357 patients who did not receive the treatment. All the patients had a subsequent (index) pregnancy.

RESULTS

The two groups were not statistically different in terms of their demographic and clinical characteristics or evaluation results. In a univariate analysis, no statistically significant differences were found between the groups in terms of live birth rates (80.6% vs. 84%; p-value = 0.209). In a multivariate logistic analysis adjusted for maternal age, the ratio of pregnancy losses to the number of pregnancies, other administered treatments, antiphospholipid syndrome, and body mass index, dydrogesterone treatment was found to be independently associated with a higher rate of live births than the control group (adjusted OR = 1.592; CI 95% 1.051-2.413; p-value = 0.028).

CONCLUSIONS

Progesterone treatment is associated with an increased live birth rate in RPL patients. Studies with larger sample sizes are recommended to strengthen these results.

Prevention of Pregnancy Loss: Combining Progestogen Treatment and Psychological Support

Pregnancy loss can be defined as a loss before either 20 or 24 weeks of gestation (based on the first day of the last menstrual period) or the loss of an embryo or fetus less than 400 g in weight if the gestation age is unknown. Approximately 23 million pregnancy losses occur worldwide every year, equating to 15-20% of all clinically recognized pregnancies. A pregnancy loss is usually associated with physical consequences, such as early pregnancy bleeding ranging in severity from spotting to hemorrhage. However, it can also be associated with profound psychological distress, which can be felt by both partners and may include feelings of denial, shock, anxiety, depression, post-traumatic stress disorder, and suicide. Progesterone plays a key part in the maintenance of a pregnancy, and progesterone supplementation has been assessed as a preventative measure in patients at increased risk of experiencing a pregnancy loss. The primary objective of this piece is to assess the evidence for various progestogen formulations in the treatment of threatened and recurrent pregnancy loss, postulating that an optimal treatment plan would preferably include a validated psychological support tool as an adjunct to appropriate pharmacological treatment.

Preconceptual thyroid peroxidase antibody positivity in women with recurrent pregnancy losses may contribute to an increased risk for another miscarriage

OBJECTIVE

To investigate preconceptual thyroid peroxidase antibody (TPO-ab) positivity and/or thyroid stimulating hormone (TSH) levels in the upper range of normal as risk factors for recurrent unexplained first-trimester miscarriage.

DESIGN

A post-hoc study of a randomized trial, in which acetylsalicylic acid did not affect the risk of a new miscarriage.

PATIENTS

Women (n = 483) with at least three unexplained recurrent first-trimester miscarriages investigated at a Swedish secondary referral center.

MEASUREMENTS

The levels of TPO-ab and TSH were determined before pregnancy. The occurrence of a new first-trimester miscarriage was analyzed by logistic regression with adjustments when applicable, for age, number of previous miscarriages, obesity and the investigated covariates levels of TPO-ab and TSH.

RESULTS

Including all first trimester miscarriages, odds ratio (OR) according to presence of TPO-ab was 1.60 (95% confidence interval [CI]; 0.99-2.57), after adjustment 1.54 (95% CI; 0.94-2.53). Very early (biochemical) pregnancy losses occurred more often in women with than without preconceptual TPO-ab (6.8% vs. 2.0%), OR 3.51 (95% CI; 1.15-10.71), after adjustment 2.91 (95% CI; 0.91-9.29). There was no association between TSH in the upper range of normal and a new miscarriage, adjusted OR 0.76 (95% CI; 0.32-1.83). A prediction model for a new miscarriage included number of previous miscarriages, woman's age and presence of TPO-ab.

CONCLUSION

In women with at least three recurrent unexplained pregnancy losses, the presence of TPO-ab may contribute to an increased risk of a first-trimester miscarriage, possibly more pronounced in very early pregnancy. TSH levels 2.5-4.0 mU/L do not seem to increase the miscarriage risk.

Association of B Cells with Idiopathic Recurrent Pregnancy Loss: A Systematic Review and Meta-Analysis

Recurrent pregnancy loss (RPL) affects 1-2% of women and is defined as having experienced two or more failed pregnancies. In almost 50% of cases, the causes are idiopathic (IRPL), but increasing evidence has suggested an immunological cause. B cells are known to provide crucial support for a successful pregnancy outcome. However, their involvement in the mechanisms underlying IRPL is still unclear. This systematic review and meta-analysis aimed to comprehensively summarise the existing evidence regarding the levels and profiles of B cells in IRPL. An extensive computerized search in PubMed/Medline, Embase, Scopus, and Web of Science databases was performed with no imposed limits. Two reviewers independently screened all retrieved studies, extracted all the data, and assessed the methodological quality. Disagreements were resolved by a third reviewer. From a total of 1125 retrieved studies, 19 studies were included in the systematic review, and 8 studies were quantitatively analysed. We highlight a potential association between women with IRPL and increased levels of endometrial B cells. In addition, the flow cytometry technique seems to be preferred over immunohistochemistry for identifying those differences, while further studies are necessary to clarify the role of B cells as an immunological risk factor for RPL.

Understanding recurrent pregnancy loss: recent advances on its etiology, clinical diagnosis, and management

Recurrent pregnancy loss (RPL) has become an important reproductive health issue worldwide. RPL affects about 2%-3% of reproductive-aged women, and makes serious threats to women's physical and mental health. However, the etiology of approximately 50% of RPL cases remains unknown (unexplained RPL), which poses a big challenge for clinical management of these patients. RPL has been widely regarded as a complex disease where its etiology has been attributed to numerous factors. Heretofore, various risk factors for RPL have been identified, such as maternal ages, genetic factors, anatomical structural abnormalities, endocrine dysfunction, prethrombotic state, immunological factors, and infection. More importantly, development and applications of next generation sequencing technology have significantly expanded opportunities to discover chromosomal aberrations and single gene variants responsible for RPL, which provides new insight into its pathogenic mechanisms. Furthermore, based upon patients' diagnostic evaluation and etiologic diagnosis, specific therapeutic recommendations have been established. This review will highlight current understanding and recent advances on RPL, with a special focus on the immunological and genetic etiologies, clinical diagnosis and therapeutic management.

The effect of paternal and maternal factors on the prognosis of live birth in couples with recurrent pregnancy loss

INTRODUCTION

Currently, recurrent pregnancy loss (RPL) examinations focus on the woman, although paternal factors are also involved. Men in couples with RPL have higher sperm DNA fragmentation levels than fertile men, but the effect of sperm DNA damage on couple's later prognosis is unknown. Advanced maternal age and obesity are associated with RPL, but paternal lifestyle factors are less studied. Therefore, we aimed to study the associations of couples' lifestyle factors, causes of RPL, and sperm DNA fragmentation with their prognosis of future live birth.

MATERIAL AND METHODS

This descriptive cohort study comprised 506 couples investigated for RPL at Helsinki University Hospital, Finland, between 2007 and 2016, linked with national health and population registers. The primary outcome was couple's live birth after RPL investigations. Data on couple's background factors, including age, body mass index, smoking, and alcohol use, were collected from medical records. Sperm DNA fragmentation index was analyzed from 211 men using the sperm chromatin dispersion test. The associations between background factors, sperm DNA fragmentation, and cumulative probability of live birth over time were analyzed using cross-tabulations and age-adjusted Cox regression.

RESULTS

In all, 352 of 506 couples (69.6%) achieved live birth. Maternal age, unexplained RPL, prolonged pregnancy attempts before investigations, paternal obesity, and maternal smoking were associated with prognosis: unadjusted hazard ratio for couple's live birth for women aged 35-39 vs younger than 30 years was 0.63 (95% confidence interval [CI] 0.47-0.84), and for 40 years or older was 0.36 (95% CI 0.22-0.58). Age-adjusted hazard ratio for unexplained vs explained RPL was 1.39 (95% CI 1.12-1.72), for couple's pregnancy attempt at least 4 years vs less than 2 years was 0.50 (95% CI 0.33-0.76), for paternal body mass index at least 30 kg/m² vs less than 25 kg/m² was 0.67 (95% CI 0.46-0.98), and for maternal smoking was 0.71 (95% CI 0.51-0.99). Altogether, 96/135 (71.1%) couples with normal (<15%), 38/60 (63.3%) with intermediate (15-30%), and 11/16 (68.8%) with high sperm DNA fragmentation index achieved live birth (p = 0.56).

CONCLUSIONS

In couples with RPL, prolonged pregnancy attempts, a cause found in RPL examinations, lifestyle factors, and maternal age are negatively associated with their prognosis of future live birth. Sperm DNA fragmentation was not associated, but the number of men with damaged spermatozoa was small. We suggest that clinicians include women and men in RPL counseling because couple's joint lifestyle seems to determine their later prognosis.

Thyroid autoimmunity and its negative impact on female fertility and maternal pregnancy outcomes

Thyroid autoimmunity (TAI) is commonly defined as the presence of thyroperoxidase antibodies (TPOAbs) and/or thyroglobulin antibodies (TgAbs), which predisposes an individual to hypothyroidism. TAI affects nearly 10% of women of reproductive age and evokes great interest from clinicians because of its potentially negative impact on female fertility and pregnancy course. In this mini-review, we review the current literature concerning the influence of TPOAb or TPOAb/TgAb positivity without thyroid dysfunction on reproduction. TAI may negatively affect female fertility; several studies have found an increased prevalence of TAI in infertile women, especially in those with unexplained infertility and polycystic ovary syndrome. According to some observations, TAI might also be connected with premature ovarian insufficiency and endometriosis. The relationship between TAI and an increased risk of pregnancy loss is well documented. The pathophysiological background of these observations remains unclear, and researchers hypothesize on the direct infiltration of reproductive organs by thyroid antibodies, co-existence of TAI with other autoimmune diseases (either organ specific or systemic), immunological dysfunction leading to inhibition of immune tolerance, and relative thyroid hormone deficiency. Interestingly, in the current literature, better outcomes of assisted reproductive technology in women with TAI have been reported compared with those reported in earlier publications. One plausible explanation is the more widespread use of the intracytoplasmic sperm injection method. The results of randomized clinical trials have shown that levothyroxine supplementation is ineffective in preventing adverse pregnancy outcomes in women with TAI, and future research should probably be directed toward immunotherapy.

Correlation Between the Presence of Antinuclear Antibodies and Recurrent Pregnancy Loss: A Mini Review

In the past decade, the incidence of recurrent pregnancy loss (RPL) has increased significantly, and immunological disorders have been considered as one of the possible causes contributing to RPL. The presence of antinuclear antibodies (ANAs) is regarded as a typical antibody of autoimmunity. However, the relationship between the presence of ANAs and RPL, the underlying mechanism, and the possible role of immunotherapy is still controversial. The aim of this mini review is to assess the association between ANAs and RPL and the effects of immunotherapy on pregnancy outcomes in women with positive ANAs and a history of RPL from the available data and to provide a relevant reference basis for clinical application in this group of women.

Infertility and subsequent recurrent miscarriage: Current state of the literature and future considerations for practice and research

Background: Recurrent miscarriage (RM) and infertility are independently associated with adverse pregnancy outcomes, in addition to psychological sequelae. Experiencing pregnancy loss alongside infertility is particularly difficult. International guidance regarding RM is conflicting, and applicability to women with infertility is undetermined. The aim of this study was to: (i) establish if women/couples with a history of infertility are recognised in the literature on the investigation and management of RM, and (ii) determine if the specific needs of women/couples experiencing RM and infertility are ascertained and incorporated into clinical management strategies. Methods: We examined the wide-ranging literature to ascertain what gaps existed. Studies were retrieved through searches of PubMed and Google Scholar up to 21 January 2021 using appropriate controlled vocabulary and combinations of key words. No language or study design restrictions were applied. Results: While women/couples experiencing RM after infertility appear in studies evaluating investigations and proposed treatments, high-quality studies are lacking. Furthermore, they are largely excluded from international clinical guidance and qualitative research. Conclusions: The experiences of women/couples with RM and infertility and their specific care needs within maternity and fertility services are underexplored. It is unclear from current RM guidelines how best to manage and support this complex cohort. Women/couples with infertility and RM are underserved in the literature and in clinical guidance. Further robust studies are warranted to examine pregnancy outcomes, investigations and treatments currently used. Qualitative research is also required to identify their medical and psychological needs to better support this vulnerable group.

Genetic testing of products of conception in recurrent pregnancy loss evaluation

Genetic testing of products of conception (POC) has been proposed as a tool to be used in the evaluation of patients with recurrent pregnancy loss (RPL). Following a complete RPL evaluation, POC results may reveal an aneuploidy and provide an explanation for the miscarriage in more than 55% of cases. When the cytogenetic result of the pregnancy loss reveals a euploid pregnancy, management should be directed towards the identification of treatable abnormalities. Furthermore, the results of POC testing might better define a subgroup of patients with unexplained RPL who may benefit from expectant management versus preimplantation genetics (aneuploid unexplained RPL) or investigational therapy (euploid unexplained RPL).

Is there a Role of Intravenous Immunoglobulin in Immunologic Recurrent Pregnancy Loss?

Recurrent pregnancy loss (RPL) commonly refers to three or more miscarriages that occur before 20 weeks of pregnancy. The immunological cause of RPL could be either an auto- or alloimmune-related event or both. Because of the discovery of immunological abnormalities in RPL patients in clinical practice, several immunomodulatory therapies were introduced to maintain the immune balance at the maternal-fetal interface. Intravenous immunoglobulin (IVIg) is one of the immunomodulators. In recent years, several studies have analyzed the therapeutic effect of IVIg on RPL patients with antiphospholipid syndrome (APS) or unexplained RPL. However, their results are controversial. IVIg can be used in RPL patients with APS who have previously failed in other treatments. It is recommended that IVIg infusion could be considered used before conception in RPL patients who have cellular immune abnormalities such as increased natural killer (NK) cell counts, NK cell cytotoxicity, or increased T helper (Th)1/Th2 ratio, depending on the cut-off values of each hospital. The aim of this review was to summarize the mechanisms, efficacy, pharmacokinetics, and side effects associated with passive immunization using IVIg in immunologic RPL, according to the literature published in recent years. We hope that more obstetricians will be able to understand the timing and indication of IVIg properly in immunologic RPL patients and effectively enhance pregnancy outcomes for mothers and neonates.

A proposed prognostic prediction tool for a live birth among women with recurrent pregnancy loss

PURPOSE

To develop a prognostic tool to predict the live birth rate in cases of repeated pregnancy losses.

STUDY DESIGN

A retrospective cohort study including patients treated in the dedicated RPL clinic between 2000 and 2015. Background data was collected in the primary visit via questionnaires and medical records. The recurrent pregnancy loss workup includes a genetic testing, endocrine testing, and anatomic abnormalities as well as thrombophilia.The prognostic tool took into account the unique contribution of the different risk factors, including maternal age, number of pregnancy losses, primary vs. secondary RPL and positive RPL workup.

RESULTS

A total of 675 women were included in the study. The live birth rate was 72% (484). It was significantly associated with age (p=.002), number of previous pregnancy losses (p=.016), primary and secondary RPL and positive RPL workup. Each variable was assigned points according to the odds ratio found in the logistic regression to create two prediction models, before and after the RPL workup. Both models show a rise in the live birth rate as the score increases.

CONCLUSIONS

We constructed a proposed innovative prognostic tool to predict the chance of a live birth on the consecutive pregnancy following the visit to the RPL clinic. Locating, identifying and improving risk assessment can enable the provision of up-to-date information to couples and the treating staff. This knowledge will reduce stress among the patients and will allow the staff to constructed custom intervention programs.

Hold your needles in women with recurrent pregnancy losses with or without hereditary thrombophilia: Meta-analysis and review of the literature

OBJECTIVES

The use of antithrombotic prophylaxis in women with recurrent pregnancy losses (RPL) remains controversial.

METHODS

We performed meta-analysis of randomized controlled trials (RCTs) comparing low molecular weight heparin (LMWH) versus No LMWH in women with or without hereditary thrombophilia and RPL. Twelve RCTs met our inclusion criteria and 2298 women were included in this meta-analysis. Our primary end point was live birth and odds ratio (OR) for live birth are reported.

RESULTS

In women with thrombophilia the benefit of LMWH on live birth is not significant but heterogeneity of the studies is significant (OR, 2.09; 95 % CI, 0.58-7.57; p = 0.26; I² = 86 %, p = 0.0001). Considering women without thrombophilia there is no benefit of LMWH in OR of live birth and data from studies have low heterogeneity (OR, 1.25; 95 % CI, 0.88-1.78; p = 0 0.21; I² = 44 %, p = 0.07).

CONCLUSIONS

Hold your needles in women with RPL. Probably in some hereditary thrombophilic defects LMWH has a positive effect on OR for live birth.

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.

Preimplantation genetic testing in assisted reproduction technology

A significant proportion of clinically recognized pregnancies end in miscarriage. About 50 % of early pregnancy losses are due to chromosome abnormalities. In assisted reproduction technology (ART), a high proportion of top-quality embryos with morphological values are aneuploid whenever they have been evaluated in terms of genetic integrity in human preimplantation embryos either from in vitro or in vivo matured oocytes. It is plausible to think of preimplantation genetic testing (PGT) as a means of increasing pregnancy rates and minimizing the risk of fetal aneuploidy. It is believed that PGT will assume a prominent role in the field of ART, especially in a successful pregnancy, so it is embraced recently as a popular diagnostic technique. The PGT includes three sub-categories of PGT for aneuploidies (PGT-A), PGT for single gene / monogenic disorders (PGT-M), and PGT for chromosome structural rearrangements (PGT-SR). PGT-A is used to detect aneuploidies and previously it was known as PGS. PGT-M, formerly known as PGD, is intended to reduce monogenic defects. Previously known as PGS translocation, PGT-SR is PGT to identify structural chromosomal rearrangements. Since many of the old and new definitions for PGT are still vague and confusing for some researchers in the field of reproductive genetics, the main purpose of this study is to introduce all PGT classifications as well as elaborate on different aspects of this technology to improve ART outcomes.

Low-molecular-weight-heparin increases Th1- and Th17-associated chemokine levels during pregnancy in women with unexplained recurrent pregnancy loss: a randomised controlled trial

Low-molecular-weight heparin (LMWH) is widely used to treat recurrent pregnancy loss (RPL) because of its anti-coagulant effects. Although in vitro studies have suggested additional immunological effects, these are debated. We therefore investigated whether LMWH could modulate immune responses in vivo during pregnancy of women with unexplained RPL. A Swedish open multi-centre randomised controlled trial included 45 women treated with tinzaparin and 42 untreated women. Longitudinally collected plasma samples were obtained at gestational weeks (gw) 6, 18, 28 and 34 and analysed by multiplex bead technology for levels of 11 cytokines and chemokines, chosen to represent inflammation and T-helper subset-associated immunity. Mixed linear models test on LMWH-treated and untreated women showed differences during pregnancy of the Th1-associated chemokines CXCL10 (p = 0.01), CXCL11 (p < 0.001) and the Th17-associated chemokine CCL20 (p = 0.04), while CCL2, CCL17, CCL22, CXCL1, CXCL8, CXCL12, CXCL13 and IL-6 did not differ. Subsequent Student's t-test showed significantly higher plasma levels of CXCL10 and CXCL11 in treated than untreated women at gw 28 and 34. The consistent increase in the two Th1-associated chemokines suggests a potential proinflammatory and unfavourable effect of LMWH treatment during later stages of pregnancy, when Th1 immunity is known to disrupt immunological tolerance.

Reproductive immunology from the perspective of the clinician

Investigators generate new and innovative ideas needed to advance knowledge, while physicians want proven treatments that provide the best care for their patients. Along with advances in reproductive immunology research, there have also been controversies such as immunologic treatments for recurrent pregnancy loss. Research deficiencies that are wasteful and misleading include: over-interpretation and extrapolation from animal studies to the human, inadequate sample sizes, lack of appropriate control groups, use of surrogate markers, associations presented as causation, un-blinded testing and treatments, unreproducible results, and non-standardized outcomes. The purpose of the EQUATOR Network (Enhancing the QUAlity Of health Research) is to improve the quality of research and its publication. These guidelines (CONSORT, STROBE, PRISMA, STARD, ARRIVE) have been accepted as mandatory by virtually all major medical journals, and all investigators should prospectively incorporate them into their study designs. From the perspective of a clinician-scientist and an editor, my premise is that the purpose of much basic science research and all clinical research is to improve the medical care of patients. Unproven and costly diagnostic tests and treatments for potential immunologic clinical problems can no longer be justified. The primary and most important outcome that should be reported for all pregnancy-related immunologic studies is the live birth rate of a healthy infant. Today's clinicians and patients expect unbiased research that leads to evidence-based recommendations for practical and effective treatments.

Recurrent Implantation Failure-update overview on etiology, diagnosis, treatment and future directions

Recurrent implantation failure (RIF) refers to cases in which women have had three failed in vitro fertilization (IVF) attempts with good quality embryos. The definition should also take advanced maternal age and embryo stage into consideration. The failure of embryo implantation can be a consequence of uterine, male, or embryo factors, or the specific type of IVF protocol. These cases should be investigated to determine the most likely etiologies of the condition, as this is a complex problem with several variables. There are multiple risk factors for recurrent implantation failure including advanced maternal age, smoking status of both parents, elevated body mass index, and stress levels. Immunological factors such as cytokine levels and presence of specific autoantibodies should be examined, as well as any infectious organisms in the uterus leading to chronic endometritis. Uterine pathologies such as polyps and myomas as well as congenital anatomical anomalies should be ruled out. Sperm analysis, pre-implantation genetic screening and endometrial receptivity should be considered and evaluated, and IVF protocols should be tailored to specific patients or patient populations. Treatment approaches should be directed toward individual patient cases. In addition, we suggest considering a new initial step in approach to patients with RIF, individualized planned activities to activate the brain's reward system in attempt to improve immunological balance in the body.

Acetylsalicylic acid does not prevent first-trimester unexplained recurrent pregnancy loss: A randomized controlled trial

INTRODUCTION

Recurrent pregnancy loss occurs in about 1% of fertile couples. Without proper evidence for an effect, different treatments have been used when no etiological factor has been detected. The present trial is the first randomized trial to compare 75 mg acetylsalicylic acid with placebo for women with recurrent pregnancy loss.

MATERIAL AND METHODS

This randomized, double-blind, placebo-controlled trial was conducted at a single center between 2008 and 2015. Recurrent pregnancy loss was defined as at least 3 consecutive first-trimester miscarriages within the couple. Women < 40 years old with a body mass index < 35 kg/m² were eligible if the workup was negative. Randomization was through a third party, who manufactured and delivered the study drugs, and occurred when fetal heartbeat was detected, to either 75 mg acetylsalicylic acid or placebo; 200 women in each group. Group allocation was concealed until all the study participants had a pregnancy outcome registered. All women attended the same control program. Primary outcome was live birth. Statistical analyses were according to intention-to-treat.

RESULTS

All 400 women completed the follow up. Live birth rate was 83.0% (n = 166) and 85.5% (n = 171) for the acetylsalicylic acid and placebo groups, respectively (P = 0.58). The difference was -2.5% (95% CI -10.1% to 5.1%). The risk ratio was 0.97 (95% CI 0.89-1.06).

CONCLUSIONS

Treatment with acetylsalicylic acid did not prevent recurrent miscarriage in women with at least three consecutive miscarriages in the first trimester, of unknown reasons and in the same relationship. The fertility prognosis is very good, the live birth rate being > 80% with or without acetylsalicylic acid.