Live Birth Rates after Active Immunization with Partner Lymphocytes

Exploring the Immunological Aspects and Treatments of Recurrent Pregnancy Loss and Recurrent Implantation Failure

Recurrent pregnancy loss (RPL) is defined as the occurrence of two or more consecutive pregnancy losses before 24 weeks of gestation. It affects 3-5% of women who are attempting to conceive. RPL can stem from a variety of causes and is frequently associated with psychological distress and a diminished quality of life. By contrast, recurrent implantation failure (RIF) refers to the inability to achieve a successful pregnancy after three or more high-quality embryo transfers or at least two instances of egg donation. RIF shares several causative factors with RPL. The immunological underpinnings of these conditions involve alterations in uterine NK cells, reductions in M2 macrophages and myeloid-derived suppressor cells, an increased Th1/Th2 ratio, a decreased Treg/Th17 ratio, the presence of shared ≥3 HLA alleles between partners, and autoimmune disorders. Various therapeutic approaches have been employed to address these immunological concerns, achieving varying degrees of success, although some therapies remain contentious within the medical community. This review intends to explore the immunological factors implicated in RPL and RIF and to analyze the immunological treatments employed for these conditions, which may include steroids, intravenous immunoglobulins, calcineurin inhibitors, anti-TNF antibodies, intralipid infusions, granulocyte colony-stimulating factor, and lymphocyte immunotherapy.

Alloimmune Causes of Recurrent Pregnancy Loss: Cellular Mechanisms and Overview of Therapeutic Approaches

Recurrent pregnancy loss (RPL) is a complex early pregnancy complication affecting 1-2% of couples and is often linked to immune dysfunction. Aberrations in T and B cell subpopulations, as well as natural killer (NK) cell activity, are particularly influential, with studies showing that abnormal NK cell activation and imbalances in T and B cell subtypes contribute to immune-mediated miscarriage risk. Successful pregnancy requires a tightly regulated balance between pro-inflammatory and anti-inflammatory immune responses. In the early stages, inflammation supports processes such as trophoblast invasion and spiral artery remodeling, but this must be tempered to prevent immune rejection of the fetus. In this review, we explore the underlying immune mechanisms of RPL, focusing on how dysregulated T, B, and NK cell function disrupts maternal tolerance. Specifically, we discuss the essential role of uterine NK cells in the early stages of vascular remodeling in the decidua and regulate the depth of invasion by extravillous trophoblasts. Furthermore, we focus on the delicate Treg dynamics that enable the maintenance of optimal immune homeostasis, where the balance, and not only the quantity of Tregs, is crucial for fostering maternal-fetal tolerance. Other T cell subpopulations, such as Th1, Th2, and Th17 cells, also contribute to immune imbalance, with Th1 and Th17 cells promoting inflammation and potentially harming fetal tolerance, while Th2 cells support immune tolerance. Finally, we show how changes in B cell subpopulations and their functions have been associated with adverse pregnancy outcomes. We further discuss current therapeutic strategies aimed at correcting these immune imbalances, including intravenous immunoglobulin (IVIg), glucocorticoids, and TNF-α inhibitors, examining their efficacy, challenges, and potential side effects. By highlighting both the therapeutic benefits and limitations of these interventions, we aim to offer a balanced perspective on clinical applications for women facing immune-related causes of RPL.

Molecular Determinants of Uterine Receptivity: Comparison of Successful Implantation, Recurrent Miscarriage, and Recurrent Implantation Failure

Embryo implantation is one of the most remarkable phenomena in human reproduction and is not yet fully understood. Proper endometrial function as well as a dynamic interaction between the endometrium itself and the blastocyst-the so-called embryo-maternal dialog-are necessary for successful implantation. Several physiological and molecular processes are involved in the success of implantation. This review describes estrogen, progesterone and their receptors, as well as the role of the cytokines interleukin (IL)-6, IL-8, leukemia inhibitory factor (LIF), IL-11, IL-1, and the glycoprotein glycodelin in successful implantation, in cases of recurrent implantation failure (RIF) and in cases of recurrent pregnancy loss (RPL). Are there differences at the molecular level underlying RIF or RPL? Since implantation has already taken place in the case of RPL, it is conceivable that different molecular biological baseline situations underlie the respective problems.

Effects of NGS-based PGT-a for idiopathic recurrent pregnancy loss and implantation failure: a retrospective cohort study

To clarify the effect of next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) combined with trophectoderm (TE) biopsy on the pregnancy outcomes of idiopathic recurrent pregnancy loss (iRPL) and idiopathic recurrent implantation failure (iRIF), we conducted a retrospective cohort study of 212 iRPL couples and 66 iRIF couples who underwent PGT-A or conventional in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. The implantation rate (IR) per transfer (64.2%), clinical pregnancy rate (CPR) per transfer (57.5%), and live birth rate (LBR) per transfer (45%) of iRPL couples of the PGT-A treatment group were significantly higher (p < 0.05) than those of the conventional IVF/ICSI group (IR per transfer,38.2%; CPR per transfer,33.3%; LBR per transfer, 28.4%), whereas the pregnancy loss rate (PLR) per transfer was similar between the two groups. These effects were also significant (p < 0.05) in iRPL couples with advanced maternal age (AMA, ≥35 years), whereas no significant differences were found in clinical outcomes between the PGT-A and conventional IVF/ICSI groups in younger iRPL couples (<35 years). The cumulative clinical outcomes of iRPL couples were comparable between the PGT-A and conventional IVF/ICSI groups. No significant differences were found in any clinical outcomes between the PGT-A and conventional IVF/ICSI groups for young or AMA couples with iRIF. In conclusion, NGS-based PGT-A involving TE biopsy may be useful for iRPL women to shorten the time to pregnancy and reduce their physical and psychological burden, especially for iRPL women with AMA; however, couples with iRIF may not benefit from PGT-A treatment. Considering the small sample size of the iRIF group, further investigations with a larger sample size are needed to verify our findings.

Immune Cell Functionality during Decidualization and Potential Clinical Application

Due to a vast influx in the secretory phase of the menstrual cycle, leukocytes represent 40-50% of the decidua at the time of implantation. Their importance for the implantation, maintenance of pregnancy, and parturition are known yet not fully understood. Thus, in idiopathic infertility, decidual immune-related factors are speculated to be the cause. In this review, the immune cell functions in the decidua were summarized, and clinical diagnostics, as well as interventions, were discussed. There is a rising number of commercially available diagnostic tools. However, the intervention options are still limited and/or poorly studied. In order for us to make big steps towards the proper use of reproductive immunology findings, we need to understand the mechanisms and especially support translational research.

Recurrent implantation failure: A comprehensive summary from etiology to treatment

Implantation is the first step in human reproduction. Successful implantation depends on the crosstalk between embryo and endometrium. Recurrent implantation failure (RIF) is a clinical phenomenon characterized by a lack of implantation after the transfer of several embryos and disturbs approximately 10% couples undergoing in vitro fertilization and embryo transfer. Despite increasing literature on RIF, there is still no widely accepted definition or standard protocol for the diagnosis and treatment of RIF. Progress in predicting and preventing RIF has been hampered by a lack of widely accepted definitions. Most couples with RIF can become pregnant after clinical intervention. The prognosis for couples with RIF is related to maternal age. RIF can be caused by immunology, thrombophilias, endometrial receptivity, microbiome, anatomical abnormalities, male factors, and embryo aneuploidy. It is important to determine the most possible etiologies, and individualized treatment aimed at the primary cause seems to be an effective method for increasing the implantation rate. Couples with RIF require psychological support and appropriate clinical intervention. Further studies are required to evaluate diagnostic method and he effectiveness of each therapy, and guide clinical treatment.

Adverse drug reactions following lymphocyte immunotherapy for the treatment of infertility: A retrospective study

AIM

Unexplained infertility is a major burden for couples who want to have children. Lymphocyte immunotherapy (LIT) could be a therapeutic help for these couples. Although LIT has been carried out for decades, the data on the success of therapy are still controversial and there is hardly information on possible adverse drug reactions.

METHODS

In this study, we used a questionnaire to determine the frequency of local and systemic adverse drug reactions in our patients who were treated with LIT between 2017 and 2020 (n = 302). In addition, we asked about pregnancies and/or live births after LIT in a 2-year follow-up (n = 140).

RESULTS

Most of the patients reported the occurrence of mild local adverse drug reactions in a period of less than 4 weeks: Over 75% reported moderate erythema, itching or swelling, over 10% erythema, itching or swelling as more pronounced adverse drug reaction. Blistering was specified in 10% of the cases. Serious adverse drug reactions or adverse events were not described. In the follow-up, 69% of our patients stated a pregnancy after LIT, and 50% a life birth.

CONCLUSIONS

Overall, LIT represents a well-tolerated therapy for couples with unexplained infertility, however, more evidence is needed on the benefits.

MTR, MTRR and CBS Gene Polymorphisms in Recurrent Miscarriages: A Case Control Study from North India

Background:

According to various epidemiological studies, the aetiology of recurrent miscarriages (RMs) is multifactorial. The goal of this study is to learn more about the link between genetic polymorphisms and RM.

Aim:

To evaluate the association of 5-Methytetrahydrofolate-Homocysteine Methyltransferase (MTR) A2756G, 5-Methytetrahydrofolate-Homocysteine Methyltransferase Reductase (MTRR) A66G and cystathionine beta-synthase (CBS) 844INS68 genetic polymorphisms with RM and also to understand the combined effect of the selected genotypes.

Study Setting and Design:

This was a hospital-based, case–control, observational study.

Materials and Methods:

A total of 516 participants were recruited in the present study, of which 200 RM cases and 258 controls were included in the present study. Fasting blood sample (~5ml) was drawn from all the participants and were screened for genetic polymorphisms of MTR A2756G, MTRR A66G and CBS 844INS68.

Statistical Analysis:

The frequency, odd's ratio and Hardy-Weinberg equilibrium were evaluated. SPSS (version 21.0) was used for the data analysis.

Results:

MTR A2756G genetic polymorphism was not associated with the risk of RM. The ancestral allele of MTRR A66G and the mutant allele of CBS 844INS68 was causing an increased risk of more than two folds for RM. CBS 844INS68 in combination with MTR A2756G was found to pose an increased risk of more than two folds for RM.

Conclusion:

Genetic polymorphisms particularly MTRR A66G and CBS 844INS68 seems to be elevating the risk and hence making women susceptible for RM.