Efficacy of intrauterine administration of autologous peripheral blood mononuclear cells on the pregnancy outcomes in patients with recurrent implantation failure: A systematic review and meta-analysis

Uterine infusion strategies for infertile patients with recurrent implantation failure: a systematic review and network meta-analysis

BACKGROUND

Intra-uterine infusion treatments were reported to be beneficial to embryo implantation and pregnancy outcomes, and considered as potential therapies for infertile patients with recurrent implantation failure (RIF). Nevertheless, their efficiencies were controversial and there lack of consensus on which intrauterine treatment is the most effective.

METHODS

All prospective trials (in Chinese or English) were searched in Databases PubMed, Cochrane, Web of Science, and CNKI from July 2013 to July 2023. We included studies that investigated various uterine infusions, including chorionic gonadotropin, granulocyte colony-stimulating factor, monocytes, platelet-rich plasma, etc. during IVF treatment and reported subsequent pregnancy outcomes.

RESULTS

We finally included 56 researches, including 40 randomized controlled trials, 14 non-randomized controlled trials, and 3 prospective cohort studies. This study included a total of 11 uterine perfusion methods: Placebo, Human Chorionic Gonadotropin (HCG), Granulocyte Colony-Stimulating Factor (G-CSF), platelet-rich plasma (PRP), Peripheral Blood Mononuclear Cell (PBMC), Growth hormone (GH), dexamethasone (DEX), Embryo culture supernatant (ESC), PRP combined with G-CSF (PRP + G-CSF), RPR combined with subcutaneous injection of G-CSF (RPR + G-CSFsc), G-CSF combined with subcutaneous injection of AXaIU (G-CSF + AXaIUsc). Intrauterine infusion of HCG, PBMC, G-CSF, and PRP significantly improves pregnancy outcomes in patients with repeated implantation failure compared with blank controls or placebo, and PRP improved the clinical pregnancy and live birth most. GH and ESC infusion might improve the pregnancy outcomes, but uterine infusion of DEX was shown with high miscarriage. The combination therapy did not show a significant advantage over the mono-therapy.

CONCLUSIONS

Intrauterine infusion of HCG, PBMC, G-CSF, and PRP are promising strategies for improving pregnancy outcomes for infertile patients with recurrent implantation failure. Among these treatments, PRP may be the best. More researches are required to explore the effect of drug combinations and less commonly used drugs as well.

TRIAL REGISTRATION

Our study was registered in PROSPERO and the ID was CRD42023467188.

Sequential embryo transfer combined with intrauterine perfusion improved pregnancy outcomes in patients with recurrent implantation failure

OBJECTIVE

To compare the application of sequential embryo transfer, cleavage embryo transfer, and blastocyst transfer combined with intrauterine perfusion in frozen-thawed embryo transfer cycles in patients with recurrent implantation failure to provide a reference for reproductive clinicians.

METHODS

The 166 patients who underwent frozen-thawed embryo transfer due to recurrent implantation failure in the reproductive center from January 2021 to March 2022 were retrospectively analyzed. According to the different embryos transferred, they were divided into cleavage embryo transfer groups (72 cases in Group A), blastocyst transfer group (29 cases in Group B), and sequential transfer group (65 cases in Group C). All three groups were treated with intrauterine perfusion 5 days before embryo transfer. The general data and clinical pregnancy outcome indicators, such as embryo implantation rate, clinical pregnancy rate, ongoing pregnancy rate, live birth rate, twin rate, were compared among the three groups.

RESULTS

The embryo implantation rate (53.1%), clinical pregnancy rate (76.9%), ongoing pregnancy rate (67.7%) and live birth rate(66.15%) in the sequential transfer group were significantly higher than those in the other two groups (P < 0.05), and the ectopic pregnancy rate was lower in the sequential transfer group.

CONCLUSION

Sequential transfer combined with intrauterine perfusion partially improves clinical pregnancy outcomes and reduces the risk of ectopic pregnancy in frozen embryo cycle transfers in patients with recurrent implantation failure, which may be a favourable transfer reference strategy for patients with recurrent implantation failure.

Embryo Transfer Strategies for Women with Recurrent Implantation Failure During the Frozen-thawed Embryo Transfer Cycles: Sequential Embryo Transfer or Double-blastocyst Transfer?

OBJECTIVE

Both sequential embryo transfer (SeET) and double-blastocyst transfer (DBT) can serve as embryo transfer strategies for women with recurrent implantation failure (RIF). This study aims to compare the effects of SeET and DBT on pregnancy outcomes.

METHODS

Totally, 261 frozen-thawed embryo transfer cycles of 243 RIF women were included in this multicenter retrospective analysis. According to different embryo quality and transfer strategies, they were divided into four groups: group A, good-quality SeET (GQ-SeET, n=38 cycles); group B, poor-quality or mixed-quality SeET (PQ/MQ-SeET, n=31 cycles); group C, good-quality DBT (GQ-DBT, n=121 cycles); and group D, poor-quality or mixed-quality DBT (PQ/MQ-DBT, n=71 cycles). The main outcome, clinical pregnancy rate, was compared, and the generalized estimating equation (GEE) model was used to correct potential confounders that might impact pregnancy outcomes.

RESULTS

GQ-DBT achieved a significantly higher clinical pregnancy rate (aOR 2.588, 95% CI 1.267-5.284, P=0.009) and live birth rate (aOR 3.082, 95% CI 1.482-6.412, P=0.003) than PQ/MQ-DBT. Similarly, the clinical pregnancy rate was significantly higher in GQ-SeET than in PQ/MQ-SeET (aOR 4.047, 95% CI 1.218-13.450, P=0.023). The pregnancy outcomes of GQ-SeET were not significantly different from those of GQ-DBT, and the same results were found between PQ/MQ-SeET and PQ/MQ-DBT.

CONCLUSION

SeET relative to DBT did not seem to improve pregnancy outcomes for RIF patients if the embryo quality was comparable between the two groups. Better clinical pregnancy outcomes could be obtained by transferring good-quality embryos, no matter whether in SeET or DBT. Embryo quality plays a more important role in pregnancy outcomes for RIF patients.

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.

Effects of Intrauterine Infusion of Autologous Platelet-Rich Plasma in Women Undergoing Treatment with Assisted Reproductive Technology: a Meta-Analysis of Randomized Controlled Trials

Purpose This meta-analysis was conducted to systematically retrieve relevant randomized controlled trials (RCTs) and evaluate the effects of intrauterine infusion of autologous platelet-rich plasma (PRP) in women with thin endometrium, implantation or pregnancy failure undergoing treatment with assisted reproductive technology (ART).

Methods We conducted a systematic review and meta-analysis of the retrieved RCTs. Studies on the intrauterine infusion of PRP in women undergoing treatment with ART that were published in PubMed, the Cochrane library, Web of Science, and Embase from inception until June 2022 were included. The data were extracted and analyzed independently using the fixed-effects or random-effects model according to heterogeneity.

Results Seven RCTs involving 861 patients (435 in the intervention group and 426 in the control group) were included. The rates of clinical pregnancy (risk ratio [RR]: 2.51; 95% confidence interval [CI]: 2.0–3.13; P < 0.00001), chemical pregnancy (RR: 1.96; 95% CI: 1.58–2.45; P < 0.00001), live births (RR: 7.03; 95% CI: 3.91–12.6; P < 0.00001), and implantation (RR: 3.27; 95% CI: 1.42–7.52; P = 0.005) were significantly higher in the women who received PRP infusion than in the control group. No significant differences were noted in the miscarriage rate (RR: 0.98; 95% CI: 0.39–2.42; P = 0.96) between the two groups.

Conclusion In summary, intrauterine infusion of PRP may be an effective therapy for women with thin endometrium and recurrent implantation failure (RIF) undergoing treatment with ART. More population-based RCTs are warranted to verify the efficacy of our evidence.

The effectiveness of immunomodulatory therapies for patients with repeated implantation failure: a systematic review and network meta-analysis

This meta-analysis analyzed the clinical pregnancy outcomes of repeated implantation failure (RIF) patients treated with immunomodulatory therapies. Publications (published by August 16, 2021) were identified by searching the PubMed, Embase, and Web of Science databases. The quality of the studies was evaluated with the Cochrane bias risk assessment tool, and a network meta-analysis was performed with Stata 14.0. The outcomes were clinical pregnancy rate (CPR), live birth rate (LBR), and implantation rate (IR). The results of our network meta-analysis of 16 RCTs (including 2,008 participants) show that PBMCs, PRP, and SC-GCSF can significantly improve the CPR compared with LMWH (PBMCs: OR 2.15; 95% CI 1.21-3.83; PRP: OR 2.38; 95% CI 1.08-5.24; SC-GCSF: OR 2.46; 95% CI 1.05-5.72). The LBR of PRP was significantly higher than those of IU-GCSF (OR 3.81; 95% CI 1.22-11.86), LMWH (OR 4.38; 95% CI 1.50-12.90), and intralipid (OR 3.85; 95% CI 1.03-14.29), and the LBR of PBMCs was also significantly better than that of LMWH (OR 2.35; 95% CI 1.14-4.85). Furthermore, PRP treatment significantly improved the IR compared with LMWH treatment (OR 2.81; 95% CI 1.07-7.4). The limited evidence from existing RCTs suggests that PBMCs and PRP are the best therapeutic options for RIF patients. However, owing to the quantity limitation, more top-quality research is required to obtain additional high-level evidence.

Evaluating interventions and adjuncts to optimize pregnancy outcomes in subfertile women: an overview review

BACKGROUND

There is a wealth of information regarding interventions for treating subfertility. The majority of studies exploring interventions for improving conception rates also report on pregnancy outcomes. However, there is no efficient way for clinicians, researchers, funding organizations, decision-making bodies or women themselves to easily access and review the evidence for the effect of adjuvant therapies on key pregnancy outcomes in subfertile women.

OBJECTIVE AND RATIONALE

The aim was to summarize all published systematic reviews (SRs) of randomized controlled trials (RCTs) of interventions in the subfertile population, specifically reporting on the pregnancy outcomes of miscarriage and live birth. Furthermore, we aimed to highlight promising interventions and areas that need high-quality evidence.

SEARCH METHODS

We searched the Cochrane Database of Systematic Reviews and PubMed clinical queries SR filter (inception until July 2021) with a list of key words to capture all SRs specifying or reporting any miscarriage outcome. Studies were included if they were SRs of RCTs. The population was subfertile women (pregnant or trying to conceive) and any intervention (versus placebo or no treatment) was included. We adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) for determining the quality of the evidence. Exclusion criteria were overview reviews, reviews that exclusively reported on women conceiving via natural conception, reviews including non-randomized study designs or reviews where miscarriage or live birth outcomes were not specified or reported.

OUTCOMES

The primary outcome was miscarriage, defined as pregnancy loss <24 weeks of gestation. Data were also extracted for live birth where available. We included 75 published SRs containing 121 251 participants. There were 14 classes of intervention identified: luteal phase, immunotherapy, anticoagulants, hCG, micronutrients, lifestyle, endocrine, surgical, pre-implantation genetic testing for aneuploidies (PGT-As), laboratory techniques, endometrial injury, ART protocols, other adjuncts/techniques in the ART process and complementary interventions. The interventions with at least moderate-quality evidence of benefit in reducing risk of miscarriage or improving the chance of a live birth are: intrauterine hCG at time of cleavage stage embryo transfer, but not blastocyst transfer, antioxidant therapy in males, dehydroepiandrosterone in women and embryo medium containing high hyaluronic acid. Interventions showing potential increased risk of miscarriage or reduced live birth rate are: embryo culture supernatant injection before embryo transfer in frozen cycles and PGT-A with the use of fluorescence in situ hybridization.

WIDER IMPLICATIONS

This review provides an overview of key pregnancy outcomes from published SRs of RCTs in subfertile women. It provides access to concisely summarized information and will help clinicians and policy makers identify knowledge gaps in the field, whilst covering a broad range of topics, to help improve pregnancy outcomes for subfertile couples. Further research is required into the following promising interventions: the dose of progesterone for luteal phase support, peripheral blood mononuclear cells for women with recurrent implantation failure, glucocorticoids in women undergoing IVF, low-molecular-weight heparin for unexplained subfertility, intrauterine hCG at the time of cleavage stage embryo or blastocyst transfer and low oxygen concentrations in embryo culture. In addition, there is a need for high-quality, well-designed RCTs in the field of reproductive surgery. Finally, further research is needed to demonstrate the integrated effects of non-pharmacological lifestyle interventions.

Comparative efficacies of different immunotherapy regimens in recurrent implantation failure: A systematic review and network meta-analysis

For patients with recurrent implantation failure (RIF), immune system imbalances have become the focus of research. The effects of different classes of immunotherapies on improving pregnancy outcomes have not been fully established. This network meta-analysis was performed to assess the impact of popular immunotherapies in women with RIF. We systematically searched the Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of Science databases as well as clinical trial registration websites. Randomized controlled trials comparing immunotherapeutic outcomes were included. We performed the random-effects network meta-analysis to compare efficacy measures. A total of 21 trials involving 2277 participants and 8 immunotherapies were eligible for this study. Patients that had been administered with PBMCs, G-CSF, PRP, and sirolimus exhibited higher CPR than those administered with the placebo (2.63, 1.71-4.06; 2.03, 1.35-3.05; 1.98, 1.02-3.84; 2.55, 1.36-4.79; and 3.95, 1.33-11.72, respectively). For IR, only PBMCs and G-CSF were significantly more effective than the placebo (2.92, 1.39-6.12; 2.66, 1.16-6.06, respectively). In terms of LBR, PBMCs (2.96, 1.67-5.27) and sirolimus (3.55, 1.18-10.64) were effective. However, r-hLIF (0.25, 0.10-0.62) had a reduced risk of LBR. No therapeutic regimen was found to have significantly decreased MR, but PBMCs exhibited the lowest rank among all interventions (0.28, 0.06-1.44). To improve clinical pregnancy while reducing miscarriage outcomes, PBMCs might be a beneficent therapeutic option for RIF in the future.

Immune checkpoints and reproductive immunology: Pioneers in the future therapy of infertility related Disorders?

As co-stimulatory receptors, immune checkpoint molecules are found on the surface of various immune cells and transduce inhibitory signals following ligand binding. The most studied members in this regard include PD-1, TIM-3, and CTLA-4. The physiological part immune checkpoints possess is the prevention of dangerous immune attacks towards self-antigens throughout an immune response, which takes place through the negative regulation of the effector immune cells, through the induction of T-cell exhaustion, for instance. It has recently been suggested that each checkpoint reduces immunoactivation via distinct intracellular mechanisms of signaling. Regulators of immune checkpoints are supposed to participate actively in immune defense mechanisms against infections, preventing autoimmunity, transplantation, and tumor immune evasion. In pregnancy, as an active immunotolerance mechanism which is also natural, the maternal immune system encounters two simultaneous challenges; in addition to accepting the semi-allogeneic fetus, the maternal immune system should also prevent infections. In this regard, the part immune checkpoint molecules possess is particularly interesting. Herein, the current understanding of such part in reproductive immunology is described.

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.

Approaches to Improve Endometrial Receptivity in Case of Repeated Implantation Failures

Repeated implantation failures are a constant challenge in reproductive medicine with a significant impact both on health providers and on infertile couples. Several approaches have been proposed so far as effective; however, accumulative data have clarified that most of the treatment options do not have the evidence base for a generalized application to be suggested by the relevant societies. Implantation failures are attributed to either poor quality embryos or to defected endometrial receptivity. The current review aims to summarize in a systematic way all the new trends in managing RIF via interference with endometrial receptivity. The authors focus mainly, but not exclusively, on endometrial injury prior to embryo transfer and endometrial priming with autologous cells or biological agents. To this direction, a systematic search of the Pubmed database has been conducted taking into account the emerged evidence of the last two decades. All the suggested interventions are herein presented and analyzed in terms of reproductive outcomes. It is evident that properly powered and designed randomized trials are needed to support a new standard approach in RIF treatment that will safely be incorporated in national and international guidelines.

Lymphocyte immunotherapy in recurrent miscarriage and recurrent implantation failure

PROBLEM

Lymphocyte immunotherapy (LIT) emerged in the early 1980s as a new therapeutic proposal for couples with a history of recurrent miscarriages (RM). However, in the early 2000s, the effectiveness of LIT was questioned. Recently, meta-analyses have observed the effectiveness and safety of LIT in treating couples with RM. Some studies evaluated the use of LIT in recurrent implantation failure (RIF) in in vitro fertilization cycles.

METHODS

This systematic and narrative review evaluated the data available in the literature regarding the efficacy and safety of the use of LIT. Searches in PubMed/Medline, Embase, and Cochrane Library databases were conducted, using the following keywords: "recurrent miscarriage," "lymphocyte immunotherapy," and "recurrent implantation failure".

RESULTS

This review describes the historical aspects of LIT and discusses its protocols, mechanisms of action, side effects, complications, and current evidence of the effectiveness in cases of reproductive failure. It also discusses the use of LIT during the COVID-19 pandemic and new immunological therapies.

CONCLUSION

In the vast majority of studies, the use of LIT for RM couples has shown an improvement in pregnancy outcomes. The most of the current studies that support the evidence are quasi-experimental, with few randomized, double-blind studies (Level of evidence III). However, the current evidence are not convincing for the use of LIT in RIF patients.

Efficacy of therapies and interventions for repeated embryo implantation failure: a systematic review and meta-analysis

The aim of the present systematic review and meta-analysis was to assess the effect of the different therapeutic options for repeated embryo implantation failure (RIF) on a subsequent IVF cycle outcome. Twenty-two RCTs and nineteen observational studies were included. Pooling of results showed a beneficial effect of intrauterine PBMC infusion on both CPR (RR 2.18; 95% CI 1.58-3.00; p < 0.00001; OR 2.03; 95% CI 1.22-3.36; p = 0.006) and LBR (RR 2.41; 95% CI 1.40-4.16; p = 0.002; OR 3.73; 95% CI 1.13-12.29; p = 0.03), of subcutaneous G-CSF administration on CPR (RR 2.29; 95% CI 1.58-3.31; p < 0.0001) and of intrauterine PRP infusion on CPR (RR 2.45; 95% CI 1.55-3.86; p = 0.0001). Observational studies also demonstrated a positive effect of IVIG and intrauterine hCG infusion on both CPR and LBR and of atosiban on CPR. Studies investigating intrauterine G-CSF infusion, LMWH, intravenous intralipid, hysteroscopy, blastocyst-stage ET, ZIFT, PGT-A and AH failed to observe an impact on IVF outcome. The quality of the evidence that emerged from RCTs focused on intrauterine PBMC infusion and subcutaneous G-CSF administration was moderate. For all other therapies/interventions it varied from low to very low. In conclusion, intrauterine PBMC infusion and subcutaneous G-CSF administration are the most promising therapeutic options for RIF. However, further well conducted RCTs are necessary before their introduction into clinical practice.

Intrauterine perfusion immunotherapies in recurrent implantation failures: Systematic review

Studies have investigated the gestational outcomes of new immunological therapies in the treatment of patients with recurrent implantation failure (RIF) in assisted reproductive technology (ART). The objective of this article is to assess the current state of evidence available in the literature on intrauterine perfusion immunotherapies in women undergoing ART treatments. By considering the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), the authors performed systematic review by searching the databases of PubMed/MEDLINE and Scopus using the following key words: "recurrent implantation failure," "intrauterine infusion," "Platelet-Rich Plasma (PRP)," "Peripheral Blood Mononuclear Cells (PBMC)," "Granulocyte Colony-Stimulating Factor (G-CSF)," and "Human Chorionic Gonadotropin (hCG)." The authors analyzed the indications and the impact of new immunological therapies with intrauterine infusions on the pregnancy outcomes of patients undergoing ART. PRP, PBMC, G-CSF, and hCG were the four most used immunological therapies with intrauterine infusion. These new therapies appear to improve the results of ART treatments in cases of RIF. However, the small number of studies does not allow definitive conclusions about the effectiveness of these therapies.

Promoting Roles of Embryonic Signals in Embryo Implantation and Placentation in Cooperation with Endocrine and Immune Systems

Embryo implantation in the uterus is an essential process for successful pregnancy in mammals. In general, the endocrine system induces sufficient embryo receptivity in the endometrium, where adhesion-promoting molecules increase and adhesion-inhibitory molecules decrease. Although the precise mechanisms remain unknown, it is widely accepted that maternal–embryo communications, including embryonic signals, improve the receptive ability of the sex steroid hormone-primed endometrium. The embryo may utilize repulsive forces produced by an Eph–ephrin system for its timely attachment to and subsequent invasion through the endometrial epithelial layer. Importantly, the embryonic signals are considered to act on maternal immune cells to induce immune tolerance. They also elicit local inflammation that promotes endometrial differentiation and maternal tissue remodeling during embryo implantation and placentation. Additional clarification of the immune control mechanisms by embryonic signals, such as human chorionic gonadotropin, pre-implantation factor, zona pellucida degradation products, and laeverin, will aid in the further development of immunotherapy to minimize implantation failure in the future.