Platelet-rich plasma or blood-derived products to improve endometrial receptivity?

Platelet secretions exert anti-inflammatory effects in vitro on neutrophils and uterine epithelia in cattle: a possible role in amplifying the uterine immune network toward pregnancy

Background

Platelet derivatives improve the uterine immune environment and increase pregnancy success in humans and animals. Platelet-conditioned media (PCM) contain all molecules derived from platelets in vitro (platelet secretions). The present study aimed to investigate the immunological impacts of platelet secretions on polymorphonuclear neutrophils (PMNs) and bovine endometrial epithelial cells (BEECs), in vitro.

Methods

Platelets (10×107 platelets/mL) from Holstein dairy cows were incubated for 0.5 h or lysed to obtain the PCM and platelet lysate (Lysate), respectively. PMNs were stimulated with PCM for 3h. While BEECs were exposed to PCM or Lysate for 24 h. Real-time PCR was performed to detect the expression of targeted genes (cytokines), including TNFA, IL1B and PGES1. Lipoxin A4 (LXA4; anti-inflammatory mediator) and PGE2 concentrations in the supernatants of PMNs cultured with PCM were measured via ELISA. Cell proliferation in BEECs was assessed using the Cell Counting Kit-8 (CCK-8). Additionally, uterine explants were prepared and processed for immunofluorescence to determine the expression of the LXA4 receptor.

Results

In PMNs, platelet secretions downregulated the mRNA expression of pro-inflammatory cytokines (TNFA and IL1B) and increased LXA4 production. In both PMNs and BEECs, platelet secretions upregulated PGES1 expression and PGE2 production. In BEECs, platelet secretions and Lysate upregulated TGFB1. While Lysate suppressed IL1B mRNA expression. Further, platelet secretions showed an anti-proliferative effect in BEECs and increased the LXA4 receptor protein expression in the endometrial epithelia.

Conclusions

Our findings reveal for the first time that platelet secretions directly act on PMNs and BEECs in vitro, thereby assisting the uterine immune network to shift anti-inflammatory environment toward pregnancy. The present study can explain, in part, the successful applications of platelet derivatives in reproductive medicine.

Effects of autologous platelet-rich plasma intrauterine perfusion on clinical outcomes in recurrent implantation failure patients with non-thin endometrium undergoing frozen-thawed embryo transfer

PURPOSE

To explore the effects of autologous platelet-rich plasma (PRP) intrauterine perfusion on clinical outcomes in recurrent implantation failure (RIF) patients with non-thin endometrium undergoing frozen-thawed embryo transfer (FET), and the effects of PRP used at different times before FET on clinical outcomes.

METHODS

A total of 160 RIF patients with non-thin endometrium undergoing FET were retrospectively analyzed. Among them, 82 patients received PRP intrauterine perfusion at 24-72 h before FET (PRP group), and 78 patients did not (non-PRP group). In PRP group, 59 patients underwent PRP at 24-48 h before FET (≥ 24 to  ≤ 48 h group), and 23 patients was at 48-72 h (> 48 to  ≤ 72 h group). The clinical outcomes were compared, including β-hCG positive rate, clinical pregnancy rate, embryo implantation rate, abortion rate, ectopic pregnancy rate, live birth rate and the incidence of adverse events.

RESULTS

The clinical pregnancy rate, embryo implantation rate and live birth rate in PRP group were significantly higher than those in non-PRP group (P < 0.05), and there were no statistical differences in β-hCG rate, abortion rate and ectopic pregnancy rate between the two groups (P > 0.05). Meanwhile, there was no adverse events occurred in PRP group. However, the C-type endometrium rate in PRP group was observably higher on FET day (Χ2 = 8.309, P = 0.004), though there was no statistical difference in endometrial thickness (P > 0.05). The multiple logistics regression analysis showed that PRP intrauterine perfusion are closely related with clinical pregnancy and live birth in RIF patients with non-thin endometrium (OR: 2.379, 95% CI 1.137-4.977, P = 0.021; OR: 2.107, 95% CI 1.006-4.412, P = 0.048). Moreover, we found no significant difference in clinical outcomes between the two groups of PRP intrauterine perfusion at ≥ 24 to ≤ 48 h and > 48 to ≤ 72 h before FET (P > 0.05), except for β-hCG positive rate.

CONCLUSIONS

PRP intrauterine perfusion can safely and effectively improve the clinical pregnancy rate, implantation rate and live birth rate in RIF patients with non-thin endometrium possibly by increasing the C-type endometrium rate on FET day. In addition, PRP intrauterine perfusion at different times of 24-72 h before FET does not affect the clinical outcomes, which will be helpful to guide clinical work flexibly.

Is it justified to offer intrauterine infusion of autologous PRP in women with repeated implantation failure?

In recent years, an increased interest in the efficacy of intrauterine infusion of autologous platelet-rich plasma (PRP) in women with repeated implantation failure (RIF) has resulted in the publication of 13 randomized controlled trials (RCTs) and 11 meta-analyses. Although these meta-analyses support an increase in pregnancy rates after intrauterine infusion of autologous PRP, the low quality of the available original clinical studies along with concerns regarding their trustworthiness seriously questions their internal validity and does not allow for definitive conclusions to be drawn. In addition, the variability in the definition of RIF used in the individual studies limits their external validity, renders the pooling of the results problematic, and, overall, complicates the extrapolation of the results published. The variability in the definition of RIF has been recently addressed by the ESHRE, which published an evidence-based definition of RIF to facilitate the evaluation of interventions in these patients. Taking into consideration this definition, which identifies a real clinical problem, evaluation of intrauterine infusion of PRP in the published literature has not so far been performed explicitly in patients with RIF. The potential of intrauterine infusion of autologous PRP to improve outcomes for women with RIF remains an important area of research in ART. However, the current evidence is insufficient to inform clinical practice, highlighting the need for well-designed studies to provide clearer guidance.

A novel technique- subendometrial autologous platelet rich plasma injection in patients with unresponsive thin endometrium undergoing frozen-thawed embryo transfer: a prospective cohort study

BACKGROUND

The purpose of this study was to investigate the effects of subendometrial PRP injection on endometrial thickness and pregnancy outcomes in patients with a history of unresponsive thin endometrium undergoing frozen-thawed embryo transfer (FET).

METHODS

This prospective cohort study was conducted at Acibadem Mehmet Ali Aydinlar University-Istanbul, Turkey. Women with a history of suboptimal endometrial proliferation (< 7 mm) were offered to participate in the study. Group 1 consisted of 100 individuals who consented to subendometrial PRP injection, while Group 2 consisted of 100 individuals who did not accept PRP injection. Within ten days of the menstrual cycle ending, autologous PRP was produced by centrifuging peripheral blood and administered transvaginally into the subendometrial region under ultrasound monitoring. After the PRP procedure, 14 days of oral estradiol supplementation were started as part of the hormonal treatment on the 2-4th day of the second menstrual cycle. Women determined to have adequate endometrial thickness following the initiation were scheduled for embryo transfers. Embryo transfer was scheduled for women who were found to have adequate endometrial thickness after the initiation of progesterone. Pregnancy (positive serum hCG) and livebirth rates were followed.

RESULTS

A total of 200 women (age 36.4 ± 5.8) were included in the study. Endometrial thickness increased after PRP therapy as compared to the control group (7.7 ± 1.9 mm vs. 6.1 ± 1.2 mm; p < 0.01). Three women (3.0%) in the PRP group conceived spontaneously, whereas 97 women (97.0%) attempted FET; no spontaneous pregnancies occurred in the control group. Compared to 75/100 (75% of the total) in the control group, 33/97 women (34.0%) in the PRP group were unable to undertake ET because of persistently unresponsive thin endometrium or fluid in the endometrial cavity (p < 0.001). The PRP group had a considerably higher percentage of positive serum hCG tests than the control group (25.8% vs. 9.0%; p = 0.002). Additionally, the PRP group had a higher clinical pregnancy rate (22.7% vs. 7.0%; p = 0.002). The live birth rate was significantly higher in the PRP group than the controls (17.5% vs. 2.0%; p < 0.001).

CONCLUSIONS

In women with a history of suboptimal endometrial development, subendometrial PRP injection was associated with improved endometrial thickness and livebirth rate.

TRIAL REGISTRATION

Baskent University institutional review board and ethics committee (KA-20/23) http://www.

CLINICALTRIALS

gov , (NCT04424160), 2020.06.15.

Comparative efficacy of intrauterine infusion treatments for recurrent implantation failure: a network meta-analysis of randomized controlled trials

OBJECTIVE

Recurrent implantation failure (RIF) is a significant challenge in assisted reproductive technology (ART), affecting many women undergoing in vitro fertilization (IVF). This study aims to compare the efficacy of various intrauterine infusion treatments, including granulocyte colony-stimulating factor (G-CSF), platelet-rich plasma (PRP), human chorionic gonadotropin (HCG), and peripheral blood mononuclear cells (PBMCs), in improving clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate (MR) in women with RIF.

METHODS

A comprehensive search was conducted in multiple databases, including Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Web of Science, and China National Knowledge Internet (CNKI), to identify randomized controlled trials (RCTs) evaluating the efficacy of intrauterine infusion treatments for RIF. Data extraction and quality assessment were performed independently by two reviewers. Network meta-analysis was conducted using a random-effects model to compare the outcomes of different treatments.

RESULTS

A total of 25 RCTs involving 3035 patients were included in the network meta-analysis. The treatments involved G-CSF, PRP, HCG, PBMCs, placebo, and blank control. The results of the network meta-analysis for CPR and LBR were statistically significant among treatments, but there was no statistical significance in MR. The surface under cumulative ranking curve (SUCRA) ranking of CPR and LBR showed that intrauterine infusion treatments of G-CSF, PRP, HCG, and PBMCs were much better than placebo and blank. The SUCRA values of CPR were ranked probabilistically from high to low as follows: PRP (84.5%) > PBMCs (76.5%) > G-CSF (65.7%) > HCG (52.5%) > placebo (20.8%) > blank (0.1%). The SUCRA values of LBR were ranked probabilistically from high to low as follows: PRP (81.4%) > PBMCs (64.6%) > G-CSF (58.0%) > HCG (48.7%) > placebo (42.4%) > blank (4.9%).

CONCLUSION

All these findings confirmed that intrauterine infusions of PRP and PBMCs significantly improve pregnancy outcomes in women with RIF. PRP emerged as the most effective treatment. However, to establish the most effective approach for managing patients with RIF, future research should prioritize direct and robust comparisons between PRP and other therapeutic strategies, ensuring a comprehensive evaluation of their relative efficacy.

Improvement of endometrial thickness and in vitro fertilization outcomes in patients with Asherman's refractory endometrium using autologous mesenchymal stem cells from the stromal vascular fraction

OBJECTIVE

Patients with Asherman's Syndrome (AS) and an endometrial thickness (EMT) less than 7 mm are infertile women with suboptimal endometrium due to uterine scarring or endometrial atrophy. This study aimed to examine the effect of intrauterine injections of adipose-derived mesenchymal stem cells (ADMSC) from the Stromal Vascular Fraction (SVF) of adipose tissue on EMT and in vitro fertilization (IVF) outcomes: which are improvements in EMT and pregnancy rates.

METHODS

This double-arm retrospective study included 41 AS patients with hysteroscopic adhesiolysis. Twenty-one patients with AS refractory endometrium (Group 2) were given ADMSC to improve EMT, and 20 non-treated, age-matched patients served as controls (Group 1). For Group 2, SVF was isolated from 15 ml of adipose tissue and transmyometrial injected into the patient's uterine cavity. For all patients, EMT was examined using ultrasound before embryo transfer.

RESULTS

In Group 2, after ADMSC treatment, EMT significantly improved (3.2 ± 1.8 mm, P<0.001). Afterward, three patients spontaneously became pregnant, and eighteen underwent frozen embryo transfer. A significant increase in implantation (66.7% vs. 4.8%, P = 0.002) and live birth rates (0.0% vs. 47.6%, P = 0.001) were recorded. No significant difference was observed in EMT, cycle implantation, or clinical pregnancy between the two groups, but the live birth rate in Group 2 after ADMSC treatment was higher than in Group 1.

CONCLUSION

The results demonstrate that autologous intrauterine ADMSC injection can improve EMT, implantation, and pregnancy rates in AS patients with refractory endometrium. This research underscores the life-changing potential of autologous ADMSC treatment for patients with refractory endometrium, providing a promising avenue for future treatments.

Obesity attenuates the beneficial effect of an intrauterine infusion of autologous platelet-rich plasma during in vitro fertilization

OBJECTIVE

To assess how obesity, normal weight (NW) versus overweight/obese (OW/OB), impacts platelet-rich plasma's (PRP) effectiveness during in vitro fertilization and how obesity affects platelets during the menstrual cycle.

METHODS

Endometrial mean thickness (EMT), embryo implantation, and clinical pregnancy were assessed using a self-controlled retrospective study that enrolled 59 patients with two failed cycles and treated with autologous PRP (three-dose scheme). The NHANES dataset was used to assess platelet changes during the menstrual cycle, using the mean platelet volume to platelet count ratio (MPR) index. The COSINOR packages for R were used to determine rhythmicity.

RESULTS

PRP treatments significantly improved the EMT (2.5 ± 1.4 mm, P<0.001), unaffected by obesity. After the PRP treatment, one patient spontaneously became pregnant; therefore, 58 patients underwent embryo transfer (62 cycles), of which in 39 cycles the embryos implanted (63.9%). This was a significant improvement from their previous cycle (vs. 22.6%, P<0.001). Clinical pregnancy also improved with the PRP treatment over the previous cycle (57.4% vs. 16.1%, P<0.001). When stratified by obesity, there was an appreciable decrease in embryo implantation and clinical pregnancy rates for the OW/OB group; nevertheless, the PRP treatment significantly improved embryo implantation and clinical pregnancy (P<0.05). A rhythm was observed with the MPR index (P<0.05) only for the NW group, suggesting that the platelets normally fluctuate during the menstrual cycle.

CONCLUSION

PRP improved embryo implantation and clinical pregnancy rates; however, these beneficial effects were attenuated by obesity. PRP presumptively promoted a change in the uterine environment to mimic the normal findings associated with normal-weight women.

Effect of intrauterine infusion of platelet-rich plasma for women with recurrent implantation failure: a systematic review and meta-analysis

This study evaluated the effect of intrauterine perfusion of autologous platelet-rich plasma (PRP) on pregnancy outcomes in women with recurrent implantation failure (RIF). Key biomedical databases were searched to identify relevant clinical trials and observational studies. Outcomes included clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate, and abortion rate. Data was extracted from ten studies (six randomised controlled trials, four cohort studies) involving 1555 patients. Pregnancy outcomes were improved in women treated with PRP compared to controls: clinical pregnancy rate (RR = 1.96, 95% CI [1.67, 2.31], p < 0.00001, I² = 46%), chemical pregnancy rate (RR = 1.79, 95% CI [1.54, 2.08], p < 0.00001, I² = 29%), implantation rate (RR = 1.90, CI [1.50, 2.41], p < 0.00001, I² = 0%), live birth rate (RR = 2.83, CI [1.45, 5.52], p = 0.0007, I² = 83%), abortion rate (RR = 0.40, 95% CI [0.18, 0.90], p = 0.03, I² = 59%). These data imply PRP has potential to improve pregnancy outcomes in women with RIF, suggesting a promising role in assisted reproductive technology.IMPACT STATEMENTWhat is already known on this subject? Platelet-rich plasma (PRP) is an autologous blood product that contains platelets, various growth factors, and cytokines at concentrations above the normal baseline level. Recent studies have shown that intrauterine infusion of autologous PRP can improve pregnancy outcomes in infertile women.What do the results of this study add? This systematic review and meta-analysis of data from ten studies (n = 1555; 775 cases and 780 controls) investigated the effect of intrauterine perfusion of autologous PRP on pregnancy outcomes in women with recurrent implantation failure (RIF). Findings suggest that pregnancy outcomes, including clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate and abortion rate were improved in women treated with PRP compared to controls.What are the implications of these findings for clinical practice and/or further research? RIF remains a challenge for researchers, clinicians, and patients. Our study identified PRP as a potential intervention in assisted reproduction. As an autologous blood preparation, PRP eliminates the risk of an immune response and transmission of disease. PRP is low cost and effective and may represent a new approach to the treatment of patients with RIF.

Value of Intrauterine Autologous Platelet-Rich Plasma Therapy on Endometrial Receptivity: A Literature Review

Endometrial receptivity is an important factor that influences embryo implantation. Thus, it is important to identify an applicable approach to improve endometrial receptivity in women undergoing assisted reproductive technology. Recently, growing evidence has indicated that intrauterine platelet-rich plasma (PRP) infusion is an effective method to obtain a satisfactory reproductive outcome by increasing endometrial thickness and improving endometrial receptivity. Therefore, the present review aims to outline the possible mechanisms of PRP on endometrial receptivity and summarize the present literature on the effects of PRP therapy in improving endometrial receptivity.

Use of platelet lysate for in-vitro embryo production and treatment of repeat breeding in cows

Platelet-rich plasma (PRP) is a biological hemocomponent derived from blood after the complete removal of red blood cells and the partial or complete removal of white blood cells to concentrate platelets in an appropriate volume of plasma. Platelets have important growth factors, cytokines, and active metabolites that improve the endometrial environment and positively affect implantation. This study evaluated the effect of the addition of activated PRP (platelets lysate; PL) on in vitro bovine oocyte maturation and embryonic development and the effect of intrauterine (IU) infusion of autologous PL in repeat breeder (RB) cows. Experiment 1 examined the effects of allogeneic PL, fetal calf serum (FCS), mixed PL + FCS, or platelet-poor plasma (PPP) supplementations to in vitro maturation and development media on in vitro oocyte maturation and embryo development in good- and poor-quality oocytes of Japanese Black cows. Experiment 2 examined the IU infusion of autologous PL, 24 h post-insemination, in 21 RB Holstein-Friesian dairy cows. The cleavage rate of good-quality oocytes was higher in the PL group (85.93 ± 2.50%) than in the PPP group (67.16 ± 3.41%) (P < 0.05), while the cleavage rate of the poor-quality oocytes was higher in the PL alone (76.13 ± 4.04%) and mixed PL + FCS treated (73.59 ± 4.22%) groups than in the PPP group (54.64 ± 2.93%) (P < 0.05). The blastocyst rate of the good-quality oocytes was higher in the PL group (40.97 ± 3.03%) than in the FCS (27.97 ± 3.31%) and PPP (25.33 ± 2.15%) groups (P < 0.05). The blastocyst rate of poor-quality oocytes and the hatching rates of both good and poor-quality oocytes showed no significant differences among all groups. The conception rate in the autologous PL-treated group was 41.67% (5/12), while it was 11.11% (1/9) in the control group. The platelets' count in the pregnant PL-treated cows (n = 5; mean ± SEM, 1.07 ± 0.10 × 109/mL) was higher than in the non-pregnant ones (n = 7; 0.67 ± 0.10 × 109/mL) (P < 0.05). In conclusion, allogeneic PL was effective in stimulating the in vitro oocyte maturation and embryonic development in both good and poor-quality bovine oocytes, and post-insemination IU infusion of autologous PL derived from high platelets' count-PRP would be recommended for the treatment of RB cows.

Factors Affecting the Potential Efficacy of Intrauterine Platelet-Rich Plasma Infusion on Thin Endometrium in Women with Recurrent Implantation Failure

Optimizing endometrial thickness (EMT) is crucial for successful embryo implantation, but enhancing thin endometrium remains a significant challenge. Platelet-rich plasma (PRP)-derived therapies have emerged as a promising approach in reproductive medicine due to their capacity to facilitate tissue repair and regeneration. This study aims to identify the risk factors associated with the failure of intrauterine PRP infusion for thin endometrium in women with recurrent implantation failure (RIF). We retrospectively reviewed data from 77 women with RIF, all exhibiting an EMT of <7 mm. These women underwent programmed hormone therapy for frozen embryo transfer (FET) and received two autologous intrauterine PRP infusions. Following intrauterine PRP-lysate (PL) infusions, the mean increase in EMT was 1.9 ± 1.2 mm, with EMT reaching 7 mm in 86% of the cases (66/77; average EMT, 8.3 mm). We identified an exceedingly thin EMT as a risk factor impacting the therapeutic efficacy in increasing EMT (p = 0.04, OR: 3.16; 95% CI: 1.03-9.67). Additionally, the number of previous uterine surgeries emerged as a prognostic factor for pregnancy failure following PL infusion (p = 0.02, OR: 2.02; 95% CI: 1.12-3.64). Our findings suggest that an extremely thin EMT and a history of numerous uterine surgeries can impede successful pregnancy, even when an optimal EMT is achieved following PRP infusion.

How platelet-rich plasma (PRP) intra-uterine injection improve endometrial receptivity of intrauterine adhesions in women: A time-series-based self-controlled study

Platelet-rich plasma (PRP) treatment proven to improve fertility outcomes in patients with a poor endometrial environment. However, the mechanism is not yet clear. In this study, we recruited 6 patients with infertility due to IUA and 6 normal control women. The subjects in the IUA group collected samples before and after PRP treatment. Endometrial receptivity was improved after PRP treatment. After PRP treatment, the endometrial NK cells, CD8 T cells and Th1 cells were significantly lower than those before treatment. Functional enrichment analysis suggested that the effects of changes in microbial composition played an important role in changes in the endometrial immune environment. Among them, the most significant difference was Bacillus. Our self-controlled cohort in this study can fully describe the detailed mechanism by which PRP treatment improves the endometrial environment.

[Non-drug technologies in restoring endometrial receptivity as a cause of impaired fertility in women of reproductive age. (Literature review)]

Globally, 13% of the population has difficulty conceiving. In Russia, the proportion of infertile marriages ranges from 8 to 17.5%, with half of all forms of female infertility being the uterine form. The main etiological factors for impaired endometrial receptivity are infectious diseases leading to the development of chronic endometritis (most often found in tuboperitoneal infertility), dishormonal background associated with the development of hyperplastic processes in endocrine infertility, uterine fibroids, chronic endometritis and endometriosis. The frequency of detection of uterine cavity diseases in patients with repeated unsuccessful IVF programs ranges from 18 to 50%. The review examines the etiological factors and other causes of endometrial pathology leading to the development of chronic endometritis, possible mechanisms for the development of impaired growth and receptivity of the endometrium, and, as a consequence, the impossibility of pregnancy. Therapeutic strategies for restoring endometrial thickness and receptivity using pharmacological and non-pharmacological methods are described. Based on the analysis of literature data, it is shown that the use of physiotherapeutic factors in treatment programs that have pronounced anti-inflammatory, immuno- and hormone-modulating, reparative-regenerative, metabolic, vasocorrective and defibrosing effects allows for a relatively short period of time to improve endometrial receptivity, normalize hormonal levels and restore fertility in women of reproductive age, which ensures the possibility of successful embryo implantation, fetal development and childbirth.

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.

Zooming in on the endometrial factor of recurrent implantation failure

Recurrent implantation failure (RIF) is a major limiting factor in the success rates of in-vitro fertilisation despite the remarkable clinical and technological advancement made at improving assisted reproductive technology. The primary purpose of the endometrium is to provide a receptive site for the implantation of the blastocyst and support its growth and subsequent development. Endometrial pathologies such as endometrial polyps, adenomyosis, Asherman's syndrome, chronic endometritis, and congenital Müllerian ducts defect negatively influence the integrity and receptivity of the endometrium, as well as the implantation of the embryo. This review highlights the implications of these endometrial pathologies and their association with RIF.

Human platelet lysates stimulate in vitro proliferation of human endometrial cells from patients with a history of recurrent implantation failure

OBJECTIVE

To optimize and compare the isolation of platelet-rich plasma (PRP) and its cryopreserved derivative, platelet lysate (PL), to a commercial human platelet lysate (HPL) product PLUS and investigate their proliferative stimulation on primary human endometrial cells in vitro.

DESIGN

Basic research.

SETTING

Academic fertility center.

PATIENT(S)

Three healthy blood donors and eight patients with a history of recurrent implantation failure.

INTERVENTIONS(S)

Stimulated proliferation of isolated primary endometrial epithelial cells and endometrial stromal cells in vitro with autologous and nonautologous HPL (PLUS; Compass Biomedical).

MAIN OUTCOME MEASURE(S)

Platelet-derived growth factor BB homodimer protein content in isolated PRP/PL and commercial HPL and endometrial epithelial cell and endometrial stromal cell proliferation after 24- or 48-hour stimulation with PL (measured by metabolic activity and Ki67 expression).

RESULT(S)

To optimize and compare the isolation of autologous PRP/PL, three double-centrifugation protocols were assessed by flow cytometry for platelet yield (CD45^-CD41⁺CD61⁺) and platelet-derived growth factor BB homodimer protein content by enzyme-linked immunosorbent assay. Cryopreserved PL, especially isolated by our fastest protocol, contained higher protein concentrations and, thus, was optimal for experimental flexibility compared with fresh PRP. The autologous and commercial PLs displayed comparable immune and growth factor content and stimulation of cell proliferation in vitro.

CONCLUSION(S)

Our results provide the groundwork for the isolation and use of HPL to stimulate endometrial growth. Furthermore, commercial PL consistently stimulated cell proliferation and may allow standardization of clinical treatment for recurrent implantation failure.

Appraisal of Experimental Methods to Manage Menopause and Infertility: Intraovarian Platelet-Rich Plasma vs. Condensed Platelet-Derived Cytokines

The first published description of intraovarian platelet-rich plasma (PRP) appeared in mid-2016, when a new experimental technique was successfully used in adult human ovaries to correct the reduced fertility potential accompanying advanced maternal age. Considering the potential therapeutic scope of intraovarian PRP would likely cover both menopause and infertility, the mainstream response has ranged from skeptical disbelief to welcome astonishment. Indeed, reports of intraovarian PRP leading to restored menses in menopause (as an alternative to conventional hormone replacement therapy) and healthy term livebirths for infertility patients (from IVF or as unassisted conceptions) continue to draw notice. Yet, any proper criticism of ovarian PRP applications will be difficult to rebut given the heterogenous patient screening, varied sample preparations, wide differences in platelet incubation and activation protocols, surgical/anesthesia techniques, and delivery methods. Notwithstanding these aspects, no adverse events have thus far been reported and ovarian PRP appears well tolerated by patients. Here, early studies guiding the transition of ‘ovarian rejuvenation’ from experimental to clinical are outlined, with mechanisms to explain results observed in both veterinary and human ovarian PRP research. Current and future challenges for intraovarian cytokine treatment are also discussed.

Three Manual Noncommercial Methods to Prepare Equine Platelet-Rich Plasma

In light of PRP's increasing popularity in veterinary practice, this study aimed to compare three manual methods to prepare and cool equine PRP. The blood of 18 clinically healthy mares was collected via venipuncture in a blood transfusion bag (method 1), blood tubes (method 2), and a syringe (method 3). In method 1, samples were double centrifuged; method 2 involved one centrifugation, and in method 3 the syringe was kept in an upright position to sediment for 4 h. After processing with three methods, PRP and platelet-poor plasma (PPP) were extracted and assessed for red (RBC) and white blood cell counts (WBC), platelet counts, and viability. In a subset of mares (n = 6), samples were processed with the three methods, and PRP was evaluated at 6 and 24 h postcooling at 5 °C. Method 1 resulted in the highest and method 3 in the lowest platelet concentration (p < 0.05), and the latter also had greater contamination with WBC than the others (p < 0.001). Platelet viability was similar across treatments (p > 0.05). Cooling for 24 h did not affect platelet counts in all methods (p > 0.05); however, platelet viability was reduced after cooling PRP produced by method 3 (p = 0.04), and agglutination increased over time in all methods (p < 0.001). The three methods increased (1.8-5.6-fold) platelet concentration in PRP compared to whole blood without compromising platelet viability. In conclusion, all three methods concentrated platelets and while cooling affected their viability. It remains unknown whether the different methods and cooling would affect PRP's clinical efficacy.

Intrauterine Blood Plasma Platelet-Therapy Mitigates Persistent Breeding-Induced Endometritis, Reduces Uterine Infections, and Improves Embryo Recovery in Mares

Microorganisms, including pathogenic or opportunistic bacteria and fungi, may gain access to the uterus during breeding, and infectious endometritis plays a major role in equine subfertility. This study aimed to assess the post-breeding inflammatory response, endometrial culture, and embryo recovery of mares susceptible to persistent breeding-induced endometritis (PBIE) treated with plasma-rich (PRP) or -poor (PPP) plasma. Mares (n = 12) susceptible to PBIE had three cycles randomly assigned to receive intrauterine infusions of lactate ringer solution (LRS, control), or autologous PRP or PPP pre- (−48 and −24 h) and post-breeding (6 and 24 h). Mares were bred with fresh semen from one stallion. Intrauterine fluid accumulation (IUF) and endometrial neutrophils were assessed every 24 h up to 96 h post-breeding. Uterine cytokines (Ilβ, IL6, CXCL8, and IL10) were evaluated before (0 h), 6, and 24 h post-breeding, and endometrial culture three and nine days after breed. Embryo flushing was performed 8 days post-ovulation. Data were analyzed with mixed model, Tukey’s post-hoc test, and multivariate regression. PRP treatment reduced endometrial neutrophils, post-breeding IUF, and pro-inflammatory cytokines when compared to control-assigned cycles, but not significantly different than PPP. Controls had a significantly higher percentage of positive bacterial cultures (33%) in comparison to PRP-assigned cycles (0%), whereas cycles treated with PPP were not significantly different from the other groups (25%). The PRP-assigned cycles had significantly greater embryo recovery rates (83%) than the control (33%), though not significantly different than PPP (60%). Plasma infusion reduced the duration and intensity of the post-breeding inflammatory response and improved embryo recovery in mares susceptible to PBIE. Platelets incrementally downregulate PBIE and appear to have a dose-dependent antimicrobial property.

Use of Intra-uterine Injection of Platelet-rich Plasma (PRP) for Endometrial Receptivity and Thickness: a Literature Review of the Mechanisms of Action

Endometrial receptivity and thickness play an important role in achieving a pregnancy. Intrauterine autologous platelet-rich plasma (PRP) infusion has been used in infertile women with recurrent implantation failure (RIF) and thin endometrial lining thickness (EMT). Literature search was performed in PubMed for studies including in vitro, animal, and human studies as well as in abstracts presented at national conferences. Animal studies demonstrated a decrease in the expression of inflammatory markers and fibrosis, and increased endometrial proliferation rate, increased expression of proliferative genes, and increased pregnancy rates. The in vitro studies showed that PRP was associated with increased stromal and mesenchymal cell proliferation, increased expression of regenerative enzymes, and enhancement in cell migration. In infertile women undergoing assisted reproductive technology, one randomized clinical trial showed that PRP intrauterine infusion improved EMT, implantation rate, and clinical pregnancy rate (CPR) in patients with thin EMT, while 3 other trials involving subjects with RIF showed conflicting results related to CPR. Case series and cohort studies showed conflicting results pertaining to CPR. Data to date suggest that PRP may be beneficial in improving endometrial thickness and endometrial receptivity. However, further large prospective and high-quality trials are needed to assert its effect and to identify the population of patients that would benefit the most.

Platelet-Rich Plasma as a Potential New Strategy in the Endometrium Treatment in Assisted Reproductive Technology

The success rate of assisted reproduction techniques (ART) has long been less than satisfactory albeit the great progress made in recent years, demonstrating the need for alternative options in the ART cycles. Growing evidence correlates the effect of intrauterine platelet-rich plasma (PRP) infusion on the endometrium with reassuring reproductive results. Thus, in this review, we focus on the current clinical and mechanical evidence on PRP and its effect on endometrial receptivity, and assess the features, benefits and limitations of the current studies and potential risks of PRP in ART.

Platelet-Rich plasma as an effective alternative approach for improving endometrial receptivity - a clinical retrospective study

Objective:

The aim of the present case series was to describe our experience with the use of PRP on patients with refractory thin endometria.

Methods:

This retrospective analysis included 24 IVF cycles in which patients presenting different infertility factors received intrauterine PRP infusion prior to embryo transfer. Outcomes of interest were: clinical and ongoing pregnancies, miscarriages, and births.

Results:

54% of the cycles in which PRP was employed resulted in ongoing gestation or birth; 12.5% of the cycles ended in miscarriages.

Conclusion:

Our data suggest that PRP improves intrauterine receptivity to embryo implantation, regardless of whether the endometrium reached the appropriate growth for embryo transfer.

JG. New therapeutic protocol for improvement of endometrial receptivity (PRIMER) for patients with recurrent implantation failure (RIF) - A pilot study

OBJECTIVE

To evaluate whether or not one should use a new Protocol for Endometrial Receptivity Improvement (PRIMER) based on platelet-rich plasma (PRP) and granulocyte colony-stimulation factor (G-CSF) to enhance ongoing pregnancy rates in patients with recurrent implantation failure (RIF).

METHODS

Women undergoing IVF/ICSI were prospectively divided into two groups: - PRIMER/RIF group (n:33): patients with RIF (defined as ≥2embryo transfers (ETs) and at least 5 morphologically good embryos transferred) in which intrauterine PRP injection and subcutaneous G-CSF-injection were performed. - Control group (n:33): patients in their first IVF/ICSI attempt/cycle (without PRP or G-CSF injection). The PRP was prepared using autologous fresh-whole blood processed to increase platelet-concentration in 2 to 4 fold. All patients undergoing the PRP-treatment received 0.7ml of it through intrauterine-injection 48 hours before the ET. G-CSF (300mg/0.5ml) started simultaneously to PRP and was administered subcutaneously every week.

RESULTS

Regarding implantation, clinical pregnancy and miscarriage rates, we found no statistically significant difference (18.2% versus 17.6%, p=0.90; 36.4% versus 30.3%, p=0.61 and 25.0% versus 9.0%, p=0.43, respectively). The use of PRIMER enabled RIF patients (previous ET µ: 4.0±1.5) to reach similar ongoing pregnancy and live birth rates like those patients who had their first IVF/ICSI cycle attempt (27.3% versus 27.3%, p=0.99).

CONCLUSIONS

Our results showed, for the first time, evidence that this therapeutic protocol (PRIMER) could be used as a feasible treatment based on biological rationale for patients with RIF, considering its promising outcomes, it is a simple procedure and not associated with patient complications.