Assessment of uterine receptivity by endometrial and sub-endometrial blood flow using SlowflowHD in hormone prepared frozen embryo transfer cycles: a pilot study

Effect of a novel copper chloride gel on endometrial growth and function in healthy volunteers

RESEARCH QUESTION

Does the application of a micro-dose of copper chloride gel increase endometrial production of vascular endothelial growth factor (VEGF) without compromising endometrial function or producing embryo toxicity?

DESIGN

An estimate of optimal dose was made based on cell culture studies. Ten healthy participants received an initial uterine application of placebo gel, followed by copper chloride gel (37.5 μM, 75 μM, or 150 μM dose) in a later hormone replacement cycle. Endometrial biopsies (day 5.5 luteal) and pelvic ultrasound were carried out during each cycle to evaluate endometrial function and growth. Uterine fluid was assessed for residual copper levels on the day of biopsy, and copper chloride gel underwent mouse embryos assay assessment for potential embryo toxicity.

RESULTS

The copper gel significantly increased endometrial VEGF expression (quantitative polymerase chain reaction), and also increasing endometrial thickness by an average of 2.2 mm compared with matched control cycles. The copper gel did not adversely affect endometrial morphology or maturation (histological dating and molecular receptivity testing), and mouse embryos assay studies showed no evidence of embryo toxicity. Furthermore, uterine cavity flush samples mostly lacked copper, with only negligible amounts present in one sample.

CONCLUSION

Applying copper chloride gel to the uterine cavity upregulated endometrial VEGF and significantly increased endometrial thickness and volume. No adverse effects on the endometrium or embryos were observed. Copper chloride gels show promise for treating suboptimal endometrial thickness if the results of this study are confirmed by larger randomized controlled trials.

Pregnancy prediction via ultrasound-detected endometrial blood for hormone replacement therapy-frozen embryo transfer: a prospective observational study

BACKGROUND

This study aimed to assess the predictive value of endometrial blood flow branches on pregnancy outcomes after hormone replacement therapy-frozen embryo transfer (HRT-FET).

METHODS

This prospective observational study involved 292 reproductive-aged women who underwent endometrial receptivity assessment in a tertiary care academic medical center in southwest China using power Doppler ultrasonography during HRT-FET. Three-dimensional power Doppler ultrasound was performed on the day of endometrial transformation and the day before embryo transfer. The endometrial blood flow branches of the endometrial and subendometrial regions were compared in the non-pregnant and pregnant groups at the two time points mentioned above.

RESULTS

The endometrial blood flow branches were higher in pregnant patients than in non-pregnant patients on the day of endometrial transformation (P = 0.009) and the day before embryo transfer (P = 0.001). Changes in endometrial blood flow pattern and endometrial blood flow branches at the two time points did not differ among the pregnancy outcome samples. After adjusting for age, antral follicles, and embryos transferred, the endometrial blood flow branches on the day before embryo transfer was the independent factor influencing the chance of clinical pregnancy, with an odds ratio of 3.001 (95% confidence interval: 1.448 - 6.219, P = 0.003).

CONCLUSIONS

Endometrial blood flow perfusion during the peri-transplantation period of the HRT-FET cycle is a good indicator of pregnancy outcomes, suggesting that valuation of endometrial branches via power Doppler ultrasound is a simple and effective approach for achieving indicator measurements.

Association between endometrial blood and clinical outcome in frozen single blastocyst transfer cycles

Background: The success of embryo transfer cycle depends mainly on the quality of embryo and endometrial receptivity. Ultrasound examination is still the most widely used non-invasive evaluation method for its advantages of convenience, non-invasiveness and repeatability. Ultrasound-measured endometrial blood flow is one of the important evaluation indicators of morphology. Aims: To investigate the effect of the number of endometrial blood flow branches on pregnancy outcome of frozen-thawed embryo transfer cycles which have undergoing hormone replacement therapy (HRT-FET). Material and methods: A retrospective cohort study was performed looking at a total of 1390 HRT-FET cycles from our reproductive medicine center between January 2017 to December 2021, which transferred one blastocyst frozen on day 5 with good quality in morphology. Associations between endometrial blood flow branches and pregnancy outcomes were evaluated with multivariable linear regression analysis. Results: The number of endometrial blood flow branches was independently associated with clinical pregnancy (OR 1.10; 95% CI 1.02-1.20). After adjusting for potential confounders, the effect size (odds ratio) was 1.09 (95% CI 1.00-1.19), and the results showed that the clinical pregnancy rate and live birth rate of T2 and T3 groups were significantly higher than those in group T1 (p < 0.05). Subgroup analysis showed that a consistent association between the endometrial blood flow branches and clinical pregnancy in all subgroups. Conclusion: Our study provided evidence for the influence of endometrial blood flow on pregnancy outcomes. There may be an independent association between the number of endometrial blood flow branches and pregnancy outcomes in frozen-thawed single blastocyst transfer cycles.

Efficacy of intrauterine infusion therapy before embryo transfer in recurrent implantation failure: A systematic review and network meta-analysis

Previous studies of intrauterine infusion therapy in recurrent implantation failure (RIF) patients have shown conflicting results, and there is a lack of head-to-head horizontal comparisons between different drugs. This study aimed to assess the effectiveness of four intrauterine infusion drugs, including human chorionic gonadotropin (HCG), granulocyte colony-stimulating factor (G-CSF), peripheral blood mononuclear cells (PBMCs) and autologous platelet-rich plasma (PRP), in improving pregnancy outcomes in RIF patients through the network meta-analysis. Randomized controlled trials (RCTs) of preimplantation intrauterine infusion for RIF were searched in the Cochrane Library, Embase, Medline and CINAHL. Meanwhile, relevant data were extracted and Stata 15.0 software was applied to statistical analysis. A total of 21 studies with a sample size of 2917 cases were included in this study. Clinical pregnancy rate network meta-analysis showed that, intrauterine infusion of all four drugs is significantly better than the blank and placebo groups, while only PRP could significantly increase live birth rate compared with the blank and placebo groups. The SUCRA plots of clinical pregnancy and live birth rates showed a higher ranking of PRP and PBMCs. Early abortion intervention analysis found that only G-CSF is significantly better than the blank and placebo groups, and the SUCRA plot of G-CSF showed the highest ranking. All these findings confirmed that all four intrauterine infusion drugs can improve pregnancy outcomes in RIF patients to varying degrees, with PRP being the most effective. Further prospective, large-scale and high-quality RCTs are still necessary to determine the exact subgroups of benefit for the different drugs.

Abnormal expression of galectin-1, -3 leading to unexplained infertility by decreasing endometrial receptivity: a retrospective analysis

OBJECTIVE

To explore the relationship between galectin-1, -3 and unexplained infertility and the effect on endometrial receptivity.

METHODS

The clinical data of 100 female patients at childbearing age coming to Xingtai People's Hospital from February 2019 to February 2021 were collected retrospectively. Based on normal pregnancy or not, 50 infertility patients were placed into an infertility group, and 50 patients with normal pregnancy history were placed into a normal group. The mRNA and protein levels of galectin-1, -3, endometrial wave-like activity, endometrial thickness, uterine artery pulsatility index (PI), resistance index (RI), end diastolic velocity (EDV) and peak systolic velocity (PSV) ratio (S/D = PSV/EDV) were compared between the two groups of patients.

RESULTS

The mRNA and protein levels of galectin-1, -3 in the infertile group were lower than those in the normal group (P<0.05). In addition, the endometrial wave-like activity in the infertile group was more than that in the normal group (P<0.05). The endometrial thickness was less, while PI, RI and S/D were higher in the infertile group than those in the normal group (P<0.05).

CONCLUSION

The low mRNA and protein expressions of galectin-1, -3 in unexplained infertility can affect endometrial receptivity, which may be closely related to unexplained infertility.

The role of timing in frozen embryo transfer

The process of implantation is characterized by a complex cross-talk between the endometrium and the blastocyst, with the endometrium only being receptive to implantation during a transient window of implantation of approximately 2-3 days during the midsecretory phase. The timing of embryo transfer, including frozen embryo transfer, is therefore critical to the success of implantation. In this article, we discuss various elements that may guide the timing of frozen embryo transfer, including the role of endometrial characteristics such as thickness, days postovulation or length of progesterone administration, stage of the embryo, and the application of endometrial receptivity tests to guide personalized embryo transfer.