Metformin ameliorates endometrial thickness in a rat model of thin endometrium

Metformin, a well-established anti-diabetic drug, is also used in managing various other metabolic disorders including polycystic ovarian syndrome (PCOS). There are evidences to show that metformin improves endometrial functions in PCOS women. However, fewer studies have explored the direct effects of metformin on endometrium. Previous in vitro studies have shown that therapeutic serum concentrations of metformin enhance endometrial epithelial cell proliferation. The present study was undertaken to investigate in vivo effects of metformin on endometrial proliferation in a rat model of thin endometrium. Toward this, a rat model of thin endometrium was developed. Metformin (0.1% or 1% w/v) was administrated orally for 15 days in rats with thin endometrium. Oral metformin administration for three consecutive estrous cycles (15 days) in the thin endometrium rat model led to an increase in endometrial thickness compared to sham endometrium. Histological analysis showed a significant increase in the number of endometrial glands (P < 0.05), stromal cells (P < 0.01) and blood vessels (P < 0.01) in metformin-treated (n = 10 in each group) uterine horns compared to sham (saline-treated) uterine horns in rats. The expression of proliferating cell nuclear antigen and vascular epithelial growth factor was found to be upregulated on treatment with 1% metformin-treated group (n = 7). However, pregnancy outcomes in the rats treated with metformin remained unaltered despite the restoration of endometrial thickness. In conclusion, the study demonstrated that metformin ameliorates endometrial thickness in a rat model of thin endometrium by increasing endometrial proliferation and angiogenesis, without restoration of embryo implantation.

Short-term reproductive outcomes analysis and prediction of the modified uterine stent treatment for mild to moderate intrauterine adhesions: experience at a single institution

BACKGROUND

To evaluate the efficacy of modified uterine stent in the treatment of mild-to-moderate intrauterine adhesions and explore the relative indicators affecting prognosis prediction.

METHODS

A total of 115 patients with mild-to-moderate intrauterine adhesions received a modified uterine stent placement after hysteroscopy adhesiolysis. The second-look hysteroscopy operated after 3 months surgery, and the third-look hysteroscopy operated after 6 months surgery if necessary. The stent was removed when the cavity shape was repaired, then the reproductive outcomes were followed up one year.

RESULTS

Menstrual blood volume, endometrial thickness and volume had increased significantly after 3 months surgery. The rates of cavity repaired were 86.96% (100/115) after 3 months surgery and 100% (115/115) after 6 months surgery cumulatively. Endometrial thickness after 3-months surgery was positively associated with uterine cavity shape repaired (P<0.01). The receive operating characteristic (ROC) curve showed the rate of uterine cavity shape repaired predicted by the model was 0.92, based on the endometrial thickness after 3-months surgery. The rate of pregnancy was 86.09% (99/115) in one year, while the rate of miscarriage accounted for 26.26% (26/99). The median time interval between stent removal and subsequent conception was 3 months. It showed adhesion recurrence was the risk factor for subsequent pregnancy (P<0.01).

CONCLUSIONS

A modified uterine stent placement under hysteroscopy was an effective approach for mild-to-moderate intrauterine adhesions, which is easy to operate and worthy for clinical promotion. Endometrial thickness measured by ultrasonography probably has predictive value in adhesion recurrence and subsequent pregnancy.

TRIAL REGISTRATION

ChiCTR2100051524. Date of registration (retrospectively registered): 26/09/2021.

Low Estradiol Level and Endometrial Thickness on the Day of Endometrial Transformation Influence Clinical Pregnancy After Intrauterine Insemination

Background

The causes of pregnancy failure after intrauterine insemination (IUI) are controversial. The purpose of this study was to investigate the influencing factors on clinical pregnancy after IUI.

Methods

This study retrospectively analyzed 1464 cycles of IUI performed at the Meizhou People's Hospital between March 2014 and June 2023. The χ2 test and logistic regression analysis was applied to assess the associations between the some factors (maternal age, paternal age, cycle type (natural cycle or ovulation induction cycle), hormone level on the day of endometrial transformation (estradiol (E2), luteinizing hormone (LH), and progesterone (P)), endometrial thickness on the day of endometrial transformation, and forward motile sperm concentration after treatment) and pregnancy failure.

Results

Among the 1464 IUI cycles in this study, 268 cycles of assisted reproduction resulted in clinical pregnancy, with a clinical pregnancy rate of 18.3%. During the cycles with clinical pregnancy, there were 25 (12.9%) preterm births and 169 (87.1%) full-term births. The E2 level on the day of endometrial transformation in clinical pregnancy group was higher than that in the pregnancy failure group (658.79±656.02 vs 561.21±558.83 pg/mL)(P=0.025). The clinical pregnancy group had a higher percentage of endometrial thickness between 8 and 13mm on the day of endometrial transformation than the pregnancy failure group (83.2% vs 75.0%)(P=0.002). The results of regressions analysis showed that low E2 level on the day of endometrial transformation (<238.3 pg/mL vs ≥238.3 pg/mL: OR 1.493, 95% CI: 1.086-2.052, P=0.014), and endometrial thickness <8mm on the day of endometrial transformation (<8mm vs 8-13mm: OR 1.886, 95% CI: 1.284-2.771, P=0.001) may increase risk of pregnancy failure performed IUI.

Conclusion

Low estradiol level, and endometrial thickness on the day of endometrial transformation may increase risk of pregnancy failure performed intrauterine insemination.

A sonographic endometrial thickness <7 mm in women undergoing in vitro fertilization increases the risk of placenta accreta spectrum

BACKGROUND

The prevalence of placenta accreta spectrum, a potentially life-threatening condition, has exhibited a significant global rise in recent decades. Effective screening methods and early identification strategies for placenta accreta spectrum could enable early treatment and improved outcomes. Endometrial thickness plays a crucial role in successful embryo implantation and favorable pregnancy outcomes. Extensive research has been conducted on the impact of endometrial thickness on assisted reproductive technology cycles, specifically in terms of pregnancy rates, live birth rates, and pregnancy loss rates. However, limited knowledge exists regarding the influence of endometrial thickness on placenta accreta spectrum.

OBJECTIVE

This study aimed to evaluate the association between preimplantation endometrial thickness and the occurrence of placenta accreta spectrum in women undergoing assisted reproductive technology cycles.

STUDY DESIGN

A total of 4637 women who had not undergone previous cesarean delivery and who conceived by in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment and subsequently delivered at the Third Affiliated Hospital of Guangzhou Medical University between January 2008 and December 2020 were included in this study. To explore the relationship between endometrial thickness and placenta accreta spectrum, we used smooth curve fitting, threshold effect, and saturation effect analysis. Multivariate logistic regression analysis was performed to evaluate the independent association between endometrial thickness and placenta accreta spectrum while adjusting for potential confounding factors. Propensity score matching was performed to reduce the influence of bias and unmeasured confounders. Furthermore, we used causal mediation effect analysis to investigate the mediating role of endometrial thickness in the relationship between gravidity and ovarian stimulation protocol and the occurrence of placenta accreta spectrum.

RESULTS

Among the 4637 women included in this study, pregnancies with placenta accreta spectrum (159; 3.4%) had significantly thinner endometrial thickness (non-placenta accreta spectrum, 10.08±2.04 mm vs placenta accreta spectrum, 8.88±2.21 mm; P<.001) during the last ultrasound before embryo transfer. By using smooth curve fitting, it was found that changes in endometrial thickness had a significant effect on the incidence of placenta accreta spectrum up to a thickness of 10.9 mm, beyond which the effect plateaued. Then, the endometrial thickness was divided into the following 4 groups: ≤7, >7 to ≤10.9, >10.9 to ≤13, and >13 mm. The absolute rates of placenta accreta spectrum in each group were 11.91%, 3.73%, 1.35%, and 2.54%, respectively. Compared with women with an endometrial thickness from 10.9 to 13 mm, the odds of placenta accreta spectrum increased from an adjusted odds ratio of 2.27 (95% confidence interval, 1.33-3.86) for endometrial thickness from 7 to 10.9 mm to an adjusted odds ratio of 7.15 (95% confidence interval, 3.73-13.71) for endometrial thickness <7 mm after adjusting for potential confounding factors. Placenta previa remained as an independent risk factor for placenta accreta spectrum (adjusted odds ratio, 11.80; 95% confidence interval, 7.65-18.19). Moreover, endometrial thickness <7 mm was still an independent risk factor for placenta accreta spectrum (adjusted odds ratio, 3.91; 95% confidence interval, 1.57-9.73) in the matched cohort after PSM. Causal mediation analysis revealed that approximately 63.9% of the total effect of gravidity and 18.6% of the total effect of ovarian stimulation protocol on placenta accreta spectrum were mediated by endometrial thickness.

CONCLUSION

The findings of our study indicate that thin endometrial thickness is an independent risk factor for placenta accreta spectrum in women without previous cesarean delivery undergoing assisted reproductive technology treatment. The clinical significance of this risk factor is slightly lower than that of placenta previa. Furthermore, our results demonstrate that endometrial thickness plays a significant mediating role in the relationship between gravidity or ovarian stimulation protocol and placenta accreta spectrum.

Successful live birth of thin endometrium: A case report

RATIONALE

The success of pregnancy depends on various factors, with the endometrial receptivity being a crucial component. Endometrial thickness (EMT) serves as a direct indicator for assessing endometrial receptivity. Previous studies have suggested that a thin endometrium is associated with lower pregnancy rates, especially in patients with an EMT of less than 4 mm. Even in assisted reproductive technology cycles with high success rates, clinical pregnancy cases in patients with such thin endometrium are reported to be very few, let alone in natural conception cycles. Therefore, a thin endometrium poses significant challenges for infertility patients. In this study, patients with an extremely thin endometrium were able to achieve clinical pregnancy and successful live births through natural conception, highlighting the possibility of success even in challenging cases.

PATIENT CONCERNS

The patient presented with polycystic ovary syndrome and ovulation disorders. She underwent a natural cycle of letrozole-induced ovulation. On the day of the human chorionic gonadotropin trigger, she had an EMT of 3.8 mm.

DIAGNOSES

Polycystic ovary syndrome, ovulation disorders, thin endometrium.

INTERVENTIONS

The patient received medications including Progynova, Aspirin, and Dydrogesterone.

OUTCOMES

The patient achieved spontaneous conception and subsequently had a live birth.

LESSONS

This case report underscores the significance of managing a thin endometrium during letrozole-induced ovulation. While EMT is traditionally pivotal for predicting embryo implantation success, our findings indicate that endometrial receptivity extends beyond thickness alone. Factors such as endometrial morphology, type, and blood supply play crucial roles. Successful pregnancies with a 3.8 mm EMT are rare, making this case a beacon of hope for such patients. It highlights that, with appropriate interventions, successful pregnancies remain attainable. For those with a thin endometrium, emphasis should extend beyond thickness, addressing ways to enhance both endometrial blood supply and morphology for improved pregnancy rates.

The influence of radical trachelectomy on endometrial thickness in in vitro fertilization-embryo transfer

AIM

Both morbidity and mortality rates of cervical cancer are increasing, especially in reproductive-aged women. Radical trachelectomy (RT) is an effective fertility-preserving surgery for early-stage cervical cancer. This study aimed to determine the influence of RT on endometrial thickness during in vitro fertilization-embryo transfer (IVF-ET).

METHODS

Forty-four patients had undergone RT, and 23 women undergoing IVF-ET treatment (105 ET cycles) were included. Endometrial thickness during hormone replacement therapy (HRT) was retrospectively evaluated and compared between patients with and without RT.

RESULTS

Eleven patients (50 ET cycles) in the RT group and 12 (52 ET cycles) in the control group were investigated. Compared with the control group, higher ET cancellation rates were observed in patients in the RT group (1 of 52 cycles [control group] vs. 8 of 50 cycles [RT group], p < 0.01). Endometrial thinning was not affected by patient age at first IVF-ET treatment, history of artificial abortion, preservation of uterine arteries during RT, or postoperative chemotherapy (p = 0.27, 1, 1, and 1, respectively).

CONCLUSIONS

Our data revealed that RT influenced endometrial thickness in IVF-ET. This was not affected by the background of the patients or perioperative management in this study. We could not reveal the underlying mechanism, but it is postulated that the transient postoperative uterine blood flow status and postoperative infections may have some effect on the endometrium. To resolve these issues, accumulation of evidences are required. We recommend informing patients about the impact of RT on IVF-ET before starting assisted reproductive technology (ART).

An investigation of endometrial vascularity in normally menstruating women and those in other physiological states using 3D ultrasound imaging

OBJECTIVES

This study aimed to determine the normal vasculature indices of the endometrium and to correlate them with those in various physiological states.

METHODS

Women undergoing ultrasound at the Feto-Maternal Center, Qatar in 2020-2021 as part of their gynecologic evaluation were enrolled into the study. They were divided into those with normal menses and no additional pathology, those following spontaneous miscarriage, postpartum and menopausal. Three-dimensional (3D) evaluation of the endometrial vasculature was done and the parameters quantified included vascularization index (VI), flow index (FI), vascularization flow index (VFI), endometrial thickness, endometrial volume and uterine volume. JASP, an open-source statistical analysis software, was used for analysis and an independent t-test to compare the vascularity indices. A multivariate regression analysis was also done to look at the factors affecting the endometrial vascular indices within the luteal phase.

RESULTS

A total of 461 women were studied: 122 in the follicular phase, 199 in the luteal phase, 90 after a spontaneous miscarriage, 29 postpartum, and 16 menopausal. The vascularity indices were highest after miscarriage and lowest postnatally. There were no significant effects of age, gravida, para, or abortions on VI and VFI. However, there was a significant positive effect of age on FI (P = 0.019) There was a significant increase in endometrial volume and thickness in the luteal phase as compared to follicular phase (P < 0.01), but there was no difference in the vascularity indices. The uterine and endometrial volume in the postnatal group were nearly double that of the luteal group (P value <0.01 and 0.014, respectively). There was a significant decrease in flow index in the postnatal group compared to the luteal group (P < 0.01), suggesting low flow intensity in the postnatal group.

CONCLUSIONS

Endometrial vascular indices measured using 3D Doppler can be used to determine normal vascular indices and vary with physiological states such as after miscarriages, postnatally and in the menopausal states.

Impact of biomimetic electrical stimulation combined with Femoston on pregnancy rate and endometrium characteristics in infertility patients with thin endometrium: a prospective observational study

OBJECTIVE

To explore the impact of biomimetic electrical stimulation combined with Femoston (estradiol tablets/estradiol and dydrogesterone tablets) on pregnancy rate and endometrium characteristics (endometrial thickness and type) in patients with infertility and a thin endometrium.

METHODS

This prospective study enrolled patients with infertility and a thin endometrium admitted to Urumqi Maternal and Child Health Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China, between May 2021 and January 2022. The patients received Femoston alone (Femoston group) or Femoston combined with biomimetic electrical stimulation (electrotherapy group). The outcomes were the pregnancy rate and endometrium characteristics.

RESULTS

Finally, 120 patients were enrolled (60/group). Before treatment, the endometrial thickness (p = 0.515) and the percentages of patients with endometrial types A + B and C (p = 0.769) were comparable between the two groups. After treatment, the endometrium of the patients in the electrotherapy group was thicker than those in the Femoston group (6.48 ± 0.96 mm vs. 5.27 ± 0.51 mm, p < 0.001). Furthermore, the percentages of patients with endometrial types A + B and C in the electrotherapy group were larger than in the Femoston group (p = 0.027). In addition, the pregnancy rates between the two groups (28.33% vs. 16.67%, p = 0.126) were similar.

CONCLUSIONS

The results suggest the possibility that biomimetic electrical stimulation combined with Femoston could improve endometrial type and thickness in patients with infertility and thin endometrium compared with Femoston alone, but the pregnancy rate showed no significant improvement. The results need to be confirmed.

Follicular phase length is not related to live birth outcome in women with unexplained infertility undergoing ovarian stimulation with intrauterine insemination cycles in a multicenter trial

Objective

To evaluate the effect of follicular phase length (FPL) on pregnancy outcomes and endometrial thickness (ET) among women with unexplained infertility undergoing ovarian stimulation with intrauterine insemination (OS-IUI) with clomiphene citrate, letrozole, or gonadotropins.

Design

Cohort analysis of the Reproductive Medicine Network's Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation randomized controlled trial.

Setting

Multicenter randomized controlled trial.

Patients

A total of 869 couples with unexplained infertility who underwent OS-IUI treatment cycles as part of the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation study.

Interventions

FPL was evaluated as a categorical variable defined by quintiles (q1: ≤11 days, q2: 12 days, q3: 13 days, q4: 14-15 days, and q5: ≥16 days).

Main outcome measures

Clinical pregnancy, live birth rates, and ET.

Results

Decreasing FPL quintiles did not reduce clinical pregnancy or live birth rates in unadjusted or adjusted models with all treatment groups combined or when stratified by the ovarian stimulation medication. All FPL categories had significantly thinner ET compared with the 5th quintile (≥16 days) among women treated with clomiphene citrate or letrozole. Similar but diminished associations were observed among women who underwent ovarian stimulation with gonadotropins, but the observed differences were limited to those with FPL of 12 days or shorter when compared with FPL ≥16 days.

Conclusions

Although shorter FPL was associated with reduced ET, it was not associated with the outcomes of clinical pregnancy or live birth in women with unexplained infertility undergoing OS-IUI in all treatment groups combined. Similar patterns existed when analyses of clinical pregnancy and live birth rates were stratified by treatment.

Clinical trial registration

NCT01044862.

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.

Autologous Platelet-Rich Plasma (PRP) in Infertility-Infusion versus Injectable PRP

(1) Background: During IVF (in vitro fertilization) procedures, endometrial thickness has a significant role in the success of pregnancy outcomes for embryo transfers. Endometrial thickness, a crucial component of endometrial receptivity, is a contentious issue. The regenerative properties of PRP have been shown in recent research to have positive effects on the endometrium. PRP increases the pregnancy rate in IVF patients with thin endometrium and recurrent implantation failure. In order to demonstrate the efficacy of PRP therapies, this work compares the administration of injectable and infusible PRP during endometrial preparation. (2) Methods: This prospective single-arm control study was conducted at an IVF center in Oradea, Romania. This study included 50 patients; 27 were included in the group with Injectable PRP and 23 in the group with Infusible PRP. The outcome was compared between the two groups, with the primary outcome being the endometrial thickness after the PRP infusion or injection and the secondary outcome being the pregnancy rate in both groups. (3) Results: Patients who were treated with Injectable PRP had a higher pregnancy rate. An improvement in the quality of the endometrium, in terms of thickness, was also observed in the patients who were injected with PRP. (4) Conclusions: Compared to PRP infusions inside the uterus, sub-endometrial PRP injections in frozen embryo transfer methods have a greater pregnancy rate.

Does endometrial compaction before embryo transfer affect pregnancy outcomes? a systematic review and meta-analysis

Objective

There is no clear evidence of clinical significance of endometrial compaction, which can be measured by a reduction in endometrial thickness (EMT) during the follicular-luteal transition before the day of embryo transfer. In this study, we aim to determine whether endometrial compaction has an effect on in vitro fertilization (IVF) success.

Methods

We searched PubMed, Cochrane, Embase, and Web of Science electronic databases for studies published in English up to March 2023. Heterogeneity between studies was assessed using the I2 statistic. The random effects model and fixed effects model was used to pool the risk ratio (RR) with a corresponding 95% confidence interval (CI). A subgroup analysis was performed based on different methods of ultrasonic measurement and different endometrial compaction rates (ECR). Stata 17.0 software was used for meta-analysis. Pregnancy outcomes, which included clinical pregnancy rate, ongoing pregnancy rate, live birth rate, and spontaneous abortion rate, were evaluated.

Results

In this study, 18 cohort studies were included, involving 16,164 embryo transfer cycles. Pooled results indicated that there was no significant difference between the endometrial compaction group and the non-compaction group in terms of clinical pregnancy rate (RR [95% CI]=0.98 [0.90,1.08]; I2 = 69.76%), ongoing pregnancy rate (RR [95% CI]=1.18 [0.95,1.47]; I2 = 78.77%), live birth rate (RR [95% CI]= 0.97 [0.92,1.02]; I2 = 0.00%) or spontaneous abortion rate (RR [95% CI]= 1.07[0.97,1.26]; I2 = 0.00%). According to the subgroup analysis of ultrasonic measurement methods, in the transvaginal ultrasound (TVUS) combined with abdominal ultrasonography (AUS) cycles of the endometrial compaction group, the rate of ongoing pregnancy (RR [95% CI] = 1.69 [1.26, 2.26]; I2 = 29.27%) and live birth (RR [95% CI] = 1.27 [1.00,1.61]; I2 = 62.28%) was significantly higher than that of the non-compaction group. Additionally, subgroup analysis based on ECR revealed a significantly higher rate of ongoing pregnancy when ECR ≥ 15% (RR [95% CI] = 1.99 [1.61, 2.47]; I2 = 0.00%).

Conclusion

Endometrial compaction has no adverse effect on clinical pregnancy rate, ongoing pregnancy rate, live birth rate, or spontaneous abortion rate. A possible explanation for the contradictory findings of previous studies lies in the method by which the EMT is measured.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023430511, identifier CRD42023430511.

Impact of endometrial compaction on reproductive outcomes after cryotransfer of euploid embryos in a modified natural cycle: protocol for a prospective cohort study

Introduction

Embryo implantation is a complex and poorly understood process. Most studies to date have focused on the analysis of the endometrium at the end of the estrogenic phase, while the available data on its importance after secretory transformation are limited and inconsistent. Current evidence does not allow for a conclusive interpretation of the changes observed in the pre-implantation endometrium, whether in the natural or replacement cycle, and their relevance in the development of a pregnancy or the implications for clinical practice.

Methods

Multicenter prospective observational cohort study. Based on our sample size calculation, the study group will consist of 206 women (exposed or "compaction" group: 103 women with a decrease of ≥ 5% in endometrial thickness between the estrogenic phase and the day of embryo transfer; non-exposed "non-compaction" group: 103 women with similar or greater endometrial thickness between these time points). The main objective of this study is to compare the ongoing pregnancy rates in natural cycles for euploid embryo transfer in patients who present endometrial compaction at the time of transfer versus those who with a stable or greater endometrial thickness with respect to the estrogenic phase. The estimated duration of the study is 30 months. Inclusion criteria are: 18 to 50 years of age, with primary or secondary infertility, subjected to endometrial preparation in a modified natural cycle for transfer of a genetically euploid blastocyst, from their own oocyte or oocyte donation, with a normal uterine cavity. Exclusion criteria are: uterine or endometrial disease (e.g., multiple myomatosis, severe adenomyosis, Asherman syndrome, refractory endometrium), conditions that prevent correct ultrasound assessment (tilted uterus), or a history of recurrent implantation failure or repeated miscarriages.

Discussion

The findings from this study will provide valuable insights into the potential influence of the "endometrial compaction" phenomenon on reproductive outcomes during natural cycle endometrial preparation. By examining this aspect, we aim to contribute to a better understanding of the factors that may impact successful outcomes in fertility treatments.

Establishment of a prediction model for the impact of endometrial thickness on the day of embryo transfer on ectopic pregnancy in frozen-thawed embryo transfer cycle

Objective

This study aims to investigate the factors affecting the ectopic pregnancy (EP) rate in the frozen-thawed embryo transfer (FET) cycle.

Methods

This study retrospectively analyzed 5606 FET cycles, including 5496 cycles resulting in intrauterine pregnancy and 110 cycles resulting in EP. Smooth curve fitting and piece-wise linear regression were utilized to evaluate a non-linear association between endometrial thickness (EMT) and EP. Multiple logistic regression analysis was used to study the effect of EMT on the embryo transfer (ET) day and other indexes on EP rate after adjusting for confounding factors. A nomographic prediction model was employed to predict EP occurrence. The predictive efficacy of the model was assessed using the area under the receiver operating characteristic (ROC) curve (AUC), utilizing the bootstrap sampling method for internal validation.

Results

After accounting for the confounding factors, the segmented linear regression analysis indicated that the EMT inflection point was 9 mm; the EP rate significantly decreased by 28% with each additional millimeter of EMT up to 9 mm (odds ratio (OR) = 0.72; 95% confidence interval (CI), 0.53-0.99; P = 0.0412) while insignificantly decreased when the EMT was greater than 9 mm (OR = 0.91; 95% CI, 0.76-1.08; P = 0.2487). Multivariate logistic regression analysis revealed that after adjusting for confounders, EP risk significantly increased in the number of previous EPs ≥ 1 (OR = 2.29; 95% CI, 1.26-4.16; P = 0.0064) and tubal factor infertility (OR = 3.86; 95% CI, 2.06-7.24; P < 0.0001). Conversely, EP risk was significantly reduced by the increased EMT (OR = 0.84; 95% CI, 0.74-0.96; P = 0.0078) and the blastocyst transfer (OR = 0.45; 95% CI, 0.27-0.76; P = 0.0027). These variables were used as independent variables in a nomogram prediction model, resulting in an AUC of 0.685. The nomination models were internally verified using self-sampling (bootstrap sampling resampling times = 500). This validation yielded an AUC of 0.689, with a sensitivity of 0.6915 and a specificity of 0.5790. The internal validation indicated minimal fluctuations in the AUC, signifying a relatively stable model.

Conclusion

Undergoing EMT on the day of ET poses a separate EP risk in the FET cycle; to mitigate the EP incidence, the EMT should exceed 9 mm before ET. Furthermore, previous EPs and tubal factor infertility were additional factors independently increasing EP risk. Furthermore, implementing blastocyst transfer demonstrated that EP incidence was significantly reduced. Utilizing a nomogram predicting system enables EP risk evaluation before ET for individual patients, establishing a basis for devising clinical strategies for ET.

Impact of letrozole co-treatment during ovarian stimulation on oocyte yield, embryo development, and live birth rate in women with normal ovarian reserve: secondary outcomes from the RIOT trial

STUDY QUESTION

Does letrozole (LZ) co-treatment during ovarian stimulation with gonadotropins for in IVF impact follicle recruitment, oocyte number and quality, embryo quality, or live birth rate (LBR)?

SUMMARY ANSWER

No impact of LZ was found in follicle recruitment, number of oocytes, quality of embryos, or LBR.

WHAT IS KNOWN ALREADY

Multi-follicle stimulation for IVF produces supra-physiological oestradiol levels. LZ is an aromatase inhibitor that lowers serum oestradiol thus reducing negative feedback and increasing the endogenous gonadotropins in both the follicular and the luteal phases, effectively normalizing the endocrine milieu during IVF treatment.

STUDY DESIGN, SIZE, DURATION

Secondary outcomes from a randomized, double-blind placebo-controlled trial (RCT) investigating once-daily 5 mg LZ or placebo during stimulation for IVF with FSH. The RCT was conducted at four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018 and pregnancy outcomes of frozen-thawed embryo transfers (FET) registered until May 2023.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One hundred fifty-nine women with expected normal ovarian reserve (anti-Müllerian hormone 8-32 nmol/l) were randomized to either co-treatment with LZ (n = 80) or placebo (n = 79). In total 1268 oocytes were aspirated developing into 386 embryos, and morphology and morphokinetics were assessed. One hundred twenty-nine embryos were transferred in the fresh cycle and 158 embryos in a subsequent FET cycle. The effect of LZ on cumulative clinical pregnancy rate (CPR), LBR, endometrial thickness in the fresh cycle, and total FSH consumption was reported.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of usable embryos of retrieved oocytes was similar in the LZ group and the placebo group with 0.31 vs 0.36 (mean difference (MD) -0.05, 95% CI (-0.12; 0.03), P = 0.65). The size and number of aspirated follicles at oocyte retrieval were similar with 11.8 vs 10.3 follicles per patient (MD 1.5, 95% CI (-0.5; 3.1), P = 0.50), as well as the number of retrieved oocytes with 8.0 vs 7.9 oocytes (MD 0.1, 95% CI (-1.4; 1.6), P = 0.39) in the LZ and placebo groups, respectively. The chance of retrieving an oocyte from the 13 to 16 mm follicles at trigger day was 66% higher (95% CI (24%; 108%), P = 0.002) in the placebo group than in the LZ group, whilst the chance of retrieving an oocyte from the ≥17 mm follicles at trigger day was 50% higher (95% CI (2%; 98%), P = 0.04) in the LZ group than in the placebo group. The proportion of fertilized oocytes with two-pronuclei per retrieved oocytes or per metaphase II oocytes (MII) (the 2PN rates) were similar regardless of fertilization with IVF or ICSI with 0.48 vs 0.57 (MD -0.09, 95% CI (-0.24; 0.04), P = 0.51), and 0.62 vs 0.64 (MD -0.02, 95% CI (-0.13; 0.07), P = 0.78) in the LZ and placebo groups, respectively. However, the MII rate in the ICSI group was significantly lower with 0.75 vs 0.88 in the LZ vs the placebo group (MD -0.14, 95% CI (-0.22; -0.06), P = 0.03). Blastocysts on Day 5 per patient were similar with 1.5 vs 2.0, P = 0.52, as well as vitrified blastocysts per patient Day 5 with 0.8 vs 1.2 in (MD -0.4, 95% CI (-1.0; 0.2), P = 0.52) and vitrified blastocysts per patient Day 6 with 0.6 vs 0.6 (MD 0, 95% CI (-0.3; 0.3), P = 1.00) in the LZ vs placebo group, respectively. Morphologic evaluation of all usable embryos showed a similar distribution in 'Good', 'Fair', and 'Poor', in the LZ vs placebo group, with an odds ratio (OR) of 0.8 95% CI (0.5; 1.3), P = 0.68 of developing a better class embryo. Two hundred and ninety-five of the 386 embryos were cultured in an embryoscope. Morphokinetic annotations showed that the odds of having a high KIDscore™ D3 Day 3 were 1.2 times higher (CI (0.8; 1.9), P = 0.68) in the LZ group vs the placebo group. The CPR per transfer was comparable with 31% vs 39% (risk-difference of 8%, 95% CI (-25%; 11%), P = 0.65) in the LZ and placebo group, respectively, as well as CPR per transfer adjusted for day of transfer, oestradiol and progesterone levels at trigger, progesterone levels mid-luteal, and number of oocytes retrieved (adjusted OR) of 0.8 (95% CI (0.4; 1.6), P = 0.72). Comparable LBR were found per transfer 28% vs 37% (MD -9%, 95% CI (-26%; 9%), P = 0.60) and per randomized women 24% vs 30% (MD of -6%, CI (-22%; 8%), P = 0.60) in the LZ group and placebo group, respectively. Furthermore, 4.8 years since the last oocyte aspiration, a total of 287 of 386 embryos have been transferred in the fresh or a subsequently FET cycle, disclosing the cumulative CPR, which is similar with 38% vs 34% (MD 95% CI (8%; 16%), P = 0.70) in the LZ vs placebo group.

LIMITATIONS, REASONS FOR CAUTION

Both cleavage stage and blastocyst transfer and vitrification were permitted in the protocol, making it necessary to categorize their quality and pool the results. The study was powered to detect hormonal variation but not embryo or pregnancy outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

The similar utilization rate and quality of the embryos support the use of LZ co-treatment for IVF with specific indication as fertility preservation, patients with previous cancer, or poor responders. The effect of LZ on mature oocytes from different follicle sizes and LBRs should be evaluated in a meta-analysis or a larger RCT.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from EU Interreg for ReproUnion, Sjaelland University Hospital, Denmark, Ferring Pharmaceuticals, and Gedeon Ricther. Roche Diagnostics contributed with assays. A.P. has received grants from Ferring, Merck Serono, and Gedeon Richter, consulting fees from Preglem, Novo Nordisk, Ferring, Gedeon Richter, Cryos, & Merck A/S, speakers fees from Gedeon Richter, Ferring, Merck A/S, Theramex, & Organon, and travel support from Gedeon Richter. The remaining authors declare that they have no competing interests in the research or publication.

TRIAL REGISTRATION NUMBERS

NCT02939898 and NCT02946684.

Autologous Platelet-Rich Plasma (PRP) Efficacy on Endometrial Thickness and Infertility: A Single-Centre Experience from Romania

(1) Background: During IVF (in vitro fertilization), a proper endometrium thickness is one of the most difficult parameters to achieve and one of the most important prognostic factors of the success rate. One major problem is the high cancelation percentage in frozen embryo transfer cycles. The focus on the adjuvant methods for improving endometrium thickness is an on-going subject of interest. (2) Methods: This prospective single-arm self-control study was conducted in an IVF centre in Oradea, Romania. The patients were divided into two groups. The control group included 51 patients with at least one attempt to transfer a good-quality blastocyst, but the endometrial thickness did not surpass 7 mm under standard endometrial preparation protocol with oestradiol and with adjuvant therapy (other than PRP, such as aspirin, vitamin C, and vitamin E), and the study group included the same 51 patients that had the embryo transfer performed under the same standard endometrial preparation protocol with oestradiol preparation protocol and intrauterine PRP infusion. (3) Results: In our study, the PRP treatment had a positive impact on the parameters that were followed for the evaluation of the success rate of the embryo transfer procedure. The endometrial thickness (an increase in endometrial thickness by 0.6 mm after PRP treatment with p = 0.0001) and the clinical pregnancy rate (having a MD ± SD of 0 ± 0.38 before PRP treatment and with an increase to 0.5 ± 0.1 after the PRP treatment, p = 0.0004) were statistically significant (4) Conclusions: PRP has a positive effect in promoting endometrial proliferation, improving embryo implantation rate and clinical pregnancy rate for women with thin endometrium.

Endometrial thickness and early pregnancy complications after frozen-thawed embryo transfers

Background

The relationship between endometrial thickness and pregnancy safety after in vitro fertilization treatment is an important topic that should provoke attention. The aim of this study was to demonstrate the relationship between endometrial thickness on day of embryo transfer and early pregnancy complications, including ectopic pregnancy and early miscarriage, in frozen thawed embryo transfer (FET) cycles.

Methods

Patients undergoing their first FET cycles were included into this study from January 2010 to December 2021. Patients were divided into three groups according to endometrial thickness on day of embryo transfer: Thin, ≤ 7 mm; Medium, 7-14 mm; Thick, ≥ 14 mm. Ectopic pregnancy and early miscarriage were the two primary outcomes. Endometrial thickness was the main measured variable. The risk factors of these two compilations were determined based on univariate analysis and multivariate logistic regression analysis.

Results

A total of 11138 clinical pregnancies were included. The overall ectopic pregnancy and early spontaneous miscarriage rates were 2.62% and 13.40%. The ectopic pregnancy and early spontaneous miscarriage rates were significantly higher in patients with thin endometrium as compared with those in the other two groups (ectopic pregnancy rate: 5.06% vs. 2.62% vs. 1.05%; P < 0.001; early spontaneous miscarriage rate: 15.18% vs. 13.45% vs. 11.53%; P < 0.001). In multivariate logistic regression analysis, thin endometrium was an independent factor to predict ectopic pregnancy [adjusted odds ratio (aOR): 5.62; 95% confidence interval (CI): 2.51-12.58, P < 0.001], and to predict early spontaneous miscarriage rate (aOR: 1.57; 95% CI: 1.21-1.74, P < 0.001).

Conclusion

Thin endometrium on day of embryo transfer in FET cycles is an independent predictor for early pregnancy compilations, including ectopic pregnancy and early spontaneous miscarriage.

Antimüllerian hormone and endometrial thickness in predicting xfollicular maturation in patients with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome is an anovulatory infertility problem that requires the treatment of ovulation induction. Clomiphene citrate is a first-line regimen for ovulation induction. The antimüllerian hormone is produced by granulosa cells of small, growing follicles in the ovary. Folliculogenesis is an essential process for ovarian function. Endometrial thickness is important throughout a female's life, especially concerning medications for ovulation induction.

OBJECTIVE

This study aimed to determine the role of basal antimüllerian hormone and midcycle endometrial thickness in predicting follicular maturation and pregnancy in patients with polycystic ovary syndrome treated with clomiphene citrate.

STUDY DESIGN

This was a prospective cohort study that was conducted at El-sir Abualhassan's Fertility Center (September 2020 to August 2021). The study included 197 patients with polycystic ovary syndrome diagnosed using the Rotterdam criteria. The patients were treated with a dosage of 100 mg of clomiphene citrate. Data were collected using a questionnaire that was filled out after informed consent was provided by the patients. The basal antimüllerian hormone level was measured using enzyme immunoassay, and endometrial thickness and follicular size were measured before and after clomiphene citrate treatment using transvaginal ultrasound. The data were analyzed using SPSS (version 23; IBM Corporation, Armonk, NY). Moreover, the correlation was performed using the chi-square test.

RESULTS

Almost two-thirds of the participants have normal antimüllerian hormone levels. Before clomiphene citrate was used as the treatment regimen, 95.40% of the patients had an endometrial thickness of ≤5 mm and a follicular size of 1 to 6 mm. After clomiphene citrate treatment, 74.60% of the patients had an endometrial thickness of 6 to 10 mm, and 46.20% of the patients had a follicular size of 7 to 12 mm. A significant correlation was found between basal antimüllerian hormone, follicular maturation, and pregnancy (P=.001). There was a significant association between endometrial thickness after clomiphene citrate treatment and achieving pregnancy (P=.001).

CONCLUSION

Clomiphene citrate is a first-line regimen for patients with polycystic ovary syndrome with normal antimüllerian hormone levels. After clomiphene citrate treatment, there was a correlation between antimüllerian hormone and follicular maturation and pregnancy. Moreover, there was a correlation between midcycle endometrial thickness and pregnancy.

Clinical evaluation of autologous platelet-rich plasma therapy for intrauterine adhesions: a systematic review and meta-analysis

Objective

This meta-analysis aims to evaluate the efficacy and safety of autologous platelet-rich plasma (PRP) administration in reducing adhesion recurrence and improving pregnancy outcomes in patients with intrauterine adhesion (IUA).

Methods

We conducted a comprehensive search of Pubmed, Embase, the Cochrane Library, Web of Science, Scopus, and China National Knowledge Internet (CNKI) from inception to February 10, 2023, without any language or regional restrictions. We used random-effects models to assess odds ratios (OR) and weight mean differences (WMD) with 95% confidence intervals (CI).

Results

Our meta-analysis included a total of 730 patients from 10 clinical studies (6 RCTs and 4 non-RCTs). The results showed that PRP administration significantly increased endometrial thickness (WMD = 0.79, 95% CI: 0.40-1.19; P < 0.001; I² = 0.0%), menstrual volume (WMD = 2.96, 95% CI = 2.30-3.61; P < 0.001; I² = 0.0%), and days of menstruation (WMD = 1.13, 95% CI = 0.86-1.41; P < 0.001; I² = 0.0%). Additionally, the clinical pregnancy rate was also improved (OR = 1.82, 95% CI: 1.19-2.78; P = 0.006; I² = 0.0%). However, there was insufficient evidence to reach a conclusion regarding the effects of PRP on the recurrence rate of moderate to severe IUA, changes in AFS scores, miscarriage rate, and live birth rate.

Conclusions

Our analysis confirms that autologous PRP is an effective treatment for IUA. However, the limited sample size suggests that the results should be interpreted with caution. Therefore, larger and well-designed studies are necessary in the future to confirm these findings and explore the optimal PRP dosing regimens further.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023391115.

Effect of the endometrial thickness on the live birth rate: insights from 959 single euploid frozen embryo transfers without a cutoff for thickness

OBJECTIVE

To investigate whether endometrial thickness (ET) independently affects the live birth rate (LBR) after embryo transfer.

DESIGN

Retrospective study.

SETTING

Private assisted reproductive technology center.

PATIENT(S)

A total of 959 single euploid frozen embryo transfers.

INTERVENTION(S)

Vitrified euploid blastocyst transfer.

MAIN OUTCOME MEASURE(S)

Live birth rate per embryo transfer.

RESULT(S)

The conditional density plots did not demonstrate either a linear relationship between the ET and LBR or a threshold below which the LBR decreased perceivably. Receiver operating characteristic curve analyses did not suggest a predictive value of the ET for the LBR. The area under the curve values were 0.55, 0.54, and 0.54 in the overall, programmed, and natural cycle transfers, respectively. Logistic regression analyses with age, embryo quality, day of trophectoderm biopsy, body mass index, and ET did not suggest an independent effect of the ET on the LBR.

CONCLUSION(S)

We did not identify a threshold of the ET that either precluded live birth or under which the LBR decreases perceivably. Common practice of cancelling embryo transfers when the ET is <7 mm may not be justified. Prospective studies, in which the management of the transfer cycle would not be altered by ET, would provide higher-quality evidence on the subject.

Endometrial compaction is associated with the increased live birth rate in artificial frozen-thawed embryo transfer cycles

We aimed to assess the effect of endometrial compaction on the live birth rate in frozen-thawed embryo transfer (FET) cycles and to investigate the parameters associated with compaction. FET cycles performed in a tertiary care infertility centre between May 2013 and October 2019 were reviewed retrospectively. The decremental change of endometrial thickness between the end of oestrogen phase and ET day was defined as endometrial compaction. The primary outcome measure was endometrial compaction, and the secondary outcome was the live birth rate. Among all, 89 had endometrial compaction and 194 did not. The live birth rate was significantly higher in the compaction group (23.6 vs. 13.4%, respectively; p = 0.039). Multivariate logistic regression analysis revealed that in FET cycles with artificial endometrial preparation, the chance for live birth was significantly higher in cycles with endometrial compaction [OR: 3.133, 95% confidence interval (CI) 1.104-8.892; p = 0.032] when adjusted for age, stage of the embryo, and endometrial thickness at the end of the oestrogen phase. According to receiver operating characteristic (ROC) curve analysis the sensitivity and specificity of 9.25 mm endometrial thickness at the end of oestrogen phase were 76.4 and 58.8%, respectively (area under the curve: 0.701, 95% CI 0.640-0.763; p < 0.001) to predict endometrial compaction.

Endometrial thickness and live birth rates after IVF: a systematic review

AIM

This study aims to systematically review the current literature on published studies with data on the clinical significance of endometrial thickness on ultrasound for live birth rates after IVF or intracytoplasmic sperm injection (ICSI).

METHODS

An extensive systematic review of PubMed, Web of Science, ScienceDirect, Google Scholar, and Open Gray databases, and following hand-search of the reference list of the included studies was performed.

RESULTS

We found 20 eligible studies that evaluated 20 546 patients for endometrial thickness, presented risk factors for decreased endometrial receptivity, and IVF outcomes with fresh and frozen embryo transfer (FET) cycles. The mean age of the patients ranged from 28.86 to 41.03 years. Reported endometrial thickness ranged from <4 mm to >15 mm. The clinical pregnancy rate varied from 9,09% to 61,49% in fresh embryo transfer cycles and from 13,3% to 79,31% in FET cycles. Overall, LBR varied between 4,80% and 48,99% in fresh embryo cycles and between 6.06% and 39,19% in FET cycles.

LIMITATIONS

Only English-language studies were included; most studies were from the China region; retrospective study design used in most studies; different ET thresholds, which in turn could significantly alter the correlation with pregnancy outcomes; different IVF procedure protocols in fresh or FET cycles.

CONCLUSIONS

IVF outcomes in patients with impaired endometrial receptivity do not depend only on the condition of the endometrium. Risk factors and endometrial thickness significantly affect LBR in fresh and FET cycles.

Effect of intrauterine infusion of autologous platelet-rich plasma in patients with refractory thin endometrium undergoing in vitro fertilization

Introduction

Treatment of refractory thin endometrium during IVF is a relatively challenging problem, considering that optimal endometrium thickness is one of the critical factors for successful implantation and pregnancy. Autologous intrauterine platelet-rich plasma (PRP) infusion is an adjuvant therapeutic alternative for enhancing the endometrial thickness (EMT) and echo pattern. It was shown that PRP could expand EMT and improve pregnancy outcomes with its high content of growth factors and cytokines, and its role in the regulation of the immunological interaction between the embryo and the endometrium. The aim of the study is to evaluate the effect of autologous PRP in improving the ongoing pregnancy rate in patients with refractory thin endometrium undergoing IVF.

Material and methods

A prospective study in Ain Shams University Hospital including 66 infertile women with a refractory thin endometrium below 7 mm by ultrasound on the day of human chorionic gonadotropin injection in fresh embryo transfer (ET) cycle, who did not respond to standard medical therapies after more than 2 cycles of previous medical therapy, and who were candidates for IVF cycle were given intrauterine PRP.

Results

A significant increase in EMT was noted and enhancement of endometrial pattern after intrauterine PRP infusion in the days of ovum pick-up and ET. There was also a significant increase in ongoing pregnancy, chemical pregnancy, clinical pregnancy, and implantation rates, while the miscarriage rate decreased after PRP infusion.

Conclusions

Intrauterine PRP infusion improved ongoing pregnancy, chemical pregnancy, clinical pregnancy, and implantation rates, in addition to EMT and pattern on the days of ovum pick-up and ET, while the miscarriage rate significantly decreased.

Comparative Evaluation of Sildenafil Citrate and Estrogen as an Adjuvant Therapy for Treatment of Unexplained Infertility in Women

BACKGROUND

Uterine blood flow determines endometrial thickness. This study examined how vaginal sildenafil citrate and estradiol valerate altered endometrial thickness, blood flow, and fertility in infertile women.

METHODS

This study observed 148 infertile women whose infertility was unexplained. Group 1 comprised 48 patients who received oral estradiol valerate (Cyclo-Progynova 2 mg/12 h white tablets) from day 6 till ovulation was initiated with clomiphene citrate. A number of 50 participants in group 2 received oral sildenafil (Respatio 20 mg/12 h film-coated tablets) for 5 days starting the day after their previous menstrual period and finishing on the day they ovulated with clomiphene citrate. Group 3 was the control group, with 50 patients receiving clomiphene citrate (Technovula 50 mg/12 h tablets) ovulation induction from the 2nd to 7th day of cycle. All patients had transvaginal ultrasounds to determine ovulation, follicle count, and fertility. Miscarriage, ectopic pregnancy, and multiple pregnancies were monitored for three months.

RESULTS

The three groups' mean ETs differed statistically at p = 0.0004. A statistically significant difference was found between the three groups in terms of the number of follicles, with 69% of patients in group 1 having one and 31% having two or more, 76% of patients in group 2 having one and 24% having two or more, and 90% of patients in the control group having one and 10% having two or more (p = 0.038). The clinical pregnancy rates of the three groups were 58%, 46%, and 27%, respectively (p = 0.005). The distribution of all side effects was not statistically different between the three groups.

CONCLUSION

It is possible to claim that adding oral estrogen to clomiphene citrate therapy as an adjuvant therapy can improve endometrial thickness and, as a result, increase the pregnancy rates in unexplained infertility compared to sildenafil, especially in cases where the infertility has lasted less than two years. Most people who take sildenafil end up with a mild headache.

Novel application to evaluate endometrial blood flow using transvaginal superb microvascular imaging: A preliminary study describing physiological changes from ovulation to mid-luteal phase

INTRODUCTION

We aimed to describe physiological changes in endometrial blood flow (minute arterioles running through the endometrium) from ovulation to the mid-luteal phase using superb microvascular imaging.

MATERIAL AND METHODS

The study involved 17 women (median age, 32.5 years; first to third interquartile range, 29.8-40.0 years) with regular menstrual cycles who were managed in our institute from 2020 to 2021. The uterus was delineated at the sagittal section using transvaginal ultrasonography incorporated with superb microvascular imaging. For each participant, a total of 28 cycles were observed; 17 cycles observed within one day of ovulation and the implantation period, 5-7 days (D5-7) after ovulation in the same cycle, and nine cycles in which only ovulation was observed, and two cycles in which only D5-7 was observed. Therefore, 26 and 19 images at ovulation and D5-7, respectively, were acquired. Endometrial blood flow was evaluated by depth of the vascular signal in the endometrium and categorized as follows: signals only in the basal layer of the endometrium (grade 1), reaching up to half the endometrium (grade 2), and covering the whole endometrium (grade 3). Changes in the grade of endometrial blood flow from ovulation to D5-7 after ovulation, and the relationship between the grade of endometrial blood flow and the endometrial thickness on ovulation and D5-7 after ovulation, were analyzed. Statistical significance was set at p < 0.05.

RESULTS

The endometrial blood flow from ovulation to D5-7 after ovulation during the same menstrual period showed a downgrade in 14 of 17 cycles (82.3%) and no change in the remaining three cycles (17.6%), indicating a decrease in the endometrial blood flow from ovulation to D5-7 after ovulation (p = 0.001). There were differences between the grade of endometrial blood flow and median endometrial thickness on ovulation (grade 1: 5.9 mm, grade 2: 9.1 mm, and grade 3: 11.2 mm); however, no differences in the endometrial thickness were found between the grades on D5-7 after ovulation.

CONCLUSIONS

In the normal menstrual cycle, endometrial blood flow decreased from ovulation to the mid-luteal phase, and the endometrial thickness in the ovulatory phase was related to the endometrial perfusion.

Endometrial Histopathology in Abnormal Uterine Bleeding and Its Relation With Thyroid Profile and Endometrial Thickness

INTRODUCTION

Abnormal uterine bleeding (AUB) is a common complaint in postmenopausal and perimenopausal women, caused by a range of disorders, including structural and systemic diseases. The evaluation of endometrial thickness (ET) via radiological methods, followed by a histopathological examination of the endometrium, is useful for proper diagnosis. Among systemic diseases, thyroid dysfunction, specifically hypothyroidism and hyperthyroidism, contribute significantly to AUB cases.

MATERIALS AND METHODS

This descriptive cross-sectional study was conducted at Sri Aurobindo Medical College, Indore, Madhya Pradesh, India, over a period of 16 months, from May 2021 to September 2022. Patients presenting with abnormal uterine bleeding and undergoing thyroid function tests (TFTs), ultrasonography, and endometrial biopsy/hysterectomy at the gynecological outpatient department were included. Hospital records were used to obtain clinical details and investigation results. Endometrial thickness and thyroid status were recorded, and descriptive statistics were used to analyze the collected data.

RESULTS

This study included 150 patients with abnormal uterine bleeding, with a mean age of 44 years and 80.6% of patients in the premenopausal age group. A total of 48% of patients had a deranged thyroid profile, with hypothyroidism being more common (91.6%). Structural causes of AUB were identified in 81.3% of cases, with adenomyosis (33.65%), concomitant adenomyosis and leiomyoma (31.5%), and leiomyoma (14.8%) being the most common. Endometrial polyps (4.6%) and endometrial carcinoma (0.6%) were also observed and were consistent with the final histopathology. The remaining 18 patients had no structural causes and were categorized as cases of dysfunctional uterine bleeding (DUB). Increased ET was more commonly observed in postmenopausal patients (4.3%) compared to premenopausal patients (0.7%) among those with AUB, while the reverse was true for patients with DUB. Increased ET was commonly associated with hypothyroidism in both groups. Histopathological examination of endometrial biopsies/hysterectomy specimens revealed additional findings in some patients, including hyperplasia of the endometrium with (0.7%) and without atypia (4%), leading to a more accurate diagnosis.

CONCLUSION

AUB is a prevalent condition affecting women in both pre-menopausal and postmenopausal stages, frequently caused by structural anomalies. However, thyroid dysfunction, especially hypothyroidism, is also a significant contributing factor. As such, thyroid function tests (TFTs) are an effective and economical means of identifying potential underlying causes of AUB. Hypothyroidism is frequently associated with increased endometrial thickness, and histopathological examination remains the gold standard for determining the precise cause of AUB.

Is it possible to predict the success of single dose methotrexate in the treatment of tubal ectopic pregnancies?

OBJECTIVES

In this study, the aim was to determine whether the use of endometrial thickness or neutrophil/lymphocyte and platelet/lymphocyte ratio would be useful in predicting the success of methotrexate in the treatment of ectopic pregnancies located in the fallopian tubes.

MATERAL AND METHODS

This study was carried out by retrospectively examining 68 study group cases with an ultrasonographically detectable gestational sac in the fallopian tubes and 189 control group cases with an unruptured ectopic pregnancy diagnosis at any location. The cut-off value of endometrial thickness was calculated as a new marker between the cases in which single-dose methotrexate treatment was successful and the cases with treatment failure. Treatment success was evaluated with different models including endometrial thickness, fetal cardiac activity status, measurable crown-rump length, and β-hCG.

RESULT

The cut-off value of β-hCG for treatment success was determined as 2960.5 ng/mL, and the cut-off value for endometrial thickness was determined as 10.5 mm. Although NLR seems to be a marker with a cut-off value of 2.49, it does not provide an extra benefit in combined use as it is not a specific predictor. The highest success in predicting treatment success was achieved in the modeling in which crown-rump length + fetal cardiac activity + β-hCG + endometrial thickness were used together.

CONCLUSIONS

The use of endometrial thickness as a marker seems to be quite reliable in predicting treatment success. And we think it would be beneficial to thin the endometrium before using methotrexate.

Impact of an estrogen replacement regimen on live birth rate in frozen-thawed good-quality embryo transfer

OBJECTIVE

To assess the impact of an estrogen replacement regimen on frozen embryo transfer (FET) cycle outcome.

METHODS

In the present retrospective cohort study, data of infertile women undergoing FET with good-quality embryos were reviewed. The first group received 2 mg of estradiol hemihydrate (EH) once daily for 6 to 7 days, then twice daily for 4 to 5 days, and then three times a day until embryo transfer. The second group received EH twice daily for 7 to 8 days, then three times a day. The third group received EH three times a day constantly. The main outcome measure was live birth rate.

RESULTS

In total, 394 FET cycles were included. The fixed 6-mg group required the highest estradiol hemihydrate dose. The duration of estrogen treatment was significantly longer in the first group. Maximal endometrial thickness was highest in the second group (10.2 ± 1.3 mm vs. 9.6 ± 1.4 mm vs. 8.6 ± 0.9 mm, respectively; P < 0.001). The clinical pregnancy rates in the groups were 41.1%, 55.2%, and 42.2%, respectively (P = 0.035). Live birth rates were 40.8%, 50.9%, and 48.1%, respectively (P = 0.320).

CONCLUSION

In FET cycles with hormone replacement therapy, a step-up 4-mg regimen provides thicker endometrium with optimal-dose estrogen in an adequate time frame. The tendency for increased clinical pregnancy and live birth rates is remarkable.

Comparison of tamoxifen and hormone replacement cycle (HRT) in frozen embryo transfer. A randomized controlled trial

OBJECTIVE

The use of frozen embryos in the treatment of infertility with assisted reproductive techniques has been increased. Different methods are used to prepare the endometrium for frozen embryo transfer (FET). The aim of this study was to compare pregnancy outcomes after treatment with tamoxifen and hormonal replacement therapy (HRT) in FET.

METHODS

This randomized clinical trial was carried out with 214 infertile women in the infertility research center of Milad Hospital in Mashhad during 2018-2020. We had 84 patients receiving tamoxifen and 92 took HRT. Endometrial thickness (ET) and pregnancy outcome were measured in both groups.

RESULTS

Mean infertility duration (p=0.328), number of embryos (p=0.649), FSH (p=0.390), LH (p=0.051) and LH/FSH ratio (p=0.287) as well as type of infertility (primary or secondary) (p=0.295), causes of infertility (p=0.750) and pattern of menstruation (p=0.676) were not significantly different in the two groups. Mean ET in the TMX and HRT groups were 8.72±1.45mm and 9.00±1.69mm, respectively (p=0.423). There was no statistically significant difference between chemical pregnancy (p=0.663), clinical pregnancy (p=0.994) and ongoing pregnancy (p≥0.999) in the TMX and HRT groups.

CONCLUSIONS

Treatment with tamoxifen can be as effective as GnRH agonist for endometrial preparation in FET.

Association between endometrial thickness before ovulation, live birth, and placenta previa rates in clomiphene citrate-treated cycles

BACKGROUND

Although a recent study reported that the pregnancy outcomes in the first trimester were more correlated with endometrial thickness on the day of the trigger than with endometrial thickness on the day of single fresh-cleaved embryo transfer, it remains unclear whether endometrial thickness on the day of the trigger can predict live birth rate after a single fresh-cleaved embryo transfer.

OBJECTIVE

This study aimed to examine whether endometrial thickness on the trigger day is associated with live birth rates and whether modifying the single fresh-cleaved embryo transfer criteria to reflect endometrial thickness on the trigger day improved the live birth rate and reduced maternal complications in a clomiphene citrate-based minimal stimulation cycle.

STUDY DESIGN

This was a retrospective study of the outcomes of 4440 treatment cycles of women who underwent single fresh-cleaved embryo transfer on day 2 of the retrieval cycle. From November 2018 to October 2019, single fresh-cleaved embryo transfer was performed when endometrial thickness on the day of single fresh-cleaved embryo transfer was ≥8 mm (criterion A). From November 2019 to August 2020, single fresh-cleaved embryo transfer was conducted when endometrial thickness on the day of the trigger was ≥7 mm (criterion B).

RESULTS

A multivariate logistic regression analysis revealed that increased endometrial thickness on the trigger day was significantly associated with an improvement in the live birth rate after single fresh-cleaved embryo transfer (adjusted odds ratio, 1.098; 95% confidence interval, 1.021-1.179). The live birth rate was significantly higher in the criterion B group than in the criterion A group (22.9% and 19.1%, respectively; P=.0281). Although endometrial thickness on the day of single fresh-cleaved embryo transfer was sufficient, the live birth rate tended to be lower when endometrial thickness on the trigger day was <7.0 mm than when endometrial thickness on the day of the trigger was ≥7.0 mm. The risk for placenta previa was reduced in the criterion B group when compared with the criterion A group (4.3% and 0.6%, respectively; P=.0222).

CONCLUSION

This study demonstrated an association of decreased endometrial thickness on the trigger day with low birth rate and a high incidence of placenta previa. A modification of the criteria for a single fresh-cleaved embryo transfer based on endometrial thickness may improve pregnancy and maternal outcomes.

Comparison of pregnancy outcome after fresh embryo transfer between GnRH antagonist and GnRH agonist regimens in patients with thin endometrium

Objective

To compare the pregnancy outcome after fresh embryo transfer between GnRH antagonist and GnRH agonist regimens in patients with thin endometrium.

Methods

This retrospective study included all fresh embryo transfers following GnRH agonist or GnRH antagonist protocols in patients with thin endometrium from 2016 to 2021. The thin endometrium was defined as an endometrial thickness of 7.5 mm or less on the triggering day. Multivariant regression analysis was applied to assess the association of GnRH agonist or GnRH antagonist regimen with live birth following fresh embryo transfer in patients with thin endometrium.

Results

A total of 69 and 192 cases were, respectively, included in the GnRH antagonist or GnRH agonist group. The stimulation duration was significantly longer by the GnRH agonist protocol than the GnRH antagonist protocol (11.2 ± 2.1 vs. 9.1 ± 1.9 days, P = 0.002). The rates of clinical pregnancy or live birth were significantly lower in the GnRH antagonist group compared to the GnRH agonist group (26.1 vs. 47.9%, P = 0.027; 17.4 vs. 40.1%, P = 0.01, respectively). Multivariable regression analysis demonstrated that GnRH agonist regimen was related to higher live birth rate compared with GnRH agonist protocol [adjusted OR: 2.6, 95% confidence intervals (CI): 1.3-5.3]. No significant difference in miscarriage rate and the neonatal outcome was present between the two protocols.

Conclusion

Our findings suggest that GnRH agonist protocol results in a higher rate of live birth after fresh embryo transfer than GnRH antagonist protocol in patients with thin endometrium.

Factors Influencing the Pregnancy Outcome of Intrauterine Insemination and Follow-up Treatment

Background

Many factors were reported associated with the pregnancy rate of intrauterine insemination (IUI), which played key role is still debated.

Aims

The aim of this study was to explore related clinical pregnancy outcome factor in IUI cycles of non-male factor.

Settings and Design

The clinical data of 1232 IUI cycles in 690 couples experiencing infertility who attended the Reproductive Center of Jinling Hospital between July 2015 and November 2021 were retrospectively analysed.

Materials and Methods

Female and male age, body mass index (BMI), anti-Müllerian hormone (AMH), male semen parameters before and after wash, endometrial thickness (EMT), artificial insemination timing and ovarian stimulation (OS) protocols were compared between the pregnant group and the non-pregnant group in order to explore any correlation.

Statistical Analysis Used

Continuous variables were analysed using independent-samples t-test, and Chi-square test was used for comparison of measurement data between the two groups. P <0.05 was considered statistical significance.

Results

There were statistically significant differences in female AMH, EMT and duration of OS between the two groups. The AMH was higher in the pregnant group than in the non-pregnant group (P < 0.01), the stimulated days was significantly longer (P < 0.05) and EMT was significantly greater (P < 0.01) in the pregnant group than in the non-pregnant group. Further analysis showed that when patients with IUI had the following conditions: AMH > 4.5 ng/ml, EMT between 8 and 12 mm and letrozole + human menopausal gonadotropin stimulation with higher clinical pregnancy. However, there were no differences between the pregnant group and the non-pregnant group amongst the female and male age, BMI, hormones on baseline and day of human chorionic gonadotrophin, number of ovulated oocytes, sperm parameters before and after wash, treatment protocols and the timing of IUI (P > 0.05). Furthermore, there were 240 couples who not pregnant received one or more cycles of in vitro fertilisation/intracytoplasmic sperm injection/ pre-implantation genetic technology treatment, and another 182 couples forgo follow-up treatment.

Conclusion

The results of the present study demonstrate that the clinical IUI pregnancy rate is correlated with the factors of female AMH, EMT and OS protocol; more studies and samples are necessary to evaluate whether other factors affect pregnancy rate.

Risk of endometrial cancer in asymptomatic postmenopausal women in relation to ultrasonographic endometrial thickness: systematic review and diagnostic test accuracy meta-analysis

OBJECTIVE

This study aimed to evaluate the risk of endometrial carcinoma and atypical endometrial hyperplasia in asymptomatic postmenopausal women concerning the endometrial thickness measured by stratified threshold categories used for performing subsequent endometrial sampling and histologic evaluation.

DATA SOURCES

MEDLINE, Scopus, ClinicalTrials.gov, SciELO, Embase, the Cochrane Central Register of Controlled Trials, LILACS, conference proceedings, and international controlled trials registries were searched without temporal, geographic, or language restrictions.

STUDY ELIGIBILITY CRITERIA

Studies were selected if they had a crossover design evaluating the risk of atypical endometrial hyperplasia and endometrial carcinoma in postmenopausal asymptomatic women and calculated the diagnostic accuracy of transvaginal ultrasonography thresholds (at least 3.0 mm) confirmed by histopathologic diagnosis.

METHODS

This was a systematic review and diagnostic test accuracy meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy and Synthesizing Evidence from Diagnostic Accuracy Tests guidelines. Endometrial thickness thresholds were grouped as follows: from 3.0 to 5.9 mm; between 6.0 and 9.9 mm; between 10.0 and 13.9 mm; and ≥14.0 mm. Quality assessment was performed using the Quality Assessment Tool for Diagnostic Accuracy Studies 2 tool. Publication bias was quantified using the Deek funnel plot test. Coprimary outcomes were the risk of atypical endometrial hyperplasia or endometrial carcinoma according to the endometrial thickness and diagnostic accuracy of each threshold group.

RESULTS

A total of 18 studies provided the data of 10,334 women who were all included in the final analysis. Overall, at an endometrial thickness threshold of at least 3.0 mm, the risk of atypical endometrial hyperplasia or endometrial carcinoma was increased 3-fold relative to women below the cutoff (relative risk, 3.77; 95% confidence interval, 2.26-6.32; I2=74%). Similar degrees of risk were reported for thresholds between 3.0 and 5.9 mm (relative risk, 5.08; 95% confidence interval, 2.26-11.41; I2=0%), 6.0 and 9.9 mm (relative risk, 4.34; 95% confidence interval, 1.68-11.23; I2=0%), 10.0 and 13.9 mm (relative risk, 4.11; 95% confidence interval, 1.55-10.87; I2=86%), and ≥14.0 mm (relative risk, 2.53; 95% confidence interval, 1.04-6.16; I2=78%) with no significant difference among subgroups (P=.885). Regarding diagnostic accuracy, the pooled sensitivity decreased from thresholds below 5.9 mm (relative risk, 0.81; 95% confidence interval, 0.49-0.85) to above 14.0 mm (relative risk, 0.28; 95% confidence interval, 0.18-0.40). Furthermore, the specificity increased from 0.70 (95% confidence interval, 0.61-0.78) for endometrial thickness between 3.0 and 5.9 mm to 0.86 (95% confidence interval, 0.71-0.94) when the endometrial thickness is ≥14.0 mm. For 3.0 to 5.9 mm and 10.0 to 13.9 mm thresholds, the highest diagnostic odds ratios of 10 (95% confidence interval, 3-41) and 11 (95% confidence interval, 2-49), with areas under the curve of 0.81 (95% confidence interval, 0.77-0.84) and 0.82 (95% confidence interval, 0.79-0.86), respectively, were retrieved. The summary point analysis revealed that the 3.0 to 5.9 mm cutoff point was placed higher in the summary receiver operator curve space than the other subgroups, indicating increased endometrial carcinoma or atypical endometrial hyperplasia diagnosis using these cutoffs.

CONCLUSION

Both low and high endometrial thickness thresholds in postmenopausal asymptomatic women seem equally effective in detecting endometrial carcinoma and atypical endometrial hyperplasia. However, although using a 3.0 to 5.9 mm cutoff results in a lower specificity, the offsetting improvement in sensitivity may justify using this cutoff for further endometrial evaluation in patients with suspected endometrial malignancy.

Thin endometrial lining: is it more prevalent in patients utilizing preimplantation genetic testing for monogenic disease (PGT-M) and related to prior hormonal contraceptive use?

STUDY QUESTION

Is a thin endometrial lining before ovulation triggering more prevalent in patients utilizing preimplantation genetic testing for monogenic disease (PGT-M) compared to the regular IVF/ICSI population and is this associated with prior hormonal contraceptive use?

SUMMARY ANSWER

Thin (<8 mm) endometrial lining is more prevalent in PGT-M patients compared to the regular IVF/ICSI population and is associated with both longer prior hormonal contraceptive use and a shorter cessation interval of hormonal contraceptives before IVF/ICSI treatment.

WHAT IS KNOWN ALREADY

Thin endometrial lining has been associated with lower pregnancy rates in IVF/ICSI cycles and increased chances of miscarriage and low birth weight. Endometrial thinning and atrophy occur during hormonal contraceptive use. Patients utilizing PGT-M typically use hormonal contraceptives up until treatment to avoid the risk of conception of a genetically affected child. Whether this could negatively affect endometrial thickness achieved during subsequent IVF/ICSI cycles is not known.

STUDY DESIGN, SIZE, DURATION

A retrospective case control study was performed, including all PGT-M patients attending the University Medical Centre Groningen (cases), between 2009 and 2018. The control group consisted of two non-PGT IVF/ICSI patients for each PGT-M patient, matched for age and treatment period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

First cycles of 122 PGT-M patients and 240 controls were included. Cessation interval of hormonal contraceptives was categorized as late cessation (cessation <1 year prior to treatment) or early cessation (>1 year prior to treatment). Endometrial thickness was routinely measured on the day of hCG triggering or 1 day prior. The prevalence of an endometrial lining <8 mm was compared between PGT-M patients and controls. Hormonal contraceptive use (both duration and cessation interval) was compared between both groups. Univariable and multivariable regression analyses were performed to identify risk factors for thin endometrial lining. In addition, cycle and pregnancy outcomes were compared within control/PGT-M groups between patients with endometrial lining > or <8 mm.

MAIN RESULTS AND THE ROLE OF CHANCE

Thin endometrial lining on the day of hCG triggering was found significantly more often in the PGT-M group, compared to controls: 32% vs 11% (mean difference 21.0%, 95% CI: 11.7, 30.3%). As expected, more patients in the PGT-M group ceased their hormonal contraception late (<1 year): 64% vs 2% in the control group (mean difference 61.9%, 95% CI: 53.0, 70.8%). Average duration of hormonal contraceptive use was 10.6 years in the PGT-M group vs 9.3 years in controls (mean difference 1.3 years, 95% CI: 0.2, 2.3 years). Multivariable logistic regression analysis identified late cessation (OR: 6.0, 95% CI: 1.9-19.2) and duration of prior hormonal contraceptive use (OR per year increase 1.1, 95% CI: 1.0-1.2) as significant independent risk factors for a thin endometrial lining. In relation to outcome, we found a statistically significant increase in miscarriage rate in PGT-M patients with an endometrial lining <8 mm compared to those with an endometrial lining >8 mm (20.0% vs 1.7%, mean difference 18.3%, 95% CI: 2.3, 34.3%). A trend towards lower birth weight and gestation- and gender-adjusted birth weight (z-score) was also found in this group. No statistically significant differences were detected in pregnancy rate, live birth rate, or incidence of preterm delivery or SGA. Within the control group, no statistically significant differences were found in outcomes between patients with an endometrial lining <8 compared to an endometrial lining >8 mm.

LIMITATIONS, REASONS FOR CAUTION

The study is retrospective. Various types of hormonal contraceptives were reported which possibly exert different effects on the endometrial lining. In relation to pregnancy outcome measures, numbers were very limited; therefore, no firm conclusions should be drawn.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides further insight into the role of prior hormonal contraceptive use as a possible contributor to the occurrence of thin endometrial lining during ART treatment. Future studies should provide more information on its clinical relevance, to determine whether PGT-M patients can be reassured, or should be counselled to stop hormonal contraceptive use and change to an alternative contraceptive method prior to PGT treatment.

STUDY FUNDING/COMPETING INTERESTS

No specific funding was used and no conflicts of interests are declared.

TRIAL REGISTRATION NUMBER

N/A.

The Effect of Human Growth Hormone on Endometrial Growth in Controlled Ovarian Hyperstimulation Cycles

This study aims to compare endometrial growth before and after the addition of human growth hormone (hGH) in controlled ovarian hyperstimulation (COH) cycles. A 5-year retrospective cohort study of patients treated with hGH to improve oocyte development during COH cycles was conducted. Each patient’s cycle without hGH immediately preceding cycle(s) with hGH was used for patients to serve as their own controls. Primary outcome was absolute growth in endometrial thickness from pre-stimulation start to day of hCG trigger. Mixed-model regression analysis controlled for patient correlation over repeat cycles and potential confounders. 80 patients were included. Mean age was 39.7 years; mean BMI was 23.8 kg/m2. Majority of patients were nulliparous, non-smoking, and White or Asian. Most common diagnosis was diminished ovarian reserve. Endometrial growth was compared between 159 COH cycles with hGH and 80 COH control cycles; mean increase was 4.5 mm and 3.9 mm, respectively-an unadjusted difference of 0.6 mm (95% CI: 0.2−1.1, p = 0.01). After adjusting for demographic/clinical factors, hGH was associated with 0.9 mm greater endometrial growth (0.4−1.4, p < 0.01). Absolute increase in endometrial thickness was higher in COH cycles that included hGH. Further prospective studies in embryo transfer cycles are needed.

The Impact of High Circulating Anti-Müllerian Hormone on Endometrial Thickness and Outcome of Assisted Reproductive Technology in Women with Polycystic Ovarian Syndrome: A Cohort Study

Background

Elevated circulating anti-Müllerian hormone (AMH) in women with the polycystic ovarian syndrome (PCOS) has been found to have a detrimental effect on endometrial function. This may adversely affect the outcome of in vitro fertilisation (IVF) in PCOS women.

Aims

To investigate the impact of high serum AMH concentrations on endometrial thickness (ET) and the outcome of IVF in women with PCOS.

Settings and Design

This retrospective cohort study included all PCOS women who underwent fresh IVF\intracytoplasmic sperm injection cycles between January 2016 and December 2021 in one major IVF centre.

Materials and Methods

PCOS diagnosis was based on Rotterdam criteria, and participants were identified from centre database. All women received antagonist protocol. Primary outcomes were trigger-day ET and live birth rate (LBR). Circulating AMH was correlated with ET and ovarian response.

Statistical Analysis Used

AMH levels were compared between women with and without live birth. ET and LBRs were compared between women with AMH <7.0 ng/ml versus those with AMH ≥7.0 ng/ml.

Results

The study included 102 PCOS women, of which six were excluded due to poor response (n = 4), hyperresponse (n = 1) or fertilisation failure (n = 1). Of the remaining 96 women, 42 (43.8%) achieved a live birth. There was no statistically significant (P > 0.05) correlation between AMH and ET. Mean ± standard deviation AMH concentration was not significantly (P > 0.05) different between women with live birth (6.5 ± 3.4 ng/ml) and those without (6.5 ± 2.4 ng/ml). High AMH positively correlated with the number of oocytes retrieved, metaphase II oocytes and embryos (P = 0.003, 0.006 and 0.006, respectively). There was no statistically significant (P > 0.05) difference in ET or LBR between women with AMH <7.0 ng/ml (n = 72; ET, 10.7 ± 1.8 mm; LBR, 45.8% [33/72] versus those with AMH ≥7.0 ng/ml (n = 24; ET, 10.8 ± 1.7 mm; LBR, 37.5% [9/24]).

Conclusions

High circulating AMH in PCOS women does not seem to negatively affect ET or LBRs during assisted reproductive technology.

Determining a threshold measurement of endometrial thickness for asymptomatic postmenopausal women: A tertiary centre case series

BACKGROUND

An incidental finding of a thickened endometrium on ultrasound in the postmenopausal patient without bleeding is a common presentation to gynaecological services; however there is limited evidence to guide clinical practice as to when hysteroscopic evaluation and endometrial sampling is required.

AIMS

To determine the endometrial thickness at which endometrial sampling is indicated in asymptomatic postmenopausal women referred with thickened endometrium on ultrasound.

MATERIALS AND METHODS

A single-centre retrospective case series of postmenopausal women without bleeding undergoing hysteroscopy was conducted. Logistic regression was used to examine the association between a range of variables and pre-malignant or malignant pathology and endometrial thickness. The optimal endometrial thickness threshold was identified to maximise model sensitivity.

RESULTS

A total of 404 postmenopausal women were included in this study, having undergone a hysteroscopy at the study site between 1 July 2008 and 30 June 2018. The mean (SD) age of patients at presentation was 65 (9.09) years and the mean body mass index was 29.86 kg/m² (6.52). Of these women, nine (2.2%) were diagnosed with endometrial carcinoma and seven (1.7%) had endometrial hyperplasia with atypia. The most common histopathological finding was of a benign endometrial polyp (153: 37.9%). When including hyperplasia with or without atypia in histopathology of interest, a cut-off of ≥9 mm provides the greatest sensitivity (83.3%) and specificity (63.8%) for a diagnosis of pre-malignant or malignant pathology (classification accuracy of 64.8%; area under the receiver operating characteristic: 0.7358, 95% CI: 0.6439, 0.8278) in this cohort.

CONCLUSIONS

Using an endometrial thickness of ≥9 mm can be used as a cut-off for endometrial sampling in postmenopausal women without bleeding.

STROBE-GnRHa pretreatment in frozen-embryo transfer cycles improves clinical outcomes for patients with persistent thin endometrium: A case-control study

The well-prepared endometrium with appropriate thickness plays a critical role in successful embryo implantation. The thin endometrium is the main factor of frozen-embryo transfer (FET), resulting in the failure of implantation undergoing FET. Hormone treatment is suggested to improve endometrium thickness; however, among the larger numbers of cases, it cannot reach the sufficient thickness, which leads to a high cancelation rate of embryo transfer as well as waste high-quality embryos. Thus, it increases the burden to patients in both economic and psychological perspectives. We performed a retrospective observational study, which was composed with 2 cohorts, either with the conventional hormone replacement therapy (HRT) protocol or HRT with gonadotrophin-releasing hormone agonist (GnRHa) pretreatment to prepare the endometrium before FET. The measurements of endometrium thickness, hormone level, transfer cycle cancelation rate, pregnancy rate, and implantation rate were retrieved from the medical records during the routine clinic visits until 1 month after embryo transfer. The comparisons between 2 cohorts were performed by t-test or Mann-Whitney U test depending on the different attributions of data. In total, 49 cycles were under HRT with GnRHa pretreatment and 84 cycles were under the conventional HRT protocol. HRT with GnRHa pretreatment group improved the endometrial thickness (8.13 ± 1.79 vs 7.51 ± 1.45, P = .031), decreased the transfer cancelation rate (P = .003), and increased clinical pregnancy rate and implantation rate significantly (both P = .001). Additionally, luteinizing hormone level in pretreatment group was consistently lower than conventional HRT group (P < .05). Our study revealed HRT with GnRHa pretreatment efficiently improved the endometrial thickness, therefore, decreased the FET cycle cancelation. It also elevated the embryo implantation rate and clinical pregnancy rate by improving endometrial receptivity.

Long-term use of ospemifene in clinical practice for vulvo-vaginal atrophy: end results at 12 months of follow-up

OBJECTIVE

To assess the improvement in vulvovaginal atrophy (VVA) of postmenopausal women treated with oral ospemifene 60 mg/day under conditions of routine clinical practice after 12 months of follow-up.

METHODS

The AYSEX study is a Spanish observational, prospective, and unicentric study in which five gynecologists recruited postmenopausal women with VVA in routine clinical practice treated with oral ospemifene 60 mg/day as an appropriate therapeutic option. Vaginal health, the most bothersome symptoms, sexual health, endometrial safety, bone resorption markers, bone densitometry, mammography, treatment satisfaction, and quality of life were assessed at baseline and after 12 months using appropriate scales.

RESULTS

A total of 100 postmenopausal women cytologically and clinically diagnosed with VVA were included in the study. After 3 months of treatment with ospemifene, a significant improvement was observed in all domains of Vaginal Health Index. This improvement was maintained at month 12 and only one patient remained with vaginal atrophy. In addition, a significant improvement was observed in the most bothersome symptoms, sexual function, and quality of life. There was no significant change in endometrial thickness, mammography, and bone health during the 12 months of treatment.

CONCLUSIONS

This study in routine clinical practice conditions confirms the results previously reported by randomized controlled trials, including a significant improvement in VVA, sexual function, quality of life, endometrial safety, and satisfaction with the treatment.

Impact of Endometrial Thickness and Volume Compaction on the Live Birth Rate Following Fresh Embryo Transfer of In Vitro Fertilization

OBJECTIVES

The aim of our study was to compare the live birth rate following fresh embryo transfer (ET) during in vitro fertilization (IVF) in women with or without endometrial compaction in thickness and volume between the day of human chorionic gonadotrophin (hCG) and the ET day.

METHODS

This is a retrospective analysis of infertile women undergoing the first IVF cycle with fresh ET. A single operator performed all the ultrasound measurements for endometrial thickness and endometrial volume using three-dimensional ultrasound. Endometrial compaction was calculated as the difference of the measurement between the hCG day and ET day. The predictive values of age of women, number of embryos transferred, and endometrial compaction in thickness and volume on live birth were studied.

RESULTS

A total of 268 women who underwent the first IVF cycle with fresh ET between June 2005 and August 2006 were included in this retrospective analysis. Endometrial thickness was significantly higher on the ET day than the hCG day while endometrial volume was significantly smaller on the ET day than the hCG day. Women with a live birth were younger, had a higher serum estradiol level on the hCG day, and similar absolute or percentage change of endometrial thickness and volume when compared to those without a live birth.

CONCLUSION

Endometrial thickness and volume compaction was not a significant predictor of live birth in the multivariate logistic regression model. Endometrial thickness and volume compaction did not affect the live birth rate in the fresh IVF cycle.

Administration of growth hormone improves endometrial function in women undergoing in vitro fertilization: a systematic review and meta-analysis

BACKGROUND

The positive effects of growth hormone (GH) on IVF are often attributed to improvements in oocyte and embryo quality. While emerging evidence emphasizes GH-induced improvements in the endometrium, these results are controversial.

OBJECTIVE AND RATIONALE

This meta-analysis aimed to evaluate whether GH administration improved endometrial function and reproductive outcomes during IVF cycles and to thus guide clinical practice.

SEARCH METHODS

A literature search in the Cochrane Central Register of Controlled Trials, PubMed and Embase was performed through to 30 November 2021, without language restrictions. Randomized controlled trials (RCTs) evaluating the effects of GH on IVF outcomes were included. Risk of bias and quality of evidence (QoE) were assessed according to the Cochrane Collaboration's tool and the Grading of Recommendations Assessment, Development and Evaluation system. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were assessed by random-effects models.

OUTCOMES

A total of 25 trials with 2424 women were included. Seventeen RCTs with poor responders (n = 1723) showed that GH administration significantly increased endometrial thickness (EMT) (MD = 0.38, 95% CI: 0.18-0.59; moderate QoE), which contributed to an improved live birth rate (OR = 1.67, 95% CI: 1.13-2.49; very low QoE) and clinical pregnancy rate (CPR) (OR = 1.97, 95% CI: 1.43-2.72; low QoE). Subgroup analyses showed a dose- and time-dependent relationship between GH cotreatment and IVF outcomes; the optimal recommendation for improving CPR was consistent with that for EMT, rather than for oocytes and embryos. Hence, GH might improve fertility via effects on the endometrium. Administration of GH daily from the follicular phase of previous cycle until the hCG trigger with < 5 IU/day led to a thicker endometrium and a greater chance of becoming pregnant, while 5-10 IU/day or administration from the luteal phase of the previous cycle until the hCG trigger resulted in higher oocyte and embryo quality. Poor responders might benefit from cotreatment with the GnRH agonist long protocol more than other stimulation protocols. Pooled data from four trials (n = 354) on women with a thin endometrium indicated that improved endometrial function might be critical for improving reproductive outcomes during GH treatment, as no improvements in embryo quality were found. GH administration not only increased EMT (MD = 1.48, 95% CI: 1.21-1.75; moderate QoE) but also promoted endometrial morphology (OR = 2.67, 95% CI: 1.36-5.23; low QoE) and perfusion (OR = 5.84, 95% CI: 1.30-26.17; low QoE), thereby improving the CPR (OR = 2.71, 95% CI: 1.69-4.34; P < 0.0001; low QoE). There was insufficient evidence to reach a conclusion regarding the effects of GH in normal responders (n = 80). Due to obvious improvements in the CPR, women with a thin endometrium might be the most appropriate population to benefit from GH administration.

WIDER IMPLICATIONS

Improving endometrial function might be another vital mechanism by which GH improves IVF outcomes. Optimal treatment should be offered to the target population according to their personal conditions and needs. The QoE was moderate to very low, due to limited sample sizes and methodological problems; thus, the results should be interpreted with caution. More rigorous RCTs with large sample sizes are needed to confirm the effects and determine optimal GH protocols.

Influence of Maternal Age on the Relationship Between Endometrial Thickness and Ongoing Pregnancy Rates in Frozen-Thawed Embryo Transfer Cycles: A Retrospective Analysis of 2,562 Cycles

Background

In frozen-thawed embryo transfer (FET) cycles, endometrial thickness (EMT) has been used routinely as the main clinical monitoring index. However, the current findings are conflicting.

Method

This was a single-center retrospective study of 2,054 couples (2,562 cycles) who underwent FET (including cleavage stage embryos and blastocysts) between January 2017 and August 2020 in the reproductive centers of First Affiliated Hospital of Xinjiang Medical University. The primary outcome measure was the ongoing pregnancy rate (OPR); the secondary outcome was the clinical pregnancy rate.

Results

After stratified analysis and adjusting for confounders such as maternal age, duration of infertility, number of high-quality embryos transferred, endometrial preparation protocol, number of transfer cycles, and stages of embryo transferred, we found a curvilinear relationship between EMT and the OPR in women < 35 years of age. For women with EMT ≤ 8 mm, the OPR increased by 150% for cleavage stage embryo transfer for every 1 mm increase in the EMT; similarly, it increased by 97% for blastocyst stage FET. However, there was a linear relationship between EMT and OPR in women aged ≥ 35 years. When blastocysts were transferred, for every 1 mm increase in the EMT the OPR increased significantly by 12%. But OPR after frozen-thawed cleavage stage embryos transfer did not increase significantly with increased EMT.

Conclusions

Our study showed that the OPR increased significantly with increased EMT between young women aged < 35 years with EMT ≤ 8 mm and older women who underwent transfer of blastocysts.

A Novel Xeno-Free Method to Isolate Human Endometrial Mesenchymal Stromal Cells (E-MSCs) in Good Manufacturing Practice (GMP) Conditions

The cyclic regeneration of human endometrium is guaranteed by the proliferative capacity of endometrial mesenchymal stromal cells (E-MSCs). Due to this, the autologous infusion of E-MSCs has been proposed to support endometrial growth in a wide range of gynecological diseases. We aimed to compare two different endometrial sampling methods, surgical curettage and vacuum aspiration biopsy random assay (VABRA), and to validate a novel xeno-free method to culture human E-MSCs. Six E-MSCs cell samples were isolated after mechanical tissue homogenization and cultured using human platelet lysate. E-MSCs were characterized for the colony formation capacity, proliferative potential, and multilineage differentiation. The expression of mesenchymal and stemness markers were tested by FACS analysis and real-time PCR, respectively. Chromosomal alterations were evaluated by karyotype analysis, whereas tumorigenic capacity and invasiveness were tested by soft agar assay. Both endometrial sampling techniques allowed efficient isolation and expansion of E-MSCs using a xeno-free method, preserving their mesenchymal and stemness phenotype, proliferative potential, and limited multi-lineage differentiation ability during the culture. No chromosomal alterations and invasive/tumorigenic capacity were observed. Herein, we report the first evidence of efficient E-MSCs isolation and culture in Good Manufacturing Practice compliance conditions, suggesting VABRA endometrial sampling as alternative to surgical curettage.

Optimal endometrial thickness in fresh and frozen-thaw in vitro fertilization cycles: an analysis of live birth rates from 96,000 autologous embryo transfers

OBJECTIVE

To study the effect of increasing endometrial thickness on live birth rates in fresh and frozen-thaw embryo transfer (FET) cycles.

DESIGN

Retrospective cohort study.

SETTING

National data from Autologous in vitro fertilization (IVF) embryo transfer and FET cycles in Canada from the Canadian Assisted Reproductive Technology Registry Plus (CARTR Plus) database for records between January 2013 and December 2019.

PATIENTS

Thirty-three Canadians clinics participated in voluntary reporting of IVF and pregnancy outcomes to the Canadian Assisted Reproductive Technology Registry Plus database, and a total of 43,383 fresh and 53,377 frozen transfers were included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy, pregnancy loss, and live birth rates.

RESULTS

In fresh IVF-embryo transfer cycles, increasing endometrial thickness is associated with significant increases in the mean number of oocytes retrieved, peak estradiol levels, number of usable embryos, clinical pregnancy rates, live birth rates, and mean term singleton birth weights, and a decrease in pregnancy loss rates. However, live birth rates plateau after 10-12 mm. In contrast, in FET cycles live birth rates plateau after the endometrium measures 7-10 mm. The improvement in live birth rates with increasing endometrial thickness was independent of patient age, timing of embryo transfer (e.g., cleavage stage vs. blastocyst stage), or the number of oocytes at retrieval.

CONCLUSIONS

In cycles with a fresh embryo transfer, live birth rates increase significantly until an endometrial thickness of 10-12 mm, while in FET cycles live birth rates plateau after 7-10 mm. However, an endometrial thickness <6 mm was associated clearly with a dramatic reduction in live birth rates in fresh and frozen embryo transfer cycles.

Differences between proximal and distal endometrial monolayer thickness in women aged over 50 years undergoing saline infusion sonohysterography

BACKGROUND

Saline infusion sonohysterography (SIS) is a procedure performed to evaluate the endometrium in women with postmenopausal bleeding.

PURPOSE

To investigate differences in endometrial monolayer measurements in women aged >50 years undergoing SIS.

MATERIAL AND METHODS

Retrospective study of women aged >50 undergoing SIS. Endometrial echo (EE) was measured according to the International Endometrial Tumor Analysis (IETA) guidelines. Monolayer thickness was compared between anterior and posterior uterine walls and between the monolayer that was proximal or distal to the ultrasound probe. Presence and location of focal thickening and polyps on each of the monolayers were assessed.

RESULTS

SIS was performed in 608 patients. Of them, 485 (79.8%) had anteverted, 85 (14%) retroverted, and 38 (6.2%) a midposition uterus. The mean posterior monolayer was thicker than the anterior monolayer (2.14 mm vs. 1.88 mm; P = 0.002). The distal monolayer was thicker than the proximal layer in both anteverted and retroverted uteri (2.18 mm vs. 1.84 mm; P < 0.0001). In 16% of women, the difference between distal and proximal monolayers was ≥1 mm. Focal thickening was seen 3.3 times more frequently in the distal endometrium. Among women with a double layer EE >4 mm, 18.8% had a proximal layer of <2 mm while only 4.6% had a distal EE <2 mm.

CONCLUSION

Distal endometrium measures thicker than the proximal endometrium in most SIS cases and in one out of six women, the difference is >1 mm. The distal layer is three times more likely to contain focal thickening. Sonologists should be conscious of possible enhancement artifact when measuring the EE during SIS.

Thin endometrium is associated with higher risks of preterm birth and low birth weight after frozen single blastocyst transfer

BACKGROUND

It has been demonstrated that a thin endometrium is associated with a lower chance of pregnancy, but there is a paucity of research into whether a thin endometrium adversely affects perinatal outcomes.

METHODS

This was a retrospective cohort study on 10098 frozen cycles with single blastocyst transfer, resulting in 5505 singleton clinical pregnancies, and 4314 singleton live births. Patients were divided into a thin endometrium group (<8 mm) and a normal endometrium group (≥8 mm). Multivariable logistic regression with restricted cubic splines, receiver operating characteristic curve, and multivariable linear model were used for statistical analysis.

RESULTS

The incidences of preterm birth (15.65 vs. 9.80%, aOR=1.69 [1.19-2.42]), low birth weight (8.40 vs. 4.10%, aOR=2.05 [1.27-3.30]) and gestational diabetes (6.87 vs. 4.17%, aOR=1.74 [1.05-2.90]) were all higher in the endometrial thickness (EMT) <8 mm group. The miscarriage rate was higher in the EMT <8 mm group than the EMT ≥8 mm group (27.91 vs. 20.39%, aOR=1.40 [1.10-1.79]).

CONCLUSION

A thin endometrium may be associated with a higher incidence of preterm birth, low birth weight, and miscarriage. Therefore, embryo transfer should be performed with caution in these patients, and postponing to a later cycle with a thicker endometrium should be considered.

An endometrial receptivity scoring system basing on the endometrial thickness, volume, echo, peristalsis, and blood flow evaluated by ultrasonography

BACKGROUND

Establishing a successful pregnancy depends on the endometrium and the embryo. It is estimated that suboptimal endometrial receptivity account for one-third of implantation failures. Despite the indepth understanding of the processes associated with embryo-endometrial cross-talk, little progress has been achieved for diagnosis and treatments for suboptimal endometrial receptivity.

METHODS

This retrospective study included women undergoing their first frozen-thawed embryo transfer (FET) cycles at our reproductive medicine center from March 2021 to August 2021. Transvaginal three-dimensional (3D) ultrasound was performed in the morning on the day of embryo transfer for all the thawed embryo transfer patients, to evaluate endometrial receptivity, including endometrial thickness, echogenicity, volume, movement and blood flow.

RESULTS

A total number of 562 patients of FET with 315 pregnancies (56.0%) was analyzed. It was found that only the echo of the endometrial central line was different between the pregnant group and non-pregnant group. Other parameters, such as endometrial thickness, volume, endometrial peristalsis, or the endometrial blood flow were not statistically different between the two groups. Then, according to the relationship between the different groups and the clinical pregnancy rate, a score of 0 to 2 was respectively scored. The sum of the scores for the six items was the patient's endometrial receptivity score. It showed that the clinical pregnancy rate increased as the endometrial receptivity score increased, and when the receptivity score reaches at least 5, the clinical pregnancy rate is significantly improved (63.7% versus 49.5%, P=0.001).

CONCLUSION

We developed an endometrial receptivity scoring system and demonstrated its validity. It may aid clinicians in choosing the useful marker in clinical practice and for informing further research.

Vaginal health, endometrial thickness and changes in bone markers in postmenopausal women after 6 months of treatment with ospemifene in real clinical practice

OBJECTIVE

To assess vaginal health, endometrial thickness, and changes in bone markers in postmenopausal women with vulvovaginal atrophy (VVA) treated with 60 mg/day of ospemifene under routine clinical practice.

METHODS

The AYSEX study is a Spanish observational and prospective study performed in one center in which 5 gynecologists recruited postmenopausal women with VVA in routine clinical practice treated continuously with ospemifene 60 mg/day for 12 months as an appropriate therapeutic option. This article refers to the 3- and 6-months analysis. Vaginal health was assessed by pH and using Vaginal Health Index (VHI) at baseline and 3 months later. Endometrial thickness, measured by vaginal ultrasonography, and bone resorption marker (CTx) were assessed at baseline and 6 months later.

RESULTS

A total of 100 postmenopausal women cytologically and clinically diagnosed with VVA were included in the study. After 3 months of treatment with ospemifene, pH improved from 6.1 to 4.5 (p < .0001), and VHI improved from 10 to 19 points (p < .0001). The percentage of patients with VVA according to VHI decreased from 100% to 5.2% (p < .0001). After 6 months, mean CTx levels decreased from 0.42 pg/ml at baseline to 0.37 pg/ml 6 months later (p = .0018), and mean endometrial thickness changed from 2.24 to 2.15 mm (p = .6066).

CONCLUSIONS

Up to date, this is the only prospective and observational study with ospemifene in routine clinical practice conditions and confirms the results previously reported from randomized controlled clinical trials, improving VVA, not increasing endometrial thickness, and decreasing CTx levels by exerting an anti-resorptive function.

Clinical outcome of intrauterine infusion of platelet-rich plasma in patients with recurrent implantation failure

Purpose

This study aimed to evaluate the effectiveness of intrauterine infusion of platelet-rich plasma (PRP) before embryo transfer (ET) in recurrent implantation failure (RIF) cases.

Methods

The authors retrospectively analyzed 54 ET cycles involving frozen and thawed high-quality blastocysts after intrauterine PRP infusion between September 2019 and November 2020. All patients had a history of at least two times of implantation failure on ET. A total of 54 patients were categorized into two groups: thin endometrium (39 patients) and unexplained implantation failure (15 patients). In the thin-endometrium group, the endometrial thickness (EMT) was <8.0 mm at cycle days 12-14 in the prior ET cycle.

Results

Among the 54 ET cycles after PRP infusion, 31 (57.4%) were positive for human chorionic gonadotropin (hCG) and 27 (50%) achieved clinical pregnancy, which was significantly better than that in prior ET cycles without PRP infusion (27.2% and 9.6%, respectively). The EMT was not increased at ET date on the PRP cycle compared with that in the prior ET cycle in both patient groups. Moreover, EMT was not different between the hCG-positive and hCG-negative groups.

Conclusion

Although intrauterine PRP infusion had no superior effect on increasing the EMT than conventional therapeutic agents, it resulted in high pregnancy rates in patients experiencing RIF with or without thin endometrium.