Impact of endometrial cavity fluid on assisted reproductive technology outcomes

Hyperlipidemia negatively impacts implantation by dysregulating tight junction and Claudin-3 and Claudin-4 expression in the endometrium

Clinical observational studies have suggested hyperlipidemia may disturb embryo implantation through endometrium; however, the mechanism has been unclear. With its profound implications for reproductive health, the present study aims to investigate whether hyperlipidemia affects endometrial epithelial cell tight junctions for implantation failures. By constructing hyperlipidemia mice model, the number and distribution of embryo implantation status were investigated after both natural mating and in vitro fertilization and embryo transfer (IVF-ET). Transmission electron microscopy (TEM) was used to compare the ultrastructure of tight junctions in endometrial endothelial cells. Western blot and immunofluorescence were used to explore the expression and localization of tight junction proteins, such as Claudin (CDLN)3, CLDN4, occludin (OCLN), and zonula occludens-1 (ZO1). For women with reproductive failure, mid-luteal phase endometrial tissues were collected, and gene expression of tight junction proteins was investigated using RNA sequencing and qRT-PCR. In hyperlipidemic mice, the number of embryo implantation sites significantly decreased with uneven distribution after natural mating and IVF-ET. Disrupted tight junctions were found, characterized by a decreased number of tight junctions by TEM, downregulated expressions of CDLN4, OCLN, and ZO1, and an increased expression of CLDN3 by western blot. In hyperlipidemic women with reproductive failure, the dysregulated expression of CLDN3 and CLDN4 was also present in the luteal phase endometrium. In this study, evaluation of both animal models and infertile women in vivo demonstrated that hyperlipidemia reduced female fertility, accompanied by disruption of tight junction structures and dysregulation of CLDN3 and CLDN4 expression in the endothelial cells of luteal phase endometrium.

Hysteroscopic Management of Symptomatic Cesarean Scar Diverticulum in Patients Undergoing Frozen-Thawed Embryo Transfer: Impact on Clinical Pregnancy Rates and Pregnancy Complications

This retrospective cohort study aimed to compare the clinical outcomes of patients with cesarean scar defect (CSD) undergoing frozen embryo transfer (FET) with or without hysteroscopic repair surgery. The study included 82 patients, with 48 patients in surgical group A (undergoing CSD repair) and 34 patients in surgical group B (undergoing hysteroscopic treatment for other uterine lesions). The results showed that patients in group A had a larger CSD volume and a different shape compared to group B. However, there was no significant difference in clinical pregnancy rates between the two groups. Additionally, there were no differences in miscarriage, live birth, or preterm birth rates, and no complications such as scar pregnancy or placental abnormalities were observed in either group. These findings suggest that hysteroscopic treatment of CSD in symptomatic patients undergoing FET does not increase the risk of pregnancy complications and can lead to comparable clinical pregnancy rates with asymptomatic patients. Further studies with larger sample sizes are needed to confirm these results and evaluate long-term reproductive outcomes following CSD repair.

Systematic review analyzing significance of endometrial cavity fluid during assisted reproductive techniques

OBJECTIVE

The objective of our study is to estimate the prevalence of endometrial cavity fluid (ECF) in Assisted Reproductive Techniques (ART) cycles and analyze its effects on pregnancy outcome in such cycles.

DATA SOURCES

PubMed, Cochrane Central, Scopus, and clinicaltrials.gov were searched for articles. The reference lists of relevant publications were explored for other studies.

STUDY ELIGIBILITY CRITERIA

Studies that had assessed the pregnancy outcome in ART cycles and had commented on ECF accumulation were included. Pregnancy outcomes were assessed in all ART cycles where ECF was observed and were compared to the non-ECF cycles.

RESULTS

A total of nine studies were included in the meta-analysis for a total of 28,210 cycles. Pooled analysis of the prevalence of ECF cycles out of total cycles in females undergoing ART using a fixed effect model showed that it was 14% (95% CI is 13% to 14%; I2 = 99%, p =  < 0.01). The random effect model prevalence of ECF cycles was around 7% (95% CI: 4% to 10%). There was a statistically significant (25%) decrease in pregnancy rates per cycle transfer in the ECF cycle versus the non-ECF cycle group during ART [OR = 0.75, 95% CI = 0.67-0.84), p < 0.001; moderate quality evidence]. When ECF size was compared, there was a statistically significant increase in pregnancy rates if ECF size was less than 3.5 mm versus greater than or equal to 3.5 mm [OR = 13.67, 95% CI = 1.43-130.40), p = 0.02; high quality evidence]. Sub-group analysis revealed that the ECF present at the time of embryo transfer significantly decreased the pregnancy rates by 26% as compared to the group where the ECF was not present at the time of embryo transfer [OR = 0.74, 95% CI = 0.65-0.85), p < 0.001].

CONCLUSIONS

This meta-analysis proposes that the presence of ECF significantly decreases the implantation and pregnancy rates of ART cycles, and even more so if its size is greater than 3.5 mm. Interventions to decrease ECF formation or treat it have enhanced the pregnancy outcome in ART cycles.

PROSPERO REGISTRATION

Date: 17th September 2020; Number: CRD42020182262.

Live birth rates after resolution of endometrial cavity fluid in frozen embryo transfer cycles

RESEARCH QUESTION

Are live birth rates affected in frozen embryo transfer cycles that develop transient endometrial cavity fluid that resolves by day of embryo transfer?

DESIGN

The first frozen blastocyst transfer cycle between January 1st, 2016 and December 31st, 2019 were included in this retrospective cohort study at an academic fertility center. The presence or absence of endometrial cavity fluid (ECF) detected on initial ultrasound and at time of transfer was recorded. Patients who had persistent ECF at time of transfer were excluded from the study. The primary outcome was live birth rate in the group with resolved ECF relative to the group without ECF.

RESULTS

A total of 1034 frozen blastocyst transfer cycles were included, 54 with resolved ECF and 980 without ECF. Adjusted analyses were performed using a log-binomial regression model. Live birth rates were 35.2% and 34.2%, adjusted risk ratio 1.00 [95% CI 0.70-1.50] in the two groups, respectively.

CONCLUSION

Live birth rates in frozen embryo transfer cycles are equivalent between patients with resolved endometrial cavity fluid compared to those who never had endometrial cavity fluid. Our findings suggest that the presence of endometrial cavity fluid is likely not detrimental to live birth rates if the fluid spontaneously resolves by the time of embryo transfer.

Four-dimensional ultrasound guided embryo transfers improve live birth rates when compared to the clinical touch technique: a randomised controlled trial

Most aspects of in-vitro fertilisation (IVF) have changed dramatically since introduction, but embryo transfer (ET) technique remains largely unaltered. We aimed to determine whether four-dimensional ultrasound guided embryo transfers (4D UGET) could improve pregnancy rates when compared with clinical touch technique (CTT). This was a single centre open labelled randomised controlled trial in a tertiary fertility centre in the UK. 320 women were randomised on the day of single ET. The primary outcome was clinical pregnancy rate (CPR), secondary outcomes included live birth rate (LBR), biochemical pregnancy rate (BPR), miscarriage, pregnancy of unknown location (PUL) and ectopic pregnancy. 4D-UGET resulted in significantly higher CPR [50% vs 36% p = 0.02, OR 1.78 (1.12-2.84)] and LBR [41% vs 28%, p = 0.02, OR 1.77 (1.09-2.87)] when compared to CTT technique. Miscarriage (p = 0.49), PUL (p = 0.14) and ectopic pregnancy (p = 0.96) were similar between the two groups. LBR, from this trial, are significantly higher than the current UK average (41% vs 24%). 4D UGET allows for superior imaging of the uterine cavity, whilst tailoring the embryo deposition point specifically to the patient. Further RCTs are required to determine if these results can be replicated in other units and whether 4D UGET is superior to 2D UGET.

Aspiration with Diosmin Intake in Endometrial Cavity Fluid Accumulation in ART Cycles: A Randomized Controlled Trial

Background

This was a prospective randomized controlled trial in 200 cases presented with endometrial cavity fluid at the day of oocyte retrieval at a private fertility center from 2013 to 2021. The cases were randomized at day of ovum pickup into 2 groups: Group 1 (control group) (n = 100): conventional management with follow-up and reassessment by transvaginal ultrasound on day 5. Group 2 (interventional group) (n = 100): aspiration of the fluid was done and cases were given diosmin 500 mg 3 times per day till reassessment at embryo transfer day. In both groups, we proceeded with fresh embryo transfer if no fluid is present on day 5 or freeze-all policy if persistent fluid was detected.

Results

Endometrial fluid on the 5th day was significantly higher in the control group (28.0%) than in the interventional group (6.0%) (P < 0.001). Regarding pregnancy rate, although being higher in the interventional group (54.3% vs 50.0%), the difference was not statistically significant (P = 0.5). It was found that the intervention was associated with risk reduction of endometrial fluid (OR = 0.168, 95% CI = 0.065-0.429, P < 0.001.

Conclusion

Aspiration of endometrial cavity fluid with diosmin intake increased the likelihood of fresh embryo transfer and with a slightly better pregnancy rate compared to conservative management.Clinical trial number: NCT02158000, Date of registration: 6/6/2014, Date of initial enrollment (first patient recruiting): 1/11/2014, URL: https://clinicaltrials.gov/ct2/show/NCT02158000.

Higher Prevalence of Chronic Endometritis in Women with Cesarean Scar Defect: A Retrospective Study Using Propensity Score Matching

(1) Background: A cesarean scar defect may cause localized inflammation of the endometrial tissue, and various researchers believe that the presence of a cesarean scar defect is associated with chronic endometritis. However, there is no report on the possible association between cesarean scar defects and chronic endometritis thus far. This study aimed to assess the role of having a cesarean scar defect in a person's susceptibility to chronic endometritis. (2) Methods: This retrospective propensity-score-matched study comprised 1411 patients with chronic endometritis that were admitted to Henan Provincial People's Hospital in China from 2020 to 2022. Based on whether a cesarean scar defect was present or not, all cases were assigned to the cesarean scar defect group or the control group. (3) Results: Of the 1411 patients, 331 patients with a cesarean scar defect were matched to 170 controls. All unbalanced covariates between groups were balanced after matching. Before matching, the prevalence of chronic endometritis in the cesarean scar defect group and in the control group was 28.8% and 19.6%, respectively. After correcting for all confounding factors, a logistic regression analysis showed that cesarean scar defect occurrence may increase the risk of chronic endometritis (odds ratio (OR), 1.766; 95% confidence interval (CI), 1.217-2.563; p = 0.003). After matching, the prevalence of chronic endometritis was 28.8% in the cesarean scar defect group and 20.5% in the control group. Thus, even after correcting for all confounding factors, the logistic regression analysis still showed that a cesarean scar defect remained an independent risk factor for chronic endometritis prevalence (OR, 1.571; 95% CI, 1.021-2.418; p = 0.040). The findings were consistent throughout the sensitivity analyses. (4) Conclusions: The present results suggest that the onset of a cesarean scar defect may increase the risk of chronic endometritis.

The Cystic Anechoic Zone of Uterine Cavity Newly Observed during Controlled Ovarian Hyperstimulation Affects Pregnancy Outcomes of Fresh Embryo Transfer

During controlled ovarian hyperstimulation (COH), cystic anechoic zones in the uterine cavity are occasionally visible. This retrospective matched cohort study collected information on patients who underwent in vitro fertilization/intracytoplasmic injection (IVF/ICSI) from January 2014 to December 2020 at our center. The propensity score algorithm matched 179 cases that had uterine cystic anechoic zones, with 358 which did not have uterine cystic anechoic zones cases. After matching, the live birth rate (38.0% vs. 48.6%, p = 0.025) of patients with uterine cystic anechoic zones was lower than that in the no uterine cystic anechoic zone group, while for clinical pregnancy miscarriage rate (22.2% vs. 12.4%, p = 0.031), the rate was higher. The results showed no correlation in the association between live birth rate (r = −0.027, p = 0.718), clinical pregnancy rate (r = −0.037, p = 0.620) or biochemical pregnancy rate (r = −0.015, p = 0.840) and the diameters of the cystic anechoic zones in the uterine cavity. There was a significant difference in the type of endometrium between the two groups (p < 0.001). The result of this study can provide guidance to patients on whether to undergo fresh embryo transfer in the current cycle.

Microbial Flora Changes in Cesarean Section Uterus and Its Possible Correlation With Inflammation

Background: It has not been fully elucidated whether the change of the uterus flora is correlated to impaired fecundity. This case-control study aimed to analyze the differences in uterus microbial flora between women with post-cesarean section (CS) scar diverticulum (PCSD) (CS group) and women after vaginal delivery (control group), exploring the correlation between differentially expressed microbial flora and inflammation.

Methods: Infertile women who underwent hysteroscopy were enrolled in this case-control study. The swab samples were classified into four subgroups: CS cervix group, CS endometrium group, control cervix group, and control endometrium group. The total DNA obtained from 16 women (a total of 31 samples, the cervix or endometrium) was extracted for 16S recombinant DNA (rDNA) analysis. The Luminex platform was used to detect the abundance of 34 kinds of local inflammatory cytokines in 32 endometrium samples, and the correlation between microbial flora and inflammatory cytokines was analyzed.

Results: The alpha and beta diversity analysis indicated that the microbial diversity was higher in the CS group compared to the control group, especially in endometrium tissues. The heatmaps revealed that the microbial flora structure differs at each level of the phylum-class-order-family-genus among the groups. The analysis of four of the most prominently changed microbial flora revealed that Lactobacillus in the cervix was significantly higher in the control group when compared with the cesarean section group (P < 0.05). Furthermore, Proteobacteria and Neisseriaceae had a higher abundance in the CS groups, especially in the cervical tissue (P < 0.05), while Staphylococcaceae increased only in the CS endometrium tissue (P < 0.05). Next, these women were re-divided into the high- and low-Staphylococcaceae, and the abundance of 34 kinds of local inflammation cytokines was compared between groups. It was found that there was a positive correlation between Staphylococcaceae and IL-2, and a negative correlation between Staphylococcaceae and IL-8 (P < 0.05).

Conclusion: The present results suggest that the disrupted uterus microbiota composition in women with CS may be closely associated with local inflammation. The interplay between the microbiota and the immune system may be linked to clinical disorders. The potential mechanisms require further exploration.

National Survey Highlights the Urgent Need for Standardisation of Embryo Transfer Techniques in the UK

Embryo transfer (ET) is one of the vital steps in the in vitro fertilisation (IVF) process, yet there is wide variation in ET technique throughout the UK, without a nationally approved standardised approach. The aim of this study was to gain contemporaneous information regarding the current clinical ET practice in the UK.

METHOD

A 38-question electronic survey was distributed to the 79 UK Human Fertilisation and Embryology Authority (HFEA) registered clinics performing ETs.

RESULTS

In total, 59% (47/79) of units responded, 83% (39/47) performing ultrasound-guided transfers, with 42% (20/47) of units using a tenaculum; 22% (10/45) would proceed with transfer regardless of fluid in the endometrial cavity. In 91% (43/47) of units, embryos were deposited in the upper/middle portion of the uterine cavity, but interpretation of this area ranged from 0.5 to >2 cm from the fundus, with 68% (32/47) allowing patients to mobilise immediately after transfer. In 60% (27/45) of clinics, success rates were based on clinical pregnancy rates (CPR).

CONCLUSION

Within the UK there is a wide range of variability in ET techniques, with >70% of discordance in survey-responses between clinics. Whilst there are areas of good practice, some disadvantageous techniques continue to persist. This survey emphasises the importance of developing a standardised, evidence-based approach to improve ET success rates.

Identification and treatment of a cervical sinus tract in a patient with 10 years of infertility

OBJECTIVE

To introduce a special case of endometrial cavity fluid (ECF), highlighting the application of hysteroscopy and laparoscopic surgical techniques in the treatment of cervical sinus tract.

DESIGN

Narrated video featuring the diagnosis and surgical management of a case of recurrent ECF. Informed consent was obtained from the patient, and approval was granted by the ethics committee of the First Affiliated Hospital of the Wenzhou Medical University.

SETTING

Academic tertiary hospital.

PATIENT(S)

A 36-year-old woman, gravida 0, had menstrual spotting for 13 years after abdominal myomectomy of a 104 × 86 × 111-mm myoma on the posterior uterine wall near the cervix. She failed to conceive after her marriage for 10 years, and 5 operations, including hysteroscopy and laparoscopy, were performed to increase pregnancy opportunities. She also underwent in vitro fertilization and embryo transfer procedures many times, but failed. Transvaginal sonography preoperatively suggested that ECF sometimes appeared and sometimes disappeared. The local echo of the posterior wall of the cervix was enhanced. A 40-mm cystic dark area was found beside the right ovary, which seemed to connect with the cervical hyperechoic part. Additionally, a solid mass of the right adnexa with abundant blood supply was detected.

INTERVENTION(S)

First, hysteroscopy was performed to explore the ECF. A deep and narrow cervical sinus with a steady stream of accumulated blood overflowed in the lower part of the cervix, and a normal uterine cavity was found. Laparoscopic adhesiolysis and enucleation of the cystic structure that connected to the sinus tract then were performed. Hysteroscopy was repeated to determine the thinnest cervical region by the light transmission test. A horizontal incision was made on the thinnest layer. Scar tissues were removed. The incision was sutured in full layer intermittently and continuously under laparoscopy. The postoperative thickness of the muscular layer in the sinus was confirmed by light transmission test of hysteroscopy. The patient was discharged on the third day after operation, uneventfully. Histopathologic examination showed that the cystic structure and scar tissue contained smooth muscle tissue and were covered by both mucinous columnar epithelium of the cervical canal and endometrial glandular epithelium.

MAIN OUTCOME MEASURE(S)

Restoration of normal anatomy, removal of uterine effusion, and symptomatic relief.

RESULT(S)

At the 6-month follow-up, the patient's menstrual cycles returned to normal without the recurrence of menstrual spotting. The ultrasound scan also showed a symmetrical uterus without ECF.

CONCLUSION(S)

Patients with ECF who underwent assisted reproductive surgeries were related to the poor prognosis. However, the treatment should be different according to the causes, appearance time, and accumulation amount, including expectant treatment, postponement of embryo transfer, transvaginal aspiration, laparoscopic salpingectomy, or proximal tubal occlusion. For patients with recurrent ECF and/or special appearance on ultrasound, endoscopic examination is necessary. In addition, patients with large myomas at difficult locations required a uniform strategy to reduce the intraoperative and postoperative complications, especially for the nulligravida women.

Endometrial cavity fluid is associated with deleterious pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection: a retrospective cohort study

Background

The effects of endometrial cavity fluid (ECF) on in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) pregnancy outcomes following embryo transfer (ET) are still controversial. We conducted the present study to investigate whether the presence of ECF in infertile patients scheduled to undergo IVF or ICSI was associated with pregnancy outcomes.

Methods

A retrospective cohort study design was used. Among infertile patients undergoing IVF/ICSI, those with and without ECF were matched 1:1 using propensity score matching (PSM). After ensuring that the baseline levels of the two matched groups were consistent, the pregnancy and obstetrical outcomes of the two groups were compared.

Results

Patients with ECF had significantly lower clinical rates of pregnancy (1,061/1,862, 57% vs. 1,182/1,862, 63.5%; P<0.001), live birth (902/1,862, 48.4% vs. 1,033/1,862, 55.5%; P<0.001), biochemical pregnancy (1,182/1,862, 63.5% vs. 1,288/1,862, 69.2%; P<0.001), and embryo implantation (1,500/3,740, 40.1% vs. 1,661/3,740, 44.4%, P<0.001) than patients without ECF. Also, patients with ECF had a higher incidence of gestational diabetes (17/78, 22% vs. 8/94, 9%, P=0.014). However, there were no differences in gestational weeks at delivery or birth weight between the two groups.

Conclusions

ECF was significantly associated with adverse pregnancy outcomes but showed no significant association with adverse obstetric outcomes (except for gestational diabetes).

Uterine aquaporin expression is dynamically regulated by estradiol and progesterone and ovarian stimulation disrupts embryo implantation without affecting luminal closure

The study investigated the effect of normal and supraphysiological (resulting from gonadotropin-dependent ovarian stimulation) levels of estradiol (E2) and progesterone (P4) on mouse uterine aquaporin gene/protein (Aqp/AQP) expression on Day 1 (D1) and D4 of pregnancy. The study also examined the effect of ovarian stimulation on uterine luminal closure and uterine receptivity on D4 of pregnancy and embryo implantation on D5 and D7 of pregnancy. These analyses revealed that the expression of Aqp3, Aqp4, Aqp5 and Aqp8 is induced by E2 while the expression of Aqp1 and Aqp11 is induced by P4. Additionally, P4 inhibits E2 induction of Aqp3 and Aqp4 expression while E2 inhibits Aqp1 and Aqp11 expression. Aqp9, however, is constitutively expressed. Ovarian stimulation disrupts Aqp3, Aqp5 and Aqp8 expression on D4 and AQP1, AQP3 and AQP5 spatial expression on both D1 and D4, strikingly so in the myometrium. Interestingly, while ovarian stimulation has no overt effect on luminal closure and uterine receptivity, it reduces implantation events, likely through a disruption in myometrial activity and embryo development. The wider implication of this study is that ovarian stimulation, which results in supraphysiological levels of E2 and P4 and changes (depending on the degree of stimulation) in the E2:P4 ratio, triggers abnormal expression of uterine AQP during pregnancy, and this is associated with implantation failure. These findings lead us to recognize that abnormal expression would also occur under any pathological state (such as endometriosis) that is associated with changes in the normal E2:P4 ratio. Thus, infertility among these patients might in part be linked to abnormal uterine AQP expression.