Interventions to optimize embryo transfer in women undergoing assisted conception: a comprehensive systematic review and meta-analyses

Improvement of early miscarriage rates in women with adenomyosis via oxytocin receptor antagonist during frozen embryo transfer-a propensity score-matched study

BACKGROUND

Dysfunctional uterine peristalsis seems to play a pivotal role in hindering embryo implantation among women diagnosed with adenomyosis. This research aims to investigate whether administering an oxytocin receptor antagonist during a frozen embryo transfer (FET) cycle using a hormone replacement therapy (HRT) protocol can enhance in vitro fertilization (IVF) outcomes for infertile women affected by adenomyosis.

METHODS

Between January 2018 and June 2022, our reproductive center conducted IVF-FET HRT cycles for infertile women diagnosed with adenomyosis. Propensity score matching was employed to select matched subjects between the two groups in a 1:1 ratio. Following this, 168 women received an oxytocin receptor antagonist during FET, constituting the study group, while the matched 168 women underwent FET without this antagonist, forming the control group. We conducted comparative analyses of baseline and cycle characteristics between the two groups, along with additional subgroup analyses.

RESULTS

The study group exhibited notably lower rates of early miscarriage compared to the control group, although there were no significant differences in clinical pregnancy rates, ongoing pregnancy rates, and live birth rates between the two groups. Multivariate analysis revealed a negative correlation between the use of oxytocin receptor antagonists and early miscarriage rates in women with adenomyosis. Subgroup analyses, categorized by age, infertility types, and embryo transfer day, showed a substantial decrease in early miscarriage rates within specific subgroups: women aged ≥ 37 years, those with secondary infertility, and individuals undergoing day 3 embryo transfers in the study group compared to the control group. Furthermore, subgroup analysis based on adenomyosis types indicated significantly higher clinical pregnancy rates, ongoing pregnancy rates and live birth rates in the study group compared to the control group among women with diffuse adenomyosis.

CONCLUSIONS

Administering an oxytocin receptor antagonist during FET may reduce the early miscarriage rates in women with adenomyosis.

Meta-analysis of intrauterine hCG perfusion efficacy in recurrent implantation failure as defined by ESHRE guidelines

PURPOSE

This study evaluates the efficacy of intrauterine hCG perfusion for RIF, as defined by ESHRE 2023 guidelines, highlighting hCG as a cost-effective alternative to other immunotherapies, especially suitable for less developed regions. It aims to clarify treatment guidance amidst previous inconsistencies.

METHODS

This meta-analysis, registered with PROSPERO (CRD42024443241) and adhering to PRISMA guidelines, assessed the efficacy and safety of intrauterine hCG perfusion in enhancing implantation and pregnancy outcomes in RIF. Comprehensive literature searches were conducted through December 2023 in major databases including PubMed, Web of Science, Embase, the Cochrane Library, and key Chinese databases, without language restrictions. Inclusion and exclusion criteria were strictly aligned with the 2023 ESHRE recommendations, with exclusions for studies lacking robust control, clear outcomes, or adequate data integrity. The risk of bias was evaluated using the Newcastle-Ottawa Scale, ROBINS-I, and RoB2 tools. Data analysis was performed in R using the 'meta' package, employing both fixed and random effect models to account for study variability. Subgroup analyses by dosage, volume, hCG concentration, timing of administration, and type of embryo transfer were conducted to deepen insights, enhancing the reliability and depth of the meta-analysis in elucidating the role of hCG perfusion in RIF treatments.

RESULTS

Data from 13 studies, comprising six retrospective and six prospective studies from single centers, along with one multi-center RCT, totaling 2,157 participants, were synthesized to evaluate the effectiveness of intrauterine hCG perfusion in enhancing implantation and pregnancy outcomes in patients with RIF. Significant improvements were observed in clinical pregnancy and embryo implantation rates across various dosages, timing of administration, and embryo developmental stages, without impacting miscarriage rates. Notably, the most significant efficacy within subgroups occurred with a 500 IU dosage and perfusion parameters of ≤ 500µL volume and ≥ 2 IU/µL concentration. Additionally, a limited number of studies showed no significant increases in ectopic pregnancy or multiple pregnancy rates, and a modest improvement in live birth rates, although the small number of these studies precludes definitive conclusions.

CONCLUSIONS

The analysis suggests that intrauterine hCG perfusion probably enhances embryo implantation, clinical pregnancy, and live birth rates slightly in RIF patients. Benefits are indicated with a dosage of 500 IU and a maximum volume of 500µL at concentrations of at least 2 IU/µL. However, substantial heterogeneity from varying study types and the limited number of studies necessitate cautious interpretation. These findings underscore the need for more rigorously designed RCTs to definitively assess the efficacy and safety.

Transcatheter mitral valve-in-valve for pregnancy with anti-phospholipid syndrome: a case report

BACKGROUND

Perioperative management and cardiac surgery in pregnant women with anti-phospholipid syndrome combined with heart valve disease have been rarely reported.

CASE PRESENTATION

We describe a case of transcatheter mitral valve-in-valve replacement in a pregnant woman with bioprosthetic valve failure and anti-phospholipid syndrome at 18 weeks' gestation. The patient underwent a cesarean section delivery at 34 weeks of gestation, resulting in the birth of a healthy baby.

CONCLUSIONS

Transapical mitral valve-in-valve surgery resulted in safe maternal and infant outcomes in a pregnant woman with anti-phospholipid syndrome combined with mitral bioprosthetic valve failure. The success of this procedure underscored the importance of multidisciplinary teamwork.

Effect of nifedipine administration before embryo transfer on reproductive outcome in ICSI cycles, a double-blind control trial study

PURPOSE

Nifedipine is a calcium channel blocker with smooth muscle relaxing properties. This study set out to investigate the efficacy of nifedipine administered orally before embryo transfer (ET) on the improvement of the intracytoplasmic sperm injection (ICSI) outcome. This randomized, double-blind, comparator-controlled, was carried out between 2019 and 2020 in the infertility center of Babol, Iran. 200 women candidates for ICSI and recipients of frozen-thawed ET aged 18-40 years were randomly assigned in the ratio 1:1 to an intervention group that received nifedipine 20 mg tablets orally 30 min before ET (n = 100) or to a group of placebo (n = 100). A randomization center in Babol University of Medical Science used computer-generated numbers to allocate treatments. The allocation treatment was blind to the participants, the sonographer of endometer monitoring, the staff of the ICSI laboratory, and the outcome assessor. The primary analysis was based on the intention-to-treat principle done on 200 participants, (n = 100), comparing chemical pregnancy rates in the two comparing groups at 14 days' follow-up after ET. Implantation rate and clinical pregnancy were considered secondary outcomes.

RESULT

200 participants were analyzed. There is no significant difference in the number of oocytes and the quality of embryos in the nifedipine and placebo groups. Despite a numerical increase in the rate of chemical pregnancy, there were no statistical differences in the study group versus the comparison group (24% vs 14%, P = 0.1, rate ratio 0.88, 95% CI 0.77 to 1.01), respectively. Also, no significant increase in clinical pregnancy was found compared with the placebo (17% vs 8%, P = 0.26, rate ratio 0.90, 0.81 to 1.00).

CONCLUSION

Nifedipine administered orally 30 min before embryo transfer did not improve the chemical pregnancy rate, and clinical pregnancy rate in infertile women undergoing ICSI. This trial has been registered on the Iranian Clinical Trials Registration Site (IRCT) with the number IRCT20180417039338N3.

Atosiban interacts with growth hormones as adjuvants in frozen-thawed embryo transfer cycles

Objective

To investigate the interaction between atosiban and growth hormone (GH) as adjuvants in frozen-thawed embryo transfer (FET) cycles.

Method

A total of 11627 patients who underwent FET at Xiamen University Affiliated Chenggong Hospital between January 2018 to December 2022 were retrospectively analyzed. Among them, 482 patients received atosiban and 275 patients received GH. The interactions were estimated by comparing the odds ratio (OR) for pregnancy comparing patients with or without atosiban adjuvant in cohorts stratified according to the presence of GH use in either the overall cohort or a propensity score (PS) matched cohort. An interaction term (atosiban × GH) was introduced to a multivariate model to calculate the ratio of OR (ORR) adjusted for confounders.

Results

For all patients receiving atosiban administration, no obvious effect on pregnancy was observed in comparison with either matched or unmatched controls. However, when the patients were stratified according to GH administration, atosiban showed a significant association with clinical pregnancy in comparison with either matched or unmatched controls among patients with GH treatment with rate ratios (RR) of 1.32 (95%CI: 1.05,1.67) and 1.35 (95%CI: 1,1.82), respectively. On the other hand, however, the association was absent among patients without GH treatment. The adjusted ORRs in both matched and unmatched cohorts were 2.44 (95%CI: 1.07,5.84) and 1.95 (95%CI: 1.05, 3.49) respectively.

Conclusion

The combination use of atosiban and GH in FET cycles is potentially beneficial to the pregnancy. However, indications for the use of atosiban and GH may need further assessment.

Effects of atosiban on clinical outcome in frozen-thawed embryo transfer: a propensity score matching study

PURPOSE

To evaluate the effects of atosiban on clinical outcomes in patients undergoing frozen-thawed embryo transfer.

METHODS

The clinical data of 1093 infertile patients who underwent frozen-thawed embryo transfer in our center from January 2019 to December 2020 were retrospectively analyzed (control, 418; atosiban, 675). Propensity score matching (PSM) analysis identified 400 matched pairs of patients. The implantation rate, clinical pregnancy rate, live birth rate, biochemical pregnancy rate, abortion rate, multiple pregnancy rate, and ectopic pregnancy rate between the two groups were compared.

RESULTS

Before PSM, patients differed by infertility factors, number of transferred embryos, and endometrial preparation protocol (P < 0.05). After PSM, characteristics were similar in corresponding patients of the atosiban and control groups. After propensity score matching, we found that there was no significant difference in the implantation rate, clinical pregnancy rate, live birth rate, biochemical pregnancy rate, abortion rate, multiple pregnancy rate, and ectopic pregnancy rate in atosiban and control group (P > 0.05).

CONCLUSION

Atosiban did not improve the clinical outcomes of infertile patients with frozen-thawed embryo transfer.

Management strategies following implantation failure of euploid embryos

Background

Euploid blastocyst implantation failure may result from embryonic factors undetectable by preimplantation genetic testing for aneuploidy (PGT-A); however, various nonembryonic factors can also intricately interfere with implantation. This review seeks to clarify evidence-based testing and treatments for implantation failure after euploid embryo transfer.

Methods

We conducted a review of the literature on implantation failure after euploid embryo transfer or multiple embryo transfer cycles, which mainly included systematic reviews and meta-analyses.

Results

The recommended tests for implantation failure include (1) hysteroscopy, (2) endometrial CD138 immunohistochemistry and bacterial culture, (3) serum 25-hydroxyvitamin D3, and (4) thrombophilia screening. Based on diagnostic findings, the following treatments have been recommended: (1) antibiotics for chronic endometritis, (2) vitamin D replacement, (3) lifestyle modification, and (4) low-dose aspirin starting from the postimplantation period for thrombophilia. Moreover, frozen-thawed single euploid blastocyst transfer using assisted hatching and hyaluronan-enriched transfer medium may support embryo implantation.

Conclusion

To ensure a successful pregnancy in subsequent embryo transfers, simple, inexpensive, and evidence-based tests and treatments should be selected.

Impact of Caesarean section on pregnancy outcomes in ART after transfer of one or more frozen blastocysts

INTRODUCTION

The prevalence of Caesarean delivery is rising steadily worldwide, and it is important to identify its future impact on fertility. A number of articles have been published on this subject, but the impact of Caesarean section on reproductive outcomes is still under debate, and none of these articles focus exclusively on frozen blastocysts.

OBJECTIVE

The aim of this study was to evaluate the impact of a previous Caesarean delivery compared with a previous vaginal delivery on the chances of a live birth following the transfer of one or more frozen embryos at the blastocyst stage.

METHODS

This was a retrospective, bicentric study at the University Hospitals of Nîmes and Montpellier, conducted between January 1st, 2016 and February 1st, 2021. Three hundred and ninety women with a history of childbirth and a transfer of one or more frozen embryos at blastocyst stage were included in the analysis. The primary outcome was the number of live births. Secondary outcomes were: the rate of positive HCG, miscarriage, ectopic pregnancy and clinical pregnancy, as well as the live birth rate according to the presence or absence of an isthmocele.

RESULTS

Of the 390 patients included, 118 had a previous Caesarean delivery and 272 a vaginal delivery. No statistically significant differences were found for the primary (p = 0.9) or secondary outcomes. A trend towards lower live birth rates was observed in patients with isthmoceles, but this did not reach significance (p>0.9). On the other hand, transfers were more often described as difficult in the Caesarean delivery group (p = 0.011).

CONCLUSION

Our study found no effect of previous Caesarean delivery on the chances of live birth after transferring one or more frozen blastocysts. However, further prospective studies are needed to confirm these results.

The impact of difficult embryo transfer on the success of IVF: a systematic review and meta-analysis

The procedure of embryo transfer (ET) must be as gentle as possible since any traumatism may cause uterine contractility that interferes with the implantation. However, this ideal conduct is not always possible, and additional measures may be necessary (difficult ET). Different studies have evaluated the impact of difficult ET on the clinical pregnancy rate (CPR), but results were not univocal. The present systematic review and meta-analysis was aimed to provide a precise estimate of the possible detrimental effects of difficult ET on CPR. The study protocol was registered online (PROSPERO number: CRD42023387197). An electronic database search was performed to identify articles published until September 2022. The primary outcome was CPR. Fifteen studies fulfilled the inclusion criteria. Difficult ET significantly reduced the CPR (OR 0.70; 95%CI: 0.64-0.76; p < 0.0001. All pre-planned subgroup analyses according to study design (retrospective vs prospective studies), historical period (studies published before and after 2010), type of catheter, frequency of difficult cases (> or < 19%) and pregnancy rate (> or < 38%) confirmed the significant association. Difficult ET is associated with a significant reduction of CPR. Further studies are warranted to understand how to prevent or manage this common clinical situation.

Effectiveness of atosiban in women with previous single implantation failure undergoing frozen-thawed blastocyst transfer: study protocol for a randomised controlled trial

BACKGROUND

Uterine contractions may interfere with embryo implantation in assisted reproductive technology. To reduce these contractions and improve success rates, the oxytocin antagonist atosiban has been suggested for administration during embryo transfer. The aim of this study is to evaluate the effectiveness of atosiban in increasing live birth rates among women who have previously experienced a single implantation failure and are scheduled for single blastocyst transfer.

METHODS AND ANALYSIS

We conduct a single-centre randomised controlled study comparing atosiban and placebo in women undergoing a single blastocyst transfer with a previous failed blastocyst transfer. Women with endocrine or systemic illnesses, recurrent miscarriages, uterine malformations or fibroids, untreated hydrosalpinx, endometriosis (stage III or IV) or uterine fibroids, as well as women undergoing preimplantation genetic testing, are ineligible. The primary outcome is live birth resulting from the frozen-thawed embryo transfer. Secondary outcomes include biochemical/clinical pregnancy, miscarriage, ectopic pregnancy, multiple pregnancies as well as maternal and perinatal outcomes. We plan to recruit 1100 women (550 women per group). This will allow us to demonstrate or refute an increase in live birth rate from 40% to 50%. Data analysis will follow the intention-to-treat principle. We will measure patterns of uterine peristalsis which will allow subgroup analysis for women with or without uterine peristalsis.

ETHICS AND DISSEMINATION

This study has been approved by the Institutional Review Board of Northwest Women's and Children's Hospital (No. SZ2019001). Written informed consent will be obtained from each participant before randomisation. The results of the trial will be presented at scientific meetings and reported in publications.

TRIAL REGISTRATION NUMBER

ChiCTR1900022333.

Effect of Chinese patent medicine Kunling Pill on endometrial receptivity: A clinical trial, network pharmacology, and animal-based study

Although pregnancy success rates are raised with assisted reproductive technology, it still cannot meet clinical demands. Kunling Pill (KLP), a traditional Chinese medicine, is widely used in various gynecological disorders, particularly in improving fertility and pregnancy rates. However, the underlying mechanism of how KLP affects pregnancy outcomes remains unclear. This study aimed to explore the effects and mechanisms of KLP on endometrial receptivity. Firstly, a retrospective trial was conducted to validate the efficacy of KLP on repeated implantation failure (RIF) patients. The result indicated a significant increase in the proportion of live birth in KLP group (30.56%) compared to the control group (16.89%). Secondly, network pharmacology methods predicted the active components and network targets of KLP. Endometrial receptivity is closely associated with the activation of inflammatory factors, predicting the function of KLP on the immune system. The estrogen and apoptotic signaling pathways were also highlighted in the gene ontology enrichment analysis. Thirdly, a decreased endometrial receptivity model was established by controlled ovarian hyperstimulation (COH) in female C57BL/6 mice, divided into the COH and KLP groups. Normal female mice are as control group. In vivo, KLP administration could increase endometrial thickness and the number of endometrial glands and pinopodes. In the endometrium, KLP supplementation upregulated the expressions of estrogen receptor α, progesterone receptor, endothelial nitric oxide synthase, and integrin αVβ3 in the murine uterus and reduced serum levels of estrogen and progesterone. KLP regulated the uterine immune cells and inhibited cell apoptosis in the ovary via Bcl-2/Bax/caspase-3 pathway. In conclusion, KLP administration raised the live birth rate in RIF patients to optimize medication regimens, mainly because KLP ameliorated impaired endometrial receptivity.

The Impact of the Microbiological Vaginal Swab on the Reproductive Outcome in Infertile Women

BACKGROUND

The thesis on which this paper is based intended to investigate whether the result of the microbiological vaginal swab has an influence on the outcome of the fertility treatment.

METHODS

The microbiological vaginal swabs of patients who received fertility treatment at Saarland University Hospital were evaluated. Depending on the microorganisms detected, the swab result was classified as inconspicuous, intermediate, or conspicuous. The SPSS software was used to determine the correlation between the swab result and the outcome of the fertility treatment.

RESULTS

Dysbiosis was associated with a worse outcome of fertility treatment. The pregnancy rate with a conspicuous swab was 8.6%, whereas it was 13.4% with an inconspicuous swab. However, this association was not statistically significant. Furthermore, an association of endometriosis with dysbiosis was found. Endometriosis was more frequent with a conspicuous swab result than with an inconspicuous result (21.1% vs. 17.7%), yet the correlation was not statistically significant. However, the absence of lactobacilli was significantly associated with endometriosis (p = 0.021). The association between endometriosis and a lower pregnancy rate was also statistically significant (p = 0.006).

CONCLUSION

The microbiological vaginal and cervical swabs can be used as predictors for the success of fertility treatments. Further studies are needed to assess the impact of transforming a dysbiotic flora into a eubiotic environment on the success of fertility treatments.

Comparison of pregnancy outcomes of cervical mucus washing with physiologic saline solution or G-Rinse medium solution, in elective single-embryo transfers

AIM

To compare the pregnancy outcomes between physiologic saline and G-Rinse medium solution for cervical mucus washing, in fresh elective single-embryo transfers (ET) in women under the age of 37.

MATERIAL AND METHODS

This was a retrospective data analysis performed in a single in vitro fertilization (IVF) center between February 2018 and November 2021. Women younger than 37 years who underwent single elective ET were included and all women had anti-Mullerian hormone (AMH) levels ≥ 1.5 ng/ml. Age, body mass index (BMI), AMH levels, and pregnancy outcomes as clinical pregnancy rate (CPR) and live birth rate (LBR) were analyzed.

RESULTS

Study population consisted of 75 women in the G-Rinse medium solution group and 97 women in the physiologic saline group. Clinical pregnancy rate was 58.7% and 61.9% in the G-Rinse medium solution group and saline group, respectively (p = 0.673), and LBR was calculated as 41.3% and 47.4% in the G-Rinse medium solution group and saline group, respectively (p = 0.430). A log-binomial regression model was used and the model was adjusted for BMI to evaluate the effect of the cervical mucus washing method on the pregnancy outcomes. There was an estimated 5% decrease in the relative risk for CPR in the G-Rinse medium solution group compared to the saline group (95% CI: 0.74 to 1.2, p = 0.673). There was an estimated 13% reduction in the relative risk for LBR in the G-Rinse medium solution group compared to the saline group (95% CI: 0.62 to 1.23, p = 0.430). They were both statistically not significant.

CONCLUSION

In our study, the replacement of using G-Rinse medium solution to physiologic saline solution for cervical cleaning did not change CPR and LBR outcomes. Using physiologic saline solution can be a good alternative approach for ectocervical washing during embryo transfer in selected population because of its lower costs, easy accessibility, and common use.

Does Intrauterine Injection of hCG Improve IVF Outcome? A Systematic Review and a Meta-Analysis

Various interventions have been proposed to improve embryo implantation in IVF. Among these, intrauterine injections of human chorionic gonadotropin seem to have promising results. Consequently, we conducted a review and meta-analysis to assess IVF outcomes by comparing couples who underwent intrauterine hCG injection transfer versus those who underwent embryo transfer with intrauterine injection of placebo, or without any additional intervention. The primary outcome was the clinical pregnancy rate. Secondary outcomes were the implantation rate, miscarriage rate, and live birth rate. A meta-analysis was conducted using the random effects model, while bias within studies was detected using the Cochrane risk of bias tool. Ectopic pregnancies and stillbirths were also assessed. The clinical pregnancy (RR 1.38, 95% CI 1.17−1.62, p < 0.0001) and implantation rate (RR 1.40, 95% CI 1.12−1.75, p = 0.003) were significantly higher in women who underwent hCG injection than in the control group. These significant effects persisted only in women who underwent cleavage-stage embryo transfer. No significant differences between groups were observed in the other secondary outcomes. In conclusion, our systematic review and meta-analysis demonstrate that intrauterine injection of hCG could be a valuable approach in women who undergo cleavage-stage embryo transfer. Given the lack of data about the live birth rate, caution should be exercised in interpreting these data.

Development of a Model Predicting the Outcome of In Vitro Fertilization Cycles by a Robust Decision Tree Method

INTRODUCTION

Infertility is a worldwide problem. To evaluate the outcome of in vitro fertilization (IVF) treatment for infertility, many indicators need to be considered and the relation among indicators need to be studied.

OBJECTIVES

To construct an IVF predicting model by a robust decision tree method and find important factors and their interrelation.

METHODS

IVF and intracytoplasmic sperm injection (ICSI) cycles between January 2010 and December 2020 in a women's hospital were collected. Comprehensive evaluation and examination of patients, specific therapy strategy and the outcome of treatment were recorded. Variables were selected through the significance of 1-way analysis between the clinical pregnant group and the nonpregnant group and then were discretized. Then, gradient boosting decision tree (GBDT) was used to construct the model to compute the score for predicting the rate of clinical pregnancy.

RESULT

Thirty-eight variables with significant difference were selected for binning and thirty of them in which the pregnancy rate varied in different categories were chosen to construct the model. The final score computed by model predicted the clinical pregnancy rate well with the Area Under Curve (AUC) value achieving 0.704 and the consistency reaching 98.1%. Number of two-pronuclear embryo (2PN), age of women, AMH level, number of oocytes retrieved and endometrial thickness were important factors related to IVF outcome. Moreover, some interrelations among factors were found from model, which may assist clinicians in making decisions.

CONCLUSION

This study constructed a model predicting the outcome of IVF cycles through a robust decision tree method and achieved satisfactory prediction performance. Important factors related to IVF outcome and some interrelations among factors were found.