Subsequent Embryo Transfer Research Articles

Transcriptomic Analysis of Vitrified-Warmed vs. Fresh Mouse Blastocysts: Cryo-Induced Physiological Mechanisms and Implantation Impact.

Blastocyst vitrification has significantly improved embryo transfer methods, leading to higher implantation success rates and better pregnancy outcomes in subsequent frozen embryo transfer cycles. This study aimed to simulate the transcriptional changes caused by vitrifying human blastocysts using mouse blastocysts as a model and to further investigate these changes' effects. Utilizing a human vitrification protocol, we implanted both vitrified and fresh embryos into mice. We observed the implantation success rates and performed transcriptomic analysis on the blastocysts. To validate the results from messenger RNA sequencing, we conducted reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) to measure the expression levels of specific genes. Based on mRNA profiling, we predicted the microRNAs responsible for the regulation and used qPCR basic microRNA assays for validation. Our observations revealed a higher implantation success rate for vitrified embryos than fresh embryos. Transcriptomic analysis showed that vitrified-warmed blastocysts exhibited differentially expressed genes (DEGs) primarily associated with thermogenesis, chemical carcinogenesis-reactive oxygen species, oxidative phosphorylation, immune response, and MAPK-related signaling pathways. RT-qPCR confirmed increased expression of genes such as Cdk6 and Nfat2, and decreased expression of genes such as Dkk3 and Mapk10. Additionally, gene-microRNA interaction predictions and microRNA expression analysis identified twelve microRNAs with expression patterns consistent with the predicted results, suggesting potential roles in uterine epithelial cell adhesion, trophectoderm development, invasive capacity, and immune responses. Our findings suggest that vitrification induces transcriptomic changes in mouse blastocysts, and even small changes in gene expression can enhance implantation success. These results highlight the importance of understanding the molecular mechanisms underlying vitrification to optimize embryo transfer techniques and improve pregnancy outcomes.

P-393 Operative hysteroscopy versus vacuum aspiration for missed miscarriage in women undergoing in vitro fertilization, a propensity score-matched cohort study

Abstract Study question Is operative hysteroscopy, compared to vacuum aspiration, associated with increased success rates in the subsequent frozen embryo transfer of women who experienced missed miscarriage? Summary answer Operative hysteroscopy does not show advantages in terms of live birth rate in the subsequent frozen embryo transfer compared to women who underwent vacuum aspiration. What is known already As hysteroscopy to remove retained product of conception is performed under direct visualization control, it may theoretically reduce risks to the uterine cavity and therefore improve future fertility. With the advancements in hysteroscopy technology, an increasing number of women with missed miscarriage are choosing operative hysteroscopy over conventional vacuum aspiration. However, there is currently insufficient research available to determine whether use of operative hysteroscopy to remove retained tissues within the uterus effectively increases the success rate of subsequent frozen embryo transfer. Study design, size, duration This was a propensity score-matched cohort study on women who had experienced an missed miscarriage at 5 to 16 gestational weeks during an IVF cycle in Peking University Third Hospital from 2015 to 2022. Participants/materials, setting, methods We aimed to focus on a specific group of patients who had experienced missed miscarriage during IVF and subsequently underwent frozen embryo transfer. Logistic regression models were used to compare the effect of operative hysteroscopy versus vacuum aspiration, after propensity score matching with a 1:1 ratio. Non-linear interaction was tested on gestational weeks and treatment effect on live birth rate. The primary outcome was the live birth rate in the subsequent frozen embryo transfer. Main results and the role of chance Out of the 3,722 fresh embryo transfer cycles and 5,948 frozen embryo transfer cycles resulting in miscarriage, a total of 2,562 women who underwent vacuum aspiration and 347 women who underwent operative hysteroscopy were included in the analysis. After propensity score matching at a 1:1 ratio, 324 women were included in each group. Compared to women who underwent vacuum aspiration, those who underwent operative hysteroscopy were associated with a lower rate of live birth in the propensity-based matched cohort (29% vs 22%, aOR = 0.67 (0.47, 0.96)). The result was further confirmed by several sensitivity analysis, including using non-imputed data, varying calliper widths for propensity score matching, and matching covariates associated with treatment assignment or pregnancy outcomes. No statistical difference was detected on the biochemical pregnancy rate, clinical pregnancy rate, multiple pregnancy rate, and miscarriage rate. No interaction was detected between the gestational week and the relative treatment effect on live birth (p = 0.75). There was no significant difference in the rate of neonatal outcomes between the vacuum aspiration and operative hysteroscopy groups. 11 women experienced surgery reintervention in the vacuum aspiration group (0.4%), while no one required surgery reintervention in the operative hysteroscopy group. Limitations, reasons for caution The retrospective design and inability to analyze certain confounding factors are notable limitations, despite achieving covariate balance through matching. Our dataset did not capture several important outcomes, including cumulative pregnancies and severe complications after surgery. Future randomised trials are warranted to provide more robust insights into our results. Wider implications of the findings Women may benefit from operative hysteroscopy with a lower rate of reintervention compared to vacuum aspiration. However, this advantage may come at the expense of lower rates of live birth. Our results should be further tested by randomised trials. Trial registration number NA

P-745 effectiveness and safety of consecutive single embryo transfer compared to double embryo transfer: results from UK HFEA registry

Abstract Study question How does two-consecutive single embryo transfer (2xSET) affect reproductive outcomes of in-vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) compared to double embryo transfer (DET)? Summary answer 2xSET may provide greater or comparable live birth rates with lower multiple birth, preterm birth, and pregnancy loss or neonatal death rates compared to DET. What is known already Elective single embryo transfer (SET) in IVF/ICSI is widely encouraged over DET to minimise the risk of multiple birth and associated morbidities. Despite this, UK multiple birth rates following IVF remain higher than spontaneous conception, with 5% of IVF pregnancies resulting in multiple birth compared to 0.4%-1.2% multiple gestation rates following spontaneous conception. Owing to advancements in cryopreservation techniques, live birth and ongoing pregnancy rates are now comparable between fresh and frozen embryo transfer. Consequently, 2xSET has been suggested as an alternate technique to achieve comparable live birth rates with fewer multiple gestation pregnancies compared to DET. Study design, size, duration This retrospective cohort study was conducted using Human Fertilisation and Embryology Authority (HFEA) register data, which encompasses national data from all IVF clinics in the UK. Within this analysis, all women who underwent their first oocyte collection and IVF or ICSI treatment cycle with subsequent SET, DET or 2xSET between 2010 and 2019 using either blastocyst or cleavage stage embryos were included (N = 125,149). Participants/materials, setting, methods This national retrospective cohort study utilised UK HFEA register data from 2010-2019, including all women who underwent their first oocyte collection and subsequent embryo transfer (N = 125,149). The rate of live birth, multiple birth, preterm birth, and pregnancy loss or neonatal death was compared between SET, DET, and 2xSET IVF/ICSI pregnancies using either blastocyst or cleavage stage embryos, and was stratified by maternal age. Data analysis was conducted in RStudio v4.2, alpha equals 0.05. Main results and the role of chance 2xSET pregnancies following blastocyst-stage transfer achieved a greater live birth occurrence rate of 0.47 (0.13) (median (interquartile range)) than SET, 0.41 (0.13), and DET, 0.38 (0.13) (P < 0.05). When using SET as a reference standard, 2xSET achieved a lower multiple birth rate, odds ratio (OR) of 6.87 (95%CI 6.14-7.68), than DET, OR 28.20 (95%CI 25.20-31.57), and lower preterm birth rate; OR 1.11 (95%CI 1.06-1.15) in 2xSET, and OR 2.80 (95%CI 2.67-2.94) in DET. Pregnancy loss or neonatal death rate was also lower in 2xSET, OR 1.14 (95%CI 1.08-1.21), compared to DET, OR 2.11 (95%CI 1.98-2.24). Conversely, in cleavage-stage embryo transfer pregnancies, no significant difference in live birth occurrence rate was observed, achieving rates of 0.27 (0.21) for SET, 0.26 (0.13) for DET, and 0.29 (0.18) for 2xSET. 2xSET was less likely to result in multiple birth than DET, OR 0.14 (95%CI 0.11-0.19). Moreover, when using SET as a reference standard, 2xSET was less likely to result in preterm birth than DET, OR 1.02 (95%CI 0.87-1.23) and 2.48 (95%CI 2.17-2.82) respectively, as well as pregnancy loss or neonatal death, OR 1.07 (95%CI 0.85-1.35) and 2.03 (95%CI 1.70-2.42) respectively. Limitations, reasons for caution Certain confounders are not recorded within HFEA registry data, including patient body mass index (BMI), evaluation of embryo quality, and endometrial thickness at embryo transfer. Consequently, while our analysis identifies broad trends in embryo transfer success and morbidity, results may differ within certain patient populations. Wider implications of the findings 2xSET may provide greater or comparable live birth rates with lower multiple birth and morbidity than DET. Promotion of 2xSET where appropriate for maternal age and embryo quality should be implemented to enhance reproductive outcomes and reduce the risk of morbidity in IVF/ICSI pregnancies. Trial registration number Not Applicable

P-262 Clinical viability of oocytes with micronuclei at fertilisation

Abstract Study question Does the presence of micronuclei at fertilisation impact on embryo potential? Summary answer Embryos displaying micronuclei at fertilisation exhibit decreased utilisation rates and lower euploidy rates, however are capable of resulting in clinical pregnancies. What is known already The appearance of two pronuclei defines normal fertilisation. With advances in imaging techniques, a range of pronuclei phenotypes can now be identified in more detail, including additional micronuclei. Micronuclei are smaller satellite structures appearing around the pronuclei. Previous studies have determined that embryos containing two primary pronuclei and one micronuclei are generally diploid and can develop to blastocyst stage. However, these studies were limited in sample size, did not have consistent imaging techniques and assessed only the presence or absence of micronuclei, not their size or number. Study design, size, duration Retrospective cohort analysis in a single, large IVF centre including all oocytes entering culture between January 2022 and December 2023 (n = 33,237). All embryos were cultured in Embryoscope+ using Vitrolife sequential media at 6% CO2 and 5% O2. ICSI and naturally inseminated oocytes were included. All embryos were cultured to day 5/6 before determining suitability for transfer, freezing and/or genetic testing. Participants/materials, setting, methods During routine daily annotation, embryologists assessed fertilised oocytes for the presence of micronuclei. This study re-examined all embryos annotated as displaying micronuclei and further assessed: number of micronuclei, their position (‘apposed’ or ‘distant’ from the pronuclei, and in the case of > 1 micronuclei ‘clustered’ or ‘spread’) along with the area (μm2) of the two largest micronuclei and area (μm2) of primary pronuclei using Embryoscope+ software. Clinical pregnancy was defined as presence of a gestational sac. Main results and the role of chance Micronuclei were observed in 0.45% (n = 149/33,237) of all oocytes assessed. The majority of these presented as one additional nuclei 92.60% (n = 138), 7.38% (n = 11) showed two additional nuclei and 0.67%(n = 1) had multiple (more than 2) micronuclei. All micronuclei appeared apposing a primary pronucleus. In the event of multiple micronuclei, 82% were clustered whereas 9% was spread throughout the around the primary pronuclei. The average area of the largest micronuclei in each oocyte was 80.33μm2 ± 26.81.The mean area of all micronuclei was 76.80μm2, approximately 16% of the size of primary pronuclei measured, 465.09μm2. The utilisation rates of embryos derived from micronuclei fertilisation were 28.18% (N = 42) compared to 49%, n = 4118 of 2PN derived embryos. All but one of these presented two primary pronuclei and one additional micronuclei, with the remaining embryo displaying two micronuclei. Twelve of these embryos were transferred (in a fresh stimulated cycle (n = 5) or a subsequent frozen embryo transfer cycle (n = 7), resulting in four clinical pregnancies, however only one ongoing clinical pregnancy. PGT testing was performed on 19 embryos, with only two, 6.67% returning a euploid results, 68.42% resulting an aneuploid, of the remaining four embryos, 2 achieved a mosaic result and 2 received a no result. Limitations, reasons for caution As the occurrence of micronuclei is rare, only a limited number of embryos were available for analysis. Furthermore, this study was conducted in a large single laboratory and can not account for differences in culture conditions between laboratories. Inter-operator variability among initial fertilisation annotations could not be excluded. Wider implications of the findings By creating a definition of the micronuclei measurement, it provides safeguard for micronuclei to be assessed in culture. The data presented here can help guide clinical decisions where micronuclei are present. Trial registration number not applicable

O-152 Pre-implantation genetic testing for aneuploidies (PGT-A) improves reproductive outcomes in advanced maternal age patients undergoing IVF/ICSI: a multicentre retrospective cohort study with propensity score matching

Abstract Study question In patients > 37 years undergoing IVF/ICSI, does PGT-A improve live birth rates (LBR) and cumulative live birth rates (CLBR)? Summary answer In advanced maternal age women with ≥1 embryo to transfer, PGT-A improves the live birth and cumulative live birth rates. What is known already The age-related rate of aneuploidy remains a major cause of IVF failure. Therefore, PGT-A has been proposed as a method to select embryos with the highest implantation potential. Previous studies have shown that women younger than 37 years old do not benefit from PGT-A given the comparable outcomes in terms of implantation, clinical pregnancy, and live-birth rates. Moreover, PGT-A may also be inherently ineffective given the risk of mitotic mosaicism, sampling errors and misinterpretation of results. However, we are currently lacking solid scientific evidence to support whether this approach benefits advanced maternal age women. Study design, size, duration A multicenter retrospective cohort study was conducted including 9328 patients >37y undergoing their first IVF/ICSI cycle with an oocyte retrieval performed between 1/01/2013-31/07/2021 in a multinational private fertility clinic. The study group (n = 4664) included patients who performed PGT-A. The control group included patients without PGT-A (n = 4664) and was selected by propensity score matching adjusted for age at oocyte retrieval, number of oocytes retrieved and year of oocyte retrieval. Participants/materials, setting, methods The primary outcome was CLBR (delivery of at least one live birth per started cycle, including the fresh and subsequent frozen embryo transfer cycles). The secondary outcomes were LBR and time to pregnancy. The analysis was conducted including all patients with an initiated cycle of ovarian stimulation and also per embryo transfer. Comparisons are presented as adjusted odd-ratios (adjOR) and 95% confidence intervals (95%CI) following multivariable logistic regression (LBR) or cox regression (CLBR) analysis. Main results and the role of chance Patients in the PGT-A group had more oocytes retrieved (11.03±6.82 vs 9.24±6.15, p < 0.001), and a higher number of available blastocysts (2.82±2.21 vs 1.22±2.00, p < 0.001). In the PGT-A group, 13.153 embryos were analysed, with an euploidy rate of 29.30% (n = 3854). In total, 49.83% (n = 2324) patients did not undergo embryo transfer due to unavailable euploid embryos. Considering all patients that initiated ovarian stimulation, the PGT-A group presented a higher unadjusted CLBR per started cycle (27.38% vs 21.81%, p < 0.001). Considering only patients who underwent embryo transfer, a total of 5934 embryo transfers were analysed (n = 3166 in the control group and n = 2768 in the PGT-A group). Following multivariable logistic regression analysis, LBR and CLBR were significantly higher in the PGT-A group (respectively, adjOR 1.56 [95% CI 1.38-1.77], adjOR 1.53 [95% CI 1.39-1.68]). Following the transfer of 5 embryos, the CLBR was approximately 100% in the PGT-A group and 74.51% in the control group. Survival analysis was also perfomed to assess the impact of PGT-A on time to pregnancy. Despite the fact that from 6 months onwards the CLBR was higher in the PGT-A group, the median time to pregnancy was higher in the PGT-A group (3.27 (95%CI 3.16-3.40) vs 2.74 months (95%CI 2.57-3.03). Limitations, reasons for caution This study is limited by its retrospective design and low number of women with more than 3 embryos transferred. Also, the fact that only the first IVF/ICSI cycle was analysed provides a proper patient counselling in this specific context but does not provide data on repeated cycle outcomes. Wider implications of the findings Our findings suggest that, in women older than 37 years with at least one available embryo to biopsy, performing PGT-A may improve the reproductive outcomes in terms of LBR and CLBR, providing a useful clinical tool for embryo selection. Trial registration number not applicable

O-075 Particulate matter (PM2.5 and PM10) exposure prior to oocyte collection is associated with decreased live birth rates in subsequent frozen embryo transfers

Abstract Study question Does exposure to particulate matter air pollution prior to oocyte collection (OPU) or frozen embryo transfer (FET) impact FET live birth rates? Summary answer Increasing PM10 and PM2.5 exposure prior to OPU is associated with decreased odds of live birth in subsequent FET, independent of the conditions at FET. What is known already Ambient air pollution is increasing, and exposure is associated with adverse reproductive health outcomes, including infertility, miscarriage, preterm birth and low birth weight. Animal studies have shown that air pollutants can impair spermatogenesis, oogenesis, ovarian reserve and embryogenesis. These findings are corroborated by human epidemiological studies. The impact of ambient air pollution on IVF outcomes is uncertain. Additionally, whether pollutants exert a greater impact during oocyte development or early pregnancy is uncertain. Therefore, studies of FETs offer an opportunity to delineate different phases of reproduction that may be adversely affected by pollution. Study design, size, duration A retrospective analysis of 3,657 FETs in a single Australian centre from January 2013 – December 2021. All FETs during the study period were included; data were collected from the clinic database. Air pollutant concentrations for each day during the study were obtained from the Governmental monitoring body, including SO2, CO, O3, NO2, PM10 and PM2.5. Evaluation of FETs allowed separation of environmental effects during oocyte development and during early pregnancy. Participants/materials, setting, methods Quartiles were created for pollutants averaged over 24 hours, 2 weeks, 4 weeks and 3 months prior to OPU and prior to FET. Multi-pollutant models were created to account for co-exposures and were adjusted for variables at the time of OPU and FET. Bonferroni correction was made to account for the 4 timepoints tested on each outcome. Linear trends were assessed for each model, and pairwise comparisons against the first quartile were performed. Main results and the role of chance Overall, air quality was excellent, with pollutant levels within published safe limits on > 99% of days during the study period. Increasing PM10 exposure in the 2 weeks prior to OPU was associated with decreased odds of livebirth (linear trend p = 0.009); the odds of livebirth decreased by 38% when PM10 concentrations were in the highest quartile compared with the lowest (OR 0.62, p = 0.010). Increasing PM2.5 exposure in the 3 months prior to OPU was also associated with decreased odds of livebirth (linear trend p = 0.011). No significant linear trends were observed between livebirths and other pollutants. The summer seasonal association with livebirth that we have previously demonstrated consistently held in the multi-pollutant models. No significant linear trends were observed between air pollutants and biochemical pregnancy, clinical pregnancy, miscarriage, gestation at birth or embryological outcomes. Limitations, reasons for caution The retrospective design is a limitation. Whilst corrections were made for multiple pollutant co-exposures, other environmental conditions, patient factors and repeated cycles, we were unable to account for all potential covariates. To reduce the risk of type 1 error due to the multiple timeframes, we utilised a Bonferroni correction. Wider implications of the findings Even when PM2.5 and PM10 exposures are within so-called “safe” ranges, increasing exposure in the weeks and months prior to OPU are associated with decreasing livebirth rates, independent of the conditions at the time of FET. Trial registration number 2022/ET000980

P-446 Personalization of the euploid embryo transfer guided by the endometrial receptivity analysis in patients with >1 previous failed transfer

Abstract Study question Does personalized embryo transfer (pET) guided by Endometrial Receptivity Analysis (ERA) increase reproductive outcome in patients with >1 previous failed transfer of an euploid embryo? Summary answer pET guided by ERA resulted in a significantly higher Pregnancy Rate (PR), Ongoing Pregnancy Rate (OGPR) and Live Birth Rate (LBR) versus standard embryo transfer. What is known already pET consists of synchronizing embryo transfer with the optimal endometrial receptivity status by the transcriptomics identification of the personalized window of implantation (WOI). Euploid transfers improve reproductive outcome controlling the embryo contribution in the implantation. Controversial results have been published regarding the clinical usefulness of pET in a range of clinical indications. Here we present data from patients with >1 previous failed embryo transfer (ET) in a subsequent euploid ET. Study design, size, duration Multicenter retrospective study involving 270 patients with at least one previous implantation failure between 2017 and 2021. These patients were divided into two groups according to their subsequent transfer: study group (pET guided by ERA) (n = 200), and control group (standard transfer) (n = 70). All the ET were done in Hormone Replacement Therapy cycles (HRT). PR, OGPR and LBR were compared between the two groups. Participants/materials, setting, methods Age, body mass index, previous failed attempts, inner cell mass (ICM) and trophectoderm (TE) quality of the transferred embryos were compared between the groups. Study group had an ERA result as standard WOI or displaced WOI and pET of an euploid embryo was carried out in a subsequent HRT cycle (following the same conditions and recommendations provided by ERA). Wilcoxon rank sum test was applied to quantitative comparations. Chi-square test was done for categorical variables. Main results and the role of chance Clinical results in terms of PR, OGPR and LBR were significantly higher when pET guided by ERA was performed when compared to the non-ERA group. PR was 65% (130/200) in pET versus 37.14% (26/70) in control group (P = 0.000088); OGPR was 49% (98/200) in pET versus 27.14% (19/70) in control group (P = 0.0024); and LBR was 48.20% (95/197) in pET versus 26.09% (18/69) in control group (P = 0.0022). Control and demographics variables did not show differences between the two groups: Age: 35.27 ± 3.86 versus 35.77 ± 3.35 (P = 0.31); BMI: 22.99 ± 3.02 versus 23.25 ± 3.72 (P = 0.52); Previous failed attempts: 2.42 ±1.78 versus 2.17 ±1.81 (P = 0.32); P values where 0.1 and 0.36 for comparisons of optimal quality of ICM and TE, respectively. Limitations, reasons for caution This is a retrospective study, having the limitations of its nature. Wider implications of the findings These results show that pET guided by the ERA test of an euploid embryo significantly increases the reproductive outcomes (PR, OGPR and LBR) in patients with ≥1 previous failed transfer compared to the standard frozen ET. Trial registration number Hospital Clínico de Valencia Ethic Committee approval nº. 2021/018.

Addition of operative hysteroscopy to vacuum aspiration for the management of early pregnancy loss after in vitro fertilization

ObjectiveTo investigate whether operative hysteroscopy in addition to vacuum aspiration for the management of early pregnancy loss effectively increases the success rate of subsequent frozen embryo transfer. DesignPropensity score-matched cohort study. SubjectsWomen with a miscarriage at 5 to 16 gestational weeks during an IVF cycle in Peking University Third Hospital from 2015 to 2022. ExposureHysteroscopy plus vacuum aspiration versus conventional vacuum aspiration. Main Outcome MeasuresLive birth rate in the subsequent frozen embryo transfer. Results347 women who underwent vacuum aspiration plus hysteroscopy and 2,562 women who underwent conventional vacuum aspiration were included in the analysis. After propensity score matching (1:1 ratio), 325 women were included in each group. Compared to women who underwent vacuum aspiration, those who underwent vacuum aspiration plus hysteroscopy were associated with a lower rate of live birth in the propensity-based matched cohort (22% vs 30%, aOR = 0.68 (0.47, 0.97)). Biochemical, clinical and multiple pregnancy rates were not significantly different, as was miscarriage rate. In the overall cohort, 11 women experienced surgery reintervention in the vacuum aspiration group (0.4%), while no one required surgery reintervention in the vacuum aspiration plus hysteroscopy group. ConclusionWomen who underwent vacuum aspiration plus hysteroscopy might be associated with lower rates of live birth compared to those who underwent vacuum aspiration. Further studies are necessary to establish this relationship definitively.

Evaluation of the maternal systemic immune system during frozen euploid embryo transfer according to cycle outcome

Infertility affects 15 % of couples in the US, and many turn to assisted reproductive technologies, including in vitro fertilization and subsequent frozen embryo transfer (FET) to become pregnant. This study aimed to perform a broad assessment of the maternal immune system to determine if there are systemic differences on the day of FET in cycles that result in a live birth compared to those that do not. Women undergoing FET of euploid embryos were recruited and blood was collected on the day of FET as well as at early timepoints in pregnancy. Sixty immune and angiogenic proteins were measured in plasma, and gene expression of 92 immune-response related genes were evaluated in peripheral blood mononuclear cells (PBMCs). We found plasma concentrations of interleukin-13 (IL-13) and macrophage derived chemokine (MDC) were significantly lower on the day of FET in cycles that resulted in a live birth. We also found genes encoding C-C chemokine receptor type 5 (CCR5), CD8 subunit alpha (CD8A) and SMAD family member 3 (SMAD3) were upregulated in PBMCs on the day of FET in cycles that resulted in live birth. Measurements of immune mediators from maternal blood could serve as prognostic markers during FET to guide clinical decision making and further our understanding of implantation failure.

Autologous PRP therapy for thin endometrium: A self-controlled case series study across menstrual cycles

ObjectivesThin endometrium (TE) compromises endometrial receptivity, often leading to implantation failure and lower clinical pregnancy rates. As autologous platelet-rich plasma (PRP) emerges as a potential remedy, the present study focused on its therapeutic effects on TE in infertile women who underwent frozen embryo transfer. Study designPatients with TE who underwent frozen embryo transfer treatment in our hospital were included. To diminish individual variability, a self-controlled series approach was used. Two menstrual study cycles were arranged for each participant before the actual embryo transfer cycle; PRP treatment was conducted in the second cycle. Key metrics analyzed included endometrial thickness and the expression of specific endometrial biomarkers including HOXA-10, Ki67, and αvβ3 integrin. Transvaginal ultrasound was employed to measure endometrial thickness on Days 11 and 14, and an endometrial biopsy was conducted on progesterone Day 5 of the first two cycles. Pregnancy outcomes were observed after the embryo transfer cycle. ResultsPRP treatment significantly increased the median endometrial thickness, from 5.8 mm to 6.5 mm (P = 0.0066). Additionally, PRP treatment resulted in a statistically significant increase in the H-score for all endometrial markers. Importantly, during the subsequent embryo transfer cycle with PRP treatment, two patients successfully achieved pregnancies, both culminating in live births. ConclusionsThese findings emphasize the potential of PRP in improving endometrial conditions, especially for individuals grappling with thin endometrium issues, as underscored by this self-comparison methodology.

Impact of time interval from cesarean delivery to frozen embryo transfer on reproductive and neonatal outcomes

To evaluate differences in reproductive and neonatal outcomes on the basis of the time interval from cesarean delivery to subsequent frozen embryo transfer (FET). Retrospective cohort. Multicenter fertility practice. Women undergoing autologous elective single embryo transfer FET after prior cesarean delivery. Time from prior cesarean delivery to subsequent FET. live birth (LB). A total of 6,556 autologous elective single embryo transfer FET cycles were included. Frozen embryo transfer cycles were divided into eight groups on the basis of the time interval from prior cesarean delivery to subsequent FET in months. A secondary analysis was then performed with time as a continuous variable. The proportion of LBs did not differ significantly across all time interval groups and over continuous time (range: 40.0%-45.6%). The mean gestational age at the time of delivery did not significantly differ as the time between prior cesarean delivery and subsequent FET increased (range: 37.3-38.4). When time was evaluated continuously, the proportion of preterm births was higher with a shorter time between cesarean delivery and subsequent FET. The mean birth weight ranged from 3,181-3,470g, with a statistically significant increase over time. However, the proportions of extremely low birth weight, very low birth weight, and low birth weight did not significantly differ. There were no significant differences in reproductive outcomes on the basis of the time interval from cesarean delivery to FET, including LB. The proportion of preterm deliveries decreased with a longer time between cesarean delivery and FET. Differences in mean neonatal birth weight were not clinically significant because the proportion of low birth weight neonates was not significantly different over time. Although large, this sample cannot address all outcomes associated with short interpregnancy intervals, particularly rarer outcomes such as uterine rupture. When counseling patients, the timing of FET after cesarean delivery must be balanced against the risks of increasing maternal age on reproductive and neonatal outcomes.

Clinical utility of office hysteroscopy following failed invitro fertilization-embryo transfer: A retrospective cohort study.

Despite its widespread use, invitro fertilization (IVF) outcomes are challenged by implantation failure, largely due to factors such as embryo quality and endometrial receptivity. In this study, we investigated the clinical effect of office hysteroscopy (OH) on the subsequent frozen-thawed embryo transfer (FET) in infertile women who experienced a failed IVF-embryo transfer (IVF-ET) cycle. We included 577 infertile women who underwent OH because of a history of failed ET between October 2019 and September 2021. During OH, visible endometrial polyps (EPs) were diagnosed and removed by curette or biopsy forceps; chronic endometritis (CE) was diagnosed by histopathology and immunohistochemistry and treated with oral doxycycline (0.2 g/d) for 14 days. According to the hysteroscopic findings and endometrial pathology with immunohistochemistry, patients were divided into three groups: group A (n = 161) had CE with or without EPs, group B (n = 156) had EPs only, and group C (n = 260) had no CE or EPs. In the following FET cycle, the implantation rates were 47%, 51%, and 45% (P = 0.411); the clinical pregnancy rates were 56%, 62%, and 55% (P = 0.436); the live birth rates were 45%, 51%, and 42% (P = 0.205); and the miscarriage rates were 18%, 16%, and 22% (P = 0.497) in groups A, B, and C, respectively. There were no significant differences among groups (P > 0.05). OH is helpful for diagnosis and treatment of abnormal intrauterine environment in women with a failed IVF cycle and further improves their pregnancy outcome in the following FET.

Impact of thyroid autoimmunity on the cumulative live birth rates after IVF/ICSI treatment cycles

BackgroundCumulative live birth rate (CLBR) is considered as the most important endpoint for assessing the probability of having a baby in a complete in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment cycle. Many previous studies have focused on the association between thyroid autoimmunity (TAI) and live birth rate after first embryo transfer cycle, however, evidence on whether the presence of TAI affects the CLBR is lacking. The purpose of this study is to investigate the impact of TAI on the CLBR in a complete IVF/ICSI cycle.MethodsThis retrospective study included 12,796 women who underwent their first IVF/ICSI treatment between January 2019 and February 2021. Based on the levels of thyroid antibodies, 2,603 women were assigned to the TAI group, and 10,193 women were assigned to the control group. Subgroup analysis was performed according to the different causes of infertility (including male factor only, ovulation disorder, tubal factor, endometriosis and unexplained infertility) and different types and titres of thyroid antibodies. The primary outcome in this study was CLBR, which included live births from the fresh embryo transfer cycle and all subsequent frozen-thawed embryo transfer cycles performed before December 2021.ResultsThere was no significant difference in the CLBR between the TAI and control groups, even after adjusting for relevant confounders including age, body mass index, cause of infertility, thyroid function, protocols of controlled ovarian stimulation, type of transfer (fresh vs. frozen), type of transferred embryo (cleavage-stage embryo vs. blastocyst), and fertilization method (IVF vs. ICSI) (cumulative live birth: 50.6% vs. 52.1%, OR 0.94, 95% CI 0.86–1.02, adjusted OR 0.97, 95%CI 0.89–1.06). Subgroup analysis showed that no significant difference was observed in CLBR between the TAI and control groups for all causes of infertility, except for infertility attributed to endometriosis. Among women with endometriosis, the CLBR was significantly lower in the TAI group than that in the control group; however, this difference was not significant after adjusting for potential confounders including age, body mass index, thyroid function, protocols of controlled ovarian stimulation, type of transfer (fresh vs. frozen), type of transferred embryo (cleavage-stage embryo vs. blastocyst), and fertilization method (IVF vs. ICSI) (cumulative live births: 43.1% vs. 51.0%, OR 0.73, 95% CI 0.53–0.99, adjusted OR 0.74, 95% CI 0.53–1.02). Another subgroup analysis demonstrated that the type and titre of thyroid antibody did not affect CLBR in women with TAI.ConclusionsIn our study, there was no significant difference in the CLBR between women with TAI and those without TAI, which suggests that TAI did not affect the chances of having a baby in a complete IVF/ICSI treatment cycle.

Influence of the storage conditions of embryo culture media on mouse development.

The culture of preimplantation embryos in vitro is an important method for human and mouse reproductive technology. This study aims to investigate the influence of different conditions of culture media on the preimplantation stage of mouse embryos cultured in vitro, and monitor the post-implantation development of new mice after embryo transfer to surrogate females. We demonstrated here that mouse embryos cultured in vitro in fresh M16, KSOM, Global, and HTF embryo culture media from one cell to the blastocyst stage and the subsequent embryo transfer to surrogate females are able to proceed through post-implantation development and, after birth, develop into healthy mice. However, culture of embryos in differently aged media shows various (often unpredictable) results. To find the optimal storage conditions of culture media, we suggest that the freezing and long-term storage of these media at - 80°C will not influence the quality of the media. To test this hypothesis, we grew embryos from one cell to blastocysts in vitro in the selected media after thawing and subsequently transferring them to surrogate females. Embryo culture in these four media after thawing does not affect preimplantation and postnatal mouse development. Thus, we have shown that storage of embryo culture media at low temperature (- 80°C) does not impact the quality of the media, and subsequently, it can be used for the culture of embryos for the full preimplantation period, the same as in fresh media.

The details matter: personalized prediction of live birth after in vitro fertilization in women with polycystic ovary syndrome

ObjectiveTo derive and internally validate a clinical prediction model for live birth in women with polycystic ovary syndrome (PCOS) undergoing in-vitro fertilization (IVF) DesignRetrospective cohort study SettingFour academic reproductive endocrinology clinics Patients207 women with PCOS confirmed by Rotterdam criteria undergoing their first fresh IVF cycle InterventionsNone Main Outcome MeasureThe primary outcome was cumulative live birth (LB) per IVF cycle start. This included any LB that resulted from either fresh embryo transfer or any subsequent frozen embryo transfer from embryos obtained at the index oocyte retrieval. A prediction model was derived using multivariable logistic regression. Covariates considered for inclusion in the prediction model included demographic characteristics, medical history, and prior fertility treatment. Predicted probabilities for live birth were calculated using the prediction model which included the 90% shrinkage factor for each adjusted OR. ResultsThe final model, based on maximization of the area under the receiver operating characteristic curve (AUROC), included age <35 years, White race, presence of polycystic ovaries on ultrasound (PCOM), normal BMI (<25 kg/m2), being metabolically healthy (no metabolic risk factors), and being a non-responder to ovulation induction (OI) agents including letrozole and clomiphene citrate. The AUROC for the model was 0.68 (95% CI: 0.60, 0.77). Predicted probabilities of live birth ranged from 8.1% (95% CI 2.8, 21.5) for a woman who had no favorable predictors to 74.2% (95% CI: 59.5, 84.9) for a woman who had all favorable predictors. ConclusionOur study demonstrates that in addition to anovulation, the underlying pathophysiology and associated co-morbidities alter the likelihood of a successful pregnancy in women with PCOS undergoing IVF. Further validation of this model is needed before it, can serve as a tool to personalize prediction estimates for probability of live birth in women with PCOS.

Management strategies following implantation failure of euploid embryos.

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

Follitropin Alpha versus Follitropin Beta in IVF/ICSI Cycle: A Retrospective Cohort Study.

The purpose of this study was to compare the efficacy of Follitropin alpha (Gonal-F) and Follitropin beta (Puregon) on cumulative live birth rate (CLBR), defined as the percentage of the number of patients who delivered for the first time in a single ovarian stimulation cycle and the number of patients in all oocyte retrieval cycles. A retrospective cohort study including 2864 infertile patients who underwent ovarian stimulation with Puregon (group A, n=1313) and Gonal-F (group B, n=1551) was conducted between July 2015 and June 2021 at a university-affiliated reproductive medicine center. Reduce potential confounding factors between groups, propensity scores and multivariable logistic regression analyses were estimated to obtain unbiased estimates of outcomes. The primary outcome was the difference in CLBR between the two groups. Each group identified 1160 individuals after propensity score matching (PSM). Baseline characteristics were similar between groups after PSM. The total gonadotrophin (Gn) dose (2400 vs 2325), p=0.038) and cost of Gn usage (5327.9¥ vs 7547.2¥, p<0.001) between the Puregon and Gonal-F groups were statistically significant. Nevertheless, the pregnancy outcomes between the two groups were comparable after fresh embryo transfer and subsequent frozen-thawed embryo transfer. Additionally, there was also no difference observed in the primary outcome of CLBR (52.8% vs 55.7%, p=0.169). Multivariable regression analysis revealed that the type of Gn was not associated with CLBR (p = 0.912). Gonal-F may be a reasonable option for infertile patients who are hesitant to receive more Gn dosage injections. Furthermore, Puregon can eliminate unneeded anxiety and expenses while also administering more flexibility. Taken together, these findings could well be utilized in everyday clinical practice to better inform patients when deciding on an ovarian stimulation strategy.

THE RESISTANCE OF OOCYTES AND IN VITRO PRODUCED CATTLE EMBRYOS TO CRYOPRESERVATION

In vitro fertilization and production of bovine embryos in vitro is method, which improves utilization of animal reproduction potential. In connection with cryopreservation methods and ability of long-term cryostorage of embryos offers suitable tool for positive influence of endangered species or breeds. In vitro embryo production with subsequent embryo transfer contributes to the improvement of reproduction rates and bypassing some reproduction failure in high productive animal breeding. The method is generally used for in vitro production of transferable bovine embryos. Worldwide about 411 000 of IVP bovine embryos are annually transferred to recipients (IETS, 2013). Most of them were transferred immediately after producing, which is difficult for organization and synchronization of animals. In contrast to this possibility the storage of embryos for later using brings undisputable advantages. In order to protect animal genetic resources and to preserve the gene pool of rare and endangered animals, it is necessary to establish gene banks containing stocks of gametes and embryos of these animals. Optimization of the methods of in vitro production of bovine embryos and increasing their resistance to cryopreservation process is an actual challenge to ensure long-term storage in the gene bank of animal resources. The main goal of this mini-review is to provide general insight into the task of oocyte and embryo resistance to cryopreservation.

Transcriptomic signature of luteinized cumulus cells of oocytes developing to live birth after women received intracytoplasmic sperm injection

ObjectiveTo compare the transcriptome of human cumulus cells (CCs) from oocytes with different outcomes (pregnancy yes/no, live birth yes/no), to identify noninvasive biomarkers for oocyte selection as well as new therapeutic targets to increase live birth rates from assisted reproductive technologies (ART). DesignRetrospective observational study. SubjectsSubfertile couples undergoing controlled ovarian superstimulation and intracytoplasmic sperm injection (ICSI) with subsequent unbiopsied embryo transfer (ET) below the female age of 43 years. Intervention(s)RNA sequencing (RNA-seq) of CCs from oocytes resulting in a pregnancy, no pregnancy, live birth and no live birth. Main outcome MeasuresDifferential gene expression (DEG) between CCs of oocytes resulting in A) “no pregnancy” versus “pregnancy” and B) “pregnancy only” versus “live birth”. ResultsWhile RNAseq did not reveal DEGs when comparing the transcriptomic profiles of the groups “no pregnancy” with “ pregnancy”, we identified 139 DEGs by comparing “pregnancy only” with “live birth” of which 28 belonged to clusters relevant to successful ART outcomes (i.e. CTGF, SERPINE2, PCK1, HHIP, HS3ST, BIRC5). A functional enrichment analysis revealed that the transcriptome of CCs associated with live birth depicts pathways of extracellular matrix, inflammatory cascades leading to ovulation, cell patterning, proliferation and differentiation, and silencing pathways leading to apoptosis. ConclusionWe identified a CCs transcriptomic profile associated with live birth after ET that, after further validation, could serve to predict successful ART outcomes. The definition of relevant pathways of CCs related to oocyte competency contributes to a broader understanding of the cumulus oocyte complex to identify further therapeutic targets for improving ART success.

Pregnancy Rates after Hysteroscopic Endometrial Polypectomy versus Endometrial Curettage Polypectomy: A Retrospective Study.

Background and Objectives: A relationship between endometrial polypectomy and in vitro fertilization (IVF) pregnancy outcomes has been reported; however, only a few studies have compared polyp removal techniques and pregnancy rates. We investigated whether different polypectomy techniques with endometrial curettage and hysteroscopic polypectomy for endometrial polyps affect subsequent pregnancy outcomes. Materials and Methods: Data from 434 patients who had undergone polypectomy for suspected endometrial polyps using transvaginal ultrasonography before embryo transfer in IVF at four institutions between January 2017 and December 2020 were retrospectively analyzed. Overall, there were 157 and 277 patients in the hysteroscopic (mean age: 35.0 years) and curettage (mean age: 37.3 years) groups, respectively. Single-blastocyst transfer cases were selected from both groups and age-matched to unify background factors. Results: In the single-blastocyst transfer cases, 148 (mean age: 35.0 years) and 196 (mean age: 35.9 years) were in the hysteroscopic and curettage groups, respectively, with the 148 cases matched by age. In these cases, the pregnancy rates for the first embryo transfer were 68.2% (odds ratio (OR): 2.14) and 51.4% (OR: 1.06) in the hysteroscopic and curettage groups, respectively; the resulting OR was 2.03. The pregnancy rates after up to the second transfer were 80.4% (OR: 4.10) and 68.2% (OR: 2.14) in the hysteroscopic and curettage groups, respectively, in which the OR was 1.91. The live birth rates were 66.2% (OR: 1.956) and 53.4% (OR: 1.15) in the hysteroscopic and curettage groups, respectively, in which the odds ratio was 1.71. These results show the effectiveness of hysteroscopic endometrial polypectomy compared to polypectomy with endometrial curettage. No significant difference was found regarding the miscarriage rates between the two groups. Conclusions: Hysteroscopic endometrial polypectomy resulted in a higher pregnancy rate in subsequent embryo transfer than polypectomy with endometrial curettage. Therefore, establishing a facility where polypectomy can be performed hysteroscopically is crucial.