Transfer Of Good Quality Embryos Research Articles

Immunotherapy is a new opportunity for managing patients with “thin” endometrium in cycles of transfer of thawed embryos

The trend of recent decades has been the search for therapeutic effects on the so-called “thin” endometrium. However, to date there is no optimal management scheme for patients with “thin” endometrium in assisted reproductive technology programs. Aim: to evaluate the effectiveness of using recombinant IL-2 before cryotransfer in women of late reproductive age with “thin” endometrium and repeated implantation failure after transfer of good quality embryos. The study included 63 patients of late reproductive age with “thin” endometrium. The first group consisted of 25 patients of late reproductive age with a history of unsuccessful in vitro fertilization programs with good quality embryos. Cryotransfer to the patients of the first group was carried out in a modified natural cycle. The second group included 38 women of late reproductive age with a history of unsuccessful in vitro fertilization programs with good quality embryos. Cryotransfer for women of the second group was carried out in a cycle with hormone replacement therapy. Recombinant IL-2 in the cycle before cryotransfer were prescribed to all women. In both groups, implantation, clinical pregnancy, and live birth rates following administration of recombinant IL-2 were valuable. In both groups, the implantation rate, clinical pregnancy rate and live birth rate were assessed after administration of recombinant IL-2. Statistical data processing was performed using application software package Statistica 6.0 (StatSoft, Ink. 1994-2001), adapted for biomedical research. p 0.05 was considered significant. After recombinant IL-2 treatment of patients with infertility and thin endometrium, endometrial thickness increases statistically significantly in the first two menstrual cycles after treatment, so transfer of thawed embryos should be planned in the first two menstrual cycles after immunotherapy. In order to increase the thickness of the endometrium during cryotransfer in a modified natural cycle, as well as in a cycle with replacement hormone therapy, recombinant IL-2 can be used in women with “thin” endometrium with repeated unsuccessful implantation attempts when transferring good quality embryos. Cryotransfer should be performed in the first two menstrual cycles after immunotherapy.

Complex preparation of patients with recurrent implantation failure for the transfer of good quality embryos in ivf-et cycles

Complex preparation of patients with recurrent implantation failure for the transfer of good quality embryos in ivf-et cycles

Clinical outcomes of fresh and frozen embryos transfer after in vitro fertilization in spouses of patients with severely low sperm concentration and motility.

To compare the pregnancy and neonatal outcomes of in vitro fertilization-embryo transfer (IVF-ET) with fresh or frozen embryos in spouses of patients with severely low sperm concentration and motility. A total of 2300 patients whose spouses have severely low sperm concentration and motility underwent IVT-ET in the Reproduction Medicine Center, Sir Run Run Shaw Hospital from April 2018 to April 2022. After applying the propensity score matching (PSM), 473 fresh embryo transferred cycles and 473 frozen embryo transferred cycles were selected for the study, and the pregnancy and neonatal outcomes were compared between the two groups. There were no significant differences in pregnancy outcomes and neonatal outcomes between fresh and frozen embryo groups (all P>0.05). In the stratification analysis, the number of retrieved oocytes in the fresh good-quality embryo transfer group was significantly increased compared with the fresh poor-quality embryo group (P<0.05), but the very early pregnancy loss rates were similar between the two groups (P>0.05), while the rate in fresh good-quality embryo transfer group was significantly higher than that in the frozen good-quality embryo transfer group (P<0.05). Among different age groups of women, the number of retrieved oocytes and the level of estrogen in the fresh embryo transfer group was significantly higher in the 20 to <30 years old group than that in the 30 to <35 years old group (both P<0.05), but the clinical pregnancy rate was lower in the 20 to <30 years old group than that in the 30 to <35 years old group (P>0.05). Additionally, the very early pregnancy loss was significantly increased in the fresh embryo group compared with the frozen embryo group in the 20 to <30 years age group (P<0.05). There were no significant differences in pregnancy and neonatal outcomes between fresh and frozen embryo transfer in spouses of patients with severely low sperm concentration and motility undergoing IVF-ET. Due to the shorter transfer times, less embryo freezing damage and reduced costs, fresh embryo transfer can be considered as the first choice. However, it is not necessary to pursue fresh embryo transfer if maternal oestrogen levels are too high and there is a tendency of overstimulation.

Impact of inclusion of a poor-quality embryo with a good-quality embryo on pregnancy outcomes in vitrified-warmed blastocyst transfers

Research questionDoes the co-transfer of a good-quality embryo and a poor-quality embryo influence pregnancy outcomes in comparison to the transfer of a single good-quality embryo in vitrified-warmed blastocyst transfer cycles? DesignThis retrospective cohort study involved a total of 11,738 women who underwent IVF/intracytoplasmic sperm injection cycles and vitrified-warmed blastocyst transfer at a tertiary-care academic medical from January 2015 to June 2022. The study population was categorized into two groups: single-blastocyst transfer (SBT; participants who underwent single good-quality embryo transfer, n = 9338) versus double-blastocyst transfer (DBT; participants who underwent transfers with a poor and a good-quality embryo, n = 2400). ResultsThe live birth rate (LBR) was significantly higher in the DBT group in comparison with the SBT group (65.6% versus 56.3%, P < 0.001). Multivariable logistic regression analysis showed that DBT was an independent predictor for LBR with a strong potential impact (adjusted odds ratio 1.55, 95% confidence interval 1.41–1.71; P < 0.001). However, the multiple birth rate was significantly higher in the good-quality embryo and poor-quality embryo group compared with patients undergoing a single good-quality embryo transfer (41.4% versus 1.8%; P < 0.001). ConclusionsIn vitrified-warmed blastocyst transfer cycles, LBR was higher following DBT with one good-quality and one poor-quality embryo compared with SBT. However, this was at the expense of a marked increase in the likelihood of multiple gestations. Physicians should still balance the benefits and risks of double-embryo transfer.

Effect of baseline prolactin levels on the pregnancy outcomes after fresh embryo transfer.

There is clinical disagreement on whether to treat hyperprolactinemia with medication before embryo transfer. The aim of this study is to identify the impact of basal prolactin (PRL) levels on pregnancy outcomes in fresh embryo transfer cycles. This retrospective study involved 2,648 women who underwent basal PRL level testing and fresh embryo transfer between January 2015 and December 2020 at our Hospital's Department of Assisted Reproduction. Basal PRL levels can be classified into three categories:<30 (n=2339), 30‑60 (n=255), and ≥60 (n=54) µg/l. Pregnancy outcome was defined as the primary outcome measure, and the live birth rate was defined as the second outcome measure. Subsequently, univariate and multivariable logistic regression analysis was used to reveal the association between basal PRL levels and pregnancy outcomes after considering several potential confounding factors. Elevated basal PRL levels were found not a risk factor for pregnancy outcomes in patients receiving good-quality embryo transfer (p>.05). For pregnancy or not, female age (OR: 1.03; 95% CI: 1.01-1.05), embryos transferred (OR: 0.52; 95% CI: 0.41-0.65), and normal fertilization rate (OR: 0.68; 95% CI: 0.48-0.97) were found to be an independent risk factor. For ongoing pregnancy or not, female age (OR: 1.07; 95% CI: 1.03-1.11), embryos transferred (OR: 0.57; 95% CI: 0.37-0.88), and menstrual cycle (OR: 1.76; 95% CI: 1.22-2.54) were also independent risk factors. There is no adverse impact on pregnancy outcomes during embryo transfer cycles with good-quality embryos when PRL levels are elevated.

#141 : Enhanced Luteal Support Following IVF/ICSI for Women with Two or More Good-Quality Embryo Transfer Failures Using Both Subcutaneous and Vaginal Progesterone: A Retrospective Cohort Study

Background and Aims: Utilizing progesterone to support the luteal phase (LP) in in vitro fertilization is a well-established practice. Subcutaneous progesterone (SC-P) administration has shown pregnancy rates comparable to vaginal progesterone (Vag-P). However, data are not available regarding the efficacy of combining SC-P with Vag-P for women with multiple good-quality embryo transfer (ET) failures. Therefore, this study aims to evaluate the effectiveness of adding SC-P to Vag-P in women who had not conceived following two or more good-quality ETs. Method: A retrospective cohort analysis of data collected from a university-affiliated fertility centre in the UK between January 2020 to May 2022. A total of 224 embryo transfer cycles, including 65 fresh embryo transfer (fresh-ET) cycles and 159 frozen embryo transfer (FET) cycles in women who had not conceived or experienced miscarriages following two or more good-quality ETs, were analysed. The luteal support protocol was either micronized Vag-P (gel 90mg daily in fresh-ET cycles or pessaries 800mg daily in FET cycles) plus SC-P 25mg once daily (enhanced group) or Vag-P alone (control group). The pregnancy outcomes between the two groups were compared. Clinical pregnancy rates (CPR) represented the primary outcome. Results: In fresh-ET cycles, the enhanced group resulted in higher CPR than the control group. However, statistical significance was not achieved (40% (14/35) vs. 30% (9/30), p=0.40; multivariate analysis adjusted OR 1.54, 95% CI 0.48–4.93, p=0.468). In FET cycles, CPRs were comparable between the enhanced group and the control group (32.3% (21/65) vs. 31.9 % (30/94), p=0.958; multivariate analysis adjusted OR 0.98, 95% CI 0.47–2.03, p=0.953). In both fresh and frozen cycles, no significant difference was observed regarding the positive pregnancy test and miscarriage rates between the two groups. Conclusion: Adding SC-P to Vag-P did not improve pregnancy outcomes for women who had not conceived following two or more good-quality ETs.

Serum steroid metabolome on the day of oocyte retrieval in women with polycystic ovarian syndrome and its association with pregnancy outcome of in vitro fertilization

Steroid hormone level is a crucial factor affecting the outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). The purpose of this study was to evaluate serum steroid metabolome on the day of oocyte retrieval in women with polycystic ovarian syndrome (PCOS) and explore whether specific steroids can be potential indicators to improve the prediction of pregnancy outcomes in PCOS patients undergoing IVF/ICSI. In this study, the serum levels of 21 steroids in 89 women with PCOS and 73 control women without PCOS on the day of oocyte retrieval of the first IVF/ICSI treatment cycle were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). All patients subsequently received good-quality embryo transfer, and the correlation between their steroid profiles and pregnancy outcomes of the first embryo transfer (ET) was retrospectively analyzed. We found PCOS patients had aberrant levels of 11 out of 21 steroid hormones compared to control individuals, with androgen steroid hormones being considerably enhanced. Enzyme activity evaluation indicated that PCOS women might have abnormal activity of CYP17A1, CYP21A2, CYP11B2, CYP19A1, HSD3B, HSD11B, and HSD17B. Additionally, the level of 18-hydroxycorticosterone (p = 0.014), corticosterone (p = 0.035), and 17-hydroxypregnenolone (p = 0.005) were markedly higher in live birth group than in non- live birth group for PCOS women following frozen embryo transfer (FET). Multiple logistic regressions indicated that 18-hydrocorticosterone and 17-hydroxypregnenolone were independently associated with live birth outcomes of PCOS women following FET. Receiver operating characteristic (ROC) curve analysis revealed that 0.595 ng/mL for 18-hydrocorticosterone level (AUC: 0.6936, p = 0.014).and 2.829 ng/mL for 17-hydroxypregnenolone level (AUC: 0.7215, p = 0.005) were the best cutoff values to predict live birth outcomes of PCOS. In conclusion, the blood steroid metabolome was closely related to the IVF/ICSI outcomes of PCOS patients. 18-hydroxycorticosterone and 17-hydroxypregnenolone might be potential indicators to predict pregnancy outcomes of PCOS undergoing IVF/ICSI treatment.

Endometrial stromal cells from women with repeated implantation failure display impaired invasion towards trophoblastic spheroids.

Implantation failure can occur even after the transfer of good-quality embryos. This study showed that the migration of human endometrial stromal cells towards embryonic trophoblasts is higher in women with live births in the first in vitro fertilization cycle than those with repeated implantation failure, suggesting that the chemotactic response of stroma cells is associated with successful pregnancy. The success rate of in vitro fertilization (IVF) remains limited in some women despite transfers of good-quality embryos in repeated attempts. There is no reliable tool for assessing endometrial receptivity. This study aimed to assess the interaction between decidualized human primary endometrial stromal cells (1°-EnSC) and human embryonic stem cell-derived trophoblastic spheroids (BAP-EB) and to compare the invasion ability of decidualized 1°-EnSC towards BAP-EB between women attaining live birth in the first IVF cycle and those with repeated implantation failure (RIF). The invasion of the decidualized human endometrial cell line (T-HESC) and 1°-EnSC towards BAP-EB was studied. Real-time quantitative PCR and immunocytochemistry were employed to determine the expression of decidualization markers at mRNA and protein levels, respectively. Trophoblast-like BAP-EB-96h, instead of early trophectoderm (TE)-like BAP-EB-48h, facilitated the invasion ability of decidualized T-HESC and decidualized 1°-EnSC. Human chorionic gonadotropin at supra-physiological levels promoted the invasiveness of decidualized 1°-EnSC. The extent of BAP-EB-96h-induced invasion was significantly stronger in decidualized 1°-EnSC from women who had a live birth in the first IVF cycle when compared to those with RIF. While no difference was found in the expression of decidualization markers, PRL and IGFBP1 among two groups of women, significantly lower HLA-B was detected in the non-decidualized and decidualized 1°-EnSC from women with RIF. Collectively, the findings suggested that the invasion of decidualized 1°-EnSC towards trophoblast-like BAP-EB-96h was higher in women who had a live birth in the first IVF cycle than those with RIF.

Сравнительный анализ эффективности и безопасности гестагенов в поддержке лютеиновой фазы в свежих циклах ЭКО/ИКСИ с переносом одного эмбриона

Objective. To study the efficacy and safety of dydrogesterone and micronized vaginal progesterone for luteal phase support in fresh IVF/ICSI cycles with single embryo transfer. Patients and methods. A retrospective comparative analysis including 146 women aged 23 to 44 years who entered an assisted reproductive technology (ART) program in 2020 was performed. Patients were divided into two groups: group 1 (n = 67) received dydrogesterone for luteal phase (LP) support in ART, while group 2 (n = 79) received micronized vaginal progesterone (MVP). All patients underwent a single good-quality embryo transfer in a fresh IVF/ICSI cycle. The rate of clinical pregnancy was considered as the primary endpoint, while the rate of live births and the safety profile of medications for mothers and neonates were considered as secondary endpoints. In addition, the incidence of adverse events with dydrogesterone and MVP was evaluated. Results. Clinical pregnancy and live birth rates with dydrogesterone as LP support in ART programs were 25/67 and 19/67 (37.3% and 28.4%, respectively), with MVP – 27/79 and 19/79 (34.2% and 24.1%, respectively). Thus, there was a tendency to improve the results of ART programs in the dydrogesterone group, but no statistically significant difference in outcomes was found (p &gt; 0.05). In the MVP group, one child was diagnosed with a malformation, syndactyly of the second and third toes. In the dydrogesterone group, one term stillbirth was registered due to chronic fetoplacental insufficiency and intrauterine growth restriction (IUGR). The suspected cause of pathological changes was COVID-19 at 30 weeks’ gestation. Based on the global report, the background risk of congenital malformations due to environmental and genetic factors is 6% of worldwide births. The results obtained did not exceed the population average, indicating a high safety profile of gestagens for a fetus in both groups. The incidence of side effects and adverse reactions was significantly lower in the group of women receiving dydrogesterone compared to MVP (3/67 (4.5%) and 11/79 (13.9%) cases, respectively, p &lt;0.05). Conclusion. LP support with gestagens in fresh IVF/ICSI cycles with single embryo transfer showed comparable efficacy. Oral dydrogesterone therapy tended to increase the rate of clinical pregnancy and live births in IVF/ICSI cycles with single embryo transfer and demonstrated a favorable safety profile. The benefits of dydrogesterone included good tolerability and positive patient satisfaction. The oral route of dydrogesterone administration was reported as the most preferred one among patients and physicians. Key words: ART cycles, single embryo transfer, gestagens, dydrogesterone, micronized progesterone

Growth hormone inhibits the JAK/STAT3 pathway by regulating SOCS1 in endometrial cells in vitro: a clue to enhance endometrial receptivity in recurrent implantation failure.

Recurrent implantation failure (RIF) is defined as failure to achieve clinical pregnancy after at least 3 transfers of good-quality embryos by natural or artificial means. RIF is often a complex problem with a wide variety of etiologies and mechanisms as well as treatment options. In this study, using immunohistochemistry and Western blot, we demonstrated that the expression of leukemia inhibitory factor (LIF), Janus kinase 1 (JAK1), and signal transducer and activator of transcription 3 (STAT3) was increased, while that of suppressor of cytokine signaling 1 (SOCS1) was decreased in RIF patients. Growth hormone (GH) administration proved to have positive effects on embryo implantation in RIF patients, but the action mechanism of GH has not been elucidated yet. To this aim, we studied the effects of GH on the proliferation in vitro of endometrial adenocarcinoma Ishikawa cells. GH stimulated the expression of LIF and SOCS1, and through SOCS1 inhibits the expression of phosphorylated STAT3, and finally inhibits the occurrence of RIF. Excessive phosphorylation of STAT can lead to decreased endometrial receptivity and abnormal embryo implantation. We also examined the effects of LIF overexpression and an LIF inhibitor (EC330) on the JAK/STAT pathway. LIF promoted cell proliferation, and the up-regulation of LIF increased the expression of SOCS1 and JAK1/STAT3 pathway-related genes in Ishikawa cells. As GH can inhibit the JAK1/STAT3 pathway through LIF, we hypothesize that upregulating SOCS1 may be a potential approach to treat RIF at the molecular level. GH can inhibit the JAK1/STAT3 pathway through LIF, up-regulating SOCS1 to treat RIF at the molecular level.

Prediction of risk factors for first trimester pregnancy loss in frozen-thawed good-quality embryo transfer cycles using machine learning algorithms.

Can the risk factors that cause first trimester pregnancy loss in good-quality frozen-thawed embryo transfer (FET) cycles be predicted using machine learning algorithms? This is a retrospective cohort study conducted at Sisli Memorial Hospital, ART and Reproductive Genetics Center, between January 2011 and May 2021. A total of 3805 good-quality FET cycles were included in the study. First trimester pregnancy loss rates were evaluated according to female age, paternal age, body mass index (BMI), diagnosis of infertility, endometrial preparation protocols (natural/artificial), embryo quality (top/good), presence of polycystic ovarian syndrome (PCOS), history of recurrent pregnancy loss (RPL), recurrent implantation failure (RIF), severe male infertility, adenomyosis and endometriosis. The first trimester pregnancy loss rate was 18.2% (693/ 3805). The presence of RPL increased first trimester pregnancy loss (OR = 7.729, 95%CI = 5.908-10.142, P = 0.000). BMI, which is > 30, increased first trimester pregnancy loss compared to < 25 (OR = 1.418, 95%CI = 1.025-1.950, P = 0.033). Endometrial preparation with artificial cycle increased first trimester pregnancy loss compared to natural cycle (OR = 2.101, 95%CI = 1.630-2.723, P = 0.000). Female age, which is 35-37, increased first trimester pregnancy loss compared to < 30 (OR = 1.617, 95%CI = 1.120-2.316, P = 0.018), and female age, which is > 37, increased first trimester pregnancy loss compared to < 30 (OR = 2.286, 95%CI = 1.146-4,38, P = 0.016). The presence of PCOS increased first trimester pregnancy loss (OR = 1.693, 95%CI = 1.198-2.390, P = 0.002). The number of previous IVF cycles, which is > 3, increased first trimester pregnancy loss compared to < 3 (OR = 2.182, 95%CI = 1.708-2.790, P = 0.000). History of RPL, RIF, advanced female age, presence of PCOS, and high BMI (> 30kg/m2) were the factors that increased first trimester pregnancy loss.

Potential of Plasma Rich in Growth Factors (PRGF-Endoret) to Enhance the Efficacy of Assisted Reproductive Techniques in Refractory Cases.

Aim: Nowadays, infertility problems affect a high percentage of couples. This study aimed to evaluate the effect of plasma rich in growth factors (PRGF-Endoret, hereafter PRGF) as a promising coadjuvant therapy in assisted reproductive techniques and its possible role in implantation and pregnancy rates. This retrospective study included 36 PRGF cycles in 27 women with one of the following reproductive disorders: recurrent implantation failure (n = 16), repeated abortion (n = 8), and thin endometrium (n = 3).Methods: PRGF was obtained from each patient and administered as three consecutive intrauterine instillations. The endometrial thickness was measured after each PRGF infusion and a good-quality embryo transfer was performed for every patient. Endometrial thickness, biochemical pregnancy, and miscarriage rate were the primary measured outcomes.Results: PRGF increased the endometrial growth respecting the initial thickness in all cases. The biochemical pregnancy rate determined as positive beta-human chorionic gonadotropin (β-hCG) was 59%, considering the total number of patients; the ongoing pregnancy percentage was 48%. PRGF application day was relevant with a significant probability of achieving pregnancy (p < 0.01) when the first PRGF infusion was carried out beyond 6.5 days after the first day of the woman's cycle and the second one beyond 9.5 days of the menstrual cycle.Conclusions: Intrauterine autologous PRGF infusion is a safe, easily accessible, and inexpensive therapy that could collaborate in fertility treatments by optimizing the endometrium for implantation and thus favoring the crosstalk between the embryo and the uterus improving the embryo-maternal dialogue.

Embryo morphologic quality in relation to the metabolic and cognitive development of singletons conceived by in vitro fertilization and intracytoplasmic sperm injection: a matched cohort study

Embryos with higher morphologic quality grading may have a greater potential to achieve clinical pregnancy that leads to a live birth regardless of the type of cleavage-stage embryos or blastocysts. Few studies have investigated the impacts of embryo grading on the long-term health of the offspring. This pilot study aimed to examine the associations between embryo morphologic quality and the physical, metabolic, and cognitive development of singletons conceived by invitro fertilization and intracytoplasmic sperm injection at preschool age. This matched cohort study included singletons born to infertile couples who underwent fresh cleavage-stage embryo transfer cycles with good- or poor-quality embryos from 2014 to 2016 at the reproductive center of the Women's Hospital, School of Medicine, Zhejiang University. A total of 144 children, aged 4 to 6 years, participated in the follow-up assessment from 2020 to 2021, and the response rate of poor-quality embryo offspring was 39%. Singletons in the good-quality embryo group were matched with singletons in the poor-quality embryo group at a 2:1 ratio according to the fertilization method and the children's age (±1 year). We measured the offspring's height, weight, body mass index, blood pressure, thyroid hormone levels, and metabolic indicators. Neurodevelopmental assessments were performed using the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition, and the Adaptive Behavior Assessment System, Second Edition. We also collected data from the medical records. A linear regression model was used to analyze the association between embryo morphologic quality and offspring health outcomes. A total of 48 singletons conceived with poor-quality embryo transfer and 96 matched singletons conceived with good-quality embryo transfer were included in the final analysis. Age, sex, height, weight, body mass index, blood pressure, thyroid function, and metabolic indicators were comparable between the 2 groups. After adjustment for potential risk factors by linear regression model 1 and model 2, poor-quality embryo offspring exhibited a tendency toward higher free thyroxine levels than offspring of good-quality embryo transfers (beta, 0.22; 95% confidence interval, 0.09-0.90; beta, 0.22; 95% confidence interval, 0.09-0.91, respectively), but this difference was not clinically significant. Regarding neurodevelopmental assessments, there was no difference in the full-scale intelligence quotient based on the Wechsler Preschool and Primary Scale of Intelligence (109.96±12.42 vs 109.60±14.46; P=.88) or the general adaptive index based on the Adaptive Behavior Assessment System (108.26±11.70 vs 108.08±13.44; P=.94) between the 2 groups. The subindices of the 2 tests were also comparable. These findings remained after linear regression analysis. At 4 to 6 years of age, singletons born from poor-quality embryo transfers have comparable metabolic and cognitive development as those born from good-quality embryo transfers using fresh cleavage-stage embryos. The results of this pilot study indicate that poor-quality embryos that can survive implantation and end in live birth are likely to have a developmental potential comparable to that of good-quality embryos.

Evaluation of IL-1β and TNF-α level in endometrial flush in patients with recurrent implantation failure

Infertility is defined as the inability to conceive within a year of regular unprotected intercourse affecting one in six couples. The most common causes of infertility are ovulatory dysfunction, male factor infertility, and tubal disease [1]. Unexplained Infertility (UI) and Recurrent Implantation Failure (RIF) are diagnoses based on failed pregnancy attempts with current infertility treatment options. UI is diagnosed when testing is inconclusive and RIF is diagnosed after three failed In Vitro Fertilization (IVF) cycles. UI is the absence of conception despite 12 months of unprotected intercourse, not explained by anovulation, poor sperm quality, tubal pathology or other known cause of infertility. RIF is defined by three failed IVF cycles in which one or two high-quality embryos are transferred in each cycle or by two failures in oocyte donor recipients after the transfer of good quality embryos [1]. UI is a common cause of infertility affecting 10-30% of infertile couples [2], while RIF is present in around 10% of in vitro fertilization (IVF) cycles [3].

Endometrial and vaginal microbiomes influence assisted reproductive technology outcomes.

The role of Lactobacillus-dominant microbiota in the endometrium in reproductive function is unclear. We therefore aimed to explore the impact of the balance of Lactobacillus and pathological bacteria in the endometrial and vaginal microbiomes on the pregnancy outcomes of women treated with assisted reproductive technology (ART). This study included 35 women with infertility submitted to good-quality embryo transfers. The cutoff values for abundance of Lactobacillus species (spp.) and pathological bacteria in the endometrium and vagina were calculated. Women with Lactobacillus spp. and pathological bacteria abundance above the cutoff values were categorized in the high-abundance group, whereas those with abundance below cutoff values were categorized in the low abundance group. We divided the patients into four groups based on the combination of high/low abundance of Lactobacillus spp. and pathological bacteria. The 35 cases of good-quality embryo transfer resulted in 21 pregnancies. Pregnant women were present in significantly higher proportions in the high Lactobacillus spp. abundance and low pathological bacteria abundance group, whereas the opposite combination (i.e., low Lactobacillus spp. abundance and high pathological bacteria abundance) saw a significantly higher proportion of nonpregnant women (p=0.022). The balance between Lactobacillus and pathological bacterial abundance in the endometrial and vaginal microbiomes is associated with pregnancy from ART.

P–423 Lower cytotoxicity: Altered natural killer cell activation in recurrent implantation failure

Abstract Study question Within this prospective study, we aim to differentiate immune cell subpopulations in recurrent implantation failure (RIF) patients and fertile controls. Summary answer A misbalanced immune profile of NK cell subpopulations is present in RIF patients and might be a potential risk factor that requires further detailed analysis. What is known already So far, there is no conclusive opinion on the prognostic value of testing immune cell populations in women with RIF. Increased numbers of cytotoxic (CD56dimCD16bright) peripheral natural killer (pNK)-cells and CD56brightCD16dim mainly in the uterus occurring NK cells (uNK) seemed to be more prevalent in RIF patients. NK cell cytotoxicity is regulated by a complex interaction of activating and inhibiting receptors, such as the NKGD2 and natural cytotoxicity receptors including NKp46, NKp30 and NKp44. Dysregulated pNK cells could affect the adhesion and implantation of the embryo thereby contributing to RIF. Study design, size, duration Within this prospective study between March 2018 and August 2020 immune diagnostics of pNK cells and subpopulations as well as regulatory T-cells in RIF patients (defined as ≥ 3 failed fresh or frozen embryo transfers of good quality embryos (Istanbul criteria) and non-pregnant controls (nulli- and multipara) were performed using flow cytometry analysis. Participants/materials, setting, methods In total, n = 42 RIF and n = 85 controls were included. Absolute numbers and percentages of total lymphocytes of CD56dimCD16bright, CD56brightCD16dim NK cells, CD45+CD25+FoxP3+-regulatory T-cells and activation markers (CD57+, CD62L+, NKGD2+, NKp46+) were measured in patients and controls (n = 60 nulligravida, n = 25 para) in the mid-luteal phase. Statistical analysis was performed using SPSS Version 26 considering p &amp;lt; 0.05 statistically significant. Main results and the role of chance RIF patients showed significantly lower numbers and percentages of CD56dimCD16bright pNK cells (mean±SD per µl: 187,5±113,3 vs. 281,9±163,4 p = 0.001;%: 87,4±8,8 vs. 90,6±6,0 p = 0.017) and higher levels of CD56brightCD16dim pNK cells (mean±SD per%: 10,5±8,3 vs. 7,6±5,5 p = 0.021) compared to controls. Further, lower percentages of CD56dimCD16brightCD62L + (mean±SD per%: 23,5±11,1 vs. 32,0±14,0 p = 0.001), CD56dimCD16brightNKGD2 + (mean±SD per%: 94,0±6,8 vs. 96,4±4,2 p = 0.014) and CD56dimCD16brightNKp46 + (mean±SD per%: 65,8±19,5 vs. 76,1±14,0 p = 0.001) were observed in RIF patients (p &amp;lt; 0.05). A different activation of pNK cells represented by high levels of CD62L+, NKGD2+, NKp46+ surface markers in controls and higher levels of CD56brightCD16dim pNK cells in RIF patients could contribute to RIF. No difference was present in levels of CD45+CD25+FoxP3+-regulatory T-cells within the study population. Limitations, reasons for caution As controls composed out of not only nulli- but also multipara, higher levels of pNK cells in controls, could be induced by fetal microchimerism in multiparas, however, results remained significant after removing multipara from statistical analysis. Wider implications of the findings: These findings condense into the assumption of a non-linear association between NK cytotoxicity and successful pregnancy. A lower NK cytotoxicity in RIF patients could potentially lead to an altered immune environment impeding a successful implantation process. Trial registration number Drks00020803

P–575 Patients with recurrent implantation failures (RIF): chromosome abnormalities in the resulting embryos

Abstract Study question Do RIF patients have the preimplantation genetic testing for aneuploidy (PGT-A) overcome their infertility condition? Summary answer PGT-A positively impact on implantation rate in RIF patients What is known already The most common definition of RIF is failure to achieve a pregnancy after three consecutive transfers of good quality embryos. This term possibly represents a heterogeneous category of infertile couples as the causes of repeated failures can be diverse. Especially intriguing is the case of patients with an age lower than 39 years for which the oocyte quality is expected not to be compromised by the well known age effect on female fertility. The chromosome analysis of the resulting embryos has been proposed as a valid method to improve implantation in the great majority of RIF patients Study design, size, duration This retrospective study included 49 patients with at least three previous consecutive implantation failures, which underwent PGT-A from January 2016 to April 2020. Both partners had a normal karyotype. Only patients with a female age below 39 years were included, who presented with a normal uterine cavity. Couples with a severe male factor were excluded. Single frozen blastocysts were transferred according to chromosomal results Participants/materials, setting, methods Maternal age was 35.5 ± 3.1 years. All blastocysts were vitrified after trophectoderm biopsy. Whole genome amplification and array comparative genomic hybridization were performed on biopsies. Only euploid embryos were transferred. The primary outcome was the live-birth delivery rate after the first transfer Main results and the role of chance Before starting a PGT-A cycle, these patients underwent 213 embryo transfers with 251 embryos replaced. A total of 264 blastocysts were analyzed, 140 of which were aneuploid (53%). Monosomy or trisomy was reported in 67 of the diagnosed samples (67/140, 48%) whereas the remaining 73 carried complex aneuploidies (73/140, 52%). The remaining 124 blastocysts (47%) were diagnosed as euploid. All patients performed an embryo transfer resulting in 28 clinical pregnancies (57%). There were 5 spontaneous abortions and the live-birth delivery rate per patient was 47% Limitations, reasons for caution This study suffers from the weakness related to retrospectivity. In addition, as euploid embryos are still cryopreserved, the delivery rate could change at completion of the cycles Wider implications of the findings: A RIF condition can be attributed, at least in a good proportion of cases, to the generation of high percentages of aneuploid embryos. In this case, the transfer of euploid blastocysts has high chances to classify this category of RIF patients has having an embryonic cause of infertilit. Trial registration number Not applicable

The Effect of Embryo Transfer Process Duration on Implantation Success

OBJECTIVE: To evaluate the effect of the embryo transfer duration of standard and simple embryo transfer method. STUDY DESIGN: This study was a retrospective cohort study conducted at a tertiary ART Centre, between June 2018- September 2018. Day 5 fresh embryo transferred patients aged between 18 - 40, BMI &lt;35 kg/m2 without uterine pathology were enrolled in the study. Patients were divided into two groups. Group-1 consisted of patients who had successful implantation and Group-2 consisted of patients who did not have implantation. Groups were compared according to their embryo transfer durations. Ninety-two patients were enrolled in the study. Also, sub-steps of as; cleaning of the cervical mucus and placing the outer catheter in the cervix, loading the embryo to the catheter, the period between embryo loading and embryo transfer, and following that, time spent for retracting the outer catheter evaluated. RESULTS: Between Group-1 and Group-2, there was no significant difference for the period of cervical cleaning and placing the outer catheter into the cervix (Respectively; 63 sec vs. 76 sec; p=0.18), the period of embryo loading (Respectively; 69sec vs. 71sec; p=0.46), the period between embryo loading and embryo transfer (Respectively; 10 sec vs. 10 sec; p=0.74, retracing the outer catheter (Respectively; 25.5sec vs. 24sec; p=0.42 and the total period of embryo transfer (182sec vs. 182.5 sec; p=0.55). CONCLUSION: The embryo transfer duration is not related to implantation rates. The duration of the embryo transfer process steps is not a distinguishing factor if a good-quality embryo transfer is done.

Management of recurrent implantation failure: British Fertility Society policy and practice guideline

Recurrent implantation failure (RIF) is defined as the absence of a positive pregnancy test after three consecutive transfers of good quality embryos. There remains significant variation in clinical practice in the management of RIF. This British Fertility Society (BFS) Policy and Practice guideline analyses the evidence for investigations and therapies that are employed in RIF and provides recommendations for clinical practice and for further research. Evidence for investigations of sperm and egg quality, uterine and adnexal factors, immunological factors and thrombophilia, endocrine conditions and genetic factors and for associated therapies have been evaluated. This guideline has been devised to assist reproductive medicine specialists and patients in making shared decisions concerning management of RIF. Finally, suggestions for research towards improving understanding and management of RIF have also been provided.

Unexplained recurrent implantation failures: Predictive factors of pregnancy and therapeutic management from a French multicentre study

IntroductionRecurrent implantation failure is defined as the absence of pregnancy after at least three transfers of good-quality embryos after in vitro fecundation/intracytoplasic sperm injection. AimThe aim of this study was to describe a multicentre cohort of women with unexplained RIF, to analyse the factors associated with clinical pregnancy and to evaluate the immunomodulatory therapies efficacy. MethodsWomen were consecutively recruited from university departments with unexplained RIF. ResultsSixty-four women were enrolled with mean age 36 ± 3 years. The rates of clinical pregnancy in 64 women were compared in untreated and treated cycles and according to therapies used during the last prospectively followed embryo transfer. A clinical pregnancy after the transfer was noted in 56 % pregnancies on intralipids and in 50 % on prednisone, versus 5 % in untreated ones (p < 0.001). The 340 embryo transfers of these 64 women resulted in 68 clinical pregnancies and 18 live births. Clinical pregnancies were significantly more frequent in treated versus untreated embryo transfers (44 % vs 9 %; p < 0.001) with odds ratio at 8.13 (95 % CI 4.49–14.72, p < 0.0001). Cumulative pregnancy rates were higher for steroid-treated transfers than for untreated transfers when considering overall transfers before and after using steroids and also only those under steroids. Cumulative pregnancy rates were not different from steroid- and intralipid-treated embryo transfers ConclusionsIn this multicentre study of women with unexplained RIF, use of immunomodulatory treatments before embryo transfer resulted in higher clinical pregnancy. Randomised, well-designed studies in well-defined population of RIF women are necessary to confirm our preliminary data.