Embryo Transfer Research Articles

Swine Industry in Canada: Biosecurity in Live Animal, Semen Transportation, and Embryo Transfer

The pork industry, a key player in the Canadian economy, significantly contributes to livestock production, international trade markets, and employment. The multi-faceted swine industry is comprised of nucleus, multiplier, and commercial herds. The recognition and application of exemplary internal and external biosecurity measures are paramount for maintaining sustainable swine production. Historically, live animal transport has been an important means of disseminating superior genetics between production herds and poses a considerable risk for disease transmission and biosecurity breach points. The industry has evolved over time to employ other methods, through the shipping of boar semen and the adoption of artificial insemination practices to acquire genetic resources with a lower risk of disease transmission. These effective changes have led to an improvement in herd health, production performance, and efficiency. In particular, the industry’s dedication to enhanced biosecurity is evident in the effort to streamline embryo collection and transfer procedures. Such advances reduce the potential need to transport live animals, thereby lowering the risk of introducing infectious agents. This review article explores the different forms of disseminating swine genetics, namely, live animal, semen transportation, and embryo transfer, examining potential breaches in biosecurity, and discussing mitigation strategies that reduce disease transmission to protect the health of animal stock.

Correlation Between Luteal Phase Serum Progesterone Levels and Pregnancy Outcome in Frozen Embryo Transfer Cycles: A Prospective Cohort Study

Objectives To study the correlation between luteal phase serum progesterone (P4) levels and pregnancy outcome in frozen embryo transfer (FET) cycles and to find out the cut-off level of luteal phase serum P4 which favours successful pregnancy outcome in FET cycles. Material and Methods This prospective cohort study included 100 women undergoing hormone replacement therapy (HRT)-FET cycle at Akanksha IVF Centre from December 2023 to June 2024, fulfilling the inclusion and exclusion criteria. Serum P4 levels were measured for all the patients in the luteal phase (days 21–23) after FET with intramuscular P4 as luteal phase support. Pregnancy outcome was assessed in terms of implantation rate, biochemical pregnancy rate, clinical pregnancy rate (CPR), first-trimester miscarriage rate and ongoing pregnancy rate. Results The most favourable pregnancy outcomes were observed at serum P4 levels 25.1-35 ng/mL. A statistically significant association was seen between the luteal phase serum P4 levels and implantation rate (36.08%), biochemical pregnancy rate (4%), CPR (52%) and ongoing pregnancy rate (42%). According to the receiver operating characteristic (ROC) curve analysis, the optimal cut-off value for favourable outcomes was determined to be 22.3 ng/mL. However, the analysis also indicated that the luteal phase serum P4 levels did not reliably predict clinical or ongoing pregnancy. Conclusion Larger studies are needed to establish a threshold level of serum P4 in the luteal phase that can differentiate between successful and unsuccessful implantation. However, it is still uncertain whether the issue of unsuccessful implantation can be resolved once it is detected on days 21–23 of the HRT-FET cycle.

Progress Toward Genetic Rescue of the Northern White Rhinoceros (Ceratotherium simum cottoni)

The northern white rhinoceros (NWR) is functionally extinct, with only two nonreproductive females remaining. However, because of the foresight of scientists, cryopreserved cells and reproductive tissues may aid in the recovery of this species. An ambitious program of natural and artificial gamete and in vitro embryo generation was first outlined in 2015, and many of the proposed steps have been achieved. Multiple induced pluripotent stem cell lines have been established, primordial germ cell–like cells have been generated, oocytes have been collected from the remaining females, blastocysts have been cryopreserved, and the closely related southern white rhinoceros (SWR) is being established as a surrogate. Recently, the first successful embryo transfer in SWR demonstrated that embryos can be generated by in vitro fertilization and cryopreserved. We explore progress to date in using advanced cellular technologies to save the NWR and highlight the necessary next steps to ensure a viable population for reintroduction. We roll out a holistic rescue approach for a charismatic megavertebrate that includes the most advanced cellular technologies, which can provide a blueprint for other critically endangered mammals. We also provide a detailed discussion of the remaining questions in such an upgraded conservation program.

Perinatal and obstetric-neonatal outcomes following frozen embryo transfer cycles with a thinner endometrium: a retrospective study

Perinatal and obstetric-neonatal outcomes following frozen embryo transfer cycles with a thinner endometrium: a retrospective study

Excess Weight Impairs Oocyte Quality, as Reflected by mtDNA and BMP-15

This prospective, case-control study evaluated the impact of obesity on oocyte quality based on mtDNA expression in cumulus cells (CC), and on bone morphogenetic protein 15 (BMP-15) and heparan sulfate proteoglycan 2 (HSPG2) in follicular fluid (FF). It included women 18 to <40 years of age, divided according to BMI < 24.9 (Group 1, n = 28) and BMI > 25 (Group 2, n = 22). Demographics, treatment, and pregnancy outcomes were compared. The mtDNA in CC, BMP-15, HSPG2, the lipid profile, the hormonal profile, and C-reactive protein were evaluated in FF and in blood samples. The BMP-15 levels in FF and the mitochondrial DNA in CC were higher in Group 1 (38.8 ± 32.5 vs. 14.3 ± 10.8 ng/mL; p = 0.001 and 1.10 ± 0.3 vs. 0.87 ± 0.18-fold change; p = 0.016, respectively) than in Group 2. High-density lipoprotein levels in blood and FF were higher in Group 1 (62 ± 18 vs. 50 ± 12 mg/dL; p = 0.015 and 34 ± 26 vs. 20.9 ± 7.2 mg/dL; p = 0.05, respectively). Group 2 had higher blood C-reactive protein (7.1 ± 5.4 vs. 3.4 ± 4.3 mg/L; p = 0.015), FF (5.2 ± 3.8 vs. 1.5 ± 1.6 mg/L; p = 0.002) and low-density lipoprotein levels (91 ± 27 vs. 71 ± 22 mg/dL; p = 0.008) vs. Group 1. Group 1 demonstrated a trend toward a better clinical pregnancy rate (47.8% vs. 28.6%: p = 0.31) and frozen embryo transfer rate (69.2% vs. 53.8; p = 0.69). Higher BMI resulted in lower BMP-15 levels and reduced mtDNA expression, which reflect decreased oocyte quality in overweight women.

Prediction of clinical pregnancy outcome after single fresh blastocyst transfer during in vitro fertilization: an ensemble learning perspective

Prediction of clinical pregnancy outcome after single fresh blastocyst transfer during in vitro fertilization: an ensemble learning perspective

AREG expression in cumulus cells as a prognostic marker of oocyte quality

Background. Assisted reproductive technologies (ART) represent the most promising and successful methods of infertility treatment. A personalized approach may enhance its efficacy. One such approach is the development of reliable methods for assessing the quality and selection of embryos for transfer. The quality of the embryo is largely contingent upon the quality of the gametes involved in fertilization; thus, the development of non-invasive methods to assess oocyte quality represents a crucial step in the advancement of personalized ART. It is proposed that molecular and biological characterization of cumulus cells can be utilized to assess oocyte quality and predict the success of implantation of transferred embryos. The aim of the study was to evaluate the expression levels of potential oocyte quality marker genes (AREG, STAR, PTGS2, HAS2 and SCD5) in cumulus cells from healthy donors and patients with primary and secondary infertility. Materials and Methods. Nine donors and 19 patients were enrolled in the study. RNA was isolated from cumulus cells obtained during oocyte preparation for fertilization, and cDNA was synthesized. The cDNA was used as a matrix for real-time PCR with primers for the above-mentioned genes of interest. Results. Significant difference in AREG gene expression was observed between patients with successful (i.e. ended with birth) outcome and with IVF failure. No difference was found for the STAR, HAS2, PTGS2 and SCD5 genes. Conclusion. The method of assessing the expression level of marker genes in cumulus cells by real-time PCR shows considerable promise for the assessment of oocyte quality. The AREG gene is a potential candidate for use as a marker of oocyte quality.

Exogenous progesterone rescue in patients with low mid-luteal serum progesterone levels undergoing true natural vitrified-warmed blastocyst transfer

Exogenous progesterone rescue in patients with low mid-luteal serum progesterone levels undergoing true natural vitrified-warmed blastocyst transfer

Elevated luteinizing hormone levels during the artificial endometrial preparation cycle do not impact pregnancy outcomes in patients undergoing single vitrified-warmed blastocyst transfer

The effect of an increase in luteinizing hormone levels on pregnancy outcomes in patients undergoing artificial endometrial preparation for frozen embryo transfer has not been definitively elucidated. We aimed to investigate the effect of elevated luteinizing hormone levels, measured prior to progesterone administration, on the ongoing pregnancy rate in patients undergoing artificial endometrial preparation for single vitrified-warmed blastocyst transfer. Patients began taking oral oestradiol valerate on menstrual day 2–3. When the endometrial thickness reached ≥7 mm, they were tested for oestradiol, progesterone, and luteinizing hormone, and luteal phase support was started. The participants were divided into four groups based on luteinizing hormone percentiles, and differences in pregnancy outcomes were examined. No significant differences were observed for on-going pregnancy rate and the other pregnancy outcomes between the groups. In multivariate logistic regression analysis, not the luteinizing hormone levels but the quality of embryo had a significant influence on ongoing pregnancy (p = 0.004; adjusted odds ratio, 1.8; 95% confidence interval, 1.213–2.675). The elevation of luteinizing hormone levels during artificial endometrial preparation did not have an impact on the ongoing pregnancy or the other pregnancy outcomes.

Melatonin supplementation attenuates cuproptosis and ferroptosis in aging cumulus and granulosa cells: potential for improving IVF outcomes in advanced maternal age

BackgroundAdvanced maternal age is associated with decreased oocyte quantity and quality and in vitro fertilization (IVF) success rates. This study aimed to investigate whether melatonin supplementation can improve IVF outcomes in women of advanced maternal age by modulating cuproptosis and ferroptosis.MethodsThis prospective cohort study included 161 women aged 35–45 years undergoing IVF-frozen embryo transfer cycles. Participants were assigned to either melatonin (n = 86, 2 mg daily for ≥ 8 weeks) or control (n = 75) groups. Cumulus cells were analyzed for cuproptosis and ferroptosis-related gene expression. Additional experiments were conducted on the HGL5 human granulosa cell line to assess mitochondrial function and metabolic reprogramming.ResultsMelatonin supplementation significantly improved IVF outcomes in women aged ≥ 38 years, increasing clinical pregnancy rates (46.0% vs. 20.3%, P < 0.01), ongoing pregnancy rates (36.5% vs. 15.3%, P < 0.01), and live birth rates (33.3% vs. 15.3%, P < 0.05). In cumulus cells from patients, gene expression analysis revealed that melatonin modulated cuproptosis and ferroptosis-related genes, including ATP7B and GPX4, with more pronounced effects in the ≥ 38 years group. This suggests melatonin enhances cellular resilience against oxidative stress and metal-induced toxicity in the ovarian microenvironment. In vitro studies using HGL5 cells showed melatonin reduced oxidative stress markers, improved mitochondrial function, restored expression of glycolysis and TCA cycle-related genes and modulated cuproptosis and ferroptosis-related gene expression. These findings provide mechanistic insight into melatonin’s protective effects against regulated cell death in ovarian cells, potentially explaining the improved IVF outcomes observed.ConclusionsMelatonin supplementation significantly improved IVF outcomes in women of advanced maternal age, particularly those ≥ 38 years old, likely by modulating cuproptosis and ferroptosis and enhancing mitochondrial function in cumulus and granulosa cells. These results suggest that melatonin could be a promising adjuvant therapy for improving IVF success rates in older women.

Support of the luteal phase in programs for transferring thawed embryos into the uterine cavity in patients with overweight and obesity

Introduction. Progesterone levels are a critical factor for embryo implantation in in vitro fertilization (IVF) programs, including thawed embryo transfer programs. Overweight/obese patients often have lower blood progesterone concentrations in the luteal phase during IVF cycles, which requires an individual approach to planning luteal support in this category of patients.Aim. To compare the pregnancy ratе and miscarriage rates up to 12 weeks of pregnancy in overweight/obese patients who underwent a program of transfer of thawed embryos into the uterine cavity, depending on the type and route of administration of gestagens.Materials and methods. The study included 76 overweight or obese patients. All patients were treated for infertility using a program for transferring a thawed embryo into the uterine cavity; luteal phase support was carried out either using micronized progesterone, identical to natural, – the drug Utrogestan in a daily dose of 800 mg intravaginally (40 patients), or combination therapy was prescribed – vaginal gel with progesterone 90 mg in combination with the synthetic progestin dydrogesterone in a daily dose of 30 mg, taken orally (36 patients).Results. The rates of pregnancy and miscarriage in the first trimester were comparable in both groups and did not depend on differences in luteal support.Conclusions. The formation of the luteal phase of the cycle in patients with overweight/obesity is equally effective using various forms of gestagens. The use of micronized progesterone may be preferable in patients with overweight/obesity in terms of the ability to monitor blood progesterone levels, a more favorable metabolic profile when used vaginally, and the possibility of switching to oral administration of the drug in the event of the development of adverse local events.

Comparative analysis of pregnancy outcomes in different time intervals following GnRH antagonist stimulation and modified natural frozen-thawed embryo transfers

To evaluate whether the interval between oocyte retrieval and frozen-thawed embryo transfer (FET) affects clinical outcomes using modified natural cycle (mNC) regimen following freeze-all GnRH antagonist stimulation. A total of 542 patients underwent first mNC-FET were divided into two groups: immediate (FET conducted in the first menstrual cycle after freeze-all) and delayed (FET performed in the second or subsequent menstrual cycle) groups. The immediate group was associated with a notably reduced duration between oocyte retrieval and transfer day (35.5 ± 5.8 vs. 88.7 ± 35.5 d, P < 0.001). Regarding pregnancy results, the immediate cycles resulted in comparable implantation rate (55.3% vs. 57.2%, P = 0.624), clinical pregnancy rate (66.9% vs. 72.2%, P = 0.236), abortion rate (16.1% vs. 12.7%, P = 0.402), ongoing pregnancy rate (59.0% vs. 65.0%, P = 0.204), and live birth rate (56.1% vs. 63.0%, P = 0.149) with the delayed cycles. After the multivariable logistic regression analysis, the difference in live birth outcome between the two regimens remained insignificant (immediate vs. delayed protocol: adjusted odds ratio = 0.87, 95% confidence interval= 0.56–1.33). Immediate mNC-FET following a freeze-all antagonist cycle displayed promising clinical outcomes and significantly shortened the time to conception compared to delayed FET.

Effect of Paternal Body Mass Index on Cumulative Live Birth Rates: Retrospective Analysis of 3048 Embryo Transfers in Couples Using Autologous Gametes

Obesity is a multifactorial disease present worldwide and correlated with hormonal alterations that may cause a decrease in reproductive outcomes and seminal quality. However, the specific mechanisms involved are unknown. This led us to examine the relationship between paternal body mass index (BMI) and clinical reproductive outcomes by evaluating the cumulative live birth rates (CLBRs) per number of embryo transfers (ETs), embryos replaced (EmbRs), and oocytes used (OUs) in consecutive treatments until achieving the first newborn. A retrospective study was performed, and Kaplan–Meier survival curves were created to observe CLBRs with regard to the paternal BMI, adjusted by relevant confounders through Cox regression models. The participants were couples undergoing intracytoplasmic sperm injection (ICSI) and ET in Spanish IVIRMA clinics using autologous gametes. The cohort was subdivided based on paternal BMI: normal (18.5–24.99 kg/m2) (N), overweight (25–29.99 kg/m2) (OV), or obese (≥30 kg/m2) (OB) patients. A total of 4750 ICSI cycles were included, encompassing 49,485 mature oocytes, 23,963 blastocysts, and 3048 ETs. When calculating CLBRs based on the number of ETs carried out until live birth was achieved, no statistically significant differences were found (p = 0.72). After adjusting for maternal age and BMI, female infertility diagnosis, the use of preimplantation genetic testing, and the number of ETs, Cox regression showed that there were no statistically significant differences between the BMI groups (HR: 0.94 [95% CI: 0.7–1.2]; p = 0.59). When calculating CLBRs considering EmbRs, there was a similarity between the BMI groups (p = 0.57). However, there were no statistically significant differences in the adjusted Cox regression (HR: 0.93 [95% CI: 0.7–1.2]; p = 0.51). Finally, when calculating CLBRs considering OUs, the results were comparable among BMI subgroups (p = 0.75), and there were no statistically significant differences with adjusted Cox regression (HR: 0.95 [95% CI: 0.8–1.2]; p = 0.66). In conclusion, paternal BMI was not associated with clinical reproductive outcomes when considering the ETs, EmbRs, or OUs needed to reach the first liveborn (LB).

High proportion of zygotes with multiple pronuclei increase the embryo multinucleation rate during conventional IVF

The incidence of multiple pronuclei (≥ 3PN) zygotes and blastomere multinucleation was found to be elevated in the presence of increased estradiol (E2) levels and a greater number of retrieved oocytes. This implies a potential link between the incidence of multinucleation at the two-cell stage (MN2) and a higher proportion of ≥ 3PN zygotes. We aimed to investigate the effect of high proportion of ≥ 3PN zygotes on MN2 incidence during conventional in vitro fertilization (C-IVF) by using time-lapse monitoring. This study included 1195 patients from January 2020 to December 2022. The patients were categorized into three groups: Group 1 comprised patients with no ≥ 3PN zygotes (n = 422), Group 2 included those with 0–25% ≥3PN zygotes (n = 617), and Group 3 consisted of patients with more than 25% ≥3PN zygotes (n = 156). The MN2 rate, types of MN2 and clinical outcomes were compared among the three groups. Our data indicated that the MN2 rate was significantly lower in groups 1 and 2 compared to group 3 (18.33 versus 25.62%; p < 0.001 and 19.45 versus 25.62%; p < 0.001). The MN2 embryos exhibited similar rates of high-quality embryos (42.27 versus 43.50 versus 40.67%; p = 0.401) and available embryos (84.96 versus 84.04 versus 83.21%; p = 0.460) rates among the three groups. There were no significant differences in the proportion of MN2 with different types among the three groups (p > 0.05). The embryos displaying binucleated at the two-cell stage in one blastomere (2BI1) and true multinucleated at the two-cell stage in one blastomere (2MULTI1) showed significantly higher blastocyst formation rates compared to embryos exhibiting true multinucleated at the two-cell stage in both blastomeres (2MULTI2) (59.50 versus 45.40%; p < 0.001 and 59.40 versus 45.40%; p < 0.001). In conclusion, the occurrence of MN2 events might be associated with high proportion of ≥ 3PN zygotes incidence. The types of MN2 had significant reference value when selecting embryos for transfer during the cleavage stage.

Development of a New Personalized Molecular Test Based on Endometrial Receptivity and Maternal-Fetal Dialogue: Adhesio.

Successful embryo implantation relies on a receptive endometrium and a maternofetal dialogue. Abnormal receptivity is a common cause of implantation failure in assisted reproductive techniques. This study aimed to develop a novel transcriptomic-based diagnostic assay, Adhesio, for assessing endometrial receptivity and guiding personalized embryo transfer. Adhesio was developed based on an initial dataset of 74 endometrial biopsies. Two types of biopsy samples were involved: 45 endometrial biopsies collected during the optimal theoretical window of implantation (WOI) and 29 endometrial biopsies which cells have been cultured with or without an autologous embryo. Microarray analysis was performed to identify differentially expressed genes associated with endometrial receptivity and selected candidate genes were assessed using quantitative real-time polymerase chain reaction (RT-qPCR) on biopsy samples. Statistical analyses were conducted to assess the performance and accuracy of Adhesio. The microarray analysis identified three distinct clusters of endometrial samples with differential gene expression patterns. Cluster 1 exhibited 1717 differentially expressed genes involved in biological processes associated with endometrial receptivity. A specific transcriptomic signature of 60 genes associated with endometrial co-culture was obtained using class prediction approach. Thereafter, an original panel of 10 genes was selected as potential biomarkers for endometrial receptivity based on their expression profiles in both endometrial biopsies and co-cultured cells. This article outlines the methodology employed to develop Adhesio, a test that assesses endometrial receptivity using an original panel of 10 genes. These genes are not only involved during the WOI but are also influenced by the maternal-fetal dialogue.

A repeated gonadotropin-releasing hormone agonist trigger improves pregnancy outcomes of frozen-thawed embryo transfer in GnRH antagonist cycles: a retrospective propensity-matched score analysis.

To evaluate whether co-treatment of repeated GnRHa triggers with GnRH antagonist protocols can improve the clinical outcomes in in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) procedures. In this retrospective study, 712 Chinese Han women aged 20-42 undergoing autologous IVF/ICSI-ET with a flexible GnRH antagonist protocol were analyzed. The 735 cycles were split into the single (n = 238) and the repeated (n = 497) GnRHa groups. In the single GnRHa group, 0.2mg of triptorelin was given for oocyte maturation, whereas in the repeated GnRHa group, two doses of 0.2mg were administered 12h apart. PSM design was used for a fair comparison. The main study outcomes included the clinical pregnancy rate (CPR), live birth rate (LBR), good-quality embryo rate, and fertilization rate. Multivariate logistic regression analyses were used to identify all potential factors affecting clinical outcomes. Post-PSM, analysis of 159 cycles per group showed the repeated GnRHa group outperforming the single GnRHa group in IVF fertilization rates (71.5% vs. 67.7%, P < 0.05) and good-quality embryo rate (47.1% vs. 43.7%, P < 0.05). Furthermore, the repeated GnRHa group achieved higher CPR (72.6% vs. 53.4%, P < 0.05) and LBR (59.7% vs. 43.8%, P < 0.05) in FET cycles. Multivariate logistic regression indicated a significant negative correlation between the use of a single GnRHa trigger and both clinical pregnancy (OR = 0.382, P < 0.05) and live birth (OR = 0.518, P < 0.05). Our study reported that individuals who received a repeated GnRHa trigger exhibited higher CPR and LBR during FET cycles compared to those who received a single dose GnRHa trigger.

Complications in equine transvaginal ultrasound‒guided follicular aspiration

Transvaginal ultrasound-guided follicular aspiration has revolutionised equine assisted reproduction, particularly in in vitro embryo production. This literature review examines the complications associated with transvaginal ultrasound-guided follicular aspiration in mares and its potential impact on future fertility. While transvaginal ultrasound-guided follicular aspiration is generally safe, it has inherent risks, ranging from mild rectal bleeding to severe complications such as peritonitis and acute haemorrhage. Factors influencing complication rates include veterinarian experience, mare anatomy and procedural technique. Despite concerns, studies suggest that repeated transvaginal ultrasound-guided follicular aspiration does not significantly impair future fertility, with normal pregnancy rates observed in mares undergoing artificial insemination or embryo transfer after transvaginal ultrasound-guided follicular aspiration. However, further research is needed to fully understand the long-term effects on ovarian function and oocyte quality. Veterinary practitioners must prioritise appropriate training and procedural precautions to minimise the risk of complications and safeguard mare welfare and fertility in the expanding field of equine assisted reproduction.

One fresh cleavage-stage single embryo transfer (SET) plus one frozen-thawed blastocyst-stage SET or one fresh cleavage-stage double embryo transfer? A retrospective matched cohort study.

Are there significant differences in fertility outcomes between transferring two cleavage-stage embryos in a single fresh cycle and transferring one cleavage-stage embryo in a fresh cycle and one blastocyst-stage embryo in the subsequent frozen-thawed cycle? In women aged <38 years with two embryos available, transferring one cleavage-stage embryo in a fresh cycle and one blastocyst-stage embryo in the subsequent frozen-thawed cycle increased live birth rates and decreased multiple live birth rates compared to transferring two cleavage-stage embryos in a single fresh cycle. The strategy of repeated single embryo transfer (SET) has emerged as a solution to address the reduced live birth rates associated with SET per cycle. There is substantial evidence indicating that the cumulative live birth rate after repeated SET is comparable to that of double embryo transfer (DET), while significantly reducing the incidence of multiple pregnancies. Evidence regarding the outcomes of transferring two cleavage-stage embryos in a single fresh cycle versus transferring one cleavage-stage embryo in one fresh cycle and one blastocyst-stage embryo in the subsequent frozen-thawed cycle is scarce. This study is a retrospective matched cohort study, where data were gathered from the clinical database of women who underwent IVF treatment at the Reproductive Center of Peking University Third Hospital between January 2011 and December 2019, with follow-up extending until December 2021. The study group included cycles with a fresh cleavage-stage SET and a subsequent frozen-thawed blastocyst-stage SET (2xSET, N = 976). Fresh cleavage-stage DET was the control group (DET, N = 976). Included cycles were divided into subgroups based on age (≥38 years vs <38 years) and total number of utilizable (transferred or cryopreserved) embryos (=2 vs >2). The duration of infertility, prevalence of unexplained infertility, and controlled ovarian stimulation regimes differed significantly between the two groups and were adjusted for in the further analysis. We observed a significant increase in clinical pregnancies (55.5% vs 42%, adjusted odds ratio (OR) 1.87 [1.55-2.26]) and live births (44.8% vs 34.5%, adjusted OR 1.63 [1.35-1.97]) in favor of the 2xSET group. The preterm birth rate was lower in the study group (adjusted OR 0.64 [0.42-0.96]). Neonatal birth weight of singletons was similar between the two groups (adjusted B 4.94 g [-84.5 to 94.4]). The beneficial effect on the live birth rate disappeared in cases where aged 38 years and older or when only two embryos were utilizable. This study is limited by differences in baseline characteristics of the two groups. Analyzing two consecutive SETs at the cleavage stage was not feasible. Additionally, the homogeneous population limits generalizability to other ethnic groups, which should be considered when interpreting the results broadly. We recommend a combination strategy for women under 38 years old and with more than two embryos available: transfer one cleavage-stage embryo in the fresh cycle, followed by one blastocyst-stage embryo in the subsequent frozen-thawed cycle. This strategy reduces the risk of blastocyst culture failure while maintaining a high success rate. It offers hope to families seeking additional children and avoids unnecessary embryo disposal. B.W.M. had received grants from NHMRC, Ferring, Merck, and Guerbet, consulting fees and stock options from ObsEva, is on the advisory board of ObsEva, and reports consultancy for Guerbet, none of which are in relation to the present manuscript. All other authors have no conflict of interest to declare. N/A.

Predictions of live birth in IVF programs of patients with recurrent implantation failure

BackgroundWhen a high-quality embryo is implanted into the uterus, but the pregnancy is not established as shown by the ultrasound visualization of an intrauterine gestational sac, this is known as “implantation failure.” Cases when more than two times implantation failure occurred was defined as recurrent implantation failure (RIF). Additional testing is done at this stage of infertility treatment to avoid a repeat of the same result with a future in vitro fertilization (IVF) effort. Aim of the studyThe study aimed to evaluate predictive value of using embryo transfer personalization because of the implantation window study in combination with preimplantation genetic testing in patients with recurrent implantation attempts. MethodsBriefly describe the main methods or treatments applied: Ninety-three infertile women make up the sample for this prospective cohort study. In regard to treatment results, the study intends to assess the predictive importance of patient characteristics, screening indicators, and several features of IVF cycles, such as the quantity, quality, and developmental stage of the transferred embryos. Statistical methods employed include the calculation of the median (Me) and interquartile range (IQR) for continuous variables. The Mann-Whitney U test was used to discern differences between unrelated samples, while categorical variables were presented as absolute and percentage values. The Pearson’s Chi-squared test assessed differences between groups. Logistic regression, utilizing both enter and backward Wald methods, was applied to establish associations with binary outcomes. ResultsThe integration of individualized embryo transfer and preimplantation genetic testing (PGT) significantly enhanced the likelihood of live births by 3.4 times in patients experiencing recurrent implantation failure (RIF), with a statistical significance of p = 0.026. In contrast, employing PGT alone increased the probability of live births by 1.5 times; however, this result was not statistically significant (p = 0.439). The predictive model for live birth in patients with RIF, based on our study findings, is defined as follows: the probability of live birth = 1.936 + [1.014 if PGT-A embryos are utilized for transfer] + [1.742 if endometrial preparation is tailored according to the Wellbeing Index (WI)] − [1.860 in cases of secondary infertility] − [1.891 when a male factor is involved]. ConclusionsThe determination of the implantation window (IW) and PGT of the embryo are efficient methods of live birth achievement for patients with RIF.

Recipients' age, fresh embryo and blastocyst-stage embryo transfer as favorable factors in a transnational oocyte donation program.

In Italy, egg donation is being allowed again following the ruling by the Constitutional Court N. 162/2014. Nevertheless, the number of voluntary donors is insignificant, probably because no reimbursement is provided. Therefore, the great majority of egg donation cycles are performed by using imported cryopreserved oocytes from foreign countries. However, recent evidence has questioned the overall efficacy of this strategy in comparison with the shipment of frozen sperm and vitrified embryos. Retrospective cohort study, conducted at ANDROS Day Surgery Clinic Palermo, Italy in the period 2016-2022, with the objective of evaluating the efficiency of each batch of vitrified oocytes, in terms of completed cycles. The cryopreserved donated oocytes came from a single Spanish clinic (Next Fertility, Valencia, Spain). The primary outcome was the cumulative live birth rate (CLBR). The secondary outcomes were the cumulative ongoing pregnancy rate (COPR), the cumulative clinical pregnancy rate (CCPR) and the miscarriage rate. The CLBR totaled 35.1%, the COPR 36.8%, the CCPR 49.2% and the miscarriage rate 24.7%. In the multivariate analysis, the probability of success was significantly higher in younger recipients, in fresh embryo transfer and in blastocyst-stage embryo transfer. Our "transnational" donation program with vitrified oocytes has good success rates. The main focus of our analysis is the negative effect of advancing recipient age on success rates, outlining a possible, important role of age-related uterine factor on implantation mechanisms. This aspect should be emphasized during the counselling with couples much more than is routinely done.