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STUDY QUESTION Can pregnancy outcomes following fresh elective single embryo transfer (eSET) in gonadotropin-releasing hormone (GnRH) antagonist protocols increase using a gonadotropin (Gn) step-down approach with cessation of GnRH antagonist on the day of hCG administration (hCG day) in patients with normal ovarian response? SUMMARY ANSWER The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on the hCG day is effective in improving live birth rates (LBRs) per fresh eSET cycle. WHAT IS KNOWN ALREADY Currently, there is no consensus on optimal GnRH antagonist regimens. Studies have shown that fresh GnRH antagonist cycles result in poorer pregnancy outcomes than the long GnRH agonist (GnRHa) protocol. Endometrial receptivity is a key factor that contributes to this phenomenon. STUDY DESIGN, SIZE, DURATION An open label randomized controlled trial (RCT) was performed between November 2021 and August 2022. There were 546 patients allocated to either the modified GnRH antagonist or the conventional antagonist protocol at a 1:1 ratio. PARTICIPANTS/MATERIALS, SETTING, METHODS Both IVF and ICSI cycles were included, and the sperm samples used were either fresh or frozen from the partner, or from frozen donor ejaculates. The primary outcome was the LBRs per fresh SET cycle. Secondary outcomes included rates of implantation, clinical and ongoing pregnancy, miscarriage, and ovarian hyperstimulation syndrome (OHSS), as well as clinical outcomes of ovarian stimulation. MAIN RESULTS AND THE ROLE OF CHANCE Baseline demographic features were not significantly different between the two ovarian stimulation groups. However, in the intention-to-treat (ITT) population, the LBRs in the modified antagonist group were significantly higher than in the conventional group (38.1% [104/273] vs. 27.5% [75/273], relative risk 1.39 [95% CI, 1.09–1.77], P  =   0.008). Using a per-protocol (PP) analysis which included all the patients who received an embryo transfer, the LBRs in the modified antagonist group were also significantly higher than in the conventional group (48.6% [103/212] vs. 36.8% [74/201], relative risk 1.32 [95% CI, 1.05–1.66], P  =   0.016). The modified antagonist group achieved significantly higher implantation rates, and clinical and ongoing pregnancy rates than the conventional group in both the ITT and PP analyses (P  <   0.05). The two groups did not show significant differences between the number of oocytes retrieved or mature oocytes, two-pronuclear zygote (2PN) rates, the number of embryos obtained, blastocyst progression and good-quality embryo rates, early miscarriage rates, or OHSS incidence rates (P  >   0.05). LIMITATIONS, REASONS FOR CAUTION A limitation of our study was that the subjects were not blinded to the treatment allocation in the RCT trial. Only women under 40 years of age who had a good prognosis were included in the analysis. Therefore, use of the modified antagonist protocol in older patients with a low ovarian reserve remains to be investigated. In addition, the sample size for Day 5 elective SET was small, so larger trials will be required to strengthen these findings. WIDER IMPLICATIONS OF THE FINDINGS The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on hCG day improved the LBRs per fresh eSET cycle in normal responders. STUDY FUNDING/COMPETING INTEREST(S) This project was funded by grant 2022YFC2702503 from the National Key Research & Development Program of China and grant 2021140 from the Beijing Health Promotion Association. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER The RCT was registered in the Chinese Clinical Trial Registry; Study Number: ChiCTR2100053453. TRIAL REGISTRATION DATE 21 November 2021. DATE OF FIRST PATIENT'S ENROLLMENT 23 November 2021 [ABSTRACT FROM AUTHOR]

STUDY QUESTION Which clinical and embryological factors should be considered to apply double embryo transfer (DET) instead of elective single embryo transfer (eSET)? SUMMARY ANSWER No clinical or embryological factor per se justifies a recommendation of DET instead of eSET in IVF/ICSI. WHAT IS KNOWN ALREADY DET is correlated with a higher rate of multiple pregnancy, leading to a subsequent increase in complications for both mother and babies. These complications include preterm birth, low birthweight, and other perinatal adverse outcomes. To mitigate the risks associated with multiple pregnancy, eSET is recommended by international and national professional organizations as the preferred approach in ART. STUDY DESIGN, SIZE, DURATION The guideline was developed according to the structured methodology for development and update of ESHRE guidelines. Literature searches were performed in PUBMED/MEDLINE and Cochrane databases, and relevant papers published up to May 2023, written in English, were included. Live birth rate, cumulative live birth rate, and multiple pregnancy rate were considered as critical outcomes. PARTICIPANTS/MATERIALS, SETTING, METHODS Based on the collected evidence, recommendations were discussed until a consensus was reached within the Guideline Development Group (GDG). A stakeholder review was organized after the guideline draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee. MAIN RESULTS AND THE ROLE OF CHANCE The guideline provides 35 recommendations on the medical and non-medical risks associated with multiple pregnancies and on the clinical and embryological factors to be considered when deciding on the number of embryos to transfer. These recommendations include 25 evidence-based recommendations, of which 24 were formulated as strong recommendations and one as conditional, and 10 good practice points. Of the evidence-based recommendations, seven (28%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (three recommendations; 12%), or very low-quality evidence (15 recommendations; 60%). Owing to the lack of evidence-based research, the guideline also clearly mentions recommendations for future studies. LIMITATIONS, REASONS FOR CAUTION The guideline assessed different factors one by one based on existing evidence. However, in real life, clinicians' decisions are based on several prognostic factors related to each patient's case. Furthermore, the evidence from randomized controlled trials is too scarce to formulate high-quality evidence-based recommendations. WIDER IMPLICATIONS OF THE FINDINGS The guideline provides health professionals with clear advice on best practice in the decision-making process during IVF/ICSI, based on the best evidence currently available, and recommendations on relevant information that should be communicated to patients. In addition, a list of research recommendations is provided to stimulate further studies in the field. STUDY FUNDING/COMPETING INTEREST(S) The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, the literature searches, and the dissemination of the guideline. The guideline group members did not receive payment. DPB declared receiving honoraria for lectures from Merck, Ferring, and Gedeon Richter. She is a member of ESHRE EXCO, and the Mediterranean Society for reproductive medicine and the president of the Croatian Society for Gynaecological Endocrinology and Reproductive Medicine. CDG is the past Chair of the ESHRE EIM Consortium and a paid deputy member of the Editorial board of Human Reproduction. IR declared receiving reimbursement from ESHRE and EDCD for attending meetings. She holds an unpaid leadership role in OBBCSSR, ECDC Sohonet, and AER. KAR-W declared receiving grants for clinical researchers and funding provision to the institution from the Swedish Cancer Society (200170F), the Senior Clinical Investigator Award, Radiumhemmets Forskningsfonder (Dnr: 201313), Stockholm County Council FoU (FoUI-953912) and Karolinska Institutet (Dnr 2020-01963), NovoNordisk, Merck and Ferring Pharmaceuticals. She received consulting fees from the Swedish Ministry of Health and Welfare. She received honoraria from Roche, Pfizer, and Organon for chairmanship and lectures. She received support from Organon for attending meetings. She participated in advisory boards for Merck, Nordic countries, and Ferring. She declared receiving time-lapse equipment and grants with payment to institution for pre-clinical research from Merck pharmaceuticals and from Ferring. SS-R received research funding from Roche Diagnostics, Organon/MSD, Theramex, and Gedeo-Richter. He received consulting fees from Organon/MSD, Ferring Pharmaceuticals, and Merck Serono. He declared receiving honoraria for lectures from Ferring Pharmaceuticals, Besins, Organon/MSD, Theramex, and Gedeon Richter. He received support for attending Gedeon Richter meetings and participated in the Data Safety Monitoring Board of the T-TRANSPORT trial. He is the Deputy of ESHRE SQART special interest group. He holds stock options in IVI Lisboa and received equipment and other services from Roche Diagnostics and Ferring Pharmaceuticals. KT declared receiving payment for honoraria for giving lectures from Merck Serono and Organon. She is member of the safety advisory board of EDQM. She holds a leadership role in the ICCBBA board of directors. ZV received reimbursement from ESHRE for attending meetings. She also received research grants from ESHRE and Juhani Aaltonen Foundation. She is the coordinator of EHSRE SQART special interest group. The other authors have no conflicts of interest to declare. DISCLAIMER This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (full disclaimer available at https://www.eshre.eu/Guidelines-and-Legal). [ABSTRACT FROM AUTHOR]

Abstract A heterotopic pregnancy is a rare and serious pathological pregnancy. In this paper, we report a rare case of heterotopic pregnancy and perform a literature review. A 30-year-old patient with a history of left adnexectomy presented with persistent lower abdominal pain and hemorrhagic shock after single embryo transfer. Emergency laparoscopic exploration revealed a ruptured mass in the right isthmus of the fallopian tube, for which right salpingectomy was performed. After anti-inflammatory treatment and fetal preservation, the intrauterine pregnancy progressed smoothly, and a healthy baby was delivered at 39 weeks gestation. In this case, the patient’s heterotopic pregnancy was possibly due to a natural pregnancy caused by sexual intercourse during treatment, so we recommend that sexual intercourse be avoided during transfer cycles.

Abstract Background The present evidence is deficient for the trade-offs between the pros and cons of single blastocyst transfer (SBT) versus double blastocyst transfer (DBT) in frozen-thawed embryo transfer cycles for women in advanced reproductive age, especially in the second cycle. The current study aimed to investigate the impact of transferred blastocyst numbers on pregnancy outcomes in the first and second embryo transfer for women ≥ 35 years. Methods This was a retrospective cohort study including 1284 frozen-thawed blastocyst transfer (FBT) cycles from two reproductive centers. We analyzed the pregnancy outcomes after SBT and DBT in the first and second FBT cycles. Moreover, stratified analysis was conducted by maternal age. Results In the first FBT cycle, the LBR was higher in the DBT group than that in the SBT group [52.3% vs. 33.9%; adjusted odds ratio (aOR), 1.65; 95% confidence interval (CI), 1.26–2.15, P

Abstract Background Several studies have demonstrated that iDAScore is more accurate in predicting pregnancy outcomes in cycles without preimplantation genetic testing for aneuploidy (PGT-A) compared to KIDScore and the Gardner criteria. However, the effectiveness of iDAScore in cycles with PGT-A has not been thoroughly investigated. Therefore, this study aims to assess the association between artificial intelligence (AI)-based iDAScore (version 1.0) and pregnancy outcomes in single-embryo transfer (SET) cycles with PGT-A. Methods This retrospective study was approved by the Institutional Review Board of Chung Sun Medical University, Taichung, Taiwan. Patients undergoing SET cycles (n = 482) following PGT-A at a single reproductive center between January 2017 and June 2021. The blastocyst morphology and morphokinetics of all embryos were evaluated using a time-lapse system. The blastocysts were ranked based on the scores generated by iDAScore, which were defined as AI scores, or by KIDScore D5 (version 3.2) following the manufacturer’s protocols. A single blastocyst without aneuploidy was transferred after examining the embryonic ploidy status using a next-generation sequencing-based PGT-A platform. Logistic regression analysis with generalized estimating equations was conducted to assess whether AI scores are associated with the probability of live birth (LB) while considering confounding factors. Results Logistic regression analysis revealed that AI score was significantly associated with LB probability (adjusted odds ratio [OR] = 2.037, 95% confidence interval [CI]: 1.632–2.542) when pulsatility index (PI) level and types of chromosomal abnormalities were controlled. Blastocysts were divided into quartiles in accordance with their AI score (group 1: 3.0–7.8; group 2: 7.9–8.6; group 3: 8.7–8.9; and group 4: 9.0–9.5). Group 1 had a lower LB rate (34.6% vs. 59.8–72.3%) and a higher rate of pregnancy loss (26% vs. 4.7–8.9%) compared with the other groups (p

To prospectively examine the association between adenomyosis type, location, and severity with reproductive outcomes in patients undergoing single embryo transfer (SET) with embryos derived from donor oocytes. A prospective observational cohort study. University-affiliated in vitro fertilization center. Patients with infertility with (n = 114) and without (n = 114) adenomyosis who received their first donor oocyte transfer between January 2019 and January 2023 were included in this study. Adenomyosis was confirmed with the presence of at least one direct feature visualized by 2- or 3-dimensional transvaginal ultrasound and classified according to type (diffuse or focal), localization (inner or outer myometrium and/or junctional zone [JZ]), and uterine extension (mild, moderate, or severe). After an artificial or natural endometrial preparation cycle, patients underwent SET in the blastocyst stage. The primary outcome was the implantation rate. The secondary outcomes were the clinical pregnancy, live birth, and miscarriage rates after SET. The presence of adenomyosis did not significantly affect the implantation, clinical pregnancy, or live birth rates. However, women with adenomyosis had a significantly higher miscarriage rate than those without adenomyosis (35.4% vs. 18.1%, respectively). The multivariate analysis assessed possible risk factors for each clinical outcome considered in the study and showed that adenomyosis affected the risk of miscarriage. Specifically, transvaginal sonography detection of adenomyosis in the JZ was associated with over threefold higher relative risk of miscarriage (relative risk [RR], 3.28; 95% confidence interval [CI], 1.38–7.78). Conversely, adenomyosis features detected exclusively in the outer myometrium were associated with a higher ongoing pregnancy rate (RR, 0.30; 95% CI, 0.13–0.72). Diffuse adenomyosis in the JZ and severe adenomyosis increased the relative risk of miscarriage two-fold (RR, 2.29; 95% CI, 1.22–4.30 and RR, 2.20; 95% CI, 1.19–4.04, respectively). This study demonstrated that although adenomyosis did not significantly reduce the odds of implantation, the direct signs of adenomyosis in the JZ and disease severity are significant risk factors for miscarriage in patients receiving donor oocyte transfers. This study highlights the importance of thorough ultrasound examination and detailed adenomyosis classification in the assessment and management of patients with infertility. [ABSTRACT FROM AUTHOR]

Background: The present evidence is deficient for the trade-offs between the pros and cons of single blastocyst transfer (SBT) versus double blastocyst transfer (DBT) in frozen-thawed embryo transfer cycles for women in advanced reproductive age, especially in the second cycle. The current study aimed to investigate the impact of transferred blastocyst numbers on pregnancy outcomes in the first and second embryo transfer for women ≥ 35 years. Methods: This was a retrospective cohort study including 1284 frozen-thawed blastocyst transfer (FBT) cycles from two reproductive centers. We analyzed the pregnancy outcomes after SBT and DBT in the first and second FBT cycles. Moreover, stratified analysis was conducted by maternal age. Results: In the first FBT cycle, the LBR was higher in the DBT group than that in the SBT group [52.3% vs. 33.9%; adjusted odds ratio (aOR), 1.65; 95% confidence interval (CI), 1.26–2.15, P < 0.001]. However, the LBR of the DBT group showed no remarkable difference compared with that of the SBT group in the second cycle of FBT (44.3% vs. 33.3%; aOR, 1.30; 95% CI, 0.81–2.08; P = 0.271). Furthermore, stratified analysis by age showed a higher LBR for the DBT group than the SBT group in patients aged 38–42 years (43.1% vs. 33.9%; aOR, 2.27; 95% CI, 1.05–4.90; P = 0.036). Conclusions: The present study demonstrated that the SBT regimen is a better choice for both, the first and second frozen-thawed embryo transfer cycles, for women aged 35–37 years. Additionally, the DBT regimen is still recommended to achieve a high LBR in women aged 38–42 years in the second FBT cycle. These findings may be beneficial for deciding the embryo transfer regimens in women of advanced reproductive age. [ABSTRACT FROM AUTHOR]

Background: Several studies have demonstrated that iDAScore is more accurate in predicting pregnancy outcomes in cycles without preimplantation genetic testing for aneuploidy (PGT-A) compared to KIDScore and the Gardner criteria. However, the effectiveness of iDAScore in cycles with PGT-A has not been thoroughly investigated. Therefore, this study aims to assess the association between artificial intelligence (AI)-based iDAScore (version 1.0) and pregnancy outcomes in single-embryo transfer (SET) cycles with PGT-A. Methods: This retrospective study was approved by the Institutional Review Board of Chung Sun Medical University, Taichung, Taiwan. Patients undergoing SET cycles (n = 482) following PGT-A at a single reproductive center between January 2017 and June 2021. The blastocyst morphology and morphokinetics of all embryos were evaluated using a time-lapse system. The blastocysts were ranked based on the scores generated by iDAScore, which were defined as AI scores, or by KIDScore D5 (version 3.2) following the manufacturer's protocols. A single blastocyst without aneuploidy was transferred after examining the embryonic ploidy status using a next-generation sequencing-based PGT-A platform. Logistic regression analysis with generalized estimating equations was conducted to assess whether AI scores are associated with the probability of live birth (LB) while considering confounding factors. Results: Logistic regression analysis revealed that AI score was significantly associated with LB probability (adjusted odds ratio [OR] = 2.037, 95% confidence interval [CI]: 1.632–2.542) when pulsatility index (PI) level and types of chromosomal abnormalities were controlled. Blastocysts were divided into quartiles in accordance with their AI score (group 1: 3.0–7.8; group 2: 7.9–8.6; group 3: 8.7–8.9; and group 4: 9.0–9.5). Group 1 had a lower LB rate (34.6% vs. 59.8–72.3%) and a higher rate of pregnancy loss (26% vs. 4.7–8.9%) compared with the other groups (p < 0.05). The receiver operating characteristic curve analysis verified that the iDAScore had a significant but limited ability to predict LB (area under the curve [AUC] = 0.64); this ability was significantly weaker than that of the combination of iDAScore, type of chromosomal abnormalities, and PI level (AUC = 0.67). In the comparison of the LB groups with the non-LB groups, the AI scores were significantly lower in the non-LB groups, both for euploid (median: 8.6 vs. 8.8) and mosaic (median: 8.0 vs. 8.6) SETs. Conclusions: Although its predictive ability can be further enhanced, the AI score was significantly associated with LB probability in SET cycles. Euploid or mosaic blastocysts with low AI scores (≤ 7.8) were associated with a lower LB rate, indicating the potential of this annotation-free AI system as a decision-support tool for deselecting embryos with poor pregnancy outcomes following PGT-A. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of hatching status on predicting pregnancy outcomes in single vitrified‐warmed blastocyst transfer (SVBT) by objectively subdividing pre‐implantation blastocysts according to hatching status. Methods: This retrospective study included 817 SVBT cycles performed between January 2016 and December 2017. Transferred embryos were categorized according to their hatching status as follows: group I (n = 147), non‐hatching blastocysts; group II (n = 484), hatching blastocysts; and group III (n = 186), completely hatched blastocysts. Hatching blastocysts (group II) were then classified based on the ratio of the blastocystic diameter outside and inside the zona pellucida into early (n = 185), mid‐ (n = 103), and late (n = 196) hatching stages. Implantation rate (IR), clinical pregnancy rate (CPR), live birth rate (LBR), multiple pregnancy rate (MPR), miscarriage rate, and neonatal outcomes were evaluated. Results: For groups I, II, and III, respectively, the results were as follows: IR (28.6%, 43.6%, and 53.8%; P < 0.001), CPR (27.9%, 42.8%, and 53.2%; P < 0.001), and LBR (23.1%, 32.0%, and 42.5%; P < 0.001). Group III had better IR, CPR, and LBR. Among hatching blastocysts, late‐hatching blastocysts had the highest IR (33.5%, 46.6%, and 51.5% for early, mid‐, and late hatching, respectively; P = 0.002) and CPR (33.0%, 45.6%, and 50.5%; P = 0.002), with a tendency for a higher rate of LBR. Neonatal outcomes were not influenced by the hatching status. Conclusion: Advanced hatching status is positively associated with a higher rate of clinical pregnancy and live birth with no negative effects on neonatal outcomes. Additionally, the quantitative classification of hatching status was found to be predictive of pregnancy outcomes. Synopsis: Hatching status in single vitrified‐warmed blastocyst transfer improved clinical pregnancy and live birth rates compared with the expanded state of the blastocyst. [ABSTRACT FROM AUTHOR]

Didelphic uterus are caused by Müllerian tube fusion failure that eventually form two uterine cavities, which is one of the rarest uterine malformations. Women with Müllerian anomalies may increase the incidence of perinatal complications and adverse outcomes of pregnancy. If Müllerian anomalies are found during pregnancy, the type of abnormality should be identified promptly, the impact on the mother and fetus should be assessed, and the frequency of prenatal care should be appropriately increased. Ovarian pregnancy as a rare ectopic gestation is often difficult to diagnose before surgery. Ovarian pregnancy seemingly has no logical relationship with the didelphic uterus. The high risk factors of ovarian pregnancy may include intrauterine device, assisted reproductive technology (ART) and intrauterine surgery history. A case of ovarian pregnancy in a woman with didelphic uterus after ART was reviewed, and the possible causes of ovarian pregnancy were summarized and analyzed. Single embryo transfer should be considered as the best transplantation strategy for those patients with didelphic uterus. Women of childbearing age should undergo a thorough pelvic examination before ART in order to make early diagnosis and proper management of congenital uterine abnormalities. [ABSTRACT FROM AUTHOR]

Purpose: Several studies investigated endometrial patterns, with respect to pregnancy rates following the transfer of embryos but did not distinguish between single- and multiple-blastocyst procedures. We clarified how the endometrial pattern imaged to transfer a frozen embryo is associated with pregnancy outcomes in single-blastocyst frozen-embryo transfer (sbFET)., Methods: Patients ≤35 years who underwent sbFET on the hormone replacement protocol. We analyzed endometrial patterns' associations with pregnancy outcomes in relation to blastocyst grade and pregnancy-related factors., Results: Of the 1383 cycles, 483 were Lf, 840 were partial-Lf, and 60 were non-Lf. Leaf pattern (Lf): central echogenic line present and continuous. Overall, decreasing distinctness of the central echogenic line was associated with significantly lower rates of clinical pregnancy (Lf: 70.4%; partial-Lf: 58.1%; non-Lf: 28.3%) and live birth (56.3%, 45.5%, and 15.0%) and a higher miscarriage rate (20.0%, 21.7%, and 47.1%). Logistic regressions showed pregnancy and live birth to be significantly more likely and miscarriage less likely in Lf than non-Lf: OR (95% CI): 6.07 (3.24-11.37), 7.43 (3.47-15.39), and 0.20 (0.07-0.57)., Conclusions: Non-Lf presentation was associated with lower rates of pregnancy and live birth, suggesting it signals unsuitable conditions for embryo transfer. We provide information on the pregnancy outcomes of sbFET for endometrial patterns., Competing Interests: The authors declare that there are no conflicts of interest., (© 2024 The Author(s). Reproductive Medicine and Biology published by John Wiley & Sons Australia, Ltd on behalf of Japan Society for Reproductive Medicine.)

In this multicenter, non-inferiority, randomized trial, we randomly assigned 992 women undergoing in-vitro fertilization (IVF) with a good prognosis (aged 20-40, ≥3 transferrable cleavage-stage embryos) to strategies of blastocyst-stage (n = 497) or cleavage-stage (n = 495) single embryo transfer. Primary outcome was cumulative live-birth rate after up to three transfers. Secondary outcomes were cumulative live-births after all embryo transfers within 1 year of randomization, pregnancy outcomes, obstetric-perinatal complications, and livebirths outcomes. Live-birth rates were 74.8% in blastocyst-stage group versus 66.3% in cleavage-stage group (relative risk 1.13, 95%CI:1.04-1.22; P non-inferiority  < 0.001, P superiority  = 0.003) (1-year cumulative live birth rates of 75.7% versus 68.9%). Blastocyst transfer increased the risk of spontaneous preterm birth (4.6% vs 2.0%; P = 0.02) and neonatal hospitalization >3 days. Among good prognosis women, a strategy of single blastocyst transfer increases cumulative live-birth rates over single cleavage-stage transfer. Blastocyst transfer resulted in higher preterm birth rates. This information should be used to counsel patients on their choice between cleavage-stage and blastocyst-stage transfer (NCT03152643, https://clinicaltrials.gov/study/NCT03152643 )., (© 2024. The Author(s).)

This study aimed to explore the relationship between female age and pregnancy outcomes in patients undergoing their first elective single embryo transfer (eSET) of in vitro fertilization (IVF) cycles. The retrospective cohort study encompassed 7089 IVF/intracytoplasmic sperm injection (ICSI) patients of the Reproductive Medicine Center, Henan Provincial Peoples' Hospital of China, from September 1, 2016, to May 31, 2022. Patients all received the first eSET in their IVF/ICSI cycles. A generalized additive model (GAM) was employed to examine the the dose-response correlation between age and pregnancy outcomes, namely the clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR). Logistic regression model was employed to ascertain the correlation between the CPR/OPR and age. The study cohort has an average age of 30.74; 3843 patients got clinical pregnancy rate of 61.40% and ongoing pregnancy rate of 54.21%. The multiple pregnancy rate of is 1.24%. For patients aged 34 and above, the CPR decreased by 10% for every 1-year increase in age (adjusted OR 0.90, 95% CI 0.84-0.96, p < 0.0001). Similarly, the OPR decreased by 16% for every 1-year increase in age (adjusted OR 0.84, 95% CI 0.81-0.88, p < 0.0001). Patients aged 35-37 years had an acceptable OPR of 52.4% after eSET, with a low multiple pregnancy rate (1.1%). Pregnancy outcomes were significantly better in blastocyst cycles compared to cleavage embryo cycles, and this trend was more pronounced in older patients. There was a non-linear relationship between female age and pregnancy outcomes in patients undergoing their first eSET cycles. The clinical pregnancy rate and ongoing pregnancy rate decreased significantly with age, especially in women older than 34 years. For patients under 37 years old, single embryo transfer should be prioritized. For patients over 38 years old with available blastocysts, eSET is also recommended., (© 2024. The Author(s).)

Objective: To assess whether the change in embryo morphology from precryopreservation to postthaw is associated with the embryo transfer success rates in single euploid embryo transfer cycles., Design: Retrospective cohort study., Setting: Academic affiliated fertility clinic., Patient(s): Patients who underwent a single euploid embryo transfer cycle from September 2016 to April 2022 were included. A decision support tool was used to assign each embryo a reproductive potential score on the basis of the day of biopsy, expansion, and grade of trophectoderm and inner cell mass at the time of cryopreservation and after thaw. Embryos were divided into 4 groups: group 1 included embryos with the same score after thaw (reference); group 2 included those with a higher score; group 3 included those with a lower score; and group 4 included those that did not re-expand after thaw., Intervention(s): No interventions administered., Main Outcome Measure(s): The primary outcome was the live birth rates (LBRs) per embryo transfer. The secondary outcomes included the chemical pregnancy, clinical pregnancy, and clinical pregnancy loss rates. Comparative statistics and univariate analyses were performed using the Kruskal-Wallis and χ 2 tests. Multivariate logistic regression fitted with generalized estimating equation was performed to compare the odds of live birth between groups., Result(s): A total of 7,750 embryo transfers performed for 4,613 patients met inclusion criteria: 5,331 in group 1; 486 in group 2; 1,726 in group 3; and 207 in group 4. In the univariate analysis, there was a statistically significant difference in the LBR between groups 1, 2, 3, and 4 (55.8% vs. 51.4%, 47.5%, and 26.6%). Logistic regression controlling for oocyte age, antimüllerian hormone, body mass index, endometrial thickness, year of embryo transfer, time from thaw to final grading, and embryo score before cryopreservation showed significantly lower odds of live birth when the embryo was downgraded (odds ratio [OR], 0.70; confidence interval [CI], 0.62-0.79) or did not re-expand (OR, 0.36; CI, 0.26-0.51) than those with no change in score. When controlling for all variables, there was a significant increase in the odds of live birth between embryos that had a higher score after thaw and those without a change (OR, 1.42; CI, 1.14-1.76). There was no significant difference in the clinical pregnancy loss rate among the 4 groups., Conclusion(s): The change in the quality of the embryo after thaw is an important factor in embryo transfer success. In an adjusted analysis, the chemical and clinical pregnancy rates and LBR per embryo transfer all significantly decrease in embryos that were downgraded or did not expand on the day of single euploid embryo transfer. Embryos that re-expand and have improved quality after thaw have the highest odds of live birth., Competing Interests: Declaration of Interests K.B. has nothing to disclose. W.B. has nothing to disclose. S.R. has nothing to disclose. R.S. has nothing to disclose. M.B. has nothing to disclose. J.L. has nothing to disclose. A.B.C. reports advisory board for Progyny. E.B. has nothing to disclose., (Copyright © 2024 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate if single serum human chorionic gonadotropin (hCG) level measurements are sufficient for pregnancy monitoring after single embryo transfer (sET) and to compare the hCG levels between fresh (FRET) and frozen embryo transfers (FET) in medically assisted reproduction., Methods: This was a retrospective exploratory cohort study including all patients who met the inclusion criteria, who received a single FRET (n = 249) or FET (n = 410) of a day five blastocyst at the IVF clinic at the Johannes Kepler University Linz between 2011 and 2020. hCG levels were measured on day 14 after embryo transfer. Threshold values for the viability of pregnancies were determined using receiver operating characteristic (ROC) curves., Results: Significantly higher hCG levels were found in those who received FET than in those who received FRET (1222.8 ± 946.7 mU/ml vs. 862.7 ± 572.9 mU/ml; p < 0.001). Optimal threshold values predicting a viable pregnancy were 368.5 mU/ml and 523 mU/ml in the FRET and FET groups, respectively., Conclusions: After FET, higher hCG values after 14 days of embryo transfer must be considered in pregnancy monitoring. Additionally, a single threshold hCG value seems to be sufficient for determining pregnancy viability. To exclude ectopic pregnancies, subsequent ultrasound examination is a mandatory requirement., (© 2024. The Author(s).)

Background: Preimplantation genetic testing for aneuploidy (PGT-A) is used as part of in-vitro-fertilization (IVF) to assist in selection of euploid embryos, which involves performing trophectoderm biopsy. The effect of possible trauma caused by biopsy and the implication on pregnancy is unknown. Hence, the objective of the study was to determine if embryo biopsy for PGT-A affects birth weight or preterm birth rate., Methods: Using National Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) data, we identified 6352 cycles which had single embryo transfer (SET) and a singleton live birth following frozen embryo transfer (FET) between 2014 and 2015., Results: From the initial cohort of 25,121 fresh stimulation cycles, 6352 cycles were included who had a singleton live birth following FET. A total of 3482 (54.8%) had PGT-A confirmed euploid embryos and 2870 (45.2%) had embryos selected based on morphology for transfer. No difference in birthweight (g) was noted when FET was performed using PGT-A confirmed euploid embryos as compared to non-tested morphologically selected embryos (3370.7 vs. 3354.5, adjusted regression coefficient 11.4; 95% CI: -12.6; 35.3). As compared to morphologically selected embryos, performance of PGT-A did not increase the risk of small for gestation age (SGA) (3.9% vs. 4.1%, OR: 1.13; 95% CI: 0.86-1.50), low birth weight (LBW) (<2500 g but ≥1500 g) (5.8% vs. 5.5%, OR: 0.90; 95% CI: 0.66-1.21), or very low birthweight (<1500 g) (1.3% vs. 1.0%, OR: 0.44; 95% CI: 0.44 (0.18-1.10). There was no increased risk of preterm birth (PTB) associated with pregnancy resulting from PGT-A embryos vs. non PGT-A embryos (15.8% vs. 16.4%, OR: 0.94; 95% CI: 0.81-1.09)., Conclusions: In our study, trophectoderm biopsy for PGT-A did not increase the risk of SGA, LBW or PTB in IVF pregnancies.

Purpose: Our aim was to evaluate if maternal age at transfer following autologous oocyte cryopreservation is associated with live birth rate (LBR)., Methods: We performed a retrospective cohort study of all patients who thawed autologous oocytes and then underwent a single frozen euploid embryo transfer between 2011 and 2021 at a large urban university-affiliated fertility center. Each oocyte thaw patient was matched 2:1 to in vitro fertilization (IVF) patients who underwent single embryo transfer < 1 year after retrieval. Primary outcome was LBR. Secondary outcomes included implantation rates (IR) and spontaneous abortion rates (SABR)., Results: A total of 169 oocyte thaw patients were matched to 338 IVF patients. As expected, oocyte thaw patients were older (median age 42.5 vs. 37.6 years, p < 0.001) and waited longer between retrieval and transfer than in vitro fertilization patients (median time 59 vs. 1 month, p < 0.001). In univariate analysis, implantation and LBR differed among oocyte thaw and IVF patients (p < 0.05), but SABR did not (p = 0.57). Transfer outcomes in oocyte thaw patients did not differ based on transfer age group (IR: p = 0.18; SABR: p = 0.12; LBR: p = 0.24). In a multiple logistic regression model, age at transfer was not predictive of live birth when controlling for age at retrieval, embryo morphology, and day of blastulation., Conclusions: Maternal age at transfer after oocyte cryopreservation is not predictive of LBR; this suggests that "an aging womb" does not impair LBR after oocyte thaw and empowers patients to return for transfer when ready for childbearing., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: To report utilization, effectiveness, and safety of assisted reproductive technologies in 2015 and 2016., Design: A retrospective, cross-sectional survey of 3,103 assisted reproductive technology clinics in 74 countries in 2015 and 3,249 clinics in 79 countries in 2016 that submitted cycle and pregnancy outcome data through national and regional registries., Setting: Seventy-nine countries and >3,000 assisted reproductive technology clinics., Patient(s): Patients undergoing assisted reproductive technology procedures., Intervention(s): Assisted reproductive technology., Main Outcome Measure(s): Outcomes on country, regional, and global levels., Result(s): Reported for 2015: 2,358,239 cycles with 548,652 infants born; for 2016: 2,807,963 cycles with 647,188 infants born. Estimated in 2015, ≥2,683,677 cycles resulted in >675,134 infants; in 2016, ≥3,100,448 cycles resulted in ≥723,026 infants. Reported cycles represent approximately 80% of global utilization. In 2015 and 2016, 27.6% and 27.8%, respectively, of women undergoing fresh autologous treatment cycles were aged ≥40 years. Frozen-thawed embryo transfer (ET) cycles accounted for 47.0% and 51.9%, respectively, of all ETs in 2015 and 2016. Oocyte donation cycles accounted for 6.7% and 7.1% of all ETs in 2015 and 2016. Intracytoplasmic sperm injection was performed in 57.7% and 56.4% of autologous aspiration cycles in 2015 and 2016, respectively. The cumulative delivery rate per aspiration cycle for fresh and frozen-thawed ET was 32.4% in 2015 and 33.1% in 2016, respectively. The average number of transferred embryos was 1.70 in 2015 and 1.69 in 2016. The proportion of single ETs in fresh autologous cycles increased from 42.1% in 2015 to 44.0% in 2016. The twin delivery rate decreased from 16.0% in 2015 to 14.7% in 2016, and the triplet rate decreased from 0.6% in 2015 to 0.4% in 2016. The proportion of single ETs in frozen-thawed ET autologous treatment cycles was 62.2% in 2015 and 64.2% in 2016, with twin and triplet rates of 10.1% and 0.3% in 2015 and 10.0% and 0.2% in 2016, respectively., Conclusion(s): Utilization of assisted reproductive technology treatment and births per cycle increased from 2015 to 2016, although multiple births were reduced. An increasing proportion of frozen-thawed ET cycles, continuing wide variation in use of intracytoplasmic sperm injection, and an increase in single ET rates are reported., Competing Interests: Declaration of Interests M.S.K. reports travel support from Ferring, IBSA, and Merck, outside the submitted work. G.M.C. reports funding from the International Committee for Monitoring Assisted Reproductive Technologies (ICMART). The National Perinatal Epidemiology and Statistics Unit (NPESU) of the University of New South Wales, Sydney (UNSW) received funding. S.D. has nothing to disclose. F.Z.H. reports travel expenses to give a scientific lecture from Ferring Pharma, Director, responsible for the Latin American Registry of ART, Chair Committee of Ethics and Public Policies; Chilean Society of Obstetrics and Gynecology, Vice Chair ICMART, outside the submitted work. J.D.M. is Chair of Société de Médecine de la Reproduction, France, unpaid, outside the submitted work. O.I. has nothing to disclose. M.B. reports consulting fees from ABBOTT INIDA; honoraria from BAZEL PHARMA and MERCK SPEC; Board of Director, Pacific Rim Society of Reproductive Medicine; Board of Director, POSEIDON Group; Regional Director, IFFS Triennial Report, outside the submitted work. S.C.J. reports travel fee for lectures supported by Ferring; travel support from the Japan Society for Reproductive Medicine for attending meetings, outside the submitted work. B.F. has nothing to disclose. E.E. has nothing to disclose. V.B. reports consulting fees from Organon, Society for Assisted Reproductive Technology Executive Council, not paid, outside the submitted work. G.D.A. reports honoraria from Organon; travel support from ESHRE; Chair, International Committee for Monitoring ART. unpaid; President, World Endometriosis Research Foundation, unpaid; ICMART NGO Liaison Observer, Board of the International Federation of Fertility Societies, unpaid; ASRM: Member, Global Health Committee, American Society for Reproductive Medicine, unpaid; founder and CEO of Advanced Reproductive Care, Inc. (d/b/a ARC®Fertility), outside the submitted work., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Among the primary objectives of contemporary assisted reproductive technology research are achieving the births of healthy singletons and improving overall fertility outcomes. Substantial advances have been made in refining the selection of single embryos for transfer, with the aim of maximizing the likelihood of successful implantation. The principal criterion for this selection is embryo morphology. Morphological evaluation systems are based on traditional parameters, including cell count and fragmentation, pronuclear morphology, cleavage rate, blastocyst formation, and various sequential embryonic assessments. To reduce the incidence of multiple pregnancies and to identify the single embryo with the highest potential for growth, invasive techniques such as preimplantation genetic screening are employed in in vitro fertilization clinics. However, new approaches have been suggested for clinical application that do not harm the embryo and that provide consistent, accurate results. Noninvasive technologies, such as time-lapse imaging and omics, leverage morphokinetic parameters and the byproducts of embryo metabolism, respectively, to identify noninvasive prognostic markers for competent single embryo selection. While these technologies have garnered considerable interest in the research community, they are not incorporated into routine clinical practice and still have substantial room for improvement. Currently, the most promising strategies involve integrating multiple methodologies, which together are anticipated to increase the likelihood of successful pregnancy.

Objective: To evaluate in vitro fertilization (IVF) and perinatal outcomes of donor egg and autologous cycles in patients with advanced reproductive age after undergoing single frozen euploid embryo transfer., Design: A multicenter, retrospective, cohort study., Setting: University-affiliated and private IVF centers., Patient(s): Patients aged 39-46 years who underwent IVF with intracytoplasmic sperm injection and preimplantation genetic testing for aneuploidy using whole-chromosome sequencing with donor (n = 278) or autologous (n = 278) oocytes between October 2017 and October 2021., Intervention(s): Single frozen euploid embryo transfer with donor or autologous euploid embryo., Main Outcome Measure(s): The main outcome measure was the live birth rate (LBR) after the first embryo transfer, calculated per embryo transfer. The secondary outcomes included the implantation rate, ectopic pregnancy rate, miscarriage rate, and gestational age and birth weight at the time of delivery., Result(s): Patients using donor or autologous oocytes had a similar likelihood of implantation (57.91% [51.87-63.78] vs. 57.19% [51.15-63.09]) and LBR (41.01% [95% confidence interval {CI}, 35.17-47.04] vs. 42.45% [95% CI, 36.56-48.49]). Furthermore, there were no significant differences in the ectopic pregnancy rate (0.72% [0.09-2.57] vs. 0.36% [0.01-1.99]), miscarriage rate (16.19% [12.06-21.05] vs. 14.39% [95% CI, 10.48-19.08]), gestational age (38.50 [38.08-38.92] vs. 39.16 [38.25-40.07] weeks), or birth weight of infants (2,982.25 [2,606.69-3,357.81] vs. 3,128.24 [2,962.30-3,294.17] kg). The univariate analysis showed no association between advanced maternal age and the LBR (relative risk, 1.03 [95% CI, 0.84-1.25]). Multivariate analysis using putative confounders for embryo competency found no associations with LBR (adjusted relative risk, 1.22 [95% CI, 0.75-1.98])., Conclusion(s): Patients with euploid blastocysts derived from donor or autologous oocytes did not reveal statistically significant differences in the LBR, implantation rate, ectopic pregnancy rate, miscarriage rate, duration of gestation, or infant birth weight. These findings suggest that age-related reproductive decline and/or poor IVF outcomes associated with women with advanced reproductive age undergoing IVF are heavily driven by embryonic aneuploidy., Competing Interests: Declaration of Interests M.C. has nothing to disclose. A.C. has nothing to disclose. J.A.G.-V. has nothing to disclose. A.P. has nothing to disclose. A.V. has nothing to disclose. D.G. has nothing to disclose. D.C. has nothing to disclose. F.M.U. has nothing to disclose. V.P. has nothing to disclose. P.E.L.-S. has nothing to disclose., (Copyright © 2024 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Background: The increased use of gestational carriers has expanded family-building opportunities for people and couples unable to carry pregnancies on their own. National American Society of Reproductive Medicine guidelines for gestational carriers have changed over time to reflect advances in reproductive technology and mounting evidence supporting the medical benefits associated with singleton gestations., Objective: Assess changes in gestational carrier cycle practice patterns and resultant pregnancy outcomes in the United States in relation to changing national American Society of Reproductive Medicine guidelines, which changed in 2013 and 2017., Study Design: This retrospective study used data from the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System and included all cycles that were reported from 2014-2020 involving an embryo transfer to a gestational carrier. Binomial regression models evaluated trends in preimplantation genetic testing for aneuploidy, American Society of Reproductive Medicine guideline adherence, number of embryos transferred, and pregnancy outcomes over time., Results: Of the 40,177 gestational carrier transfer cycles from 2014-2020, there was a significant increase in frozen-thawed cycles (41.3% increase), use of assisted hatching (53.4% increase), intracytoplasmic sperm injection (50.0% increase), and preimplantation genetic testing for aneuploidy (155.7% increase). The likelihood of preimplantation genetic testing for aneuploidy was higher in 2020 than in 2014 for autologous oocyte transfers to gestational carriers, both for those aged ≥38 years (adjusted relative risk, 2.38 [95% confidence interval, 2.11-2.70]) and than those aged <38 years (adjusted relative risk, 2.85 [95% confidence interval, 2.58-3.15]). As preimplantation genetic testing for aneuploidy usage increased, single embryo transfer rose for both autologous (adjusted relative risk, 2.22 [95% confidence interval, 1.94-2.50]) and donor cycles (relative risk, 1.91 [95% confidence interval, 1.81-2.02]). This shift toward single embryo transfer corresponded with a decrease in multiple embryo transfer by 79.2% and subsequent decreases in multiple gestations by 68.8% in donor and 73.6% in autologous oocyte cycles from 2014-2020. Gestational carrier cycles remained highly adherent to changing American Society of Reproductive Medicine guidelines throughout the study period. Among live births, there was a 19.4% and 7.9% increase in term deliveries among donor and autologous oocyte cycles, respectively, from 2014 to 2020., Conclusion: Practice patterns have drastically changed throughout the study period, with major increases in the use of preimplantation genetic testing for aneuploidy, intracytoplasmic sperm injection, assisted hatching, and frozen transfers. In response to changing American Society of Reproductive Medicine guidelines, the use of multiple embryo transfers has decreased for gestational carrier cycles with subsequent decreases in multiple gestations and miscarriages and slight increases in live birth rates., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Essential trace elements are micronutrients whose deficiency has been associated with altered fertility and/or adverse pregnancy outcomes, while surplus may be toxic. The concentrations of eight essential trace elements were measured using inductively coupled mass spectrometry (ICP-MS) and assessed with respect to clinical in vitro fertilization (IVF) outcomes in a population of 51 women undergoing IVF with intracytoplasmic sperm injection (ICSI), pre-implantation genetic screening for aneuploidy (PGT-A), and single frozen euploid embryo transfer (SET/FET). Specifically, copper (Cu), zinc (Zn), molybdenum, selenium, lithium, iron, chromium, and manganese were quantified in follicular fluid and whole blood collected the day of vaginal oocyte retrieval (VOR) and in urine collected the day of VOR and embryo transfer. We found that the whole blood Cu/Zn ratio was significantly associated with superior responses to ovarian stimulation. Conversely, the whole blood zinc and selenium concentrations were significantly associated with poor ovarian response outcomes. Higher levels of whole blood zinc and selenium, urinary selenium, lithium, and iron had significant negative associations with embryologic outcomes following IVF. Regarding clinical IVF outcomes, higher urinary molybdenum concentrations the day of VOR were associated with significantly lower odds of implantation and live birth, while higher urinary Cu/Mo ratios on the day of VOR were associated with significantly higher odds of implantation, clinical pregnancy, and live birth. Our results suggest that essential trace element levels may directly influence the IVF outcomes of Spanish patients, with selenium and molybdenum exerting negative effects and copper-related ratios exerting positive effects. Additional studies are warranted to confirm these relationships in other human populations.

Objective: Our objective was to estimate the association between in vitro fertilization (IVF) pregnancy and adverse pregnancy outcomes during delivery hospital admission in a contemporary, nation-wide cohort of births in the United States., Study Design: This retrospective, population-based cohort study used the National Inpatient Sample database to identify patients discharged from the hospital following delivery from 2014 to 2019. IVF pregnancies were identified using the International Classification of Disease-Revision 9/10 codes. Crude and adjusted odds ratios of preterm birth and other clinically significant adverse pregnancy outcomes were evaluated using multivariable logistic regression models. Trends in preterm birth and multiple pregnancy were estimated over the study period. The contribution of multiple pregnancy to preterm birth in IVF pregnancy was estimated in a mediation analysis., Results: Among 4,451,667 delivery-related discharges, IVF pregnancies were associated with 3.25 times the odds of preterm birth (95% confidence interval [CI]: 3.05-3.46, p  < 0.001) compared with non-IVF pregnancy deliveries. Odds of preterm birth in IVF pregnancy delivery discharges decreased over the study period ( p -value for linear trend = 0.009). The proportion of multiple pregnancies decreased in IVF pregnancy delivery discharges but remained stable in non-IVF pregnancy deliveries. The proportion of the adjusted effect of IVF pregnancy on preterm birth mediated through multiple pregnancy was 67.6% (95% CI: 62.6-72.7%)., Conclusion: While the odds of adverse pregnancy outcomes are increased compared with non-IVF pregnancies, the odds of preterm birth and multiple gestation have decreased among IVF pregnancies in the United States., Key Points: · Pregnancies conceived by in vitro fertilization (IVF) are at significantly higher risk of multiple gestation, preterm birth, and other pregnancy complications.. · Recent guidelines for artificial reproductive treatments recommend single-embryo transfer in IVF.. · Using population-wide data, we demonstrate a significant gradual decline in the rates of preterm birth and other pregnancy complications following IVF in the last decade, mostly mediated by a reduction in multiple pregnancies.., Competing Interests: None declared., (Thieme. All rights reserved.)

Study Question: Which clinical and embryological factors should be considered to apply double embryo transfer (DET) instead of elective single embryo transfer (eSET)?, Summary Answer: No clinical or embryological factor per se justifies a recommendation of DET instead of eSET in IVF/ICSI., What Is Known Already: DET is correlated with a higher rate of multiple pregnancy, leading to a subsequent increase in complications for both mother and babies. These complications include preterm birth, low birthweight, and other perinatal adverse outcomes. To mitigate the risks associated with multiple pregnancy, eSET is recommended by international and national professional organizations as the preferred approach in ART., Study Design, Size, Duration: The guideline was developed according to the structured methodology for development and update of ESHRE guidelines. Literature searches were performed in PUBMED/MEDLINE and Cochrane databases, and relevant papers published up to May 2023, written in English, were included. Live birth rate, cumulative live birth rate, and multiple pregnancy rate were considered as critical outcomes., Participants/materials, Setting, Methods: Based on the collected evidence, recommendations were discussed until a consensus was reached within the Guideline Development Group (GDG). A stakeholder review was organized after the guideline draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee., Main Results and the Role of Chance: The guideline provides 35 recommendations on the medical and non-medical risks associated with multiple pregnancies and on the clinical and embryological factors to be considered when deciding on the number of embryos to transfer. These recommendations include 25 evidence-based recommendations, of which 24 were formulated as strong recommendations and one as conditional, and 10 good practice points. Of the evidence-based recommendations, seven (28%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (three recommendations; 12%), or very low-quality evidence (15 recommendations; 60%). Owing to the lack of evidence-based research, the guideline also clearly mentions recommendations for future studies., Limitations, Reasons for Caution: The guideline assessed different factors one by one based on existing evidence. However, in real life, clinicians' decisions are based on several prognostic factors related to each patient's case. Furthermore, the evidence from randomized controlled trials is too scarce to formulate high-quality evidence-based recommendations., Wider Implications of the Findings: The guideline provides health professionals with clear advice on best practice in the decision-making process during IVF/ICSI, based on the best evidence currently available, and recommendations on relevant information that should be communicated to patients. In addition, a list of research recommendations is provided to stimulate further studies in the field., Study Funding/competing Interest(s): The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, the literature searches, and the dissemination of the guideline. The guideline group members did not receive payment. DPB declared receiving honoraria for lectures from Merck, Ferring, and Gedeon Richter. She is a member of ESHRE EXCO, and the Mediterranean Society for reproductive medicine and the president of the Croatian Society for Gynaecological Endocrinology and Reproductive Medicine. CDG is the past Chair of the ESHRE EIM Consortium and a paid deputy member of the Editorial board of Human Reproduction. IR declared receiving reimbursement from ESHRE and EDCD for attending meetings. She holds an unpaid leadership role in OBBCSSR, ECDC Sohonet, and AER. KAR-W declared receiving grants for clinical researchers and funding provision to the institution from the Swedish Cancer Society (200170F), the Senior Clinical Investigator Award, Radiumhemmets Forskningsfonder (Dnr: 201313), Stockholm County Council FoU (FoUI-953912) and Karolinska Institutet (Dnr 2020-01963), NovoNordisk, Merck and Ferring Pharmaceuticals. She received consulting fees from the Swedish Ministry of Health and Welfare. She received honoraria from Roche, Pfizer, and Organon for chairmanship and lectures. She received support from Organon for attending meetings. She participated in advisory boards for Merck, Nordic countries, and Ferring. She declared receiving time-lapse equipment and grants with payment to institution for pre-clinical research from Merck pharmaceuticals and from Ferring. SS-R received research funding from Roche Diagnostics, Organon/MSD, Theramex, and Gedeo-Richter. He received consulting fees from Organon/MSD, Ferring Pharmaceuticals, and Merck Serono. He declared receiving honoraria for lectures from Ferring Pharmaceuticals, Besins, Organon/MSD, Theramex, and Gedeon Richter. He received support for attending Gedeon Richter meetings and participated in the Data Safety Monitoring Board of the T-TRANSPORT trial. He is the Deputy of ESHRE SQART special interest group. He holds stock options in IVI Lisboa and received equipment and other services from Roche Diagnostics and Ferring Pharmaceuticals. KT declared receiving payment for honoraria for giving lectures from Merck Serono and Organon. She is member of the safety advisory board of EDQM. She holds a leadership role in the ICCBBA board of directors. ZV received reimbursement from ESHRE for attending meetings. She also received research grants from ESHRE and Juhani Aaltonen Foundation. She is the coordinator of EHSRE SQART special interest group. The other authors have no conflicts of interest to declare., Disclaimer: This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (full disclaimer available at https://www.eshre.eu/Guidelines-and-Legal)., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

The aim of this study was to investigate if variation in endometrial thickness affects clinical pregnancy and live birth rates among patients undergoing single euploid embryo transfer (SET). A retrospective review of IVF cycles performed at a single private fertility institution between 2015 and 2020 was performed. Patients with normal uterine anatomy undergoing their first SET of a euploid embryo undergoing their first cycle at the center were included, for a total of 796 cycles. Endometrial thickness was measured by transvaginal ultrasound following 10-14 days of estradiol exposure. Specific infertility diagnoses did not significantly impact endometrial lining thickness with means across diagnoses ranging from 9.3 to 11.0 mm. Endometrial thickness was grouped into five categories: < 8 mm, 8-10 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm. Using 8-10 mm as the reference group, the odds ratio of live birth was 0.5, 1.22, 1.05, and 1.05 for < 8 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm groups, respectively. Risk of first trimester miscarriage was equivalent across groups. There was a trend toward an increased rate of biochemical pregnancies in patients with a < 8 mm and ≥ 15 mm endometrium; however, this was not statistically significant. The clinical pregnancy and live birth rate were lowest in patients with < 8-mm endometrial thickness. For single euploid embryo transfers, an endometrial lining greater than or equal to 8 mm confers optimal live birth rates following a medicated FET cycle. These data confirm the findings of prior studies in fresh embryo transfers without the confounders of supraphysiologic ovarian hormone concentrations and genetically untested embryos., (© 2023. The Author(s), under exclusive licence to Society for Reproductive Investigation.)

The Association for the Study of Reproductive Biology (ASEBIR) Interest Group in Embryology (in Spanish 'Grupo de Interés de Embriología') reviewed key morphokinetic parameters to assess the contribution of time-lapse technology (TLT) to the ASEBIR grading system. Embryo grading based on morphological characteristics is the most widely used method in human assisted reproduction laboratories. The introduction and implementation of TLT has provided a large amount of information that can be used as a complementary tool for morphological embryo evaluation and selection. As part of IVF treatments, embryologists grade embryos to decide which embryos to transfer or freeze. At the present, the embryo grading system developed by ASEBIR does not consider dynamic events observed through TLT. Laboratories that are using TLT consider those parameters as complementary data for embryo selection. The aim of this review was to evaluate review time-specific morphological changes during embryo development that are not included in the ASEBIR scoring system, and to consider them as candidates to add to the scoring system. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the effect of an extended culture period on birth weight among singletons born after vitrified-warmed embryo transfer., Methods: A retrospective cohort study was performed among 12400 women who gave birth to 1015, 1027, 687, and 9671 singletons after single blastocyst transfer, single cleavage-stage embryo transfer, double blastocyst transfer, and double cleavage-stage embryo transfer, respectively., Results: The unadjusted birth weight of singletons born after vitrified blastocyst transfer were heavier than those born after cleavage-stage transfer (β=30.28, SE=13.17, P=0.022), as were the adjusted birth weights (β=0.09, SE=0.03, P=0.007). In addition, there was a 37% increased odd of having an infant with high birth weight after vitrified blastocyst transfer compared with vitrified cleavage stage transfer (OR=1.37, 95% CI:1.07-1.77)., Conclusion: The unadjusted and adjusted birth weight and odds of having an infant with high birth weight significantly increased after blastocyst transfer compared with cleavage-stage embryo transfer in vitrified-warmed cycles., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Lin, Zhao and Zhang.)

A heterotopic pregnancy is a rare and serious pathological pregnancy. In this paper, we report a rare case of heterotopic pregnancy and perform a literature review. A 30-year-old patient with a history of left adnexectomy presented with persistent lower abdominal pain and hemorrhagic shock after single embryo transfer. Emergency laparoscopic exploration revealed a ruptured mass in the right isthmus of the fallopian tube, for which right salpingectomy was performed. After anti-inflammatory treatment and fetal preservation, the intrauterine pregnancy progressed smoothly, and a healthy baby was delivered at 39 weeks gestation. In this case, the patient's heterotopic pregnancy was possibly due to a natural pregnancy caused by sexual intercourse during treatment, so we recommend that sexual intercourse be avoided during transfer cycles., (© 2024. The Author(s).)

Purpose: The primary objective of this investigation is to evaluate how morphological quality affects the pregnancy outcomes in euploid embryos determined by preimplantation genetic testing for aneuploidies (PGT-A). Concurrently, as a secondary objective, we aim to identify which specific aspects of morphological evaluation exert the most significant impact on these outcomes., Methods: A retrospective analysis of 451 single euploid embryo transfer cycles at our clinic was conducted. Embryos were evaluated based on the degree of blastocyst expansion, inner cell mass (ICM), trophectoderm (TE) morphology, and the day of blastocyst vitrification. Outcomes between morphologically low-grade and high-grade embryos were compared. Additionally, the study analyzed which morphological factors most influenced pregnancy outcomes., Results: Pregnancy outcomes were significantly lower in morphologically low-grade blastocysts compared to high-grade ones. Among the morphological evaluations, the ICM assessment was significantly associated with the live birth rate., Conclusion: Our study indicates that the morphological quality of euploid embryos, particularly the evaluation of the ICM, plays a crucial role in IVF-ET success., Competing Interests: The authors declare that there are no conflicts of interest., (© 2024 The Authors. Reproductive Medicine and Biology published by John Wiley & Sons Australia, Ltd on behalf of Japan Society for Reproductive Medicine.)