Single Embryo Transfer Cycles Research Articles

Prehypertension in male affects both semen quality and pregnancy outcomes in their first single blastocyst frozen-thawed embryo transfer cycles

To investigate whether prehypertension (pre-HTN) in male affects semen quality and assisted reproductive technology (ART) outcomes. Retrospective cohort study. University-affiliated reproductive medicine center. Clinical data were collected from 1,043 couples undergoing their first single blastocyst frozen-thawed embryo transfer cycles. According to the blood pressure (1 mm Hg = 0.133 kPa) in male, including systolic blood pressure (SBP) and diastolic blood pressure (DBP), the subjects were divided into the control group (90 ≤ SBP < 120 mm Hg and 60 ≤ DBP < 80 mm Hg, n = 611) and the pre-HTN group (120 ≤ SBP < 140 mm Hg and/or 80 ≤ DBP < 90 mm Hg, n = 432). The association between pre-HTN and semen quality, and ART outcomes was then evaluated. Primary outcome: live birth rate. semen quality, laboratory embryo outcomes, clinical pregnancy rate, biochemical pregnancy rate, miscarriage rate, and other pregnancy outcomes. Compared with the control group, the pre-HTN group showed lower total sperm motility, total sperm count, sperm progressive motility, progressive sperm count , and higher prevalence of oligozoospermia (17.6% vs. 13.1%), and asthenozoospermia (37.7% vs. 19.8%). Meanwhile, compared with the control group, the pre-HTN group had a lower clinical pregnancy rate (42.8% vs. 57.6%) and a lower live birth rate (32.9% vs. 47.3%). There were no differences in the remaining parameters of semen quality, laboratory embryo outcomes (except for the proportion of intracytoplasmic sperm injection), and pregnancy outcomes between the two groups. Additionally, regression analysis showed that pre-HTN in male was an independent risk factor for clinical pregnancy (adjusted odds ratio, 0.57; 95% confidence interval, 0.44-0.74) and live birth (adjusted odds ratio, 0.58; 95% confidence interval, 0.44-0.75). Prehypertension in male not only results in lower semen quality, but also has negative consequences on the success of ART. It is an independent risk factor for clinical pregnancy and live birth in the first single blastocyst frozen-thawed embryo transfer cycles.

The association between female age and pregnancy outcomes in patients receiving first elective single embryo transfer cycle: a retrospective cohort study

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.

Associations between Non-Essential Trace Elements in Women's Biofluids and IVF Outcomes in Euploid Single-Embryo Transfer Cycles.

Previous studies have found inconsistent associations between heavy metals and metalloids (cadmium, lead, mercury, and arsenic), and reproductive outcomes. The biofluid concentrations of ten non-essential trace elements (Hg, Pb, As, Ba, Sr, Rb, Cs, Sn, Ni, and Co) were evaluated in 51 Spanish women undergoing ICSI, PGT-A, and SET/FET. Nine out of ten non-essential elements were detectable in follicular fluid, whole blood, and urine collected the day of vaginal oocyte retrieval (VOR) and the day of embryo transfer and then analyzed by ICP-MS or Tricell DMA-80 for mercury. Elevated mercury and strontium concentrations in follicular fluid were associated with poor ovarian response and preimplantation outcomes. Worst preimplantation outcomes were also identified in women with elevated whole-blood strontium or mercury, urinary arsenic, barium, and tin the day of VOR. High concentrations of urinary rubidium on VOR day were linked with enhanced fertilization and blastocyst development. Excessive titanium in whole blood was associated with lower odds of implantation, clinical pregnancy, and achieving a live birth in a given IVF cycle. Excessive urinary arsenic on the day of embryo transfer was associated with lower odds of live birth. Although these preliminary results need to be confirmed in larger populations, distinguishing organic and inorganic element forms, our findings show that some non-essential elements have a detrimental impact on human IVF outcomes.

Trends and outcomes of fresh and frozen donor oocyte cycles in the United States

ObjectiveTo examine trends, characteristics, and outcomes of donor oocyte embryo transfer cycles by original oocyte and resultant embryo state and determine whether oocyte state (fresh or frozen) is differentially associated with clinical pregnancy, live birth, and term, normal birthweight neonates among singleton live births. DesignRetrospective cohort study SubjectsPatients undergoing donor oocyte embryo transfer cycles in the United States reporting to National Assisted Reproductive Technology Surveillance System (NASS) from 2013–2020 ExposureOriginal donor oocyte and resultant embryo state (fresh or frozen) Main Outcome MeasuresAnnual numbers and proportions of total donor oocyte embryo transfer cycles stratified by oocyte and embryo state and single embryo transfer cycles resulting in live birth of term (≥37 weeks gestation), normal birthweight (≥2500g) singletons during 2013–2020. Rates of live birth and term, normal birthweight neonates among singleton live births for 2018–2020 are also reported. Relative risks (RR) examine associations between donor oocyte state and live birth and term, normal birthweight neonates among singleton live births resulting from donor oocyte embryo transfer cycles. ResultsFrom 2013-2020, there were 135,085 donor oocyte embryo transfer cycles, of which the proportions increased for frozen embryos (42.3% to 76.6%), fresh embryos using frozen donor oocytes (19.9% to 68.3%) and single embryo transfer (SET) (36.4% to 85.5%). During 2018–2020, there were 48,679 donor oocyte embryo transfer cycles. Rates of live birth were lower with frozen compared to fresh donor oocytes for both fresh (46.2%, 55.9%; aRR 0.83 [95% CI 0.79–0.87]) and frozen (41.3%, 45.8%; aRR 0.94 [95% CI 0.91–0.98]) embryo transfer cycles. Among singleton live births, rates of delivering a term, normal birthweight neonate were similar for frozen compared to fresh donor oocyte transfer cycles among fresh (77.3, 77.2%; aRR 1.01 [95% CI 0.98–1.03]) and frozen (75.6, 75.1%; aRR 1.02 [95% CI 0.99–1.04]) embryos. ConclusionIn this national study of donor oocyte embryo transfer cycles, frozen embryo transfers, fresh embryo transfers using frozen oocytes, and SET increased. Although frozen compared to fresh oocytes were associated with a slightly reduced rate of live birth, rates of term, normal birthweight neonates among singleton live births were comparable between donor oocyte states.

Effects of high-normal fasting blood glucose on ART outcomes of frozen-thawed single blastocyst transfer in women with normal BMI.

This retrospective cohort study aims to investigate whether high-normal fasting blood glucose (FBG) affects assisted reproductive technology (ART) outcomes undergoing single blastocyst frozen-thawed embryo transfer (FET) cycles in women with normal body mass index (BMI). 944 women with normal BMI and FBG levels undergoing single blastocyst FET cycles were enrolled. Based on the median of FBG (4.97mmol/L, 1mmol/L = 18mg/dL), the subjects were categorized into the low-normal group (3.90 ≤ FBG ≤ 4.97 mmol/L, n = 472) and the high-normal group (4.97 < FBG < 6.10mmol/L, n = 472). Multivariable logistic regression and receiver operating characteristic (ROC) were used to analyze the relationship between high-normal FBG and ART outcomes. live birth rate (LBR). LBR was significantly lower in the high-normal group than in the low-normal group (36.8% vs. 45.1%, p = 0.010), and the miscarriage rate was considerably higher than that in the low-normal group (23.9% vs. 16.5%, p = 0.041). High-normal FBG of female was an independent predictor of live birth (adjusted OR:0.747, 95% CI: 0.541-0.963, p = 0.027) and miscarriage (adjusted OR:1.610, 95% CI: 1.018-2.547, p = 0.042). ROC analyses showed that the cut-off values of FBG (endpoints: live birth and miscarriage) were 5.07mmol/L, and 5.01mmol/L, respectively. In women with normal BMI, high-normal FBG is an independent risk factor for lower LBR and higher miscarriage rate in single blastocyst FET cycles. Attention to preconception FBG monitoring in this particular population may allow early intervention to improve ART outcomes.

P-407 Exploring the effectiveness of tailoring estradiol supplementation duration to mimic the natural cycle length in artificial endometrial preparation for frozen embryo transfer cycles

Abstract Study question Is an estrogen supplementation duration similar in length to the follicular phase of a natural cycle associated with a better clinical pregnancy rate? Summary answer An estradiol supplementation duration, which is proportional to the natural follicular phase length, results in significantly better outcomes compared to shorter exposure durations What is known already The last decade witnessed a major increase in the use of single euploid frozen embryos. Artificial endometrial preparation (AEP) has proven to be effective to prepare the endometrium for implantation. However, several features of AEP need to be clarified mainly the duration of estrogen supplementation and until now no study took into consideration the difference between exogenous estrogen supplementation and the actual length of the follicular phase of each patient during AEP. Furthermore, most of the studies focused on upper limit of estrogen exposure while few considered the lower limit. Unfortunately, the results on pregnancy rates were mixed. Study design, size, duration 663 single euploid frozen embryo transfer cycles were included. Patients underwent vaginal ultrasound and hormonal blood measurement (Estradiol, Progesterone) on day 2 of their cycle. Estradiol valerate (4 mg the first 2 days then 6 mg daily, Orally) was started on the same day and another control was done around day 10. When triple lining pattern of the endometrium was seen, vaginal progesterone was initiated (800 mg daily) and SET was done after 120 hours. Participants/materials, setting, methods Patients with reported regular menstrual cycle (25-35 days) were included and the difference between estrogen supplementation and the actual follicular phase was calculated for each patient. Patients were sorted into 2 groups as follows: 231 women with normal interval (±2 days of follicular phase length), and 432 women with short interval (-3 days or shorter). Only the first single euploid embryo transfer cycles were analyzed for these patients. Main results and the role of chance Whereas patients had similar characteristics in both groups, the corresponding clinical pregnancy rates in normal and short supplementation groups were 69.3% (160/231) and 64% (277/432), respectively. After balancing the groups for BMI, embryo quality and endometrial thickness with inverse treatment probability weighting, those who received estradiol supplementation proportional to their natural follicular phase length had significantly higher clinical pregnancy rates compared to those who received it for shorter durations (adjusted OR: 1.48, 95% CI: 1.16 – 1.89, P = 0.002). Serum estradiol levels were available for 523 cycles, the clinical pregnancy rate in those within the 1st quartile (&amp;lt;155pmol/L), 2nd to 3rd quartile (155 to 275pmol/L) and 4th quartile (&amp;gt;275pmol/L) were 70%, 64.7% and 63%. After adjusting for BMI and embryo quality, higher (&amp;gt;275pmol/L) (adjusted OR: 0.84, 95% CI: 0.53-1.32, P = 0.442) and lower(&amp;lt;155pmol/L) (adjusted OR: 1.37, 95% CI: 0.85-2.22, P = 0.202) estradiol levels were not significantly associated with clinical pregnancy. Limitations, reasons for caution The present study could not address the influence of very long estrogen supplementation on clinical pregnancy rate due to limited samples. Further prospective studies, including larger populations, are needed to confirm our findings Wider implications of the findings Our data indicate that mimicking individually the natural cycle regarding estrogen supplementation duration in AEP for single euploid embryo transfer cycles can produce significant improvement in clinical pregnancy rates. Trial registration number not applicable

P-755 Effect of female age and specific cycle characteristics on success in modified natural frozen-thawed single euploid embryo transfer cycles (mNC/FET)

Abstract Study question Does the age of woman and specific cycle characteristics impact the success of modified natural frozen-thawed single euploid embryo transfer cycles (mNC/FET)? Summary answer The success rate of mNC/FET cycles is similar in all age groups. As the LH level increased ( above 23.5ng/dL) the success was significantly increased. What is known already The success of frozen embryo transfer can depend on various factors such as the patient’s age, the number of transferred embryos, the duration of embryo culture, and the method used to prepare the endometrium (Holschbach et al. 2023). However, there is currently insufficient evidence in the literature about the effect of age and cycle characteristics on the effectiveness of mNC/FET cycles in patients who have received single top and good quality euploid embryos. Study design, size, duration This study, conducted at Istanbul Memorial Hospital, ART and Reproductive Genetics Center, is a retrospective, single-centre analysis of 583 cycles of euploid mNC/FET in women aged 22-44 years. The study period was from July 2017 to January 2024. The cycles were divided into two groups based on the age of the women. Group A (n = 408) included women under the age of 38, while Group B (n = 175) included women aged 38 or above. Participants/materials, setting, methods The study investigated success predictors in mNC/FET with top and good-quality embryos. Excluded were women with recurrent pregnancy losses, recurrent implantation failure, high BMI (&amp;gt;35kg/m2), uterine/endometrial problems, severe male infertility, and autoimmune diseases. The mNC/FET success was a pregnancy lasting 12 weeks or more. The analysis included patient demographics and cycle outcomes. Chi-square, t-tests, and Mann-Whitney U tests assessed variables with a p-value &amp;lt; 0.005, indicating statistical significance. Main results and the role of chance No significant demographic differences were observed between the two groups, except for AMH levels. AMH levels were significantly higher in younger group than older group (3.02 ng/ml vs. 1.96 ng/ml, p = 0.000). The mNC/FET success rates were similar, with 76% in the younger group and 73% in the older group. Estradiol levels the day before trigger day were significantly higher in older group (278.02 pg/ml vs. 237.84pg/ml, p = 0.028). Both groups had similar mean LH levels (32.50 IU/L and 32.41 IU/L, respectively), estradiol levels and endometrial thickness on the trigger day. In the younger group, LH rise was observed later, follicular phase was longer, and embryo transfer day was later than the older group (p = 0.001). Univariate regression analysis revealed that increased LH level was an important independent variable in achieving mNC/FET success, with a 1.001-fold increase (p = 0.043). The LH levels of 23.5 IU/L or higher predicted high mNC/FET success with 60% sensitivity and 43% specificity based on the Receiver Operating Characteristic curve. (AUC: 0.606, %95 CI 0.540-0.671, p = 0.002). Prolonged infertility duration and previous ET failures reduced mNC/FET success by 0.889 and 0.544-fold, respectively (p = 0.002, p &amp;lt; 0.001). Higher β-hCG levels on days 14 and 16 increased mNC/FET success by 1.038-fold and 1.008-fold, respectively (p &amp;lt; 0.001). Limitations, reasons for caution Our study has limitations as it was retrospective. Prospective randomized studies are needed to evaluate the differences between the young (age &amp;lt;38) and old patient groups (age ≥38) based on mNC/FET success. The association between LH rise and mNC/FET success needs verification with a larger sample. Wider implications of the findings The mNC/FET success rates are similar in young (age &amp;lt;38) and old patient groups (age ≥38). However, prolonged infertility duration and previous failed ET cycles decreased the success of mNC/FET. Additionally, It is important to schedule trigger time after the optimum LH rise, which is 23.5 IU/L or higher. Trial registration number not applicable

P-557 The contribution of PGT-A to PGT-M and PGT-SR clinical outcomes – A single centre retrospective analysis

Abstract Study question To determine if the introduction of concurrent testing with PGT-A has improved clinical outcomes for PGT-M/SR patients. Summary answer This study demonstrates that the introduction of concurrent testing may have improved clinical outcomes for this patient demographic irrespective of age. What is known already Preimplantation Genetic Testing (PGT) is utilised to investigate the genetic constitution of embryos. PGT-M (monogenic) and PGT-SR (structural rearrangements) are screening techniques considered in treatment for couples at risk of conceiving offspring with known genetic or structural chromosomal abnormalities respectively. Preimplantation Genetic testing for Aneuploidy (PGT-A) was developed in order to screen embryos for numerical chromosomal abnormalities, a leading cause of failed implantation. Nevertheless, routine use of PGT-A is discouraged due to lack of evidence regarding its efficacy. However, PGT-A is routinely used alongside PGT-M and PGT-SR despite the lack of evidence of its effectiveness in improving patient outcomes. Study design, size, duration The retrospective analysis of 496 PGT-M/SR single embryo transfer patient cycles between December 2013 and December 2021. Participants/materials, setting, methods The retrospective analysis of 496 PGT-M/SR single embryo transfer cycles at CRGH Portland was undertaken (single testing n = 77; concurrent testing n = 419). The clinical outcomes (positive urine pregnancy test, clinical pregnancy, live birth and miscarriage rates) were compared between groups using IBM SPSS Statistics (premium 27). Binary logistic regression was performed for statistical analysis, results with p &amp;lt; 0.05 were determined statistically significant. Main results and the role of chance Overall, concurrent testing was associated with statistically significant improved clinical outcomes compared to the reference group. Statistical significance was seen in positive urine pregnancy test (49% vs 68%, p = 0.012), clinical pregnancy (32.5% vs 63%; p = 0.000013), live birth rate (32.5% vs 59%; p = &amp;lt;0.00016) and miscarriage rates (34.2% vs 13%; p = 0.001). The results imply that the introduction of concurrent testing has improved the probability of obtaining a positive clinical outcome and has reduced the chance of miscarriage in this patient demographic. Further analysis showed concurrent testing improved the chances of obtaining a positive clinical outcome irrespective of the patients age or quality of the embryo. Limitations, reasons for caution This study has produced promising results. However, there are several limitations such as the small sample size, embryo biopsy techniques used, and the different molecular diagnostic techniques and providers utilised. Wider implications of the findings The results imply a justification for the use of PGT-A alongside PGT-M/SR screening techniques to improve embryo selection and clinical outcomes for this cohort of patients. Additionally, they demonstrate the efficacy of PGT-A in a previously underrepresented demographic. However, further research is required to confirm the clinical value of PGT-A. Trial registration number not applicable

P-711 Female age at embryo creation and embryo transfer do not impact the ongoing pregnancy rates in single euploid frozen embryo transfers

Abstract Study question Which factors influence the ongoing pregnancy rate in single euploid frozen embryo transfer (seFET) cycles? Summary answer Ongoing pregnancy rates in seFET cycles are significantly influenced by parity, BMI, embryo quality, trophectoderm biopsy day and endometrial preparation, but not by female age. What is known already The probability of a pregnancy is influenced by several factors and female age is the major determinant as the ovarian reserve decreases and embryo aneuploidy increases with age. Preimplantation genetic testing for aneuploidy and embryo selection was considered to mitigate the effect of female age on ART treatment outcomes by selecting euploid embryo(s) for embryo transfer (ET). Previously published data point to a decline in pregnancy rates with increased maternal age even when a euploid embryo is transferred. However, other factors besides embryo ploidy might play a role in the chance of achieving an ongoing pregnancy. Study design, size, duration Retrospective study, including 1923 women who underwent a seFET between 04/2017 and 08/2023. Patients’ (age at oocyte-pick-up and seFET, BMI, parity, endometrial preparation type) and embryo characteristics (Day of biopsy, embryo quality (EQ)) were considered for the analysis. Ongoing pregnancy was defined as viable pregnancy beyond 12 weeks of gestation. Participants/materials, setting, methods Women, undergoing a seFET either in a true natural cycle (NC) t or in a hormonal replacement cycle (HRT). Only cycles with embryos being biopsied on day 5 or day 6 and a known outcome of the cycle were included. Main results and the role of chance There were 990 (51.48%) ongoing pregnancies among 1923 included transfers. The ongoing pregnancy rates were 51.8%, 47.4%, 52.3% and 52.8% for women aged ≤35, &amp;gt;35 to ≤ 37, &amp;gt;37 to ≤ 40, and &amp;gt;40 years-old at seFET, respectively. Cochrane Armitage test did not show a significant trend for decreasing pregnancy rates with increasing female age at OPU (P = 0.679) or at transfer (P = 0.609). Multivariable regression analyses showed primiparous, and multiparous women were more likely to have an ongoing pregnancy compared to nulliparous women (OR: 2.96, 95%CI:2.22-3.94 and 2.73, 95%CI:2.10-3.55, respectively, P &amp;lt; 0.001 for both) and those who had a natural endometrial preparation (OR: 1.53, 95%CI: 1.24-1.88, P &amp;lt; 0.001). Transfers with good quality embryo had higher ongoing pregnancy rates compared to those who had a fair quality embryo (OR: 2.0, 95%CI: 1.37-2.91, P &amp;lt; 0.001). Being overweight or obese at the time of transfer were associated with lower ongoing pregnancy rates compared to normal weight (OR: 0.71, 95%CI: 0.56-0.89, and 0.68, 95%CI: 0.52-0.88, respectively, P = 0.003 for both). Age categories at the time of transfer did not show a significant effect on ongoing pregnancy rates in multivariable analyses (P &amp;gt; 0.05 for all) and there was no significant interaction between age at OPU and embryo quality categories either (P = 0.881 and 0.601). Limitations, reasons for caution The retrospective design of the study is a limitation. Wider implications of the findings This analysis did not confirm the otherwise reported negative impact of female age on the outcome of seFET cycles. Outcomes are significantly influenced by BMI, parity, EQ-related factors as well as the endometrial preparation. As BMI and endometrial preparation can be influenced, the adequate choice might improve seFET outcomes. Trial registration number not applicable

P-760 The effect of assisted hatching on pregnancy outcomes in 1,833,485 single embryo transfer based on Japan Assisted Reproductive Technology Registry System

Abstract Study question Does assisted hatching (AH) affect pregnancy outcomes especially when it was performed selectively on specified group? Summary answer No clinically significant effect of AH on pregnancy outcomes was demonstrated for the entire single embryo transfer (SET) cycle after adjusting for covariates. What is known already AH is a technique used in assisted reproduction by artificially thinning or making a small hole in the zona pellucida in order to facilitate the hatching process. It is suggested that AH may improve the chance of embryo implantation and success of pregnancy. However, there is insufficient evidence to conclude that AH improves pregnancy outcomes, despite its widespread and longtime use. In 2014, the Practice Committee of ASRM recommended that AH should not be conducted routinely for all patients. On the other hands, it has been suggested that AH could be effective for patients with poor prognosis. Study design, size, duration A retrospective observational study based on the national ART registry maintained by the Japan Society of Obstetrics and Gynecology (JSOG) was performed. The study included 1,833,485 single embryo transfer (SET) for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) from January 2010 to December 2019. This study was approved by the Registration and Research Subcommittee of the JSOG and Tokyo University Ethics Committee. Participants/materials, setting, methods To determine the effect of AH, the rate of clinical pregnancy and live birth were compared in SET with and without AH as primary outcome measures. In addition, the prevalence of miscarriage, multiple pregnancy, ectopic pregnancy, placental malposition, and placenta accreta were analyzed as secondary outcomes. We performed inverse probability of treatment weighting and outcome regression analyses. Main results and the role of chance Out of 1,833,485 SET cycles, AH was conducted in 983,242 cycles (53.6%). In all SET cycles, clinical pregnancy rate (CRP) and live birth rate (LBR) were 31.0% vs. 26.2%, and 21.6% vs. 18.7% in AH vs. without AH group, respectively. AH was more frequently performed in patients with advanced maternal age, frozen-thawed ET cycles (88% vs. 47%, AH vs. without AH), blastocyst transfer cycles (70% vs. 42%), patients with tubal factor (17% vs 14.3%), and hormonal replacement cycles (66% vs. 43%). After adjusting for these covariates, the propensity-weighted CPR (28.4% vs. 29.1%, AH vs. without AH) and LBR (20.1% vs. 20.6%) were slightly yet significantly lower in AH group. As secondary outcomes, AH may lead to increased risk of multiple pregnancy (0.21% increase), ectopic pregnancy (0.02%), and placenta accreta (0.03%), and 0.24% decreased risk of miscarriage. On the other hands, subgroup analysis suggested that AH could be effective in the following cycles: frozen-thawed cycles with either blast or cleavage with maternal age under 35 years, and fresh blastocyst transfer cycles with maternal age over 40 years. Limitations, reasons for caution The limitation of this study is that the information regarding the history of repeated implantation failure and methods of AH were not included in this registry system. Another limitation is that duplicate data from same patients who underwent multiple embryo transfers exists in this retrospective study for 10 years. Wider implications of the findings Despite of frequent use of AH in Japan, AH in SET cycles for all patients is not recommended because of increased risk of adverse events without improvement of pregnancy outcomes. On the other hands, AH may improve pregnancy outcomes for some groups associated with maternal age and duration of culture. Trial registration number not applicable’

P-174 Are new machine learning (ML) models worth it: Equivalence of iDA, KIDscore, and Gardner Scoring in Predicting IVF Pregnancy

Abstract Study question Is there a significant difference in predicting pregnancy outcomes among iDAScore 1.0, KIDScoreD5, and Gardner Score in elective blastocyst transfers? Summary answer Contrary to previous studies, iDAScore v1.0 does not demonstrate a significant Receiver Operating Characteristic (ROC) curve advantage over the traditional Scores in predicting pregnancy outcomes. What is known already iDAScore 1.0, a deep neural network integrated into the EmbryoScope system, and KIDscoreD5 have shown potential in ML-driven embryo assessment, potentially easing the workload of embryologists. While recent studies have highlighted their superior performance in predicting pregnancy outcomes, our study offers a contrasting perspective. Study design, size, duration This retrospective analysis encompassed 1762 embryos from 1112 cycles with 1424 fresh and 338 frozen single embryo transfer cycles conducted from November 2018 to September 2023 across three IVF clinics in New Zealand. No PGT cases were included. All embryos that fulfilled the defined study criteria and transferred were included in this analysis. An extended Gardner Scoring was used at our clinics: A, B, C and X, where X being poorest grades, get discarded. Participants/materials, setting, methods Retrospectively computed KID and iDAScores were analyzed alongside the pregnancy prediction accuracy of conventional grading. Gardner scores were converted to a ranked ordinal value with ‘AA’ (5), ‘AB’ and ‘BA’ at 4, ‘BB’ at 3, and both ‘AC’, ‘BC’ as 2 and ‘CC’ as 1 among the age groups; &amp;lt;35, 35-37, 38-40, 41-42, &amp;gt;42. Differences in overall predictive capacity were compared via AUC curves within age groups via paired Delong tests. P-values reported are nominal. Main results and the role of chance The study found no statistically significant differences in AUC between any of the 3 tests examined even before adjusting for multiple comparisons. Notably, in 35-37 years olds (n = 495), AUCs were 0.63 for iDAScore, 0.62 for KIDScore, and 0.61 for Gardner criteria, showing a robust ability to predict pregnancy across all methods. Similar patterns were observed in all other age groups, with no significant disparities in pregnancy prediction models (P-value &amp;gt; 0.05). Limitations, reasons for caution Given its retrospective nature, this study has inherent limitations. A prospective, controlled study would provide more definitive insights. Wider implications of the findings ML-based models are innovative, but they do not significantly exceed the predictive ability of traditional embryo assessment across a range of patient ages. Such models are not a panacea yet, but a data tool to increase reproducibility that might have over-promised and under delivered on clinical impact. Trial registration number not applicable

P-250 Only euploidy does not ensure optimal chances for successful live birth through single blastocyst cryotransfer

Abstract Study question What does a euploid blastocyst require to provide the greatest probability of successful birth? Summary answer Morphokinetic and morphological features of the inner cell mass (ICM) and trophectoderm (TE) are crucial for optimizing live birth chances in cryo-transferred euploid blastocysts. What is known already Embryo selection through preimplantation genetic testing for aneuploidy (PGT-A) alongside frozen embryo transfer strategy enhances outcomes of single-embryo transfer cycles. While euploidy is a crucial indicator, investigations on the identification of additional criteria influencing implantation and live birth rates remain imperative. Studies suggest morphokinetic and morphological quality may supplement predictive factors for euploid embryo success, with varying correlations. The impact of factors like age or gamete origin on euploid blastocyst success remains uncertain, differentiating it from clear effects on non-diagnosed embryos. Optimizing selection criteria involves navigating the intricate interplay of these variables. Study design, size, duration This retrospective study analyses the pregnancy rate (PR) in 596 single embryo cryotransfers of full euploid blastocysts (without detected mosaicism) between February 2019 and September 2023. From these, 437 had a known outcome, and the live birth rate (LBR) was calculated. The study explored the potential impact of gamete origin, oocyte provider age, recipient age, morphokinetics, and morphological quality of ICM or TE (Gardner score) on the reproductive success of the transferred embryo. Participants/materials, setting, methods All embryos were biopsied at the blastocyst stage and successively vitrified. High-resolution next-generation sequencing was used for PGT-A. Only deferred transferences of single post-thawing intact embryos were included. Morphokinetic was assessed using the KIDscoreD5 3.1. Quantitative variables (oocyte provider age, recipient age, and morphokinetic score) were compared using the t-student test, while qualitative variables (gamete origin, morphological quality of ICM and TE) were assessed using the chi-square test. Main results and the role of chance Oocytes leading to pregnancies and live births were derived from women with ages comparable to those without success (Pregnancy: 30.0±7.1 vs. 30.8±6.8, p = 0.174; Live Birth: 30.1±7.1 vs. 30.5±6.9, p = 0.499). Similar age was also observed among recipients achieving pregnancy (41.5±5.4) and live births (41.1±5.1) compared to those who did not (Pregnancy: 41.8±5.1, p = 0.506; Live Birth: 41.5±5.3, p = 0.411). The origin of oocytes and semen (own or donor) did not significantly affect PR (Oocytes: 199/273 vs. 217/323, p = 0.130; Semen: 328/473 vs. 88/123, p = 0.224) or LBR (Oocytes: 113/205 vs. 116/232, p = 0.285; Semen: 183/347 vs. 46/90, p = 0.783). Morphokinetics played a crucial role, with euploid embryos resulting in pregnancy (7.5±1.7) and live births (7.6±1.6) exhibiting significantly higher scores than those without success (6.9±1.7; 7.1±1.7; p &amp;lt; 0.05).199 ICM quality did not significantly impact PR (A:211/296, B:190/275, C:15/25; p = 0.469). However, higher miscarriage rates in C-quality ICM blastocysts significantly reduced the LBR (A:116/211, B:107/205, C:6/21; p &amp;lt; 0.05). TE quality exhibited significant differences in PR (A:221/289, B:184/289, C:11/18; p &amp;lt; 0.05). Since the miscarriage rate was similar among groups (p = 0.787), LBR remained higher in A-quality TE blastocysts (A:124/209, B:98/213, C:7/17; p &amp;lt; 0.05). Limitations, reasons for caution As a retrospective analysis, this study is inherently limited. The influence of expansion grade on success rates remains unexplored, given the use of assisted hatching on day 3 of culture. Performing assisted hatching at the time of biopsy could potentially overcome this limitation. Wider implications of the findings The pursuit of a euploid embryo often becomes the priority in IVF laboratories. However, once the milestone is achieved, morphokinetics and embryonic morphological quality must continue to be considered. This study provides valuable insights for conveying a detailed message to patients with euploid embryos about their prospects for homebirth success. Trial registration number not applicable

Racial disparities in the outcomes of euploid single frozen-thawed embryo transfer cycles – analysis of the Clinical Outcome Reporting System of the Society for Assisted Reproductive Technology 2016–2018 data

ObjectiveTo evaluate if in pregnancies conceived with the transfer of single genetically tested embryos, maternal race and ethnicity relate to pregnancy outcome. DesignRetrospective cohort. SubjectsAutologous frozen -thaw embryo transfer (FET) cycles with transfer of single genetically tested embryo in SART-CORS for years 2016-2018; cycles associated with diagnoses of recurrent pregnancy loss, gestational carrier, donor egg and donor embryo were excluded. ExposureInformation on race and ethnicity linked with in vitro fertilization and FET cycles available in the SART-CORS. Main Outcome MeasuresMultivariable analyses utilizing generalized estimating equation examined the relationship between categories of race and ethnicity with the following outcomes: Pregnancy (+βhCG following FET), clinical pregnancy, pregnancy loss (early [at gestation <13 weeks] and late [loss between ≥13 and <20 weeks]), preterm (<37 weeks), term (≥37 weeks) and live birth. Covariates adjusted for included age, BMI, AMH, infertility diagnosis and smoking history. Results79,416 FET cycles met the eligibility criteria. Information on race and ethnicity was specified for 50,820 (64.0%) and was not known in 28, 723 (36%) of the cycles . The population was predominantly non-Hispanic White (NHW, 44%). Non-Hispanic Black [NHB] comprised 2.7%, Asian 12.3%, Hispanic 3.4%, American Indian, Pacific Islander, Hawaiian and Alaskan [AI_AL_PI_H] 0.2%. Nearly 1.0 % self-identified with more than one race. On multivariable analyses, pregnancies in NHB and in Hispanic women (compared to NHWs) were significantly more likely to result in in preterm birth (p<0.001). Compared to NHW women, the likelihood of live birth was significantly lower in NHBs (p<0.01), Asian (p=0.04), Hispanic (<0.01) and AI_AL_PI_H women (p<0.01). . The likelihood for delivery by Cesarean was also disproportionately higher in the NHB (p=0.047), Hispanic (p=0.007) and in women identifying with more than one race (0.023)compared to NHWs . ConclusionRacial and ethnic differentials are apparent in the outcomes of FET conceived pregnancies resulting from the transfer of single genetically tested embryos.

Effect of time post warming to embryo transfer on human blastocyst metabolism and pregnancy outcome.

This study is aiming to test whether variation in post warming culture time impacts blastocyst metabolism or pregnancy outcome. In this single center retrospective cohort study, outcomes of 11,520 single frozen embryo transfer (FET) cycles were analyzed from January 2015 to December 2020. Patient treatments included both natural and programmed cycles. Time categories were determined using the time between blastocyst warming and embryo transfer: 0 (0- <1h), 1 (1-<2h), 2 (2-<3h), 3(3-<4h), 4 (4-<5), 5 (5-<6), 6 (6-<7) and 7 (7-8h). Non-invasive metabolic imaging of discarded human blastocysts for up to 10h was also performed using Fluorescence lifetime imaging microscopy (FLIM) to examine for metabolic perturbations during culture. The mean age of patients across all time categories were comparable (35.6 ± 3.9). Live birth rates (38-52%) and miscarriage rate (5-11%) were not statistically different across post-warming culture time. When assessing pregnancy outcomes based on the use of PGT-A, miscarriage and live birth rates were not statistically different across culture hours in both PGT-A and non-PGT cycles. Further metabolic analysis of blastocysts for the duration of 10h of culture post warming, revealed minimal metabolic changes of embryos in culture. Overall, our results show that differences in the time of post warming culture have no significant impact on miscarriage or live birth rate for frozen embryo transfers. This information can be beneficial for clinical practices with either minimal staffing or a high number of patient cases.

Effect of postthaw change in embryo score on single euploid embryo transfer success rates

ObjectiveTo assess whether the change in embryo morphology from pre-cryopreservation to post-thaw is associated with embryo transfer success rates in single euploid embryo transfer cycles. DesignRetrospective cohort study SubjectsPatients who underwent a single euploid embryo transfer cycle from September 2016 – April 2022 were included. A decision support tool was used to assign each embryo a reproductive potential score based on the day of biopsy, expansion, and grade of trophectoderm and inner cell mass (ICM) at the time of cryopreservation and post-thaw.(1) Embryos were divided into 4 groups: Group 1 included embryos with the same score post-thaw (reference), Group 2 higher score, Group 3 lower score, and Group 4 embryos that did not re-expand post-thaw. Intervention(s)No interventions administered. Main Outcome MeasuresPrimary outcome was live birth rates per embryo transfer (LBR). Secondary outcomes included chemical pregnancy, clinical pregnancy, and clinical pregnancy loss rate. Comparative statistics and univariate analyses were performed using Kruskal-Wallis and chi-square tests. Multivariate logistic regression fitted with generalized estimating equation was performed to compare the odds of live birth between groups. ResultsA total of 7750 embryo transfers performed for 4613 patients met inclusion criteria: 5331 in Group 1, 486 in Group 2, 1726 in Group 3, and 207 in group 4. On univariate analysis, there was a statistically significant difference in LBR between groups 1, 2, 3, and 4 (55.8% vs 51.4%, 47.5%, 26.6%, p<0.0001). Logistic regression controlling for oocyte age, AMH, BMI, endometrial thickness, year of embryo transfer, time from thaw to final grading, and embryo score prior to cryopreservation showed significantly lower odds of LBR when the embryo was downgraded (OR 0.70, CI 0.62-0.79, p=<.0001) or did not re-expand (OR 0.36, CI 0.26-0.51 p=<.0001) compared with no change in score. When controlling for all variables, there was a significant increase in odds of live birth between embryos that had higher score post-thaw versus those without a change (OR 1.42, CI 1.14-1.76, p=0.002). There was no significant difference in clinical pregnancy loss rate among the 4 groups. ConclusionsThe change in quality of the embryo post-thaw is an important factor in embryo transfer success. In an adjusted analysis, the chemical pregnancy, clinical pregnancy, and LBR per embryo transfer are all significantly decreased in embryos that were downgraded or did not expand on the day of single euploid embryo transfer. Embryos that re-expand and improve their quality post-thaw have the highest odds of live birth.

Time-Lapse Incubation for Embryo Culture-Morphokinetics and Environmental Stability May Not Be Enough: Results from a Pilot Randomized Controlled Trial.

Background: Does the Time-lapse Incubator (TLI) add value to reproductive outcomes when its two components, undisturbed culturing and morphokinetic embryo grading, are separated. Methods: A prospective pilot, randomized, controlled, double-blinded, single-center study was conducted during the years 2016-2020. In total, 102 patients were randomized into three groups: (1) conventional incubation with morphological evaluation only (n = 34), (2) TLI with both morphological and morphokinetic evaluations (n = 32), and (3) TLI with morphological evaluation only (n = 36). All arms were cultured in ESCO-MIRI® incubators. A total of 1061 injected mature oocytes were evaluated (420 in arm 1, 285 in arm 2, and 356 in arm 3). The primary outcome was live birth rates. Secondary outcomes included clinical and cumulative pregnancy rates as well as embryo quality. Embryos in arm 3 were retrospectively evaluated for their morphokinetic score. Results: No significant difference was found in the live birth rate for single embryo transfer cycles (SET) (35% vs. 31.6% vs. 24%, p = 0.708) or double embryo transfer (DET) cycles (41.7% vs. 38.5% vs. 36.4%, p = 0.966). Comparable pregnancy rates, clinical pregnancy rates, and cumulative pregnancy were found for similar top-quality embryos for days 2, 3, and blastocyst stages across groups. A similar number of embryos were suitable for either transfer or cryopreservation within the different groups. For 62.8% of the embryos in arm 3, the morphokinetic and morphologic evaluations were similar. In only 2/36 (5.6%) treatment cycles, the use of morphokinetic scoring may have helped the patient avoid undergoing an additional treatment cycle. In the other cases, morphokinetic scoring would not have changed the end point of pregnancy. Conclusions: The two components of the TLI system-undisturbed culturing and morphokinetic embryo grading-do not appear to have a significant additional value in reproductive outcome, although these results should be validated by an RCT.

BlastAssist: a deep learning pipeline to measure interpretable features of human embryos.

BlastAssist: a deep learning pipeline to measure interpretable features of human embryos.

Single Euploid Embryo Transfer Outcomes After Uterine Septum Resection

ObjectiveTo study pregnancy outcomes after single euploid embryo transfer (SEET) in patients who underwent prior uterine septum resection to those with uteri of normal contour, without Müllerian anomalies or uterine abnormalities including polyps or fibroids, and without a history of prior uterine surgeries. DesignRetrospective cohort study SettingSingle academic affiliated center Patients60 cycles of patients with prior hysteroscopic uterine septum resection who underwent an autologous SEET between 2012-2020 were used as the investigational cohort. A 3:1 ratio propensity score matched control cohort of 180 single euploid embryo transfer cycles from patients without a history of uterine septa were used as the control group. Intervention(s)No interventions administered. Measurements and Main ResultsPregnancy, clinical pregnancy loss, ongoing clinical pregnancy, and live birth rates in patients with history of uterine septum resection compared to matched patients without Müllerian anomalies or uterine surgeries. Patients with a prior uterine septum had significantly lower rates of chemical pregnancy (58.33% vs 77.2%, p=0.004), implantation (41.67% vs 65.6%, p=0.001), and live birth (33.33% vs 57.8%, p=0.001) per transfer. No statistical difference in clinical pregnancy loss rates was found when comparing septum patients with controls (8.33% vs 7.8%, p=0.89). ConclusionPatients with history of hysteroscopic resection who undergo in vitro fertilization are more susceptible to suboptimal clinical outcomes compared to patients with normal uteri. Early pregnancy loss rates in patients with a uterine septum are higher than in those without, however, after resection, the rates are comparable. Patients born with septate uteri require assessment of surgical intervention prior to SEET and to optimize their reproductive outcomes.

Beyond appearance: Can morphologically low-grade euploid blastocysts yield successful pregnancies?

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. 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. 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. Our study indicates that the morphological quality of euploid embryos, particularly the evaluation of the ICM, plays a crucial role in IVF-ET success.

#276 : Impact of Previous Cesarean Delivery on Pregnancy and Neonatal Outcomes of Subsequent In Vitro Fertilization/Intracytoplasmic Sperm Microinjection and Single Frozen-Thawed Embryo Transfer

Background and Aims: Cesarean delivery (CD) rates continue to rise worldwide. Prior studies have indicated that CD is associated with not only various gynaecological symptoms and obstetric complications but also lower probability of subsequent fertility. However, the recognition about impact of CD on clinical outcomes in subsequent IVF/ICSI-FET is very limited. The purpose was to investigate the effects of previous CD on pregnancy and neonatal outcomes in single frozen-thawed embryo transfer (FET) cycles so that women with a previous cesarean delivery can be given detailed fertility counseling during the ART process. Methods: This is a large retrospective cohort study including a total of 5,750 patients who desired to transfer single vitrified-thawed blastocyst from the same oocyte retrieval cycle as their last live birth between January 2011 and January 2021 in a center for reproductive medicine in Shandong, China, comprising FET cycles of 3,853 previous single CD and 1,897 previous single vaginal delivery (VD). Results: Women with a previous CD had significantly lower rates of biochemical pregnancy (64.52% vs. 71.48% before propensity score matching (PSM), P&lt;0.001; and 65.58% vs. 71.49% after PSM, P&lt;0.001), clinical pregnancy (58.16% vs. 65.79% before PSM, P&lt;0.001; and 59.22% vs. 66.17% after PSM, P&lt;0.001) and live birth (48.17% vs. 55.82% before PSM, P&lt;0.001; and 49.29% vs. 56.10% after PSM, P&lt;0.001) than those with a previous VD. Meanwhile, the CD rate was significantly higher in the CD group (97.85% vs. 18.53% before PSM, P&lt;0.001; and 98.02% vs. 20.51% after PSM, P&lt;0.001). The rates of multiple pregnancy, miscarriage, ectopic pregnancy, multiple live birth, labor complications and preterm and neonatal outcomes were comparable between the two groups. Conclusion: Compared to VD, a previous CD is associated with a significant reduction in the rates of biochemical pregnancy, clinical pregnancy and live birth in patients undergoing subsequent single frozen-thawed blastocyst transfer.