Fresh Transfer Cycles Research Articles

P-222 Early blastulation on day 4 predicts ongoing pregnancy in fresh transfer cycles

Abstract Study question Do embryos with early blastulation (EB) on D4 show higher implantation potential compared to top D5 blastocysts in fresh elective single embryo transfer (eSET) cycles? Summary answer Fresh EB transfer with time start to blastulation (tSB)<96.6h and time of expanded blastocyst (tEB)<100h post-insemination is predictive of ongoing pregnancy for patients <35. What is known already Expansion and hatching of blastocysts are correlated to implantation potential in fresh single transfers. Thanks to time-lapse morphokinetics, several time-points can be analyzed during embryonic growth. Embryos with faster growing speed are correlated to euploid status. The tSB of < 96.6h, day 4 post-insemination, is reported to have significant predictive value of euploid embryos, which are found to be associated not only with higher expansion scores, but also with shorter tSB, full expansion, and hatching. A study reported that significantly more embryos that reached the tSB by 100h implanted compared to those that did not. Study design, size, duration Prospective observational study in a single private hospital during 2022. In 160 cycles (n = 81 cIVF and n = 79 ICSI) an EB on D4 was observed. 48 patients (n = 28 ICSI and n = 20 cIVF) underwent a fresh eSET with an embryo showing EB on day 4. Participants/materials, setting, methods Patients with EB on D4 (tSB<96.6h, tEB<100h post-insemination) were enrolled regardless of indication, female age, attempt’s rank or technique. Those with a fresh eSET on D4 were included in this study. Gardner’s classification was used to rate the blastocysts in Embryoscope + (Vitrolife). The outcome data of transfer for D4 blastocysts (B3/B4 AA-AB-BA) were compared to eSET with top D5 (B4/B5 AA) of reference group (female age ≤35). The statistical analyses were performed by SPSS software. Main results and the role of chance In the study group, all the transferred embryos were graded according to Gardner’s classification as B3AA, or B3AB, or B3BA, or B4AA, or B4AB, or B4BA. In the reference group, we chose only the fresh transfer cycles with ultra-top grade D5 embryos classified as B4AA or B5AA. The results obtained in the overall population (n = 48) were compared to those obtained in the reference group (n = 92): age 34.0 ± 3.8 vs 31.8 ± 2.3, oocyte maturity (OM) 79.8% vs 80.3%, fertilization rate (FR) 80.0% vs 77.0%, overall blastulation rate (OBR) 78.1% vs 74.3%, top blastulation rate (TBR) 59.1% vs 54.4%, total pregnancy rate (PR) 75.5% vs 61.4%, implantation rate (IR) 58.3 vs 51.2% and ongoing pregnancy rate (OPR) 58.6% vs 47.1%, and showed a statistical difference only in PR (p<0.05). The results obtained in younger patients with age 32.1 ± 3.2 (n = 34) were also compared to reference group: OM 75.1% vs 80.3%, FR 85.0% vs 77.0%, OBR 78.1% vs 74.3%; TBR 58.7% vs 54.4% were comparable between the groups. A statistical difference was observed for PR (88.0% vs 61.4%, p<0.01) IR (70.6% vs. 51.2%, p<0.05) and OPR (70.6% vs 47.1%, p<0.05). Limitations, reasons for caution The small size of the sample needs to be expanded in order to confirm the encouraging findings in a larger population, especially in older patients yielding more aneuploid embryos. The study will continue during 2023 and will compel the live birth rate. Wider implications of the findings When a D4 embryo with EB is available, the best option is the fresh transfer on D4. The increased implantation with EB seems to correlate with embryo euploidy and the advanced endometrial receptivity in stimulated cycles. Higher IR and OPR are reported even in patients with lower rate of aneuploidy. Trial registration number not applicable

P-773 No impact of cleavage-stage or blastocyst-stage embryo biopsy on growth and health in children up to 2 years of age

Abstract Study question Does embryo biopsy for preimplantation genetic testing (PGT) followed by fresh or vitrified-warmed embryo transfer affect children’s health up to 2 years of age? Summary answer Cleavage- or blastocyst-stage embryo biopsy followed by fresh or vitrified-warmed-embryo transfer had neither impact on anthropometry at birth, infancy or childhood nor on health outcomes. What is known already Literature data regarding neonatal outcomes after embryo biopsy for PGT show mixed results due to small sample sizes and/or the heterogeneity in terms of embryo biopsy (cleavage- or blastocyst-stage) and type of embryo transfer (fresh or frozen-thawed). Even fewer data exist on the impact of embryo biopsy on children’s health beyond infancy, including growth. Study design, size, duration This single-center cohort-study compared outcomes in singletons conceived after cleavage- or blastocyst-stage embryo biopsy either in a fresh or vitrified-warmed transfer cycle with results after non-biopsied embryo transfer between 2014 and 2018. Pregnancies after IVM, oocyte vitrification or oocyte/embryo donation were excluded. Eligible singletons living in Belgium were invited for examination at 3-6 months and 2 years. Anthropometric measurements at birth, infancy and childhood and health outcomes including surgeries, medication use and hospitalisations are reported. Participants/materials, setting, methods Birth characteristics were available for 630 and 222 children after cleavage-stage and blastocyst-stage embryo biopsy and for 1532 children after transfer of a non-biopsied embryo. Follow-up data were available for 426, 131 and 662 children, respectively. The impact on children’s health following embryo biopsy in vitrification and fresh cycles was the primary outcome. Other outcomes were the impact of timing of biopsy and of vitrification. Subgroup analysis according to infertility background was additionally performed. Main results and the role of chance Regarding the impact of embryo biopsy, either at the cleavage or blastocyst stage, no differences in anthropometrics were found at birth, infancy or childhood in vitrified-warmed transfer cycles compared to outcomes in non-biopsied vitrified-warmed transfer cycles, even after adjustment for neonatal, treatment and maternal characteristics. Likewise, no impact of embryo biopsy (cleavage stage) was found in fresh transfer cycles. The timing (day 3 or day 5/6) of embryo biopsy did not affect anthropometrics at birth, infancy or childhood. However, children born after cleavage-stage embryo biopsy followed by a vitrified-warmed transfer cycle had larger birth sizes than children born after cleavage-stage biopsy followed by a fresh transfer. Weight and height gain from birth to infancy and from infancy to early childhood were comparable in all biopsied and non-biopsied groups. Reassuringly, comparable rates of major congenital malformations, (severe) developmental problems, hospital admissions, surgical interventions and of chronic medication use up to the age of 2 years were observed in biopsied and non-biopsied groups. Subgroup analysis in children born to parents with an infertility diagnosis showed that birth parameters were not different in children born after embryo biopsy. Limitations, reasons for caution As the majority of the PGT cycles in our center are performed for a genetic indication only, the number of children born after embryo biopsy in infertile parents is rather limited and the results should therefore be interpreted cautiously. Wider implications of the findings Our findings add reassurance that embryo biopsy does not adversely affect the health of offspring up to 2 years of age. This is of particular importance given the widespread shift to blastocyst-stage embryo biopsy in PGT. Trial registration number Not applicable

P-669 The effect of ovarian follicle size on oocyte fate and embryology outcome

Abstract Study question Does ovarian follicle size influence ultimate oocyte fate and embryology outcome? Summary answer Per punctured follicle, higher oocyte yield, MII oocytes, 2PN fertilisation, and utilisable blastocyst is observed as follicle increases in size up to threshold of 15.5mm What is known already It is well known that oocyte maturity and probability of successful fertilisation is correlated to the size of follicles where oocyte originated from. However the true cutoff and ideal size at oocyte retrieval remains elusive. Furthermore, there is no conclusive evidence that embryological outcome in terms of blastocyst morphology and utilisation differs in the mid to large ovarian follicular sizes. Study design, size, duration Prospective observational study undertaken in a tertiary fertility referral centre over 10 months. 50 participants recruited and underwent conventional controlled ovarian stimulation as per unit protocol. A total of 288 follicular punctures performed in the study period. Participants/materials, setting, methods 50 oocyte retrieval (OR) procedures were performed. The size of ovarian follicles was individually measured using transvaginal ultrasound. 288 follicular punctures were performed and up to 3 oocytes per patient were collected for the study to be individually cultured to allow for tracking of oocyte and embryo outcomes. Follicular fluid and spent culture media were collected separately for subsequent metabolomics analysis. Follicular sizes were divided into 6 groups ( < =9.5, 10-12.5, 13-15.5, 16-19.5, 20-23.5, > =24). Main results and the role of chance Oocyte fate included 113 mature oocytes, 83 bipronuclear (2PN) oocytes, 7 cleavage stage embryos, and 39 good quality blastocysts suitable for utilisation in fresh or frozen transfer cycles. When compared to overall average per punctured follicle, there is an association of higher oocyte yield, proportion of MII oocytes, 2PN fertilisation, and utilisable blastocyst as follicle size increases. The threshold for a change in fate appears to be when follicle size increases beyond 15.5mm where optimal follicle size may reach plateau. Proportion of good-quality blastocysts appears to be associated with size of follicles at rates as follow- 0% (less than 10mm), 11.1% (10-12.5mm), 13.2% (13-15.5mm), 15.9% (16-19.5mm), 14.5% (20-23.5mm), and 20% (above 24mm). 23 embryos have been utilised to date, yielding a 50% positive pregnancy rate. Of these utilised embryos resulting in a positive pregnancy test, 81.8% of embryos originated from follicles above 15.5mm. Metabolomics analysis for follicular fluid and spent culture media is ongoing. Limitations, reasons for caution The observational nature of the study along with a small sample size are limitations that did not allow clinical significance to be observed. Wider implications of the findings Oocyte retrieved from follicles less than 10mm is futile. There appears to be a plateau in optimal follicle size where no real detriment is demonstrated. This is an important findings to guide stimulation, especially in cases of asynchronous growth where sacrifice in larger follicles is commonly assumed. Trial registration number Not applicable

Impact of having surplus blastocysts cryopreserved on the ongoing pregnancy rate following a fresh transfer

Purpose This study aimed to investigate whether a surplus of vitrified blastocysts correlated with ongoing pregnancy by analyzing the clinical outcomes of fresh transfer cycles with/without a surplus of vitrified blastocysts. Methods This was a retrospective analysis carried out in the Reproductive Medicine Center of Guizhou Medical University Affiliated Hospital between January 2020 and December 2021. Overall, 2482 fresh embryo transfer cycles were included in this study, including 1731 cycles with a surplus of vitrified blastocysts (group A) and 751 cycles with no surplus of vitrified blastocysts (group B). The clinical outcomes of fresh embryo transfer cycles were analyzed and compared between the two groups. Results In total, the clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR) after fresh transfer in group A were significantly higher than those in group B (59% vs. 34.1%, p < .001; 51.9% vs. 27.8%, p < .001, respectively). Moreover, the miscarriage rate was significantly lower in group A when compared to that in group B (10.8% vs. 16.8%, p = .008). When grouped by either female age or the number of good-quality embryos transferred, the same trends for CPR and OPR were seen in all subgroups. After adjusting for potential confounding factors in multivariate analysis, a surplus of vitrified blastocysts remained significantly associated with a higher OPR (OR: 1.52; 95% CI:1.21–1.92). Conclusion Ongoing pregnancy outcome increases significantly in fresh transfer cycle with a surplus of vitrified blastocysts.

Cycle Characteristics and Pregnancy Outcomes of Early Rescue Intracytoplasmic Sperm Injection Cycles in Normal and Hyper-Ovarian Response Women: A Six-Year Retrospective Study

This study aims to analyze the cycle characteristics, pregnancy, and neonatal outcomes in early rescue intracytoplasmic sperm injection (r-ICSI) cycles in normal and hyper-ovarian response women in their first IVF/ICSI attempts. Data from short-term in vitro fertilization (IVF, N = 7148), early r-ICSI (N = 618), and ICSI (N = 1744) cycles were retrospectively analyzed from normal and hyper-ovarian women who underwent their first IVF/ICSI cycles at our center from October 2015 to October 2021. The r-ICSI group was subdivided into partial r-ICSI (N = 451) and total r-ICSI (N = 167) based on the number of fertilized oocytes in the IVF part. Cyclic characteristics, pregnancy, delivery and neonatal outcomes in the fresh cycle were compared among the four groups; pregnancy, delivery and neonatal outcomes in frozen-thawed cycles were compared regarding cleavage and blastocyst transfers derived from r-ICSI cycles. Partial r-ICSI cycles showed different cyclic characteristics compared to total r-ICSI cycles, presenting as elevated AMH and estradiol levels on trigger day and an increased number of oocytes retrieved. Early r-ICSI delayed blastocyst development as seen by the increase in the number of day 6 blastocysts. There was no significant difference among the groups in clinical pregnancy, pregnancy loss, and live birth in fresh cleavage-stage embryo transfer cycles. However, early r-ICSI groups showed a reduction in clinical pregnancy and live birth rates in fresh blastocyst transfer cycles but not in the frozen-thawed cycles. For pregnant women, early r-ICSI did not show a negative effect on the risk of preterm birth, Cesarean section, neonatal birth weight, and sex ratio. In conclusion, early r-ICSI had comparable pregnancy, delivery, and neonatal outcomes when compared with short-term IVF and ICSI groups in fresh cleavage-stage embryo transfer cycles, but early r-ICSI did result in reduced pregnancy outcomes in fresh blastocyst embryo cycles, possibly due to delayed blastocyst development and asynchronization with the endometrium.

A Trend analysis of frozen embryo transfer at Alhikmah fertility center, Addis Ababa, Ethiopia

Background: In recent years, the use of frozen embryo transfers in Artificial reproductive technology has gradually increased, owing to improvements in laboratory techniques such as vitrification and blastocyst culture making pregnancy rates approaching those of fresh transfer cycles. Objective: The objective of this study is to determine the pregnancy rate after frozen embryo transfer, analyze the clinical factors that can potentially influence the result of pregnancy and identify patients who could benefit from this approach. Methods: A retrospective cross sectional study design was used to select patients that have undergone frozen embryo transfer from January 1, 2019- March 31, 2022 at Alhikmah fertility center, Addis Ababa, Ethiopia. Baseline data and pregnancy rate was collected, computed with SPSS version 24 for statistical associations and presented with tables. The primary outcome was a positive pregnancy test defined as serum ?-HCG level of &gt;10mIU/ml. Result: A total of 180 frozen embryo transfers were done for 128 women over the study period and the pregnancy rate was 26.6%. The mean age of the patients was 31.88(± 5.04). Majority (45.3%) had tubal factor infertility. ? 13(median) oocytes were collected for 53.9%. A freeze-all technique was used in 46% of the patients and the rest had extra embryos. Age of the patient &lt;35 and retrieval of oocytes above median had relation with positive pregnancy outcome. More importantly, freezing for risk of hyperstimulation and transfer of day 5embryos had a significant association with pregnancy with p-value &lt;0.05. Conclusion: From this study, we’ve seen promising pregnancy rate after frozen embryo transfer in patients with age group &lt;35 and those having ?13 oocyte. In addition, we can conclude that freezing for women at risk of hyperstimulation and transferring day 5embryos leads to a positive pregnancy result. However, since this is a retrospective study, we suggest a prospective comparative study to be done in the future for better recommendation. Key words: frozen embryo transfer, pregnancy rate, outcome predictors, assisted reproductive technology

Outcomes and cost analysis of single-embryo transfer versus double-embryo transfer.

Studies had compared single-embryo transfer to double-embryo transfer with cleavage stage embryos and found that while single-embryo transfer was less costly, it was also associated with a lower live birth rate than double-embryo transfer. A single blastocyst transfer has been shown to improve the live birth rate per cycle compared to single-embryo transfer at cleavage stage. To compare live birth rates and real costs of elective single-embryo transfer to double-embryo transfer and to determine the incremental cost-effectiveness ratio of these two strategies in an unselected pool of women in a single center. Retrospective study. We analyzed data of 4232 women who underwent their first fresh in vitro fertilization/intra-cytoplasmic sperm injection cycles with at least two embryos available for transfer in KK Women's and Children's Hospital from 2010 to 2017. Five hundred and sixty-four women underwent elective single-embryo transfer and 3668 women underwent double-embryo transfer. One hundred and fifty-six women who failed to achieve a live birth in their fresh elective single-embryo transfer cycle underwent a sequential thaw single-embryo transfer cycle. Live birth rate of fresh elective single-embryo transfer was significantly higher at 41.3% than that of double-embryo transfer at 32.6%. Cumulative live birth rate for sequential elective single-embryo transfer (fresh elective single-embryo transfer + thaw single-embryo transfer) was 47.9%. After accounting for variables which may affect live birth rates such as age and stage of embryo transfer, the odds of achieving a live birth from double-embryo transfer was 24% lower than that from sequential single-embryo transfer, although not statistically significant. For every live birth gained from an elective single-embryo transfer compared to double-embryo transfer, cost savings were S$20,172 per woman. If a woman had to have a sequential single-embryo transfer after a failed single-embryo transfer in her fresh cycle, cost savings were reduced to S$1476 per woman. Single-embryo transfer is a dominant strategy in an unselected population and adopting it in assisted reproductive treatments (ART) can produce cost savings without compromising on live birth rates.

Parental chest computerized tomography examination before IVF/ICSI has no impact on pregnancy and neonatal outcomes: a cohort study of 2680 fresh transfer cycles

BackgroundSome concern has been expressed regarding the negative effects of low-level ionizing radiation exposure in the context of radiological evaluation prior to IVF/ICSI treatment, but the available evidence is limited and conflicting. The aim of this study is to evaluate pregnancy and neonatal outcomes of couples who did chest computed tomography (CT) prior to IVF/ICSI.MethodsThis was a retrospective cohort study of 2680 IVF/ICSI fresh embryo transfer cycles conducted from January 2019 – August 2020. Fertility outcomes were compared between couples that had or had not undergone CT examination within 3 months prior to the date of oocyte retrieval and sperm collection. Miscarriage was the primary study outcome, while secondary outcomes included the number of oocytes collected, oocyte maturation, normal fertilization, number of good quality cleavage stage embryos, blastocyst formation, implantation, clinical pregnancy, ectopic pregnancy, live birth, multiple birth, Cesarean section rates, gestational weeks, maternal obstetric complications, birth weight, newborn sex ratio, and birth defect incidence. Propensity score matching was used to control for potential confounding variables.ResultsOf the 2680 cycles included in this study, couples underwent CT examination in 731 cycles. After 1:1 propensity score matching, 670 cycles were included in each group. When comparing demographic and fertility-related variables between groups that had and had not undergone CT examination after propensity score matching, we detected no significant differences in miscarriage rates (16.99% vs. 15.77%, OR = 1.10, 95CI% = 0.74 to 1.68). Similarly, both groups exhibited comparable oocyte and embryonic development, implantation rates (41.99% vs. 40.42%, OR = 1.07, 95%CI = 0.87 to 1.31), clinical pregnancy rates (45.67% vs. 44.48%, OR = 1.05, 95%CI = 0.85 to 1.30), ectopic pregnancy rates (2.94% vs. 1.68%, OR = 1.78, 95%CI = 0.59 to 5.36), live birth rates (36.57% vs. 35.67%, OR = 1.04, 95%CI = 0.83 to 1.30), multiple birth rates, Cesarean section rates, gestational weeks, maternal obstetric complication rates, and neonatal outcomes.ConclusionsChest CT examination before IVF/ICSI has no impact on pregnancy and neonatal outcomes associated with fresh embryo transfer.Trial registrationNot applicable.

A drop in serum progesterone from oocyte pick-up +3 days to +5 days in fresh blastocyst transfer, using hCG-trigger and standard luteal support, is associated with lower ongoing pregnancy rates.

A drop in serum progesterone from oocyte pick-up +3 days to +5 days in fresh blastocyst transfer, using hCG-trigger and standard luteal support, is associated with lower ongoing pregnancy rates.

Slightly Elevated Progesterone on HCG Trigger Day Has an Impact on Pregnancy Outcomes of Fresh Single Blastocyst Transfer Cycles Under an Early Follicular Phase Prolonged Protocol Cycle.

The effect of premature progesterone elevation on assisted reproductive technology has been debated. In different ovarian stimulation protocols, ovarian responses, and embryos transferred, conflicting results reside regarding the impact of elevated progesterone on pregnancy outcomes, according to previous studies. In addition, most studies have focused on significantly elevated progesterone levels, eg, above 1.5ng/mL, 1.75ng/mL, 2ng/mL. However, studies focusing on levels that are just slightly elevated are lacking, and some have concluded that such levels have no adverse effects on pregnancy outcomes. Clinical data of patients who underwent early follicular phase prolonged protocol cycle in vitro fertilization/intracytoplasmic sperm injection treatment were collected. Patients were divided into two groups according to progesterone level on the trigger day of human chorionic gonadotropin (HCG): Group 1: <1.0ng/mL and Group 2: 1.0-1.5ng/mL. Differences in baseline characteristics, ovulation promotion, and embryo culture, along with clinical pregnancy outcomes, were compared between the two cohorts. A total of 743 participants were included in this study, of which 587 were included in Group 1 and 156 were included in Group 2. In terms of pregnancy outcomes, Group 2 had a significantly lower clinical pregnancy rate and live birth rate per cycle than Group 1 (64.1% vs 75.7%, p <0.05; 63.5% vs 72.7%, p <0.05). After correction for maternal age, maternal body mass index, infertility duration, basal follicle-stimulating hormone, anti-Müllerian hormone, antral follicle count, total dose of gonadotropin, days of stimulation, and estradiol level on HCG trigger day, slightly elevated progesterone levels (P>1.0ng/mL) remained a risk factor for pregnancy failure in fresh single D5 blastocyst transfer under an early follicular phase prolonged protocol cycle. Slightly elevated progesterone levels on HCG trigger day may negatively affect pregnancy outcomes in early follicular phase prolonged protocol cycles.

Micro-TESE strategy in patients with NOA caused by AZFc deletion: synchronous or asynchronous?

In the treatment of infertile patients with non-obstructive azoospermia (NOA) caused by the deletion of the azoospermia factor c region (AZFc) on the Y chromosome, synchronous and asynchronous surgical strategies are discussed. Clinical data from NOA patients with the AZFc deletion who underwent micro-TESE were analyzed retrospectively. The sperm retrieval rate (SRR) and sperm utilization rate of synchronous and asynchronous operation groups were followed up and compared. The fertilization rate, high-quality embryo rate, clinical pregnancy rate, abortion rate, and cumulative live birth rate of ICSI in patients with successful sperm retrieval were compared between the two groups. The two groups had sperm utilization rates of 98.9% (93/94) and 50.0% (14/28), respectively. The asynchronous group's sperm consumption rates were much lower than those of the synchronous operation group. Fertilization rate, high-quality embryo rate, clinical pregnancy rate of fresh transfer cycle, abortion rate, and cumulative live birth rate of patients in the synchronous operation group with fresh sperm, and the asynchronous operation group with thawed sperm, respectively, were 30.6% vs 33.8%, 33.8% vs 40.7%, 40.0% vs 12.5%, 30.4% vs 7.1%. Between the two groups, there was no significant difference. This suggests that individuals with NOA caused by the AZFc deletion have a high possibility of successfully acquiring sperm using micro-TESE and ICSI to conceive their own offspring. Synchronous micro-TESE is recommended to improve sperm utilization rate and the cumulative live birth rate.

GOOD QUALITY SINGLE BLASTOCYST TRANSFER IMPARTS BETTER PREGNANCY OUTCOMES COMPARED TO TRANSFER OF EITHER TWO GOOD QUALITY OR ONE GOOD AND ONE POOR BLASTOCYST IN FRESH IVF CYCLES

To compare pregnancy outcomes in terms of clinical pregnancy (CPR), Live Birth (LBR) and Missed pregnancy (MPR) rates following transfer of either one good quality blastocyst or two good quality blastocysts or one good and one poor quality blastocyst in fresh transfer cycles.

A Cross-Sectional Analysis of Live Birth Rates in Day 5 Fresh Versus Vitrified Single Blastocyst Transfer Cycles

Background: The use of frozen embryo transfers (FETs) in assisted reproduction has increased worldwide. Proponents of FETs suggest that controlled ovarian hyperstimulation (COH) in a fresh transfer impairs endometrial-embryo synchronicity, however there has been conflicting evidence on live birth rate (LBR) and clinical pregnancy rate (CPR) outcomes. Aim: To compare LBRs and CPRs between single autologous day 5 fresh versus vitrified blastocyst transfer cycles, in order to investigate the impact of COH on embryo-endometrium asynchrony. Method: A large cross-sectional analysis of 6,002 embryo transfers (ETs), comprising of 3774 fresh and 2228 FET cycles from 2016-2019. Inclusion criteria: first two stimulation cycles, single ET, and no pre-implantation genetic testing for aneuploidy (PGT-A). Multivariate analysis performed, also sub-group analysis for high-responders (&gt;20 oocytes collected). Results: Univariate analysis showed no absolute difference in LBR (28.3% vs 27.4%, p=0.43) and CPR (32.2% vs 30.9%, p=0.30), however multivariate analysis demonstrated significantly lower LBR (OR 0.864, p&lt;0.05, 95% CI 0.749-0.997) and CPR (OR 0.852, p&lt;0.05, 95% CI 0.742-0.979) in FET compared to fresh ETs. Younger patient age, previous IVF pregnancy, advanced blastocyst expansion, higher trophectoderm quality and lower cumulative number of ETs all improved the odds of both LBR and CPR (p&lt;0.001). Conventional IVF, rather than ICSI, improved CPR (p&lt;0.05) but not LBR (p=0.138). BMI affected neither LBR (p=0.492) nor CPR (p=0.359). In sub-group multivariate analysis of high-responders, no significant difference in LBR (p=0.439) or CPR (p=0.450) noted. Conclusion: This study demonstrates a relative higher LBR and CPR for fresh ETs compared to FETs, in multivariate analysis. Having a FET decreased the odds of LBR by nearly 14% compared to fresh ET, when adjusted for confounders. Our results suggest that universal freeze-all strategy, without appropriate indication, may lead to suboptimal outcomes. In high-responders, freeze-all cycles may be beneficial, as adjusted outcomes appear to be similar.

Cumulus Cell Analysis for Prediction of Oocyte Quality in IVF and IVM

Background: In order to promote single embryo transfer (SET) in in vitro fertilization (ICSI) and In Vitro Maturation (IVM) supplementary analysis beyond morphological scoring is needed. The symbiosis between oocyte and cumulus during different stages of follicle development suggests the cumulus as an obvious specimen for molecular analysis. Over the last decade several studies have shown the potential of quantitative RT-PCR to measure predictive genes in ART. However, few prospective studies have validated this potential in routine embryology. Aim: Summarize the potential clinical use of cumulus gene testing from studies in routine human IVF and IVM. Methods: Pubmed search and own unpublished data. Results: So far few prospective studies (Adriaenssens et al., 2019; Van Vaerenbergh et al., 2021) have validated the approach for SET on Day 3 in a selected group of IVF (ICSI) patients in an interventional, non-randomized, assessor-blinded cohort study, by using normalized values of three predictive genes. The outcome demonstrated a significant increase in live birth when selecting single day 3 embryo in the first ICSI fresh transfer cycle based on cumulus gene-expression (of transferable embryos) versus SET based on morphology-only (from 27% to 50%; p&lt;0.0001). A similar non-invasive approach could be developed for the decision making in IVM culture-type (depending on GV maturity grade) and to pinpoint the single IVM embryo to transfer. Conclusion: Cumulus analysis proves to be a reliable non-invasive technology with promising applications for the routine embryology laboratory.

Uterine factors modify the association between embryo transfer depth and clinical pregnancy

The embryo transfer depth may affect the chance of pregnancy. However, embryo dislodging caused by uterine contraction may occur after the transfer. The aim of the retrospective study was to investigate whether the factors associated with uterine contractilities, such as endometrial thickness and progesterone elevation, affect the association between transfer depth and implantation. A total of 7849 fresh transfer cycles on conventional stimulation in a single in vitro fertilization (IVF) center during the period 2013–2015 was reviewed. Patients were categorized according to quartiles of embryo transfer depth (≤ 9 mm, n = 1735, 9.1–11 mm, n = 2557, 11.1–14 mm, n = 1933, ≥ 1.4 mm, n = 1624, respectively). Adjusted for confounding factors, the adjusted odds ratio (aOR) (95% confidence interval, CI) for clinical pregnancy was 0.90 (0.79–1.02), 0.86 (0.74–0.99), and 0.70 (0.60–0.82) respectively in quartiles 2 through 4, comparing with quartile 1. However, the aORs were significantly increased when the endometrial thickness was < 8 mm. In comparison with that in the cycles with a normal endometrial thickness (8–11 mm), the aORs comparing quartiles 2 through 4 with quartile 1 in the cycles with an endometrial thickness < 8 mm increased from 0.78 (95% CI 0.65–0.93), 0.79 (95% CI 0.65–0.97), and 0.64 (95% CI 0.51–0.81) to 1.73 (95% CI 1.21–2.47), 1.04 (95% CI 0.69–1.56), and 1.45 (95% CI 0.91–2.31), respectively. In the cycles with elevated progesterone and blastocyst stage transfer, the aORs comparing quartiles 4 with quartile 1 decreased from 0.73 (95% CI 0.62–0.87) and 0.74 (95% CI 0.63–0.87) to 0.58 (95% CI 0.40–0.84) and 0.42 (95% CI 0.25–0.73) than those in the cycles without. However, only blastocyst transfer showed a significant interaction with transfer depth (p = 0.043). Our data suggested that endometrial thickness and blastocyst transfer significantly affect the association between embryo transfer depth and clinical pregnancy.

Hormonal profile in early luteal phase after triggering ovulation with gonadotropin-releasing hormone agonist in high-responder patients.

The major limitations associated with gonadotropin-releasing hormone agonist (GnRHa) triggering are inferior clinical outcomes in fresh embryo transfer cycles caused by luteal phase insufficiency following the GnRHa triggering. We included 153 high-risk patients in this study. In group I, the patients received gonadotropin-releasing hormone agonist (GnRHa) trigger + 1,500 IU human chorionic gonadotropin (hCG) support on the oocyte pick-up (OPU) day; in group II, the patients had a dual trigger (GnRHa + 1,500 IU hCG); and in group III (control), 10,000 IU hCG trigger was prescribed for the final oocyte maturation. The levels of LH, estradiol, and progesterone were evaluated in serum on the stimulation starting day, day 6 of stimulation, on the day of the trigger administration, OPU day, days 3 and 5 post-OPU, and day 14 post-ET, as well as in follicular fluid. Progesterone concentration was significantly lower in group I on OPU+5 compared to the hCG group (I vs. III, р = 0.0065). Progesterone levels were significantly lower in group II in serum on OPU+5 compared to groups I and III (I vs. II, р = 0.0068; II vs. III, р = 1.76 × 108). The progesterone levels were significantly higher in follicular fluid in group III compared to the study groups (I vs. III, р = 0.002; II vs. III, p = 0.009). However, no significant differences in clinical outcomes were found between the groups. Then, we divided all women into pregnant and non-pregnant groups and found that estradiol (p = 0.00009) and progesterone (p = 0.000036) on the day of the pregnancy test were significantly higher in the pregnant women group. Also, progesterone on OPU day was significantly higher in the non-pregnant group (p = 0.033). Two cases of moderate ovarian hyperstimulation syndrome (OHSS) late-onset occurred in group I (3.5%, 2/56), no case of moderate/severe OHSS late-onset in group II, and three cases of moderate late-onset in group III (5.7%, 3/53). The low-dose hCG supplementation improves the luteal phase insufficiency after GnRHa triggering, which is confirmed by the comparable pregnancy rates in fresh transfer cycles between the groups. However, low-dose hCG carries a similar risk of OHSS as the full dose of hCG in high-responder patients.

P-251 Cumulus cell analysis as a non-invasive oocyte selection strategy to reduce the number of oocytes/embryos cultured and increase pregnancy rates

Abstract Study question Can non-invasive gene expression analysis of cumulus cells (CC) improve efficiency in ART by prioritizing oocytes for further culture and fresh single embryo transfer? Summary answer CC analysis can be used for the selective processing of oocytes. This may reduce culture work and improve the outcome in ICSI elective SETs (eSET). What is known already In an interventional, blinded, prospective cohort study (Van Vaerenbergh et al. 2021), 113 patients underwent a fresh Day3 eSET with embryos ranked and transferred based on morphology and CC gene expression (Aurora Test), while 520 control patients underwent a Day3 eSET without the Aurora Test. This resulted in a significant higher clinical pregnancy of 61% in the patients with eSET based on CC ranking applied on good morphology embryos, compared to 29% in the controls with eSET based on embryo morphology only. Live birth rate was also significantly increased, while time-to-pregnancy was significantly reduced with 3 transfer cycles. Study design, size, duration In a retrospective analysis, in a subset of patients with at least 6 growing follicles and at least five 2PN oocytes (n = 80), it was investigated whether the Aurora Test, used to select transferrable Day3-embryos, could also be applied to select oocytes on Day0/1. The effect of processing only the three highest ranked oocytes (based on the Aurora Test) on embryo development and clinical pregnancy was studied compared to processing all oocytes. Participants/materials, setting, methods Patients included in this single centre study had their first or second GnRH-antagonist ICSI cycle, were younger than 40y, had normal BMI, were stimulated with HP-hMG and scheduled for Day3 eSET. Two-sided statistical analysis (p &amp;lt; 0,05) was performed between a strategy of processing only the top 3 Aurora ranked oocytes, according to CC gene expression, and a strategy of processing all available oocytes. Main results and the role of chance On average, 8 MII oocytes were obtained per patient and the average fertilization rate was 83%. In total, 407 good quality embryos (GQE) on Day3 were generated from these 80 patients when utilising all 639 oocytes. Processing the three top-ranked oocytes only (240/639 oocytes) would have reduced the number of embryos to 169 GQE and would have resulted in 2.1 GQE on average on Day3 per patient; 75/80 (94%) patients would have had a fresh Day3 transfer resulting in a 63% clinical pregnancy rate. Processing all 639 available 2PN oocytes (standard of care) resulted in a fresh Day3 transfer in all 80 patients and a similar 64% clinical pregnancy rate (ns). However, 399 more oocytes would need to be processed. The strategy of restricting the number of oocytes to be processed would not have compromised cumulative cycle outcome. Considering all subsequent freeze/thawing cycles the cumulative clinical pregnancy rate calculated per all 80 patients would increase to 90%. Limitations, reasons for caution The limitation of this approach is that the Aurora Test requires individual oocyte denudation and individual oocyte vitrification. Secondly, this new strategy should be validated in a prospective study. Wider implications of the findings By applying this oocyte selection strategy patients would benefit from a high pregnancy rate in the fresh transfer cycle, while the lab would see reduction in embryo culture work, because freeze/thawing cycles and culture of embryos with lower competence would be prevented. Trial registration number NA

GnRH Antagonist Protocol Versus GnRH Agonist Long Protocol: A RetrospectiveCohortStudy on Clinical Outcomes and Maternal-Neonatal Safety.

ObjectiveTo evaluate the clinical outcomes and maternal-neonatal safety of gonadotropin releasing hormone antagonist (GnRH-ant) and gonadotropin releasing hormone agonist (GnRH-a) protocols.MethodsA total of 2505 women undergoing their first in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) were retrospectively analyzed. Patients were divided into GnRH-ant group (n = 1514) and GnRH-a group (n = 991) according their stimulation protocol. Propensity Score Matching (PSM) was used for balancing the baseline of two groups. The pregnancy outcomes were analyzed in fresh transfer cycles, and the obstetric and perinatal outcomes were calculated in singleton live births of fresh cycles. The primary outcome was the live birth rate. The secondary outcome measures were maternal complications, preterm birth rate, low birthweight rate, multiple pregnancy rate, and moderate-severe OHSS rate.ResultsAfter 1:1 PSM, baseline characteristics of the GnRH-ant group and GnRH-a group were matched and assigned 991 cycles in each group. Before PSM, there were 700 fresh cycles including 237 singleton live births in the GnRH-ant group and 588 fresh cycles including 187 singleton live births in the GnRH-a group. After PSM, there were 471 fresh cycles including 166 singleton live births in the GnRH-ant group and 588 fresh cycles including 187 singleton live births in the GnRH-a group. No significant differences were observed in the live birth rate (44.6% vs 48.8%), maternal complications, preterm birth rate (9.0% vs 6.4%), and low birthweight rate (17.5% vs 24.1%) between two groups after PSM (P > 0.05). The moderate-severe OHSS rate (2.9% vs 6.0%, P = 0.002) and multiple pregnancy rate (24.5% vs 33.1%, P = 0.025) was significantly lower in the GnRH-ant group than that in the GnRH-a group after PSM.ConclusionGnRH-ant protocol was comparable with GnRH-a protocol in clinical outcomes, obstetric and perinatal outcomes, and with a lower risk of OHSS. For those who want to get an effective and safe outcome, and a shorter treatment period, GnRH-ant is a suitable choice.

Placental histology following assisted hatching in fresh transfer cycles.

To assess placental histological findings following assisted hatching in fresh transfer in vitro fertilization cycles. Evaluation of a historic cohort of live singleton deliveries after fresh embryo transfer (ET) at a single university medical center between 2009 and 2017. We compared perinatal outcomes and placental histology in cases where assisted hatching was performed prior to ET (AH group) and cases with no AH (no AH group). Overall, 166 deliveries following AH were compared to 494 deliveries with no AH. Patients' demographics were similar between the groups. Median antral follicle count was significantly lower in the AH group, median 11 (range 1-50) vs. 16 (range 1-80), p < 0.001, and the primary indication for infertility treatment significantly more often diminished ovarian reserve (p < 0.001). Cycle characteristics in the AH group included a higher gonadotropin dose employed, and a lower rate of single and blastocyte transfer. Pregnancies following AH were associated with less low-lying placentas, 0.6% vs. 6.2%, p = 0.001, and comparable for other perinatal outcomes. After adjusting for confounders, the rate of bilobated placentas was higher following AH, aOR 7.10, 95% CI 1.50-33.51. The rate of perivillous depositions was higher with AH, aOR, 95% CI 3.18, 1.46-6.93, and the rate of chorangiosis lower in this group, aOR, 95% CI 0.32, 0.11-0.93. The overall rate of vascular lesions was similar between the groups. Pregnancies following AH are notable for a lower rate of placenta previa, yet a higher rate of bilobated placentas and perivillous depositions and less chorangiosis, warranting further investigation.

Influences of fresh and frozen embryo transfer on neonatal birthweight and the expression of imprinted genes PEG10 /L3MBTL1 in placenta

To investigate the influences of fresh embryo transfer (ET) and frozen embryo transfer (FET) on neonatal birthweight and the expression of imprinted genes PEG10 and L3MBTL1 in the placenta after in vitro fertilization-embryo transfer (IVF-ET), we analyzed the neonatal birthweight between fresh ET and FET transfer cycles. Then, we collected placentas delivered by fresh ET and FET, and real-time quantitative PCR, Western blotting and immunohistochemistry were used to detect the expression of PEG10 and L3MBTL1. The mean neonatal birthweight of fresh ET was lower than that of FET(3348.48 ± 521.05 vs. 3450.34 ± 524.13, P < 0.001). The risks of low birthweight (LBW) and small-for-gestational age (SGA) were lower after FET (3.9 % vs. 5.4 %; 7.2 % vs. 10.3 %), with adjusted rate ratios of 0.74 (95 % CI, 0.59–0.93; P = 0.003) and 0.70 (95 % CI, 0.59–0.84; P < 0.001), respectively. FET resulted in higher frequencies of macrosomia and large-for-gestational age (LGA) (14.2 % vs. 10.3; 11.0 % vs. 7.1 %) than fresh ET, with adjusted rate ratios of 1.45 (95 % CI, 1.26–1.68; P < 0.001) and 1.62 (95 % CI, 1.37–1.91; P < 0.001), respectively. We also observed PEG10 mRNA and protein expression levels in placentas delivered by fresh ET and FET were significantly different, but there were no significant differences in L3MBTL1 between the two groups. Fresh ET may affect the expression of the imprinted gene PEG10 in the placenta and adverse to placental implantation and development, resulting to increasing incidences of LBW and SGA.