Maternal and obstetric outcomes following the transfer of embryos warmed with fatty acid-supplemented solutions.

BACKGROUND: Vitrification procedures decrease intracytoplasmic lipid content and impair developmental competence. Adding fatty acids (FAs) to the warming solution has been shown to recover the lipid content of the cytoplasm and improve developmental competence and pregnancy outcomes. However, the influence of the FA supplementation on live birth rates after embryo transfers and perinatal outcomes remains unknown. In the present study, we examined the influence of FA-supplemented warming solutions on live birth rates, pregnancy complications, and neonatal outcomes after single vitrified-warmed cleavage-stage embryo transfers (SVCTs). METHODS: The clinical records of 701 treatment cycles in 701 women who underwent SVCTs were retrospectively analyzed. Vitrified embryos were warmed using solutions (from April 2022 to June 2022, control group) or FA-supplemented solutions (from July 2022 to September 2022, FA group). The live birth rate, pregnancy complications, and perinatal outcomes were compared between the control and FA groups. RESULTS: The live birth rate per transfer was significantly higher in the FA group than in the control group. Multivariate logistic regression analysis further demonstrated a higher probability of live births in the FA group than in the control group. Miscarriage rates, the incidence and types of pregnancy complications, the cesarean section rate, gestational age, incidence of preterm delivery, birth length and weight, incidence of low birth weight, infant sex, and incidence of birth defects were all comparable between the control and FA groups. Multivariate logistic regression analysis further demonstrated no adverse effects of FA-supplemented warming solutions. CONCLUSIONS: FA-supplemented warming solutions improved live birth rates after SVCTs without exerting any adverse effects on maternal and obstetric outcomes. Therefore, FA-supplemented solutions can be considered safe and effective for improving clinical outcomes and reducing patient burden.

Is the Human Chorionic Gonadotropin Level on Day 10 After Cleaved Embryo Transfer a Predictor of Perinatal Outcome?: A Retrospective Cohort Study.

This study aimed to determine whether human chorionic gonadotropin (hCG) levels at day 10 after day 2 cleaved embryo transfer can predict pregnancy and perinatal outcomes. Patients who underwent oocyte retrieval with minimal stimulation or natural cycles and fresh or vitrified-warmed transfer of a single, day 2 cleaved embryo at our clinic between November 2018 and December 2020 were included in this study. Patients were classified into four age groups for oocyte retrieval and into ten groups based on the hCG level on day 10 after embryo transfer; pregnancy complications and delivery and neonatal outcomes were examined. Of the 5,840 cycles, 3,722 (63.7%) and 2,118 (36.3%) were fresh-cleaved and vitrified-warmed embryo transfers, respectively. The mean hCG level was 24.8 mIU/mL and the clinical pregnancy and live birth rates per transfer were 29.6% and 23.4%, respectively. Maternal age at the time of oocyte retrieval, husband's age, treatment cycle, embryo type and grade, cell number, and hCG levels were correlated with pregnancy and delivery outcomes in the univariate analysis. Conversely, only maternal age and hCG levels were correlated with the outcomes in the multivariate analysis. hCG levels on day 10 post-transfer are a useful predictor of pregnancy and delivery outcomes after cleaved embryo transfer. Live birth rates vary with maternal age, even when hCG levels are the same, but they do not vary according to the treatment cycle or type of embryo transferred. Low hCG levels may be associated with vasa previa but did not affect delivery outcomes.

Fatty acid supplementation during warming improves pregnancy outcomes after frozen blastocyst transfers: a propensity score-matched study.

This study aimed to examine the viability of human blastocysts after warming with fatty acids (FAs) using an in vitro outgrowth model and to assess pregnancy outcomes after a single vitrified-warmed blastocyst transfer (SVBT). For the experimental study, we used 446 discarded vitrified human blastocysts donated for research purposes by consenting couples. The blastocysts were warmed using FA-supplemented (FA group) or non-FA-supplemented (control group) solutions. The outgrowth area was significantly larger in the FA group (P = 0.0428), despite comparable blastocyst adhesion rates between the groups. Furthermore, the incidence of outgrowth degeneration was significantly lower in the FA group than in the control group (P = 0.0158). For the clinical study, we retrospectively analyzed the treatment records of women who underwent SVBT in natural cycles between January and August 2022. Multiple covariates that affected the outcomes were used for propensity score matching as follows: 1342 patients in the FA group were matched to 2316 patients in the control group. Pregnancy outcomes were compared between the groups. The rates of implantation, clinical pregnancy, and ongoing pregnancy significantly increased in the FA group after SVBTs (P = 0.0091-0.0266). These results indicate that warming solutions supplemented with FAs improve blastocyst outgrowth and pregnancy outcomes after SVBTs.

Assisted reproductive technology in Japan: A summary report for 2021 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

Purpose: The Japan Society of Obstetrics and Gynecology (JSOG) registry gathers comprehensive data from registered assisted reproductive technology (ART) facilities in Japan. Herein, we report 2021 ART cycle characteristics and outcomes. Methods: Descriptive statistics were used to summarize and analyze 2021 data. Results: In 2021, 625 ART facilities participated in the registry; 27 facilities did not conduct ART cycles and 598 registered treatment cycles. In total, 498 140 cycles were registered, and there were 69 797 neonates (increases of 10.7% and 15.5%, respectively, from the previous year). The number of freeze-all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles decreased in 2021; the number of neonates born was 2268 for IVF-embryo transfer (ET) cycles and 2850 for ICSI cycles. Frozen-thawed ET (FET) cycles increased markedly from 2020 (11.2% increase). In 2021, 239 428 FET cycles were conducted, resulting in 87 174 pregnancies and 64 679 neonates. For fresh transfers, the total single ET, singleton pregnancy rate, and singleton live birth rates were 82.7%, 97.0%, and 97.3%; for FET, these rates were 84.9%, 96.9%, and 97.1%. Conclusions: The 2021 Japanese ART registry analysis showed marked increases in both total treatment cycles and live births from the previous year.

Improved pregnancy prediction performance in an updated deep-learning embryo selection model: a retrospective independent validation study.

RESEARCH QUESTION: What is the effect of increasing training data on the performance of ongoing pregnancy prediction after single vitrified-warmed blastocyst transfer (SVBT) in a deep-learning model? DESIGN: A total of 3960 SVBT cycles were retrospectively analysed. Embryos were stratified according to the Society for Assisted Reproductive Technology age groups. Embryos were scored by deep-learning models iDAScore v1.0 (IDA-V1) and iDAScore v2.0 (IDA-V2) (15% more training data than v1.0) and by Gardner grading. The discriminative performance of the pregnancy prediction for each embryo scoring model was compared using the area under the curve (AUC) of the receiver operating characteristic curve for each maternal age group. RESULTS: The AUC of iDA-V2, iDA-V1 and Gardener grading in all cohort were 0.736, 0.720 and 0.702, respectively. iDA-V2 was significantly higher than iDA-V1 and Gardener grading (P < 0.0001). Group > 35 years (n = 757): the AUC of iDA-V2 was significantly higher than Gardener grading (0.718 versus 0.694, P = 0.015); group aged 35-37 years (n = 821), the AUC of iDA-V2 was significantly higher than iDA-V1 (0.712 versus 0.696, P = 0.035); group aged 41-42 years (n = 715, the AUC of iDA-V2 was significantly higher than Gardener grading (0.745 versus 0.696, P = 0.007); group > 42 years (n = 660) and group aged 38-40 years (n = 1007), no significant differences were found between the groups. CONCLUSION: The performance of deep learning models for pregnancy prediction will be improved by increasing the size of the training data.

Preimplantation genetic testing using comprehensive genomic copy number analysis is beneficial for balanced translocation carriers.

Balanced chromosomal translocation is one of chromosomal variations. Carriers of balanced chromosomal translocations have an increased risk of spontaneous miscarriage. To avoid the risk, preimplantation genetic testing (PGT) using comprehensive genomic copy number analysis has been developed. This study aimed to verify whether and how embryos from couples in which one partner is a balanced translocation carrier have a higher ratio of chromosomal abnormalities. A total of 894 biopsied trophectoderms (TEs) were obtained from 130 couples in which one partner was a balanced translocation carrier (Robertsonian translocation, reciprocal translocation, or intrachromosomal inversion) and grouped as PGT-SR. Conversely, 3269 TEs from 697 couples who experienced recurrent implantation failure or recurrent pregnancy loss were included in the PGT-A group. The transferable blastocyst ratio was significantly lower in the PGT-SR group, even when bias related to the sample number and patient age was corrected. Subgroup analysis of the PGT-SR group revealed that the transferable blastocyst ratio was higher in the Robertsonian translocation group. Because the PGT-SR group had a higher proportion of untransferable embryos than the PGT-A group, PGT using comprehensive genomic copy number analysis was more beneficial for balanced translocation carriers than for infertility patients without chromosomal translocations. The frequencies of de novo aneuploidies were further analyzed, and the frequency in the PGT-SR group was lower than that in the PGT-A group. Therefore, we could not confirm the existence of interchromosomal effects in this study.

Comparison of 1-year cumulative live birth and perinatal outcomes following single blastocyst transfer with or without preimplantation genetic testing for aneuploidy: a propensity score-matched study.

PURPOSE: We evaluated whether preimplantation genetic testing for aneuploidy (PGT-A) could increase the cumulative live birth rate (CLBR) in patients with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL). METHODS: The clinical records of 7,668 patients who underwent oocyte retrieval (OR) with or without PGT-A were reviewed for 365 days and retrospectively analyzed. Using propensity score matching, 579 patients in the PGT-A group were matched one-to-one with 7,089 patients in the non-PGT-A (control) group. Their pregnancy and perinatal outcomes and CLBRs were statistically compared. RESULTS: The live birth rate per single vitrified-warmed blastocyst transfers (SVBTs) significantly improved in the PGT-A group in all age groups (P < 0.0002, all). Obstetric and perinatal outcomes were comparable between both groups regarding both RIF and RPL cases. Cox regression analysis demonstrated that in the RIF cases, the risk ratio per OR was significantly lower in the PGT-A group than in the control group (P = 0.0480), particularly in women aged < 40 years (P = 0.0364). However, the ratio was comparable between the groups in RPL cases. The risk ratio per treatment period was improved in the PGT-A group in both RIF and RPL cases only in women aged 40-42 years (P = 0.0234 and P = 0.0084, respectively). CONCLUSION: Increased CLBR per treatment period was detected only in women aged 40-42 years in both RIF and RPL cases, suggesting that PGT-A is inappropriate to improve CLBR per treatment period in all RIF and RPL cases.

Comparing performance between clinics of an embryo evaluation algorithm based on time-lapse images and machine learning.

PURPOSE: This article aims to assess how differences in maternal age distributions between IVF clinics affect the performance of an artificial intelligence model for embryo viability prediction and proposes a method to account for such differences. METHODS: Using retrospectively collected data from 4805 fresh and frozen single blastocyst transfers of embryos incubated for 5 to 6 days, the discriminative performance was assessed based on fetal heartbeat outcomes. The data was collected from 4 clinics, and the discrimination was measured in terms of the area under ROC curves (AUC) for each clinic. To account for the different age distributions between clinics, a method for age-standardizing the AUCs was developed in which the clinic-specific AUCs were standardized using weights for each embryo according to the relative frequency of the maternal age in the relevant clinic compared to the age distribution in a common reference population. RESULTS: There was substantial variation in the clinic-specific AUCs with estimates ranging from 0.58 to 0.69 before standardization. The age-standardization of the AUCs reduced the between-clinic variance by 16%. Most notably, three of the clinics had quite similar AUCs after standardization, while the last clinic had a markedly lower AUC both with and without standardization. CONCLUSION: The method of using age-standardization of the AUCs that is proposed in this article mitigates some of the variability between clinics. This enables a comparison of clinic-specific AUCs where the difference in age distributions is accounted for.

The destinies of human embryos reaching blastocyst stage between Day 4 and Day 7 diverge as early as fertilization.

STUDY QUESTION: What clinical and laboratory differences emerge from parallel direct comparison of embryos reaching the blastocyst stage between Days 4, 5, 6, and 7 (Days 4-7)? SUMMARY ANSWER: Increasing times to blastocyst formation are associated with a worse clinical outcome and perturbations in developmental patterns appear as early as the fertilization stage. WHAT IS KNOWN ALREADY: Previous evidence indicates that later times to blastocyst development are associated with a worse clinical outcome. However, the vast majority of these data concern Day 5 and Day 6 blastocysts, while Day 4 and Day 7 blastocysts remain less thoroughly investigated. In addition, studies comparing in parallel the developmental patterns and trajectories of Day 4-7 blastocysts are lacking. This leaves unanswered the question of when and how differences among such embryos emerge. Acquisition of such knowledge would significantly contribute to understanding the relative impact of intrinsic and extrinsic causes of embryo developmental kinetics and competence. STUDY DESIGN, SIZE, DURATION: This retrospective study involved time-lapse technology (TLT) monitoring of Day 4 (N = 70), Day 5 (N = 6147), Day 6 (N = 3243), and Day 7 (N = 149) blastocysts generated in 9450 ICSI cycles. Oocyte retrievals were carried out after clomiphene citrate-based minimal ovarian stimulation, between January 2020 and April 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: Couples included in the study presented with different diagnoses, mainly male factor and unexplained infertility. Cases involving cryopreserved gametes or surgically retrieved sperm were excluded. Microinjected oocytes were assessed by a combined TLT-culture system. Day 4-7 blastocyst groups were compared in terms of morphokinetics (pronuclear dynamics, cleavage patterns and timings, and embryo quality) and clinical outcome. Clinically usable blastocysts were cryopreserved and transferred in single vitrified-warmed blastocyst transfers (SVBT). MAIN RESULTS AND THE ROLE OF CHANCE: From 19 846 microinjected oocytes, 17 144 zygotes (86.4%) were obtained. Overall, the blastocyst development rate was 56.0%. Rates of blastocysts formation on Days 4, 5, 6, and 7 were 0.7%, 64.0%, 33.8%, and 1.6%, respectively. The average expanded blastocyst development times were 98.4 ± 0.4, 112.4 ± 0.1, 131.6 ± 0.1, and 151.2 ± 0.5 h in the Day 4-7 groups, respectively. Female age was positively associated with longer times to blastocyst development. Rates of both inner cell mass (ICM) and trophectoderm (TE) morphological grade A blastocysts were negatively associated with the day of blastocyst development (P < 0.0001). The differences in development times and intervals increased progressively until blastocyst expansion (P < 0.0001 for all development times). Strikingly, such differences were already markedly evident as early as the time of pronuclear fading (tPNf) (20.6 ± 0.3, 22.5 ± 0.0, 24.0 ± 0.0, 25.5 ± 0.3; Days 4-7, respectively; P < 0.0001). Rates of cleavage anomalies (tri-/multi-chotomous mitosis or rapid cleavage) occurring at the first or second/third division cycles were also positively associated with longer times to blastocyst development. Implantation, ongoing pregnancy, and live birth rates were progressively reduced with increasing blastocyst development times (P < 0.0001), even after stratification for maternal age. When controlled for female age, male age, number of previous embryo transfer cycles, morphological grade of the ICM and TE, and progesterone supplementation, the probabilities of implantation, clinical, and ongoing pregnancy and live birth were significantly decreased in Day 6 blastocysts in comparison to Day 5 blastocysts. Follow-up data on birth length, weight, and malformations were comparable among the four blastocyst groups. LIMITATIONS, REASONS FOR CAUTION: The study is limited by its retrospective design. Having been obtained from a single centre, the data require independent validation. WIDER IMPLICATIONS OF THE FINDINGS: This study extends previous data on the relation between time of blastocyst formation and clinical outcome. It also indicates that differences in developmental times and patterns of Day 4-7 blastocysts occur as early as the fertilization stage, possibly dictated by intrinsic gamete-derived factors. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the participating institutions. The authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Fatty acid supplementation into warming solutions improves pregnancy outcomes after single vitrified-warmed cleavage stage embryo transfers.

Purpose: This study aimed to examine the embryonic development of human 4-cell stage embryos after warming with fatty acids (FAs) and to assess the pregnancy outcomes after single vitrified-warmed cleavage stage embryo transfers (SVCTs). Methods: Experimental study: A total of 217 discarded, vitrified human 4-cell stage embryos donated for research by consenting couples were used. The embryos were warmed using the fatty acid (FA)-supplemented solutions (FA group) or nonsupplemented solutions (control group). The developmental rate, morphokinetics, and outgrowth competence were analyzed. Clinical study: The treatment records of women undergoing SVCT in natural cycles between April and September 2022 were retrospectively analyzed (April-June 2022, control group; July-September 2022, FA group). Results: Experimental study: The rate of morphologically good blastocysts was significantly higher in the FA group than in the control group (p = 0.0302). The morphokinetics during cleavage, morula, and blastocyst stages were comparable between the groups. The outgrowth was significantly increased in the FA group (p = 0.0438). Clinical study: The rates of implantation, clinical pregnancy, and ongoing pregnancy after SVCTs were significantly increased in the FA group (p = 0.0223-0.0281). Conclusions: Fatty acid-supplemented warming solutions effectively improve embryo development to the blastocyst stage and pregnancy outcomes after SVCTs.

Association between endometrial thickness before ovulation, live birth, and placenta previa rates in clomiphene citrate-treated cycles.

BACKGROUND: Although a recent study reported that the pregnancy outcomes in the first trimester were more correlated with endometrial thickness on the day of the trigger than with endometrial thickness on the day of single fresh-cleaved embryo transfer, it remains unclear whether endometrial thickness on the day of the trigger can predict live birth rate after a single fresh-cleaved embryo transfer. OBJECTIVE: This study aimed to examine whether endometrial thickness on the trigger day is associated with live birth rates and whether modifying the single fresh-cleaved embryo transfer criteria to reflect endometrial thickness on the trigger day improved the live birth rate and reduced maternal complications in a clomiphene citrate-based minimal stimulation cycle. STUDY DESIGN: This was a retrospective study of the outcomes of 4440 treatment cycles of women who underwent single fresh-cleaved embryo transfer on day 2 of the retrieval cycle. From November 2018 to October 2019, single fresh-cleaved embryo transfer was performed when endometrial thickness on the day of single fresh-cleaved embryo transfer was ≥8 mm (criterion A). From November 2019 to August 2020, single fresh-cleaved embryo transfer was conducted when endometrial thickness on the day of the trigger was ≥7 mm (criterion B). RESULTS: A multivariate logistic regression analysis revealed that increased endometrial thickness on the trigger day was significantly associated with an improvement in the live birth rate after single fresh-cleaved embryo transfer (adjusted odds ratio, 1.098; 95% confidence interval, 1.021-1.179). The live birth rate was significantly higher in the criterion B group than in the criterion A group (22.9% and 19.1%, respectively; P=.0281). Although endometrial thickness on the day of single fresh-cleaved embryo transfer was sufficient, the live birth rate tended to be lower when endometrial thickness on the trigger day was <7.0 mm than when endometrial thickness on the day of the trigger was ≥7.0 mm. The risk for placenta previa was reduced in the criterion B group when compared with the criterion A group (4.3% and 0.6%, respectively; P=.0222). CONCLUSION: This study demonstrated an association of decreased endometrial thickness on the trigger day with low birth rate and a high incidence of placenta previa. A modification of the criteria for a single fresh-cleaved embryo transfer based on endometrial thickness may improve pregnancy and maternal outcomes.

Prevalence of chronic endometritis in patients with infertility due to hydrosalpinx or pelvic peritubal adhesions and effect of laparoscopic surgical correction on pregnancy rates post in vitro fertilization.

OBJECTIVE(S): To assess the prevalence of chronic endometritis (CE) in patients with infertility and hydrosalpinx or peritubal adhesions and to examine the effects of laparoscopic surgical correction (LSC) on CE and pregnancy rates post in vitro fertilization and embryo transfer (IVF-ET). STUDY DESIGN: This is a retrospective cohort study at private IVF-ET centers. A total of 438 patients, known to have hydrosalpinx (n = 194) or peritubal adhesions (n = 244), and undergoing IVF treatment between April 1, 2018 and September 30, 2020 were included in the study. Hysterosalpingography, magnetic resonance imaging, and transvaginal ultrasonography were used to diagnose the hydrosalpinx or peritubal adhesions. Laparoscopic examination and surgical correction were performed on patients with CE. IVF-ET was performed after recovery from LSC. RESULTS: CE was present in 45.9% of patients (89/194) with hydrosalpinx and 14.3% with peritubal adhesions (35/244). All the 89 patients with CE and hydrosalpinx underwent laparoscopic salpingostomy and/or fimbrioplasty, and 64 (71.9%) further underwent proximal tubal occlusion. All the 35 patients with CE and peritubal adhesions underwent laparoscopic adhesiolysis and/or fimbrioplasty, and 19 (54.3%) further underwent proximal tubal occlusion. CD138 PC levels after LSC decreased to < 5 in 70 of 124 patients (56.5%) in one menstrual cycle and decreased to < 5 in all cases within 6 months. Of the 66 patients who underwent a single blastocyst transfer, 57 delivered (cumulative live birth rate (LBR): 86.3%). The cumulative LBR of patients treated for CE with LSC (86.3%) was significantly different from those given antibiotic therapy (320 patients; 38.4%; p <.0001) and the CD138-negative groups (811; 31.8%; p <.0001). CONCLUSION: CE is prevalent in patients with hydrosalpinx and/or peritubal adhesions who present with infertility. LSC improved CE without antibiotic therapy, improving the CP and LBR after IVF-ET.

Maternal age affects pronuclear and chromatin dynamics, morula compaction and cell polarity, and blastulation of human embryos.

STUDY QUESTION: Does maternal ageing impact early and late morphokinetic and cellular processes of human blastocyst formation? SUMMARY ANSWER: Maternal ageing significantly affects pronuclear size and intra- and extra-nuclear dynamics during fertilization, dysregulates cell polarity during compaction, and reduces blastocoel expansion. WHAT IS KNOWN ALREADY: In ART, advanced maternal age (AMA) affects oocyte yield, fertilization, and overall developmental competence. However, with the exception of chromosome segregation errors occurring during oocyte meiosis, the molecular and biochemical mechanisms responsible for AMA-related subfertility and reduced embryo developmental competence remain unclear. In particular, studies reporting morphokinetics and cellular alterations during the fertilization and pre-implantation period in women of AMA remain limited. STUDY DESIGN, SIZE, DURATION: A total of 2058 fertilized oocytes were stratified by maternal age according to the Society for Assisted Reproductive Technology classification (<35, 35-37, 38-40, 41-42, and >42 years) and retrospectively analysed. AMA effects were assessed in relation to: embryo morphokinetics and morphological alterations; and the presence and distribution of cell polarity markers-Yes-associated protein (YAP) and protein kinase C-ζ (PKC-ζ)-involved in blastocyst morphogenesis. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 1050 cycles from 1050 patients met the inclusion criteria and were analysed. Microinjected oocytes were assessed using a time-lapse culture system. Immature oocytes at oocyte retrieval and mature oocytes not suitable for time-lapse monitoring, owing to an excess of residual corona cells or inadequate orientation for correct observation, were not analysed. Phenomena relevant to meiotic resumption, pronuclear dynamics, cytoplasmic/cortical modifications, cleavage patterns and embryo quality were annotated and compared among groups. Furthermore, 20 human embryos donated for research by consenting couples were used for immunofluorescence. MAIN RESULTS AND THE ROLE OF CHANCE: Static microscopic observation revealed that blastocyst formation and expansion were impaired in the 41-42 and >42-year groups (P < 0.0001). The morphological grades of the inner cell mass and trophectoderm were poorer in the >42-year group than those in the <35-year group (P = 0.0022 and P < 0.0001, respectively). Time-lapse microscopic observation revealed a reduction in nucleolus precursor body alignment in female pronuclei in the 41-42 and >42-year groups (P = 0.0010). Female pronuclear area decreased and asynchronous pronuclear breakdown increased in the >42-year group (P = 0.0027 and P < 0.0122, respectively). Developmental speed at cleavage stage, incidence of irregularity of first cleavage, type and duration of blastomere movement, and number of multinucleated cells were comparable among age groups. Delayed embryonic compaction and an increased number of extruded blastomeres were observed in the >42-year group (P = 0.0002 and P = 0.0047, respectively). Blastulation and blastocyst expansion were also delayed in the 41-42 and >42-year groups (P < 0.0001 for both). YAP positivity rate in the outer cells of morulae and embryo PKC-ζ immunoflourescence decreased in the >42-year group (P < 0.0001 for both). LIMITATIONS, REASONS FOR CAUTION: At the cellular level, the investigation was limited to cell polarity markers. Cell components of other developmental pathways should be studied in relation to AMA. WIDER IMPLICATIONS OF THE FINDINGS: The study indicates that maternal ageing affects the key functions of embryo morphogenesis, irrespective of the well-established influence on the fidelity of oocyte meiosis. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the participating institutions. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Assisted reproductive technology in Japan: A summary report for 2020 by the ethics Committee of the Japan Society of obstetrics and gynecology.

Purpose: Since 1986, the Japan Society of Obstetrics and Gynecology assisted reproductive technology (ART) registry system has collected data on national ART use and outcomes trends in Japan. Herein, we describe the characteristics and outcomes of ART cycles registered during 2020 and compare the results with those from 2019. Methods and Results: In 2020, 621 ART facilities participated in the registration. The total number of registered cycles was 449 900, and there were 60 381 live births, which decreased from the previous year (1.79% and 0.36% decrease, respectively). The number of freeze-all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles increased in 2020, and the number of neonates born was 2282 for IVF-embryo transfer (ET) cycles and 2596 for ICSI cycles, which had decreased from the previous year. Frozen-thawed ET (FET) cycles had slightly increased from 2019 (0.04%). In 2020, 215 285 FET cycles were conducted, resulting in 76 196 pregnancies and 55 503 neonates. Single ET was performed in 81.6% of fresh transfers and 85.1% of frozen-thawed cycles, respectively, resulting in over 97% singleton pregnancies/livebirths rates. Conclusion: Despite the COVID-19 pandemic during 2020, the overall number of ART cycles and neonates born demonstrated only a slight decrease in 2020 compared with 2019.

Post-warming culture of human vitrified blastocysts with prolactin improves trophoblast outgrowth.

BACKGROUND: Human embryos express the prolactin (PRL) receptor at the morula and blastocyst stages. Treatment with PRL from cleavage to the blastocyst stage improves blastocyst outgrowth on fibronectin-coated dishes. However, whether post-warming PRL treatment of blastocysts cultured without PRL could improve outgrowth competence remains unknown. Furthermore, the optimal time for post-warming PRL treatment remains to be ascertained. This study investigated the effects of PRL treatment during recovery culture on human blastocyst outgrowth and its related genes. METHODS: In total, 374 discarded vitrified blastocysts were randomly allocated to two groups, to be cultured with (n = 208) or without PRL (control; n = 166) for 120 min for recovery, and then plated on fibronectin-coated dishes. The expression level of PRL-interacting genes, blastocyst adhesion rate, outgrowth area, distance of trophoblast migration, and outgrowth degeneration were examined. RESULTS: The mRNA expression of ezrin, radixin, and moesin, which regulate cell adhesion and invasion by controlling actin reorganization during epithelial-to-mesenchymal transition (EMT), was stimulated by PRL treatment for 120 min. The expression of EMT-related genes, transforming growth factor ß1, snail1, and twist1 was also promoted following treatment with PRL for 120 min. PRL-treated blastocysts also exhibited augmented expression of cadherin 2 and transcriptional repression of cadherin 1. Higher mRNA expression of integrin-based focal adhesion-related genes, ITGA5 and ITGB1, was observed after treatment with PRL for 120 min than in the non- and shorter-treatment groups. PRL treatment for 120 min did not alter the rate of blastocyst adhesion to fibronectin-coated dishes 96 h after the outgrowth culture assay. However, multiple linear regression analysis revealed that the outgrowth area was significantly increased in PRL-treated blastocysts. The migration distance of trophoblast cells was significantly increased and degeneration rate was significantly decreased after PRL treatment. Furthermore, a more beneficial effect of PRL treatment on blastocyst outgrowth was observed when the blastocysts were vitrified on day 5 than when they were vitrified on day 6. CONCLUSIONS: Post-warming culture of human vitrified blastocysts with PRL for 120 min promoted trophoblast outgrowth in vitrified human blastocysts. Furthermore, PRL treatment may reduce outgrowth degeneration by increasing resistance to apoptosis during trophoblast migration.

Does embryo categorization by existing artificial intelligence, morphokinetic or morphological embryo selection models correlate with blastocyst euploidy rates?

RESEARCH QUESTION: Does embryo categorization by existing artificial intelligence (AI), morphokinetic or morphological embryo selection models correlate with blastocyst euploidy? DESIGN: A total of 834 patients (mean maternal age 40.5 ± 3.4 years) who underwent preimplantation genetic testing for aneuploidies (PGT-A) on a total of 3573 tested blastocysts were included in this retrospective study. The cycles were stratified into five maternal age groups according to the Society for Assisted Reproductive Technology age groups (<35, 35-37, 38-40, 41-42 and >42 years). The main outcome of this study was the correlation of euploidy rates in stratified maternal age groups and an automated AI model (iDAScore® v1.0), a morphokinetic embryo selection model (KIDScore Day 5 ver 3, KS-D5) and a traditional morphological grading model (Gardner criteria), respectively. RESULTS: Euploidy rates were significantly correlated with iDAScore (P = 0.0035 to <0.001) in all age groups, and expect for the youngest age group, with KS-D5 and Gardner criteria (all P < 0.0001). Additionally, multivariate logistic regression analysis showed that for all models, higher scores were significantly correlated with euploidy (all P < 0.0001). CONCLUSION: These results show that existing blastocyst scoring models correlate with ploidy status. However, as these models were developed to indicate implantation potential, they cannot accurately diagnose if an embryo is euploid or aneuploid. Instead, they may be used to support the decision of how many and which blastocysts to biopsy, thus potentially reducing patient costs.

Preimplantation Genetic Testing for Aneuploidy for Recurrent Pregnancy Loss and Recurrent Implantation Failure in Minimal Ovarian Stimulation Cycle for Women Aged 35-42 Years: Live Birth Rate, Developmental Follow-up of Children, and Embryo Ranking.

This study was aimed at exploring the benefits of preimplantation genetic testing for aneuploidy (PGT-A) in ensuring a successful pregnancy in patients with recurrent pregnancy loss (RPL) caused by an abnormal number of chromosomes in the embryo and recurrent implantation failure (RIF). Thirty-two patients who underwent PGT-A (18 in the RIF protocol and 14 in the RPL protocol) were enrolled in the study, and 2556 patients who did not undergo PGT-A during the same in vitro fertilization (IVF) treatment period were enrolled as controls. All patients underwent minimal stimulation cycle IVF. In the RPL protocol, the live birth rate per embryo transfer (ET) and that per patient were higher with PGT-A (80.0% each) than without it (0% each; P = 0.0050), and the rate of miscarriages was lower with PGT-A than without it (20.0% vs. 100.0%, P = 0.0098). In the RIF protocol, there were no significant differences in the live birth rate per ET and in the rate of miscarriages between groups with and without PGT-A-90.0% vs. 69.2% (P = 0.2313) and 0% vs. 10.0% (P = 0.3297), respectively. None of the children whose mothers underwent PGT-A presented adverse findings at a 1.5-year developmental check-up. In conclusion, PGT-A in RPL is advantageous for improving the live birth rate per ET and that per patient in minimal stimulation cycle IVF; it reduces the rate of miscarriages. In addition, PGT-A might be more beneficial for embryo selection than the existing morphological grades of blastocysts, resulting in earlier conception.

Letrozole-induced endometrial preparation improved the pregnancy outcomes after frozen blastocyst transfer compared to the natural cycle: a retrospective cohort study.

BACKGROUND: Letrozole treatment is considered an effective option in endometrial preparation for frozen embryo transfers in patients with ovulation disorders or irregular menstruation; however, the effectiveness of letrozole-induced endometrial preparation remains unclear in ovulatory patients. Furthermore, there is no comparative study reporting on pregnancy complications and congenital anomalies after frozen embryo transfers comparing natural and letrozole-assisted cycles. This study examined whether letrozole-induced endometrial preparation affected pregnancy outcomes, perinatal outcomes, and congenital anomalies after single vitrified-warmed blastocyst transfers (SVBTs) in ovulatory patients, as compared with the natural cycle. METHODS: This historic cohort study included only patients with unexplained infertility. Overall, 14,611 patients who underwent SVBTs between July 2015 and June 2020, comprising both natural and letrozole-assisted cycles, were included. Multiple covariates that impact outcomes were used for propensity score matching; 1,911 patients in the letrozole group were matched to 12,700 patients in the natural group, and the clinical records of 1,910 patients in each group were retrospectively analysed. Cycle characteristics, pregnancy outcomes (clinical pregnancy, ongoing pregnancy, and live birth), and incidence of pregnancy complications and congenital anomalies were statistically compared between the two groups. RESULTS: Multivariate logistic regression analysis showed that letrozole administration during SVBT cycles significantly improved the live birth rate (P = 0.0355). Gestational age, birth length, birth weight, and infant sex, as well as the incidence of pregnancy complications and birth defects, were statistically comparable between the two groups. Furthermore, multivariate logistic regression analysis revealed that the perinatal outcomes were not affected by letrozole-induced endometrial preparation. CONCLUSIONS: Letrozole-induced endometrial preparation improved the live birth rate compared with the natural cycle, without adverse effects on perinatal outcomes and congenital anomalies after SVBTs. Therefore, letrozole-induced endometrial preparation might be a safe and more effective strategy, especially for patients with insufficient luteal function.

Endometrial preparation and maternal and obstetrical outcomes after frozen blastocyst transfer.

BACKGROUND: Two types of endometrial preparation protocols are used for frozen embryo transfers in current practice: hormone replacement and the natural cycle. Endometrial preparation in the natural cycle reportedly increases the chances of live birth and decreases early pregnancy loss compared with that in the hormone replacement cycle. However, the influence of endometrial preparation on maternal and neonatal health remains unclear. OBJECTIVE: This study aimed to investigate whether the differences between hormone replacement cycle and natural cycle influence perinatal outcomes and risk of congenital anomalies in frozen-thawed blastocyst transfer fetuses or births. STUDY DESIGN: Perinatal outcomes and congenital abnormalities were compared between the natural and hormone replacement cycles. According to the timing of ovulation, frozen-thawed blastocyst transfers in the natural cycle were classified into 2 patterns: on day 4.5 (ovulation 4.5) or day 5 (ovulation 5.0) after ovulation. When the serum luteinizing hormone level was not increased on the day of the trigger, a single vitrified-warmed blastocyst transfer was performed on day 7 after the trigger (ovulation 5.0). When the luteinizing hormone level was slightly increased on the day of trigger, single vitrified-warmed blastocyst transfer was performed on day 6 after the trigger (ovulation 5.0). In total, 67,018 cycles (ovulation 4.5, 29,705 cycles; ovulation 5.0, 31,995 cycles; hormone replacement, 5318 cycles) of frozen-thawed blastocyst transfer between January 2008 and December 2017 at Kato Ladies Clinic were retrospectively analyzed. During the study period, embryo cryopreservation was performed using a vitrification method in all cycles. RESULTS: Hormone replacement cycles were associated with a higher occurrence of hypertensive disorders of pregnancy (adjusted odds ratio, 2.16; 95% confidence interval, 1.66-2.81) and placenta accreta (adjusted odds ratio, 4.14; 95% confidence interval, 1.64-10.44) compared with the natural cycle. The risks of cesarean delivery (adjusted odds ratio, 1.93; 95% confidence interval, 1.78-2.18), preterm birth (adjusted odds ratio, 1.55; 95% confidence interval, 1.25-1.93), and low birthweight (adjusted odds ratio, 1.42; 95% confidence interval, 1.18-1.73) were also higher for hormone replacement cycles. No significant difference in the risk of congenital anomalies was observed between the 2 cycles. CONCLUSION: The risk of hypertensive disorders of pregnancy, placenta accreta, cesarean delivery, preterm delivery, and low birthweight was higher in hormone replacement cycles than in natural cycles, whereas the risk of congenital anomalies was similar between both cycles. Further follow-up is needed to investigate these risks and to explore alternative endometrial preparation methods.

Association between a deep learning-based scoring system with morphokinetics and morphological alterations in human embryos.

RESEARCH QUESTION: What is the association between the deep learning-based scoring system, iDAScore, and biological events during the pre-implantation period? DESIGN: Retrospective observational study of patients (n = 925) who underwent oocyte retrieval in a clomiphene citrate-based minimal stimulation cycle and obtained expanded blastocysts between October 2019 and December 2020. The association between iDAScore with morphokinetics and morphological alteration during fertilization, cleavage stage, compaction and blastocyst stage was analysed. RESULTS: The duration of the cytoplasmic halo was significantly prolonged in low-scoring blastocysts (P < 0.0001). The timing of female and male pronuclei breakdown was significantly delayed in low-scoring blastocysts compared with high-scoring blastocysts (P < 0.0001 in both). Embryos with either trichotomous, multi-chotomous, rapid or reverse cleavage or asymmetric division had a lower score than embryos with normal cleavage (P < 0.0001-0.0098). The cell number and amount of blastomere fragmentation on days 2 and 3 were significantly associated with iDAScore (P < 0.0001-0.0008). Delayed compaction, blastulation and blastocyst expansion were observed in low-scoring embryos (P < 0.0001 in all). The incidence of blastomere exclusion and extrusion during embryonic compaction was significantly higher in low-scoring embryos than in high-scoring embryos (P ≤ 0.0001 in both). Blastocyst morphology was significantly associated with iDAScore (P < 0.0001). Multiple linear regression analysis revealed that, during the transformation to blastocyst stage, morphokinetic and morphological events were strongly associated with iDAScore (P < 0.0001-0.0116). CONCLUSIONS: iDAScore was significantly correlated with morphokinetics and morphological alterations of pre-implantation embryos, especially during the late pre-implantation period. Our findings contribute to research on deep learning model-based embryo selection, which may provide patients with a compelling explanation of blastocyst selection.