Search

• iDAScore, a deep learning scoring system, is associated with fertilisation events. • iDAScore reflects irregular first division, cell number, and fragmentation. • Delayed compaction and blastulation is correlated with a decreased iDAScore. • iDAScore is associated with embryonic morphology at the morula/blastocyst stage. What is the association between the deep learning-based scoring system, iDAScore, and biological events during the pre-implantation period? 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. 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). 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. [ABSTRACT FROM AUTHOR]

• Vitrified embryos warmed with fatty acids (FA) exhibited better developmental outcomes • FA addition during warming increased neutral lipid content in vitrified oocytes • FA-supplemented oocyte-derived embryos had higher β-oxidation gene expression • FA improved blastocyst development and morphology of vitrified human embryos Does fatty acid supplementation in vitrification and warming media influence developmental competence in oocytes after vitrification and warming? Mouse oocytes and four-cell embryos were vitrified and warmed with solutions supplemented with fatty acid and cultured to the blastocyst stage. To study lipid metabolism after vitrification, quantitative real-time polymerase chain reaction was used to analyse the expression of genes related to beta oxidation in mouse embryos vitrified and warmed with or without fatty acids. The effects of fatty acid supplementation in the warming solutions on the developmental competence of bovine and human embryos were analysed. Blastocyst outgrowth assay was used to evaluate the potential of human blastocysts for adhesion to fibronectin. The neutral lipid content of mouse oocytes in the fatty acid 1% supplementation group was significantly higher than in the fatty acid 0% group (P = 0.0032). The developmental rate to the blastocyst stage was significantly higher in the fatty acid 1% group than in the fatty acid 0% group in mice (P = 0.0345). Fatty acid supplementation in warming solution upregulated Acaa2 and Hadha in mouse embryos. Fatty acids significantly improved the developmental ability of bovine embryos to the blastocyst stage (P = 0.0048). Warming with 1% fatty acid supplementation significantly increased the proportion of human blastocysts with morphological grade A inner cell mass (P = 0.0074) and trophectoderm (P = 0.0323). Fatty acid supplementation in the warming solutions improved the developmental competence of vitrified–warmed mouse oocytes by activating the beta-oxidation pathway. Fatty acid supplementation enhanced the developmental rate of bovine embryos to the blastocyst stage and improved morphological characteristics of human embryos vitrified at the cleavage stage. [ABSTRACT FROM AUTHOR]

What is the gene expression pattern of prolactin receptor (PRLR) in human pre-implantation embryos and what are its functions during the embryonic development and adhesion process? A total of 405 discarded human vitrified oocytes and embryos donated for research by consenting couples were used in this study. The oocytes and embryos were used to analyse PRLR expression and to evaluate the influence of prolactin (PRL) supplementation in the embryo culture medium on embryo developmental competence and viability. The rates of blastocyst development and adhesion, outgrowth area, cytoskeletal reorganization and nascent adhesion formation were compared between groups. PRLR expression increased significantly after embryo compaction (P < 0.0001) and blastulation (P < 0.0001). Supplementation of the embryo culture medium with PRL did not improve the developmental rate and morphological grade. In contrast, blastocyst outgrowth was significantly increased in embryos cultured with PRL (P = 0.0004). Phosphorylation of JAK2, downstream of the prolactin receptor family, was markedly higher in the PRL-treated embryos than in embryos cultured without PRL. Furthermore, the expression of mRNAs encoding ezrin–radixin–moesin proteins and epithelial–mesenchymal transition-related genes was stimulated by the activation of PRL-JAK2 signalling. The PRL-treated embryos had higher mRNA expression of integrins than non-treated embryos, and transcriptional repression of cadherin 1 was observed after PRL treatment. More nascent adherent cells expressed focal adhesion kinase and paxillin in PRL-treated embryos than in non-treated embryos. Human embryos express PRLR at the morula and blastocyst stages, and PRLR signalling stimulates blastocyst adhesion by promoting integrin-based focal adhesions and cytoskeletal organization during trophoblast outgrowth. [ABSTRACT FROM AUTHOR]

• Halo presence correlated with preimplantation development. • Halo morphokinetics before 1st cell division positively correlated with blastocyst formation. • Halo morphokinetics could be predictive of embryo competence for transfer success. Is the spatiotemporal phenomenology of the cytoplasmic halo during fertilization related to embryonic competence? Time-lapse images from 1009 zygotes were retrospectively analysed from 560 patients who underwent IVF with minimal stimulation and single vitrified–warmed blastocyst transfer between April 2017 and March 2018. Halo presence and morphokinetics were monitored and compared relative to embryo quality, blastocyst expansion and ongoing pregnancy. Halo was observed in 88% of fertilized oocytes. Embryos derived from zygotes without halo had significantly higher rates of rapid cleavage (P = 0.0004), cell fusion (P = 0.0028) and asymmetrical division (P = 0.0002) compared with those derived from zygotes with halo. Multivariate logistic regression analysis had significantly higher developmental rates compared with the expanded blastocyst stage in embryos displaying a halo, regardless of its distribution (adjusted odds ratio 0.435; P = 0.0004). Prolonged halo time intervals were significantly correlated with increased asymmetrical division at first cell division (P = 0.0412, P = 0.0088, respectively) and decreased developmental rates to expanded blastocyst stage (P = 0.0062, P = 0.0020, respectively). Additionally, prolonged presence of the cytoplasmic halo was associated with a decreased ongoing pregnancy rate (adjusted odds ratio 0.871; P = 0.006). Poor sperm quality and decreased oocyte diameter were correlated with absence of the cytoplasmic halo (P = 0.0477, P < 0.0001, respectively) or prolonged halo presence (P = 0.0139, P = 0.0002, respectively). Halo presence and morphokinetics are associated with cleavage patterns, development to blastocyst stage and ongoing pregnancy rate after single blastocyst transfer. Halo morphokinetics seems to reflect sperm and oocyte quality. Cytoplasmic halo might be valuable predictor for refining selection of more developmentally competent blastocysts. [ABSTRACT FROM AUTHOR]

Abstract Research question What is the incidence, origin and clinical significance of blastomere movement after the first cell division in the human embryo? Design A total of 1096 embryos, cultured in the EmbryoScope+ ® time-lapse system and subjected to a single fresh cleaved embryo transfer, were retrospectively analysed. Type and duration of blastomere movement (dBMov) between the first (t2) and second cell division (t3) was monitored, and the ratio of dBMov during the 2-cell stage [dBMov/(t3–t2)] was calculated. Morphological evaluation of embryos was performed by referring to the size of the blastomere and fragmentation after first division in addition to Veeck's criteria on Day 2. The correlation between dBMov and ongoing pregnancy was evaluated and the association of dBMov with patient and embryonic characteristics was determined. Results Both movement type and the value of dBMov/(t3–t2) were significantly associated with asymmetrical first division, fragment formation and morphological grade on Day 2. Multivariate logistic regression analysis revealed that a higher value of dBMov/(t3–t2) significantly correlated with a decreased ongoing pregnancy rate, even after adjustment for co-founders (odds ratio 0.399, P = 0.0419). The time intervals of pronuclear (PN) alignment and PN fading were significantly correlated with the dBMov/(t3–t2) value. Conclusions Embryos with extended blastomere movement after the first cell division, which is associated with the delay of PN fading and first cell division, have a lower competence to initiate an ongoing pregnancy after fresh embryo transfer on Day 2. Thus, blastomere movement could be a useful predictive parameter for selecting embryos at the early cleavage stage. [ABSTRACT FROM AUTHOR]

Partial removal of the zona pellucida (ZP) has been performed using a laser system to promote hatching of vitrified-warmed blastocysts. However, low-viability blastocysts cannot hatch even after partial ZP removal. This study examined whether complete removal of the ZP improves embryonic adhesion and outgrowth of vitrified-warmed blastocysts compared with partial removal, using a blastocyst outgrowth model. In all, 217 vitrified human blastocysts, which were discarded and donated for research by consenting couples, were warmed and subjected to assisted hatching to remove the ZP partially or completely, or did not undergo assisted hatching (zona intact controls). Blastocysts were cultured using time-lapse microscopy to monitor hatching, adhesion and outgrowth. Despite partial ZP removal, 36% of blastocysts failed to hatch. Blastocyst outgrowth assays showed improved adhesion rate, shorter time for adhesion and larger outgrowth area in the blastocysts with completely removed ZP compared with those with partially-removed ZP. mRNA expression of integrin α5 and β1 was upregulated in blastocysts with completely removed ZP compared with those with partially-removed ZP. Study findings reveal the advantages of complete ZP removal for assisted hatching. In conclusion, complete ZP removal increases the chance of blastocyst adhesion and subsequent outgrowth in vitro after the vitrification-warming procedure. [ABSTRACT FROM AUTHOR]

• Chronic endometritis causes recurrent implantation failure and pregnancy loss. • Conventional chronic endometritis treatment involves the use of strong antibiotics. • Pathological fluid via fallopian tube maybe the cause of chronic endometritis. • Laparoscopically correcting the tube and adhesion improves chronic endometritis. 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). 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. 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). 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. [ABSTRACT FROM AUTHOR]

Hydroxypropyl cellulose (HPC) was investigated as a replacement for serum substitute supplement (SSS) for use in cryoprotectant solutions for embryo vitrification. Mouse blastocysts from inbred ( n = 1056), hybrid ( n = 128) strains, and 121 vitrified blastocysts donated by infertile patients ( n = 102) were used. Mouse and human blastocysts, with or without zona pellucida, were vitrified and warmed in either 1% or 5% HPC or in 5% or 20% SSS-supplemented media using the Cryotop (Kitazato BioPharma Co. Ltd, Fuji, Japan) method, and the survival and oxygen consumption rates were assessed. Viscosity of each vitrification solution was compared. Survival rates of mouse hybrid blastocysts and human zona pellucida-intact blastocysts were comparable among the groups. Mouse and human zona pellucida-free blastocysts, which normally exhibit poor cryoresistance, showed significantly higher survival rates in 5% HPC than 5% SSS ( P < 0.05). The 5% HPC-supplemented vitrification solution showed a significantly higher viscosity ( P < 0.05). The blastocysts were easily detached from the Cryotop strip during warming when HPC-supplemented vitrification solution was used. The oxygen consumption rates were similar between non-vitrified and 5% HPC groups. The results suggest possible use of HPC for supplementation of cryoprotectant solutions and provide useful information to improve vitrification protocols. [ABSTRACT FROM AUTHOR]

A retrospective cohort study of 8736 autologous single vitrified–warmed blastocyst transfer cycles was conducted in a single centre to investigate the effect of cryostorage on clinical and neonatal outcomes. Cryostorage duration was classified into three groups: (A) 0–2 months ( n = 4702); (B) 2–13 months ( n = 2853) and (C) 13–97 months ( n = 1181). Blastocysts were vitrified using the Cryotop method. No significant differences were observed in live birth rates: (A) 37.3%; (B) 34.9%; (C) (35.2%). Gestational period was significantly shorter in group C: (A) 38.7 ± 1.8; (B) 38.6 ± 1.6; (C) 38.1 ± 1.7; P < 0.05. This was clinically unimportant as the average gestational age was more than 38 weeks. No significant differences between groups were observed in birth weight: (A) 3060 ± 455 g; (B) 3052 ± 449 g; (C) 2992 ± 445 g, or congenital malformation rates: (A) 2.2%; (B) 1.9%; (C) 1.8%. The limitation of this study was that maximum storage duration was 8 years; most blastocysts were in cryostorage for much shorter periods. Long-term storage of blastocysts that are vitrified using an open device vitrification system has no negative effect on pregnancy and neonatal outcomes. [ABSTRACT FROM AUTHOR]

Abstract: Background: Mitochondrial diseases are caused by the mutations in both nuclear and mitochondrial DNA (mtDNA) and the treatment options for patients who have mitochondrial disease are rather limited. Mitochondrial DNA is transmitted maternally and does not follow a Mendelian pattern of inheritance. Since reliable and predictable detection of mitochondrial disorders in embryos and oocytes is unattainable at present, an alternative approach to this problem has emerged as partial or complete replacement of mutated mtDNA with the wild-type mtDNA through embryo manipulations. Currently available methods to achieve this goal are germinal vesicle transfer (GVT), metaphase chromosome transfer (CT), pronuclear transfer (PNT) and ooplasmic transfer (OT). Scope of review: We summarize the state of the art regarding these technologies and discuss the implications of recent advances in the field for clinical practice. Major conclusions: CT, PNT and GVT techniques hold promise to prevent transmission of mutant mtDNA through ARTs. However, it is clear that mtDNA heteroplasmy in oocytes, embryos and offspring produced by these methods remains as a legitimate concern. General significance: New approaches to eliminate transmission of mutant mtDNA certainly need to be explored in order to bring the promise of clinical application for the treatment of mitochondrial disorders. This article is part of a Special Issue entitled Biochemistry of Mitochondria, Life and Intervention 2010. [Copyright &y& Elsevier]