P–160 Sibling oocytes cultured in a time-lapse versus benchtop incubator: limited exposure of embryos outside the incubator improves outcomes

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
N D Munck ◽  
N Nobrega ◽  
A Abdala ◽  
A El-Damen ◽  
A Arnanz ◽  
...  
Keyword(s):  
Prospective Trial ◽  
Time Lapse ◽  
Poor Quality ◽  
Good Prognosis ◽  
Culture Conditions ◽  
Blastocyst Formation ◽  
Cleavage Stage ◽  
Blastocyst Development ◽  
Sibling Oocytes ◽  
Blastocyst Quality

Abstract Study question Does the limited exposure of embryos outside the incubator, during evaluation and changeover, have an impact on the blastocyst development, blastocyst quality and euploid outcomes? Summary answer Exposure of embryos outside the incubator, negatively impacts the number, quality and euploidy rate of day 5 blastocysts. What is known already The laboratory environment with its culture conditions is one of the crucial elements of the delicate equation to a successful ART outcome. It has been shown that increased fluctuations in the culture conditions have a considerable impact on the number of blastocysts obtained and cycle outcomes. Compared to conventional benchtop incubators, Time Lapse Technology (TLT) incubators capture images of the embryo and allow morphologic and morphokinetic assessment without disturbance during incubation. Several studies have been published comparing the efficiency, safety and outcome performance between conventional and TLT incubators, however, none of them explored the euploid outcomes. Study design, size, duration An observational sibling oocyte study was performed at ART Fertility Clinics, Abu Dhabi between March 2018 and April 2020 and included data of 796 mature oocytes injected from 42 stimulation cycles. Sibling oocytes were randomly split between 2 different incubators: 12 oocytes were assigned to the twelve wells of the EmbryoscopeTM (ES) and the remaining oocytes were cultured in a conventional benchtop incubator, G185 K-System (KS). Participants/materials, setting, methods Embryos from patients with primary or secondary infertility, who underwent ovarian stimulation for ICSI and PGT-A through NGS on trophectoderm biopsies, were eligible. All patients had at least 16 fresh mature oocytes, randomly allocated to two different incubators after ICSI: 503 (63.2%) oocytes were cultured in ES and 293 (36.8%) in KS. The fertilization, cleavage, useable blastocyst and euploid rates, as well as embryo/blastocyst qualities were assessed to evaluate each incubator’s performance. Main results and the role of chance The fertilization and cleavage rates were similar between incubators. Total useable blastocyst rate (64.8% vs 49.6%, p < 0.001) was significantly higher for embryos cultured in ES, mainly due a higher percentage of blastocysts biopsied on day 5 in ES (67.8% vs 57.0%, p = 0.037), with improved quality (p = 0.008). There was no difference in the total euploid rate between ES and KS (59.9% vs 50.4%, p = 0.314), but a significantly higher euploid rate was seen for blastocysts cultured in ES and biopsied on day 5 (63.5% vs 37.4%, p = 0.001). Day 3 embryo quality and total biopsied blastocyst quality was not different between incubators. No difference was observed in the total useable blastocyst development from good (p = 0.0832) and poor (p = 0.112) quality day 3 cleavage stage embryos. However, when stratifying according to the day of blastocyst development, poor quality embryos on day 3 showed superior blastocyst formation on day 5 when cultured in ES (64.1% vs 39.1% for day 5 and 35.9% vs 60.9% for day 6, p = 0.005). Accordingly, blastocyst formation from poor quality embryos on day 3, was shifted to day 6 for embryos cultured in KS. This difference in the day of blastocyst development was not observed for good quality cleavage stage embryos (p = 0.917). Limitations, reasons for caution The current observational study needs confirmation in a prospective trial and should also include the implantation potential of the euploid blastocysts, which was not followed in the current study. A good prognosis population (≥16 mature oocytes) was studied and may not reflect the outcomes in patients with lower oocyte numbers. Wider implications of the findings: This work builds evidence to the solid introduction of the TLT incubators to the clinical routine, as the reduced exposure of embryos outside the incubator – and hence decreased stress - improves the blastocyst development. Trial registration number NA

P–804 Morphokinetic development by time-lapse imaging of conceptuses generated from artificial oocytes

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A Trout ◽  
P Xie ◽  
A Petrini ◽  
Z Rosenwaks ◽  
G Palermo
Keyword(s):  
Somatic Cell ◽  
Histone Deacetylase ◽  
Nuclear Transfer ◽  
Cumulus Cells ◽  
Time Lapse ◽  
Culture Conditions ◽  
Preimplantation Development ◽  
Preimplantation Embryos ◽  
Blastocyst Development ◽  
Time Lapse Imaging

Abstract Study question What are the ideal culture conditions to enhance full preimplantation development of embryos generated by FVB somatic cell haploidization (SCH) in the mouse model? Summary answer The presence of a histone deacetylase inhibitor yielded the best morphokinetic development of expanded blastocysts generated by FVB SCH, comparable to control blastocysts. What is known already Various culture conditions and medium supplements have been proposed to promote preimplantation development of embryos generated by SCH, including supplementation with trichostatin A (TSA), fasudil, scriptaid, and RAD–51 stimulatory compound–1 (RS–1). TSA and scriptaid, both histone-deacetylase inhibitors, have been found to improve embryo development following nuclear transfer by enhancing histone acetylation and cellular reprogramming. Additionally, fasudil is a Rho-associated kinase inhibitor that has been shown to reduce apoptosis and promote cell proliferation. Finally, RS–1 stimulates RAD51 activity, which promotes the repair of DNA damage and increases the efficacy of somatic cell reprogramming. Study design, size, duration B6D2F1 mouse metaphase II (MII) oocytes underwent enucleation and nuclear transfer, or were ICSI inseminated serving as controls. Reconstituted oocytes showing development of a meiotic-like spindle demonstrated successful SCH, and were ICSI inseminated. SCH conceptuses were cultured in one of three groups: KSOM, KSOM supplemented with TSA (TSA), or KSOM supplemented with fasudil, scriptaid, and RS–1 (Cocktail). ICSI controls (ICSIC) were cultured in KSOM medium. Fertilization and full preimplantation development were compared among all groups. Participants/materials, setting, methods Ooplasts were generated from MII oocytes by removing spindle complexes under OosightÔ visualization and cytochalasin B exposure. A single FVB mouse cumulus cell was transferred into the perivitelline space and fused with the ooplast, facilitated by Sendai virus. Reconstructed oocytes with novel pseudo-meiotic spindles underwent piezo-ICSI and were cultured in different media conditions in a time-lapse imaging system up to 96h. TSA and Cocktail embryos had media changed to regular KSOM 10 hours after insemination. Main results and the role of chance A total of 274 B6D2F1 MII oocytes were enucleated, resulting in a 95.9% survival rate. All ooplasts survived nuclear transfer and 62.1% successfully haploidized after 2 hours. ICSIC and reconstituted SCH oocytes survived piezo-ICSI at rates of 81.5% and 57.0%, respectively (P < 0.01). SCH embryos were then allocated into KSOM, TSA supplied, and Cocktail media. Fertilization rates for ICSIC, KSOM, and TSA embryos were 92.4%, 90.7%, and 94.4%, respectively, while the rate for embryos cultured in Cocktail was only 71.9% (P < 0.03). While embryos cultured in Cocktail had a comparable 2-cell timing to ICSIC, embryos in TSA reached developmental milestones with a closer timing to the ICSIC, having minor delays at the 3-, 4-, and 6-cell stages (P < 0.05). KSOM- and Cocktail-cultured embryos were delayed at most of the stages (P < 0.01), except for the two-pronuclei appearance. Although the TSA group displayed the best embryo developmental pattern, the final rate of blastocyst development was somewhat homogeneous with rates of 15.4%, 23.5%, and 13.0% for the KSOM, TSA, and Cocktail groups, respectively (P < 0.001), and remarkably lower than the ICSIC (81.6%). Limitations, reasons for caution Although live pups have been obtained using BDF cumulus cells, embryos generated by FVB cumulus cells show a remarkably lower blastocyst development, but maintain morphokinetic characteristics similar to ICSIC in the presence of TSA. Wider implications of the findings: While using different strains to enhance genetic variance, the morphokinetic analysis of preimplantation embryos in ideal culture conditions is paramount to the progress of neogametogenesis. The implementation of this technique may soon help create genotyped oocytes for women with compromised ovarian reserve. Trial registration number N/A

P–032 Assessment of embryonic developmental outcome of direct unequal cleavage in patients with non-obstructive azoospermia and/or obstructive azoospermia

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A NAGANO ◽  
Y Narumiya ◽  
N Okutani ◽  
S Mizuta ◽  
T Takeuchi ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Time Lapse ◽  
Poor Quality ◽  
Obstructive Azoospermia ◽  
Testicular Sperm ◽  
Blastocyst Development ◽  
Lower Priority ◽  
Development Rates ◽  
Good Quality Embryo ◽  
Few Data

Abstract Study question Does direct unequal cleavage (DC) affect embryonic development after ICSI with testicular sperm (TESE-ICSI) in patients with non-obstructive azoospermia (NOA) and/or obstructive azoospermia (OA)? Summary answer The incidence of DC at the first cleavage (DC1) was extremely high and DC1 negatively affected embryonic development in NOA patients. What is known already It has been reported that the blastocyst development of embryos with direct cleavage (DC) was significantly lower than that without DC, but the clinical pregnancy rate after blastocyst transfer was not different with or without DC. The incidence of DC has been reported to be significantly higher after ICSI with testicular sperm (TESE-ICSI) than ICSI with ejaculated sperm (Ej), but to our knowledge, there are few reports investigating that the embryos with DC after TESE-ICSI affect embryonic development. Study design, size, duration We conducted a retrospective cohort study using time-lapse incubators (Geri, Genea Biomedx, Australia) from September 2018 to November 2020. Of 1033 two-pronuclear (2PN) embryos from TESE-ICSI, 486 and 547 embryos were from OA (35.9±5.5 years) and NOA (33.7±5.2 years), respectively. As an age matched control, we chose 581 embryos from ICSI using Ej (36.5±4.4 years). Participants/materials, setting, methods DC embryos were classified as DC1 (DC at first cleavage), DC2 (DC at second cleavage), and non-DC (without DC). The incidences of DC1 or DC2 and blastocyst development rates were compared among OA, NOA and Ej groups. In TESE-ICSI group, we compared blastocyst development rates with or without DC between good and poor quality embryos on day 3. Good quality embryos were defined as 8 cells with G3 or more by the Veeck’s classification. Main results and the role of chance DC1 incidence was significantly higher in NOA (37.3%) than OA (27.8%) and Ej (22.7%) (P < 0.01), whereas DC2 incidence was not statistically different among three groups; NOA (15.7%), OA (15.0%) and Ej (13.4%). Blastocyst development rates in DC1 were 17.8%, 19.5% and 25.8% for NOA, OA and Ej, respectively, which were significantly lower compared to non-DC in corresponding three groups (65.1%, 67.7%, and 68.5%, respectively, P < 0.01). In TESE-ICSI group, good-quality embryo rate on day 3 was significantly lower in DC1 (34.5%, P < 0.01) than DC2 (60.9%) or non-DC (54.2%). Additionally, blastocyst development rates in DC1 and DC2 were significantly lower than non-DC regardless of embryonic grades on day 3 (35.1%, 51.0%, and 81.6% for good-quality embryos on day 3, 10.1%, 27.0%, and 49.1% for poor-quality embryos on day 3, respectively, P < 0.05). When immotile sperm was used for TESE-ICSI, DC1 incidence was 40.0% (6/15), which did not show statistically differences. When performing single frozen-thawed blastocyst transfers, no pregnancies resulted from either DC1 (n = 13) or DC2 (n = 3) embryos in TESE-ICSI group. Limitations, reasons for caution We had a few data about the pregnancy rates after blastocyst transfers with DC, because embryos with DC were seldom transferred due to those lower priority. Although DC might be influenced by the sperm, we did not analyze the incidence of DC by taking the semen factors into account. Wider implications of the findings: The incidence of DC1 was extremely high and DC1 negatively affected embryonic development in NOA patients. Therefore, it is important to observe embryos using time-lapse incubator in order to recognize embryos with/without pregnancy potential, especially for embryos with DC1 in NOA patients. Trial registration number Not applicable

P–224 Multinucleated and non-multinucleated embryos in PGT-A cycles: Is there any difference?

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
M I Papadopoulou ◽  
A Papatheodorou ◽  
A Vorniotaki ◽  
N Christoforidis ◽  
A Chatziparasidou
Keyword(s):  
Clinical Outcome ◽  
Clinical Outcomes ◽  
Chromosomal Abnormality ◽  
Time Lapse ◽  
Control Group ◽  
Blastocyst Formation ◽  
Cleavage Stage ◽  
Female Age ◽  
And Control ◽  
Euploidy Rate

Abstract Study question Is multinucleation during cleavage stage correlated with the ploidy status of embryos and how does it affect the clinical outcome? Summary answer The presence of multinucleated embryos does not affect clinical outcome, although the risk of aneuploidy is higher in multinucleated embryos. What is known already Multinucleated blastomeres (ΜΝ) of cleavage stage embryos has been reported widely in scientific literature. Multinucleation has been associated with diminished embryo developmental competency and clinical outcomes such as lower implantation. Although this is an intriguing subject of research, it is not clear yet whether multinucleation is related to aneuploidy. Morphological irregularities such as multinucleation in blastomeres became a constant finding only after the perpetually evolving technology of time-lapse culture of embryos which in combination with PGT-A analysis, creates new research paths which aim to develop a new tool for selection or deselection of embryos for transfer. Study design, size, duration This retrospective study, included 97 PGT-A cycles, performed at Embryolab fertility clinic from May 2017 to December 2020, all cultured in time-lapse incubator (EmbryoScope). Two study groups were formed; the MN Group consisted of PGT-A cycles with at least one multinucleated embryo (n = 56) and the Control Group in which all PGT-A cycles had no multinucleated embryos (n = 38). Euploidy rate, type of chromosomal abnormality, cumulative pregnancy and live birth rates were compared between the two groups. Participants/materials, setting, methods Embryos were annotated for the existence of multinucleated blastomeres on Day 2 of their development. Biopsy was performed on Days 5/6 and embryos were genetically tested. One or two euploid embryos were transferred. Euploidy rate and clinical outcomes between the two groups were compared. Within the MN group, euploidy rate between multinucleated and non-multinucleated embryos was compared. For abnormal embryos, association of multinucleation with the type of abnormality was tested. SAS statistical analysis was performed. Main results and the role of chance Mean female age was 35.93 years in the MN group and 38.39 years in the control group. Blastocyst formation rate (expressed per fertilised oocytes) was similar between MN and Control group (74% vs 76%, p = 0.6303). In the MN group, 56 cases resulted in 44 embryo transfers while in the control group 38 cases resulted in 23 embryo transfers. Pregnancy rates (59.09% vs 65.21%, p = 0.6255) and clinical pregnancy rates (45.45% vs 39.13%, p = 0.4245) were not significantly different between MN and Control group. Initially, cumulative live birth rate was found to be significantly higher in the MN group compared to the Control group (62.96% vs 33.34%, p = 0.0417). However, when logistic and poisson regression was applied, it became obvious that this difference was not affected by multinucleation but from other factors such as female age. When comparing multinucleated and non-multinucleated embryos within the MN group, it was found that the mean number of euploid embryos was significantly higher in the non-multinucleated subgroup of embryos (p = 0.0021). No correlation was found between multinucleation and the type of chromosomal abnormality. Limitations, reasons for caution The sample size is the main limitation of the present study. More research with bigger sample size is needed in order to confirm the finding of the present study. Wider implications of the findings: The present study suggests that multinucleated blastomeres during embryo development is not an indication for diminished blastocyst formation and does not affect the clinical outcomes. However, within a sibling embryo population, non-multinucleated embryos tend to be euploid and this finding can be used to advance embryo selection efficiency. Trial registration number Not applicable

scholarly journals Poor-quality embryos compared with available embryos at cleavage stage have similar outcomes in vitrified-thawed single blastocyst transfer

2021 ◽  
Author(s):  
Hanyan Liu ◽  
Shaoquan Zhan ◽  
Xiaolin Long ◽  
Lei Li ◽  
Hongzi Du ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Retrospective Cohort ◽  
Endometrial Thickness ◽  
Poor Quality ◽  
Good Prognosis ◽  
Cleavage Stage ◽  
Factors Affecting ◽  
Single Blastocyst Transfer ◽  
Confounding Variables

Abstract Background It was known that in patients with good prognosis, day 5 good-quality blastocysts formed by available cleavage embryos (AEs) or poor-quality cleavage embryos (PQEs) did not affect clinical outcomes. However, the clinical outcomes of day 5/6 expanded blastocysts cultured in patients who faced with PQEs was unclear. Methods Retrospective cohort study was conducted among women aged ≤ 38 who underwent vitrified-warmed single blastocyst transfers (SBTs) which originated from AEs (n = 382), PQEs with AEs (n = 99), or only PQEs without AEs (n = 101). Results The PQEs compared to the AEs showed lower CPR (38.38% in PQEs with AEs; 36.63% in PQEs without AEs; versus 57.07% in AEs) and lower LBR (28.28%; 29.70%; versus 44.50%), but there was no statistical difference in CPR (adjusted OR 0.78, 95% CI 0.46–1.31; adjusted OR 0.82, 95% CI 0.47–1.42) and LBR (adjusted OR 0.91, 95% CI 0.53–1.59; adjusted OR 0.94, 95% CI 0.50–1.78) after controlling for confounding variables. Better outcomes were associated with thicker endometrial thickness (CPR: adjusted OR 1.18, 95% CI 1.05–1.33; LBR: adjusted OR: 1.16, 95% CI 1.03–1.30) and blastocyst expansion on day 5 (CPR: adjusted OR 2.52 95% CI 1.62–3.94; LBR: adjusted OR: 2.28, 95% CI 1.43–3.65). ICM score C (CPR: adjusted OR 0.08, 95% CI 0.01–0.67; LBR: adjusted OR: 0.10, 95% CI 0.01–0.76) were associated with worse outcomes. Conclusions Once the blastocyst was available, endometrial thickness, ICM grade, and the day of blastocyst expansion were the factors affecting the outcome, while the quality of cleavage embryos (PQEs or AEs) had no effect on subsequent clinical outcomes.

237 THE EFFECTS OF BULLS AND X-SORTING OF SPERM ON THE ACCURACY OF NONINVASIVE CRITERIA TO PREDICT BLASTOCYST FORMATION OF IN VITRO-PRODUCED BOVINE EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 208
Author(s):  
S. Matoba ◽  
T. Somfai ◽  
T. Nagai ◽  
M. Geshi
Keyword(s):  
Formation Rate ◽  
Calf Serum ◽  
Time Lapse ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Bovine Embryos ◽  
Blastocyst Formation ◽  
Blastocyst Development ◽  
Chi Square

Previously, an early first cleavage and a second cleavage after IVF with a normal cleavage pattern defined by even blastomeres without fragments or protrusions was found to be a potent marker for the selection of embryos with high developmental competence (Sugimura et al. 2012 PLoS ONE 7, e36627). The aim of this study was to investigate the effects of bulls and X-sorting of sperm on the ability of these simple noninvasive markers to predict the potency of bovine IVF embryos to develop to the blastocyst stage in vitro. Immature oocytes were matured in TCM199 supplemented with 0.02 armour unit mL–1 FSH and 5% calf serum at 38.5°C in 5% CO2 and 95% air for 22 to 23 h. After maturation, oocytes were inseminated with either of non-sorted frozen-thawed sperm from 3 bulls (A–C) or X-sorted sperm of bull A. Putative zygotes were cultured (IVC) in CR1aa medium supplemented with 5% calf serum and 0.25 mg mL–1 linoleic acid albumin at 38.5°C in 5% CO2, 5% O2, and 90% N2 for 216 h. Embryo kinetics were observed individually by time-lapse cinematography (CCM-1.3Z; Astec, Fukuoka, Japan; Sugimura et al. 2010 Biol. Reprod. 83, 970–978). First and second cleavage kinetics and pattern were categorized according to Sugimura et al. (2012). For each bull, blastocyst development from embryos possessing the following 3 selection markers was compared: (marker 1) the first cleavage within 28 h after IVF, (marker 2) marker 1 combined with 2 even blastomeres without fragments or protrusions, and (marker 3) marker 2 combined with the second cleavage within 50 h after IVF with ≥6 even blastomeres without fragments or protrusions, respectively. Data were analysed by the Yates' corrected chi-square test. A total of 823 oocytes were used in at least 3 replications. When non-sorted sperm was used for IVF, there was not difference (P > 0.05) in total blastocyst formation rates on Day 8 (Day 0 = IVF) among bulls (ranging between 49.5 and 60.8%); however, blastocyst formation rate of embryos generated from X-sorted sperm of bull A (39.5%) was lower (P < 0.05) compared with other groups despite of similar cleavage rates. Embryos having marker 3 criteria developed to the blastocysts stage at significantly higher rates than those having marker 1 criteria in case of non-sorted sperm of bulls A, B, C, and X-sorted sperm of bull A (75.9, 87.0, 90.0, and 75.0% v. 59.5, 62.2, 63.6, and 46.3%, respectively). In groups produced from non-sorted sperm of bulls A, B, C, and X-sorted sperm of bull A, blastocyst development rates of embryos with marker 2 criteria (73.7, 75.0, 90.0, and 65.8%, respectively) were higher (P < 0.05) than those of embryos having marker 1 criteria but did not differ significantly from those with marker 3 criteria. Our results reveal that a first cleavage within 28 h after IVF to 2 even blastomeres without fragments or protrusions are potent predictive markers of the developmental competence of bovine embryos to the blastocyst stage regardless of bulls and sperm sorting.Research was partly supported by JSPS KAKENHI (26450388).

scholarly journals Use of Insulin to Increase Epiblast Cell Number: Towards a New Approach for Improving ESC Isolation from Human Embryos

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Jared M. Campbell ◽  
Michelle Lane ◽  
Ivan Vassiliev ◽  
Mark B. Nottle
Keyword(s):  
Embryonic Stem ◽  
Cell Number ◽  
Poor Quality ◽  
Blastocyst Stage ◽  
Human Embryos ◽  
Cleavage Stage ◽  
Embryo Viability ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Hesc Derivation

Human embryos donated for embryonic stem cell (ESC) derivation have often been cryopreserved for 5–10 years. As a consequence, many of these embryos have been cultured in media now known to affect embryo viability and the number of ESC progenitor epiblast cells. Historically, these conditions supported only low levels of blastocyst development necessitating their transfer or cryopreservation at the 4–8-cell stage. As such, these embryos are donated at the cleavage stage and require further culture to the blastocyst stage before hESC derivation can be attempted. These are generally of poor quality, and, consequently, the efficiency of hESC derivation is low. Recent work using a mouse model has shown that the culture of embryos from the cleavage stage with insulin to day 6 increases the blastocyst epiblast cell number, which in turn increases the number of pluripotent cells in outgrowths following plating, and results in an increased capacity to give rise to ESCs. These findings suggest that culture with insulin may provide a strategy to improve the efficiency with which hESCs are derived from embryos donated at the cleavage stage.

P–168 RCT comparing the effect of Continuous ( Single Step ) embryo culture system versus a Sequential embryo culture system on the outcome of IVF/ICSI cycles

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
R Singh ◽  
M Singh
Keyword(s):  
Embryo Culture ◽  
Culture System ◽  
Culture Media ◽  
Poor Quality ◽  
Blastocyst Stage ◽  
Single Step ◽  
Blastocyst Formation ◽  
Cleavage Stage ◽  
Media Systems ◽  
Single Medium

Abstract Study question Is the outcome of IVF/ICSI cycles done with continuous (single step ) embryo culture system different from that with sequential embryo culture system ? Summary answer Yes the outcome of IVF / ICSI cycles done with continuous (single step ) embryo-culture system is better than that with sequential embryo-culture system . What is known already Embryo culture media are important factors in IVF, which can significantly influence the clinical outcome of IVF/ICSI cycles. However it is not clear which formulation is most optimal and whether sequential or continuous media (single step) should be favored. Sequential media complies with embryo demands based on developmental stage , taking into account metabolic changes embryos undergo in-vivo, while moving from the oviduct to the uterus. The embryos in the early cleavage stage prefer to use pyruvate to produce energy, whereas once development nears the blastocyst stage , the embryos start using glucose in the process of glycolysis . Study design, size, duration A prospective RCT was carried out at our centre between 2018–2019 and IVF-ICSI patients meeting inclusion criteria (at least six normal MII - Oocytes) were included in this study. The aim of study was to compare blastocyst formation rates after embryo-culture in two different culture media systems. 436 metaphase II Oocytes from 62 women were randomly and equally divided to be fertilized and cultured to the blastocyst stage in either sequential media or single-step media. Participants/materials, setting, methods In this prospective trial with sibling oocytes, 436 metaphase II oocytes from 62 women were randomly and equally divided to be fertilized and cultured to the blastocyst stage in either sequential media ( n = 218 MII oocytes) or a single medium ( n = 218 MII oocytes). In both groups, embryos were cultured in an interrupted fashion with media changes on day 3. Embryo transfer was performed on day 5. Main results and the role of chance Blastocyst formation rates on day 5 were significantly higher following culture in single step media 60.55% (132 / 218 ) as compared to sequential media 34.86% ( 76 / 218) . The percentage of good quality blastocysts was also significantly higher in single step media. In conclusion, culture in single step media was associated with higher blastocyst formation rates compared to sequential media , suggesting that the single medium may provide better support to the developing embryo. The proportion of poor quality embryos was significantly higher in the sequential media group. Results indicate that embryo culture in continuous media could be as efficient as embryo culture in sequential media. A significant difference observed was the proportion of poor quality embryos on day 5 , which was significantly higher when the embryos were cultured in sequential media. Our results suggest that the type of embryo culture media can influence the quality of embryos both at the cleavage stage and blastocyst stage. The use of continuous embryo culture media does not seem to cause an adverse effect; in fact, their use can lower the workload in busy IVF labs and lower the stress that embryos are exposed to during handling. Limitations, reasons for caution Although single-step-medium for extended culture has practical advantages and blastocyst formation rates appear to be higher, there is insufficient evidence to recommend either sequential or single-step media as being superior for the embryo-culture to days 5/6. Further studies comparing these two media systems in well-designed trials should be performed. Wider implications of the findings: When employing sequential media for embryo culture , it is necessary to transfer the embryos from one medium to another ( cleavage stage medium to blastocyst stage medium) which increases stress related embryo damage . Therefore, single-step media is beneficial as the embryos can develop undisturbed till blastocyst stage. Trial registration number Not applicable

P–259 Blastocyst quality is associated with both the start and the duration of compaction after ICSI

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
K Wouters ◽  
L Va. Landuyt ◽  
M Regin ◽  
H Tournaye ◽  
G Verheyen ◽  
...  
Keyword(s):  
Embryo Quality ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Total Duration ◽  
Time Lapse ◽  
Poor Quality ◽  
Blastocyst Stage ◽  
Human Embryos ◽  
The Poor ◽  
Blastocyst Quality

Abstract Study question Is the start and the total duration of compaction related to embryo quality? Summary answer The timing of the start, the end and the total duration of compaction are associated with blastocyst quality grade in the IVF laboratory. What is known already Preimplantation embryo development follows a programmed timeline during which a series of critical events take place. One event typically occurring on day 3/4 post fertilisation is the formation of adherence junctions between blastomeres in a process called compaction. It is considered the first morphological event in the differentiation process of the mammalian embryo. Evaluation of developmental events are used to optimize the selection of the most competent embryos for transfer and/or cryopreservation in the IVF laboratory. It has already been shown that the time of full compaction is indicative for high-quality blastocysts with a higher implantation rate. Study design, size, duration A single-centre retrospective observational study including 74 ICSI cycles performed in 2020. Injected oocytes were cultured in blastocyst medium (Origio) in the EmbryoScope + (Vitrolife) for 5/6 days. Embryos that reached the blastocyst stage were evaluated for the start of compaction, the time to reach full compaction and the total duration of compaction. These parameters were compared between good- and poor-quality blastocysts; the primary outcome parameter of the study was embryo quality. Participants/materials, setting, methods Only ICSI cycles with ejaculated fresh/frozen-thawed sperm and monitored in time-lapse incubator were included. All MNC, IVM and PGT cycles were excluded. Time zero was the start of ICSI. Good-quality embryos were full and expanded blastocysts with good-quality inner cell mass and trophectoderm (AA, AB, BA and BB according to Gardner and Schoolcraft (1999)). GraphPad Prism was used for statistical analysis. After testing for normality and homogeneity, unpaired t-test or Mann-Whitney test determined significant differences. Main results and the role of chance In this study, of the 528 included 2PN oocytes, 229 (43.4%) reached the blastocyst stage and 299 (56.6%) were arrested. Among the former, 131 (57.2%) blastocysts were classified in the good-quality group and 98 (42.8%) blastocysts in the poor-quality group. In general, human embryos compacted slowly while dividing further and the blastomeres moved during the compaction process. The start of compaction was heterogeneous (between 50.9 and 102.7 hours post ICSI; mean=80.0 hours), as well as the cell number at the initiation (between 4 and 18 blastomeres; mean=12 blastomeres). The time analysis showed that the embryos in the good-quality group started to compact significantly earlier than those in the poor-quality group (mean=78.6 vs 82.2 hours; R²=0.06; p &lt; 0.01). We confirmed that blastocysts in the good-quality group reached full compaction earlier than those in the poor-quality group (mean=86.8 vs 93.8 hours; R²=0.17; p &lt; 0.01). Furthermore, the total duration of compaction was significantly lower in the good-quality than in the poor-quality group (median=7.4 vs 10.7 hours; p &lt; 0.01). Limitations, reasons for caution As this is a retrospective study, the influence of uncontrolled variables cannot be excluded. The absence of the pregnancy outcome and live birth rate is a shortcoming and will be subject of a larger patient-to-patient study. Wider implications of the findings: These results indicate that an earlier start and a shorter duration of compaction are associated with better blastocyst quality. These morphological events can be valuable additional parameters in selecting the embryo of better quality when using a time-lapse incubator. Trial registration number Not applicable

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