The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
David K. Gardner - One of the best experts on this subject based on the ideXlab platform.
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single Blastocyst transfer a prospective randomized trial
Fertility and Sterility, 2004Co-Authors: David K. Gardner, J M Stevens, Eric S Surrey, D A Minjarez, Annette Leitz, W B SchoolcraftAbstract:Objective To determine the efficacy of single Blastocyst transfer. Design Prospective randomized trial. Setting Private assisted reproductive technology unit. Patient(s) Forty-eight women undergoing IVF-embryo transfer with day 3 FSH 12 mm in diameter on day of hCG administration. Intervention(s) Embryo culture to the Blastocyst stage in sequential media G1/G2 followed by transfer of either one or two Blastocysts. Main outcome measure(s) Implantation rate, ongoing pregnancy rate, and twinning. Result(s) The transfer of a single Blastocyst resulted in an implantation and ongoing pregnancy rate of 60.9% with no twins. The transfer of two Blastocysts resulted in an implantation rate of 56%, an ongoing pregnancy rate of 76% with a 47.4% incidence of twins. Conclusion(s) Single Blastocyst transfer is an effective method of eliminating multiple births while maintaining high pregnancy rates in this selected group of patients.
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Assessment of metabolism of equine morulae and Blastocysts.
Molecular reproduction and development, 2001Co-Authors: Michelle Lane, M.k. O'donovan, Edward L. Squires, George E. Seidel, David K. GardnerAbstract:Nutrient uptakes and metabolite production by equine morula and Blastocyst stage embryos were determined by nonhinvasive microfluorometry. Equine morula took up equal amounts of both pyruvate and glucose. However, at the early Blastocyst there was a small increase in glucose uptake and, by the expanded Blastocyst stage, glucose was the predominant nutrient. Expanded Blastocysts took up five times more glucose than pyruvate. Expanded Blastocysts exhibited an exponential increase in glucose uptake and lactate production with respect to both diameter and surface area. As less than 50p of the glucose was accounted for by lactate production, the equine Blastocyst appears to have a significant capacity to oxidize glucose. Embryos with a higher morphological grade consumed more nutrients than those with a poorer morphology. However, there was a large range in nutrient consumption within the highest grade Blastocysts. This suggests that nutrient uptake may be useful as a viability marker of equine Blastocysts. Mol. Reprod. Dev. 59:33–37, 2001. © 2001 WileyhLiss, Inc.
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Blastocyst score affects implantation and pregnancy outcome: towards a single Blastocyst transfer
Fertility and sterility, 2000Co-Authors: David K. Gardner, Michelle Lane, John Stevens, T. Schlenker, William B. SchoolcraftAbstract:Abstract Objective: To determine the relationship between Blastocyst score and pregnancy outcome. Design: Retrospective review of Blastocyst transfer in an IVF clinic. Setting: Private assisted reproductive technology unit. Patient(s): 107 patients undergoing Blastocyst culture and transfer of two embryos. Intervention(s): Culture of all pronucleate embryos in sequential media to the Blastocyst stage (day 5), followed by transfer of two Blastocysts. Main Outcome Measure(s): Implantation rates, pregnancy rates, and twinning were analyzed. Result(s): When a patient received two top-scoring Blastocysts (64% of patients), implantation and pregnancy rates were 70% and 87%, respectively. The twinning rate in this group was 61%. When only one top-quality Blastocyst was available for transfer (21% of patients), the implantation and pregnancy rates were 50% and 70%. The twinning rate for this group was 50%. In contrast, when only low-scoring Blastocysts were available for transfer (15% of patients), implantation and pregnancy rates were 28% and 44%, and the twinning rate was 29%. No monozygotic twins were observed in this group of patients. Conclusion(s): The ability to transfer one high-scoring Blastocyst should lead to pregnancy rates greater than 60%, without the complication of twins.
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Blastocyst culture and transfer analysis of results and parameters affecting outcome in two in vitro fertilization programs
Fertility and Sterility, 1999Co-Authors: W B Schoolcraft, Michelle Lane, David K. Gardner, T. Schlenker, Fredesminda Hamilton, David R MeldrumAbstract:Abstract Objective: To determine whether previously described advanced Blastocyst development and high implantation rates are confirmed in an expanded multicenter trial. Design: Retrospective review. Setting: Two private assisted reproductive technology units. Patient(s): One hundred seventy-four patients who underwent Blastocyst culture and transfer. Intervention(s): Culture of all pronucleate embryos in sequential media to the Blastocyst stage (day 5) followed by ET. Main Outcome Measure(s): The number and percentage of Blastocysts developed, implantation rates, pregnancy rates, and parameters that affected outcome were analyzed. Result(s): Only 3 of 174 patients failed to achieve Blastocyst-stage ET. The mean Blastocyst development rate was 48%. The ongoing pregnancy rate was 66.3% per oocyte retrieval, with a mean (±SE) of 2.2 ± 0.05 Blastocysts transferred and an implantation rate of 48% per Blastocyst transferred. Conclusion(s): Blastocyst culture and transfer is an effective means of treating patients who respond well to gonadotropins. High pregnancy rates can be accomplished with low numbers of embryos transferred. Patients who failed to achieve ET were rare.
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a prospective randomized trial of Blastocyst culture and transfer in in vitro fertilization
Human Reproduction, 1998Co-Authors: David K. Gardner, T. Schlenker, W B Schoolcraft, L Wagley, J M Stevens, J HeslaAbstract:The effectiveness of Blastocyst culture and transfer in human in-vitro fertilization (IVF) was evaluated in a prospective randomized trial in patients having a moderate to good response to gonadotrophin stimulation. Embryos were transferred either on day 3 after culture to around the 8-cell stage in Ham's F-10 medium supplemented with fetal cord serum, or on day 5 after culture to the Blastocyst stage in the sequential serum-free media G 1.2 and G 2.2. The pregnancy rates after transfer on day 3 or day 5 were equivalent, 66 and 71% respectively; however, significantly more embryos were transferred on day 3 (3.7) than on day 5 (2.2). The number of Blastocysts transferred did not affect the implantation rate, and pregnancy rates when either two or three Blastocysts were transferred were 68 and 87% respectively. The implantation rate of the Blastocysts (50.5% fetal heart beat) was significantly higher compared to the cleavage stage embryos transferred on day 3 (30.1%). The percentage of Blastocyst development was not affected by the number of 2-pronuclear embryos, or by maternal age. Irrespective of the number of Blastocysts formed, pregnancy rates were similar. Furthermore, the pregnancy rate following Blastocyst transfer in patients with 10 or more follicles at the time of human chorionic gonadotrophin administration was not affected by patient age. More than 60% of patients having Blastocyst culture and transfer had supernumerary embryos for cryopreservation. The establishment of a pregnancy following thaw and transfer confirmed the viability of cryopreserved Blastocysts cultured in the absence of serum or co-culture. The ability to transfer just two Blastocysts while maintaining high pregnancy rates will therefore help to eliminate high order multiple gestations and improve the overall efficiency of human IVF.
W B Schoolcraft - One of the best experts on this subject based on the ideXlab platform.
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the relationship between Blastocyst morphology chromosomal abnormality and embryo gender
Fertility and Sterility, 2011Co-Authors: S Alfarawati, W B Schoolcraft, J M Stevens, E Fragouli, P Colls, C Gutierrezmateo, M G Katzjaffe, Dagan WellsAbstract:Objective To assess correlation between Blastocyst morphology and chromosomal status. Design Observational research study. Setting An IVF clinic and a specialist preimplanation genetic diagnosis (PGD) laboratory. Patient(s) Ninety-three couples undergoing IVF treatment in combination with chromosome screening of embryos. Intervention(s) Five hundred Blastocysts underwent trophectoderm biopsy and comprehensive chromosome screening using comparative genomic hybridization (CGH). The morphology of the embryos was evaluated using standard methods. Main outcome measure(s) Association of aneuploidy and morphologic score. Result(s) A total of 56.7% of Blastocysts were aneuploid. One-half of the grade 5/6 Blastocysts were euploid, compared with only 37.5% of embryos graded 1/2, suggesting an effect of aneuploidy on Blastocyst development. Aneuploidy also had a negative effect on inner cell mass and trophectoderm grades. Morphologically poor Blastocysts had a higher incidence of monosomy and abnormalities affecting several chromosomes. The gender ratio was significantly skewed in relation to morphology. A total of 72% of Blastocysts attaining the highest morphologic scores (5AA and 6AA) were found to be male, compared with only 40% of grade 3 embryos. Conclusion(s) Morphology and aneuploidy are linked at the Blastocyst stage. However, the association is weak, and consequently, morphologic analysis cannot be relied on to ensure transfer of chromosomally normal embryos. A significant proportion of aneuploid embryos are capable of achieving the highest morphologic scores, and some euploid embryos are of poor morphology. Gender was associated with Blastocyst grading, male embryos developing at a significantly faster rate than females.
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single Blastocyst transfer a prospective randomized trial
Fertility and Sterility, 2004Co-Authors: David K. Gardner, J M Stevens, Eric S Surrey, D A Minjarez, Annette Leitz, W B SchoolcraftAbstract:Objective To determine the efficacy of single Blastocyst transfer. Design Prospective randomized trial. Setting Private assisted reproductive technology unit. Patient(s) Forty-eight women undergoing IVF-embryo transfer with day 3 FSH 12 mm in diameter on day of hCG administration. Intervention(s) Embryo culture to the Blastocyst stage in sequential media G1/G2 followed by transfer of either one or two Blastocysts. Main outcome measure(s) Implantation rate, ongoing pregnancy rate, and twinning. Result(s) The transfer of a single Blastocyst resulted in an implantation and ongoing pregnancy rate of 60.9% with no twins. The transfer of two Blastocysts resulted in an implantation rate of 56%, an ongoing pregnancy rate of 76% with a 47.4% incidence of twins. Conclusion(s) Single Blastocyst transfer is an effective method of eliminating multiple births while maintaining high pregnancy rates in this selected group of patients.
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Blastocyst culture and transfer analysis of results and parameters affecting outcome in two in vitro fertilization programs
Fertility and Sterility, 1999Co-Authors: W B Schoolcraft, Michelle Lane, David K. Gardner, T. Schlenker, Fredesminda Hamilton, David R MeldrumAbstract:Abstract Objective: To determine whether previously described advanced Blastocyst development and high implantation rates are confirmed in an expanded multicenter trial. Design: Retrospective review. Setting: Two private assisted reproductive technology units. Patient(s): One hundred seventy-four patients who underwent Blastocyst culture and transfer. Intervention(s): Culture of all pronucleate embryos in sequential media to the Blastocyst stage (day 5) followed by ET. Main Outcome Measure(s): The number and percentage of Blastocysts developed, implantation rates, pregnancy rates, and parameters that affected outcome were analyzed. Result(s): Only 3 of 174 patients failed to achieve Blastocyst-stage ET. The mean Blastocyst development rate was 48%. The ongoing pregnancy rate was 66.3% per oocyte retrieval, with a mean (±SE) of 2.2 ± 0.05 Blastocysts transferred and an implantation rate of 48% per Blastocyst transferred. Conclusion(s): Blastocyst culture and transfer is an effective means of treating patients who respond well to gonadotropins. High pregnancy rates can be accomplished with low numbers of embryos transferred. Patients who failed to achieve ET were rare.
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a prospective randomized trial of Blastocyst culture and transfer in in vitro fertilization
Human Reproduction, 1998Co-Authors: David K. Gardner, T. Schlenker, W B Schoolcraft, L Wagley, J M Stevens, J HeslaAbstract:The effectiveness of Blastocyst culture and transfer in human in-vitro fertilization (IVF) was evaluated in a prospective randomized trial in patients having a moderate to good response to gonadotrophin stimulation. Embryos were transferred either on day 3 after culture to around the 8-cell stage in Ham's F-10 medium supplemented with fetal cord serum, or on day 5 after culture to the Blastocyst stage in the sequential serum-free media G 1.2 and G 2.2. The pregnancy rates after transfer on day 3 or day 5 were equivalent, 66 and 71% respectively; however, significantly more embryos were transferred on day 3 (3.7) than on day 5 (2.2). The number of Blastocysts transferred did not affect the implantation rate, and pregnancy rates when either two or three Blastocysts were transferred were 68 and 87% respectively. The implantation rate of the Blastocysts (50.5% fetal heart beat) was significantly higher compared to the cleavage stage embryos transferred on day 3 (30.1%). The percentage of Blastocyst development was not affected by the number of 2-pronuclear embryos, or by maternal age. Irrespective of the number of Blastocysts formed, pregnancy rates were similar. Furthermore, the pregnancy rate following Blastocyst transfer in patients with 10 or more follicles at the time of human chorionic gonadotrophin administration was not affected by patient age. More than 60% of patients having Blastocyst culture and transfer had supernumerary embryos for cryopreservation. The establishment of a pregnancy following thaw and transfer confirmed the viability of cryopreserved Blastocysts cultured in the absence of serum or co-culture. The ability to transfer just two Blastocysts while maintaining high pregnancy rates will therefore help to eliminate high order multiple gestations and improve the overall efficiency of human IVF.
P Lonergan - One of the best experts on this subject based on the ideXlab platform.
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bovine embryo culture in the presence or absence of serum implications for Blastocyst development cryotolerance and messenger rna expression
Biology of Reproduction, 2003Co-Authors: D Rizos, Alfonso Gutierrezadan, S S Perezgarnelo, J De La Fuente, M P Boland, P LonerganAbstract:Abstract We have previously shown that, while the intrinsic quality of the oocyte is the main factor affecting Blastocyst yield during bovine embryo development in vitro, the main factor affecting the quality of the Blastocyst is the postfertilization culture conditions. Therefore, any improvement in the quality of Blastocysts produced in vitro is likely to derive from the modification of the postfertilization culture conditions. The objective of this study was to examine the effect of the presence or absence of serum and the concentration of BSA during the period of embryo culture in vitro on 1) cleavage rate, 2) the kinetics of embryo development, 3) Blastocyst yield, and 4) Blastocyst quality, as assessed by cryotolerance and gene expression patterns. The quantification of all gene transcripts was carried out by real-time quantitative reverse transcription-polymerase chain reaction. Bovine Blastocysts from four sources were used: 1) in vitro culture in synthetic oviduct fluid (SOF) supplemented with 3 ...
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consequences of bovine oocyte maturation fertilization or early embryo development in vitro versus in vivo implications for Blastocyst yield and Blastocyst quality
Molecular Reproduction and Development, 2002Co-Authors: D Rizos, M P Boland, F Ward, P Duffy, P LonerganAbstract:The aim of this study is to examine the effect of bovine oocyte maturation, fertilization or culture in vivo or in vitro on the proportion of oocytes reaching the Blastocyst stage, and on Blastocyst quality as measured by survival following vitrification. In Experiment 1, 4 groups of oocytes were used: (1) immature oocytes from 2-6 mm follicles; (2) immature oocytes from > 6 mm follicles; (3) immature oocytes recovered in vivo just before the LH surge; and (4) in vivo matured oocytes. Significantly more Blastocysts developed from oocytes matured in vivo than those recovered just before the LH surge or than oocytes from 2-6 mm follicles. Results from > 6 mm follicles were intermediate. All Blastocysts had low survival following vitrification. In Experiment 2, in vivo matured oocytes were either (1) fertilized in vitro or (2) fertilized in vivo by artificial insemination and the resulting presumptive zygotes recovered on day 1. Both groups were then cultured in vitro. In vivo fertilized oocytes had a significantly higher Blastocyst yield than those fertilized in vitro. Blastocyst quality was similar between the groups. Both groups had low survival following vitrification. In Experiment 3a, presumptive zygotes produced by in vitro maturation (IVM)/fertilization (IVF) were cultured either in vitro in synthetic oviduct fluid, or in vivo in the ewe oviduct. In Experiment 3b, in vivo matured/in vivo fertilized zygotes were either surgically recovered on day 1 and cultured in vitro in synthetic oviduct fluid, or were nonsurgically recovered on day 7. There was no difference in Blastocyst yields between groups of zygotes originating from the same source (in vivo or in vitro fertilization) irrespective of whether culture took place in vivo or in vitro. However, there was a dramatic effect on Blastocyst quality with those Blastocysts produced following in vivo culture surviving vitrification at significantly higher rates than their in vitro cultured counterparts. Collectively, these results indicate that the intrinsic quality of the oocyte is the main factor affecting Blastocyst yields, while the conditions of embryo culture have a crucial role in determining Blastocyst quality.
T. Schlenker - One of the best experts on this subject based on the ideXlab platform.
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Blastocyst score affects implantation and pregnancy outcome: towards a single Blastocyst transfer
Fertility and sterility, 2000Co-Authors: David K. Gardner, Michelle Lane, John Stevens, T. Schlenker, William B. SchoolcraftAbstract:Abstract Objective: To determine the relationship between Blastocyst score and pregnancy outcome. Design: Retrospective review of Blastocyst transfer in an IVF clinic. Setting: Private assisted reproductive technology unit. Patient(s): 107 patients undergoing Blastocyst culture and transfer of two embryos. Intervention(s): Culture of all pronucleate embryos in sequential media to the Blastocyst stage (day 5), followed by transfer of two Blastocysts. Main Outcome Measure(s): Implantation rates, pregnancy rates, and twinning were analyzed. Result(s): When a patient received two top-scoring Blastocysts (64% of patients), implantation and pregnancy rates were 70% and 87%, respectively. The twinning rate in this group was 61%. When only one top-quality Blastocyst was available for transfer (21% of patients), the implantation and pregnancy rates were 50% and 70%. The twinning rate for this group was 50%. In contrast, when only low-scoring Blastocysts were available for transfer (15% of patients), implantation and pregnancy rates were 28% and 44%, and the twinning rate was 29%. No monozygotic twins were observed in this group of patients. Conclusion(s): The ability to transfer one high-scoring Blastocyst should lead to pregnancy rates greater than 60%, without the complication of twins.
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Blastocyst culture and transfer analysis of results and parameters affecting outcome in two in vitro fertilization programs
Fertility and Sterility, 1999Co-Authors: W B Schoolcraft, Michelle Lane, David K. Gardner, T. Schlenker, Fredesminda Hamilton, David R MeldrumAbstract:Abstract Objective: To determine whether previously described advanced Blastocyst development and high implantation rates are confirmed in an expanded multicenter trial. Design: Retrospective review. Setting: Two private assisted reproductive technology units. Patient(s): One hundred seventy-four patients who underwent Blastocyst culture and transfer. Intervention(s): Culture of all pronucleate embryos in sequential media to the Blastocyst stage (day 5) followed by ET. Main Outcome Measure(s): The number and percentage of Blastocysts developed, implantation rates, pregnancy rates, and parameters that affected outcome were analyzed. Result(s): Only 3 of 174 patients failed to achieve Blastocyst-stage ET. The mean Blastocyst development rate was 48%. The ongoing pregnancy rate was 66.3% per oocyte retrieval, with a mean (±SE) of 2.2 ± 0.05 Blastocysts transferred and an implantation rate of 48% per Blastocyst transferred. Conclusion(s): Blastocyst culture and transfer is an effective means of treating patients who respond well to gonadotropins. High pregnancy rates can be accomplished with low numbers of embryos transferred. Patients who failed to achieve ET were rare.
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a prospective randomized trial of Blastocyst culture and transfer in in vitro fertilization
Human Reproduction, 1998Co-Authors: David K. Gardner, T. Schlenker, W B Schoolcraft, L Wagley, J M Stevens, J HeslaAbstract:The effectiveness of Blastocyst culture and transfer in human in-vitro fertilization (IVF) was evaluated in a prospective randomized trial in patients having a moderate to good response to gonadotrophin stimulation. Embryos were transferred either on day 3 after culture to around the 8-cell stage in Ham's F-10 medium supplemented with fetal cord serum, or on day 5 after culture to the Blastocyst stage in the sequential serum-free media G 1.2 and G 2.2. The pregnancy rates after transfer on day 3 or day 5 were equivalent, 66 and 71% respectively; however, significantly more embryos were transferred on day 3 (3.7) than on day 5 (2.2). The number of Blastocysts transferred did not affect the implantation rate, and pregnancy rates when either two or three Blastocysts were transferred were 68 and 87% respectively. The implantation rate of the Blastocysts (50.5% fetal heart beat) was significantly higher compared to the cleavage stage embryos transferred on day 3 (30.1%). The percentage of Blastocyst development was not affected by the number of 2-pronuclear embryos, or by maternal age. Irrespective of the number of Blastocysts formed, pregnancy rates were similar. Furthermore, the pregnancy rate following Blastocyst transfer in patients with 10 or more follicles at the time of human chorionic gonadotrophin administration was not affected by patient age. More than 60% of patients having Blastocyst culture and transfer had supernumerary embryos for cryopreservation. The establishment of a pregnancy following thaw and transfer confirmed the viability of cryopreserved Blastocysts cultured in the absence of serum or co-culture. The ability to transfer just two Blastocysts while maintaining high pregnancy rates will therefore help to eliminate high order multiple gestations and improve the overall efficiency of human IVF.
D Rizos - One of the best experts on this subject based on the ideXlab platform.
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bovine embryo culture in the presence or absence of serum implications for Blastocyst development cryotolerance and messenger rna expression
Biology of Reproduction, 2003Co-Authors: D Rizos, Alfonso Gutierrezadan, S S Perezgarnelo, J De La Fuente, M P Boland, P LonerganAbstract:Abstract We have previously shown that, while the intrinsic quality of the oocyte is the main factor affecting Blastocyst yield during bovine embryo development in vitro, the main factor affecting the quality of the Blastocyst is the postfertilization culture conditions. Therefore, any improvement in the quality of Blastocysts produced in vitro is likely to derive from the modification of the postfertilization culture conditions. The objective of this study was to examine the effect of the presence or absence of serum and the concentration of BSA during the period of embryo culture in vitro on 1) cleavage rate, 2) the kinetics of embryo development, 3) Blastocyst yield, and 4) Blastocyst quality, as assessed by cryotolerance and gene expression patterns. The quantification of all gene transcripts was carried out by real-time quantitative reverse transcription-polymerase chain reaction. Bovine Blastocysts from four sources were used: 1) in vitro culture in synthetic oviduct fluid (SOF) supplemented with 3 ...
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consequences of bovine oocyte maturation fertilization or early embryo development in vitro versus in vivo implications for Blastocyst yield and Blastocyst quality
Molecular Reproduction and Development, 2002Co-Authors: D Rizos, M P Boland, F Ward, P Duffy, P LonerganAbstract:The aim of this study is to examine the effect of bovine oocyte maturation, fertilization or culture in vivo or in vitro on the proportion of oocytes reaching the Blastocyst stage, and on Blastocyst quality as measured by survival following vitrification. In Experiment 1, 4 groups of oocytes were used: (1) immature oocytes from 2-6 mm follicles; (2) immature oocytes from > 6 mm follicles; (3) immature oocytes recovered in vivo just before the LH surge; and (4) in vivo matured oocytes. Significantly more Blastocysts developed from oocytes matured in vivo than those recovered just before the LH surge or than oocytes from 2-6 mm follicles. Results from > 6 mm follicles were intermediate. All Blastocysts had low survival following vitrification. In Experiment 2, in vivo matured oocytes were either (1) fertilized in vitro or (2) fertilized in vivo by artificial insemination and the resulting presumptive zygotes recovered on day 1. Both groups were then cultured in vitro. In vivo fertilized oocytes had a significantly higher Blastocyst yield than those fertilized in vitro. Blastocyst quality was similar between the groups. Both groups had low survival following vitrification. In Experiment 3a, presumptive zygotes produced by in vitro maturation (IVM)/fertilization (IVF) were cultured either in vitro in synthetic oviduct fluid, or in vivo in the ewe oviduct. In Experiment 3b, in vivo matured/in vivo fertilized zygotes were either surgically recovered on day 1 and cultured in vitro in synthetic oviduct fluid, or were nonsurgically recovered on day 7. There was no difference in Blastocyst yields between groups of zygotes originating from the same source (in vivo or in vitro fertilization) irrespective of whether culture took place in vivo or in vitro. However, there was a dramatic effect on Blastocyst quality with those Blastocysts produced following in vivo culture surviving vitrification at significantly higher rates than their in vitro cultured counterparts. Collectively, these results indicate that the intrinsic quality of the oocyte is the main factor affecting Blastocyst yields, while the conditions of embryo culture have a crucial role in determining Blastocyst quality.