This document discusses the potential for using time-lapse embryo imaging to non-invasively determine embryonic aneuploidy (chromosomal abnormalities) through examination of embryo morphology and timing of developmental events. Recent studies have found that early cleavage timings observed through time-lapse imaging can provide insight into chromosomal status. However, the predictive ability is limited and embryo biopsy with preimplantation genetic screening remains the most reliable method to assess chromosomal complement. Continued research aiming to improve modeling may enhance the ability to detect aneuploidy without biopsy using morphokinetic data.
The use of time lapse photography in an in vitro fertilization programme for ...鋒博 蔡
This study examined the timing of early cell divisions in human embryos using time-lapse imaging. It found that embryos producing high-quality blastocysts and resulting in pregnancies showed uniform timing of cleavage cycles and interphases. Specifically, the second interphase lasted 11±1 hours, the third interphase was 15±1 hours, and the fourth interphase was 23±1 hours. The corresponding cleavage cycles lasted 15±5 minutes, 40±10 minutes, and 55±15 minutes. In contrast, embryos with shortened or prolonged cell cycles showed poor implantation and development. The study also discovered trichotomic mitosis, where embryos cleaved into an abnormal number of cells, in 17% of cases. Only time-
This study prospectively compared pregnancy and implantation outcomes between two groups of patients undergoing preimplantation genetic screening (PGS). Group A embryos (n=582) were cultured and monitored using a time-lapse system, while Group B embryos (n=581) were cultured conventionally. Both groups underwent trophectoderm biopsy and array comparative genomic hybridization (aCGH) testing on day 5. Euploid blastocysts displaying the most predictive morphokinetic parameters (Group A) or best morphology (Group B) were transferred. Clinical pregnancy, implantation, and ongoing pregnancy rates were significantly higher in Group A compared to Group B, demonstrating improved outcomes when selecting competent blastocysts combining time-lapse monitoring
This study compared pregnancy outcomes of in vitro fertilization (IVF) patients who underwent single embryo transfer where the embryo was selected based on (1) morphology alone or (2) morphology assessed with array comparative genomic hybridization (aCGH). Patients were randomly assigned to one of the two selection methods. The clinical pregnancy and ongoing pregnancy rates were significantly higher in the group where aCGH was used in addition to morphology to select the embryo. No twin pregnancies occurred. The results suggest that aCGH may improve pregnancy outcomes compared to morphology alone by detecting chromosomal abnormalities.
This study investigated the incidence and clinical implications of multinucleated (MN) blastomeres in embryos undergoing preimplantation genetic screening (PGS) or preimplantation genetic diagnosis (PGD). The study found that 41.3% of cycles involved at least one MN embryo. While the majority of MN blastomeres showed chromosomal abnormalities, some embryos with MN blastomeres free of genetic abnormalities tested resulted in three healthy deliveries. This suggests that genetic analysis of MN embryos can identify some that may result in healthy births.
The document discusses time lapse observations of pre-implantation embryos and factors affecting implantation potential. It notes that time lapse allows non-invasive analysis of morphological parameters and temporal markers that can help identify embryos with the highest implantation potential, such as early cleavage and cell division timing. However, abnormalities like uneven cell numbers, fragmentation, and abnormal timing are linked to lower developmental potential. Future adaptations may allow more detailed membrane and metabolic analysis to better predict embryo viability.
Introduction: Preimplantation genetic screening is alive and very well. Meldr...鋒博 蔡
This document compares different technologies for 24-chromosome copy number analysis in preimplantation genetic screening and diagnosis. It discusses the differences between screening and diagnostic tests, with screening tests being noninvasive, rapid and lower cost to select embryos, while diagnostic tests require higher accuracy. Technologies reviewed include fluorescence in situ hybridization, comparative genomic hybridization, array comparative genomic hybridization and next generation sequencing, with array CGH currently being the most widely used due to its accuracy and ability to analyze all chromosomes.
The use of time lapse photography in an in vitro fertilization programme for ...鋒博 蔡
This study examined the timing of early cell divisions in human embryos using time-lapse imaging. It found that embryos producing high-quality blastocysts and resulting in pregnancies showed uniform timing of cleavage cycles and interphases. Specifically, the second interphase lasted 11±1 hours, the third interphase was 15±1 hours, and the fourth interphase was 23±1 hours. The corresponding cleavage cycles lasted 15±5 minutes, 40±10 minutes, and 55±15 minutes. In contrast, embryos with shortened or prolonged cell cycles showed poor implantation and development. The study also discovered trichotomic mitosis, where embryos cleaved into an abnormal number of cells, in 17% of cases. Only time-
This study prospectively compared pregnancy and implantation outcomes between two groups of patients undergoing preimplantation genetic screening (PGS). Group A embryos (n=582) were cultured and monitored using a time-lapse system, while Group B embryos (n=581) were cultured conventionally. Both groups underwent trophectoderm biopsy and array comparative genomic hybridization (aCGH) testing on day 5. Euploid blastocysts displaying the most predictive morphokinetic parameters (Group A) or best morphology (Group B) were transferred. Clinical pregnancy, implantation, and ongoing pregnancy rates were significantly higher in Group A compared to Group B, demonstrating improved outcomes when selecting competent blastocysts combining time-lapse monitoring
This study compared pregnancy outcomes of in vitro fertilization (IVF) patients who underwent single embryo transfer where the embryo was selected based on (1) morphology alone or (2) morphology assessed with array comparative genomic hybridization (aCGH). Patients were randomly assigned to one of the two selection methods. The clinical pregnancy and ongoing pregnancy rates were significantly higher in the group where aCGH was used in addition to morphology to select the embryo. No twin pregnancies occurred. The results suggest that aCGH may improve pregnancy outcomes compared to morphology alone by detecting chromosomal abnormalities.
This study investigated the incidence and clinical implications of multinucleated (MN) blastomeres in embryos undergoing preimplantation genetic screening (PGS) or preimplantation genetic diagnosis (PGD). The study found that 41.3% of cycles involved at least one MN embryo. While the majority of MN blastomeres showed chromosomal abnormalities, some embryos with MN blastomeres free of genetic abnormalities tested resulted in three healthy deliveries. This suggests that genetic analysis of MN embryos can identify some that may result in healthy births.
The document discusses time lapse observations of pre-implantation embryos and factors affecting implantation potential. It notes that time lapse allows non-invasive analysis of morphological parameters and temporal markers that can help identify embryos with the highest implantation potential, such as early cleavage and cell division timing. However, abnormalities like uneven cell numbers, fragmentation, and abnormal timing are linked to lower developmental potential. Future adaptations may allow more detailed membrane and metabolic analysis to better predict embryo viability.
Introduction: Preimplantation genetic screening is alive and very well. Meldr...鋒博 蔡
This document compares different technologies for 24-chromosome copy number analysis in preimplantation genetic screening and diagnosis. It discusses the differences between screening and diagnostic tests, with screening tests being noninvasive, rapid and lower cost to select embryos, while diagnostic tests require higher accuracy. Technologies reviewed include fluorescence in situ hybridization, comparative genomic hybridization, array comparative genomic hybridization and next generation sequencing, with array CGH currently being the most widely used due to its accuracy and ability to analyze all chromosomes.
Time lapse observation of embryos through incubation allows continuous monitoring of development from fertilization. This non-invasive technique creates a developmental timeline used to assess embryo health and select the best embryo for transfer based on adherence to normal timing of cleavages and divisions. Precise timing data of early embryonic events like pronuclear fading and cell divisions correlates with implantation potential, with substantial deviations linked to lower success rates. Abnormal cell patterns or asynchronous cell cycles seen through time lapse also indicate higher risk of aneuploidy.
This randomized controlled trial tested whether performing blastocyst biopsy with comprehensive chromosome screening (CCS) improves in vitro fertilization (IVF) outcomes compared to routine care. They found:
1) Sustained implantation rates (probability of embryo implanting and resulting in delivery) and delivery rates per cycle were significantly higher in the CCS group compared to the routine care group.
2) In the CCS group, 61 of 72 treatment cycles led to delivery (84.7%) compared to 56 of 83 (67.5%) in the routine care group.
3) Use of CCS with blastocyst biopsy and rapid quantitative PCR-based screening resulted in statistically significantly improved IVF outcomes, with
This document provides a cautionary commentary on recent publications claiming that time-lapse imaging can be used to assess embryo aneuploidy risk and increase pregnancy rates. The authors believe the claims are premature and unsubstantiated. They argue that the studies are underpowered and likely confounded by maternal age rather than embryo aneuploidy alone. Larger, age-adjusted datasets or randomized controlled trials are needed to validate the findings before clinical application.
This study examined 1213 human embryos at the cleavage and blastocyst stages to assess the relationship between morphological appearance and chromosomal abnormalities. The researchers found that at the cleavage stage, many embryos with the best morphological scores were still chromosomally abnormal, indicating little effect of aneuploidy on appearance at this stage. However, at the blastocyst stage aneuploidies were less common in embryos with optimal morphology, though some chromosomally abnormal blastocysts still received high scores, particularly for clinically relevant aneuploidies like trisomy 21. While morphology provides some information about chromosomal status at the blastocyst stage, comprehensive chromosome testing remains important for accurate assessment of embryo viability
This document discusses endometrial receptivity and the need for objective biomarkers to diagnose it. While past research identified some potential molecular markers, none have proven clinically useful. Recent transcriptomic analyses using microarrays have defined a gene expression signature that can classify endometrial status, including receptivity, regardless of histological appearance. This led to the development of the Endometrial Receptivity Array (ERA) tool, which uses a customized microarray and algorithm to identify the personalized window of implantation in individual patients, improving outcomes over histological dating alone.
This document discusses the advantages of blastocyst stage embryo transfer compared to cleavage stage embryo transfer, particularly in the context of oocyte donation. Key points include:
- Blastocyst stage transfer has been shown to improve outcomes like implantation and pregnancy rates compared to cleavage stage transfer based on evidence from IVF studies.
- In oocyte donation specifically, studies have found significantly higher implantation and pregnancy rates per embryo transfer with blastocyst stage transfer compared to cleavage stage.
- The development of improved embryo culture systems has made successful blastocyst development and transfer more routine. Blastocyst transfer also allows more information about embryo developmental potential.
This document discusses preimplantation genetic screening (PGS) with fresh embryo transfer. It provides an overview of PGS using comprehensive chromosome analysis (CCA) with blastocyst biopsy and either fresh embryo transfer or frozen embryo transfer. Key advantages of CCA with blastocyst biopsy include improved implantation rates, elimination of the negative effect of maternal age on implantation, and the ability to perform embryo banking which facilitates multiple cycles for patients with poor prognosis. Controlled studies show no difference in outcomes between fresh versus frozen embryo transfer when using PGS with CCA.
1) The likelihood of abnormal embryos and non-chromosomal implantation failure increases with maternal age, ranging from 54% of embryos being abnormal for women under 35 to 82% for women 41-42.
2) A study found chromosomally abnormal embryos detected by array CGH had delayed blastulation compared to normal embryos.
3) Studies have found both positive and no effects of preimplantation genetic screening using day 3 embryo biopsy and FISH, with some finding a negative effect. A recent study found day 3 biopsy reduced implantation rates compared to blastocyst biopsy or no biopsy.
4) Data suggests preimplantation genetic testing for aneuploidies by methods like array C
This document analyzes 2,204 human oocytes and embryos from fertilization through the blastocyst stage using microarray comparative genomic hybridization to determine chromosome abnormalities. It finds that aneuploidy rates increase dramatically with female age and that complex abnormalities are common. Chromosome errors originate from failures in meiotic cell division and early mitosis. Most aneuploid embryos survive until the blastocyst stage but likely fail to implant, indicating selection against aneuploidy occurs late in preimplantation development.
1) Transferring embryos at the blastocyst stage on day 5 has a higher success rate than at earlier stages. Some doctors transfer multiple embryos on day 3 to increase pregnancy rates, but this increases the risk of multiple pregnancy.
2) Routinely performing blastocyst culture and single embryo transfer (SET) allows selection of top-quality embryos for transfer while avoiding multiple pregnancies. This achieves high pregnancy rates safely.
3) SET is recommended for patients under 35 with good prognosis or blastocyst quality. Two embryos may be transferred for those over 35 or who previously failed IVF. SET allows use of remaining high-quality embryos in subsequent cycles.
This document provides a summary of developments in reproductive medicine presented by T. Cordes and K. Diedrich from the University of Schleswig-Holstein, Campus Lübeck, Germany. It discusses milestones from 1960 to present including IVF in 1970, cryopreservation in 1980, and ICSI in 1990. New developments discussed include the use of GnRH antagonists and long acting FSH for ovarian stimulation, elective single embryo transfer to reduce multiple births, blastocyst culture, and preimplantation genetic screening. In-vitro maturation is presented as an alternative for certain patient groups. Cryopreservation methods including vitrification are also summarized.
Other potential definitions of success in art itt, et, (1)鋒博 蔡
This document discusses success rates for IVF/ICSI treatment and strategies to improve the patient experience. It notes that only 50% of couples will achieve an ongoing pregnancy within 1 year of starting treatment. Risks like ovarian hyperstimulation syndrome are discussed. The importance of patient selection, stimulation protocols, and embryo transfer techniques are covered. The document advocates for single embryo transfer to reduce multiples while maintaining pregnancy rates. It also stresses providing patients with information to manage expectations and improve the IVF experience.
This document summarizes studies comparing recombinant human chorionic gonadotropin (rhCG) and recombinant luteinizing hormone (rLH) to urinary hCG (uhCG) for triggering ovulation. Seven randomized controlled trials were included in the analysis. The studies found no significant differences in ongoing pregnancy rates, clinical pregnancy rates, incidence of ovarian hyperstimulation syndrome, or miscarriage rates between rhCG and uhCG. rLH was found to have lower pregnancy rates and is no longer being developed for triggering ovulation. rhCG was found to have fewer local site reactions compared to uhCG but one open-label study found no differences. In conclusion, rhCG and uhCG have similar clinical outcomes for triggering ovulation, and
This document compares different technologies for 24-chromosome copy number analysis in preimplantation genetic screening and diagnosis. It discusses the differences between screening and diagnostic tests, with screening tests being noninvasive, low-cost and allowing analysis of all patients to prioritize embryos, while diagnostic tests require high accuracy. It reviews technologies for copy number analysis including chromosome spreading, array comparative genomic hybridization, quantitative PCR and next generation sequencing, discussing their advantages and limitations for screening and diagnosis.
Preimplantation genetic screening (pgs) current ppt鋒博 蔡
This document summarizes preimplantation genetic testing techniques used to screen embryos for genetic disorders prior to implantation. It discusses the current status and future prospects of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). PGD determines an embryo's genotype to identify genetic disorders, while PGS assesses the embryo's chromosome number (karyotype) to screen for aneuploidies. The document outlines several techniques used for PGD and PGS, including multiplex PCR, fluorescence in-situ hybridization (FISH), whole genome amplification via multiple displacement amplification, and intracytoplasmic sperm injection (ICSI). It also discusses milestones in the development of
This document discusses endometrial receptivity and the Endometrial Receptivity Array (ERA) test. The ERA test analyzes the endometrial transcriptome using microarrays to determine if a patient's window of receptivity is receptive or non-receptive. For patients found to have a non-receptive window, personalizing the timing of embryo transfer based on the ERA results can improve pregnancy rates compared to using a standard transfer schedule. The ERA test is currently being clinically validated in an international randomized controlled trial.
This document discusses several potential technologies for identifying viable oocytes, including polar body biopsy, spindle imaging, and zona pellucida birefringence. Polar body biopsy and array comparative genomic hybridization can be used to assess chromosomal disorders in oocytes. Spindle imaging using polarization microscopy can identify the meiotic stage of an oocyte. Zona pellucida birefringence imaging using polarization microscopy provides information on cytoplasmic maturity, with more structured zonae correlating with better developmental potential. These technologies, especially polar body biopsy, spindle imaging, and zona imaging, may help select the most implantation-competent embryos.
Chromosomal abnormalities are a major cause of IVF failure, with only a 20% success rate. During embryo development, errors can occur that lead to an abnormal number or structure of chromosomes. As a woman's age increases, so does the risk of chromosomal issues in embryos. Preimplantation genetic diagnosis (PGD) allows testing of embryos for chromosomal or genetic disorders before implantation, improving IVF outcomes. It involves removing a cell from 8-cell stage embryos and analyzing the DNA or chromosomes to identify healthy embryos for transfer. PGD is recommended for advanced maternal age, recurrent miscarriages, infertility or prior pregnancies with abnormalities.
This document discusses invitro fertilization (IVF) and pre-implantation genetic diagnosis (PGD). PGD involves testing embryos for genetic diseases prior to implantation. It can reduce miscarriage rates and allow parents to select embryos without diseases. However, it also enables selection based on non-medical traits and discarding of embryos, raising ethical issues. Views on the morality of embryo research and genetic selection vary between utilitarian, rights-based ethics and different religious perspectives. International policies also differ in their regulation of PGD and genetic selection.
This short document promotes creating presentations using Haiku Deck, a tool for making slideshows. It encourages the reader to get started making their own Haiku Deck presentation and sharing it on SlideShare. In a single sentence, it pitches presentation creation software.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
Time lapse observation of embryos through incubation allows continuous monitoring of development from fertilization. This non-invasive technique creates a developmental timeline used to assess embryo health and select the best embryo for transfer based on adherence to normal timing of cleavages and divisions. Precise timing data of early embryonic events like pronuclear fading and cell divisions correlates with implantation potential, with substantial deviations linked to lower success rates. Abnormal cell patterns or asynchronous cell cycles seen through time lapse also indicate higher risk of aneuploidy.
This randomized controlled trial tested whether performing blastocyst biopsy with comprehensive chromosome screening (CCS) improves in vitro fertilization (IVF) outcomes compared to routine care. They found:
1) Sustained implantation rates (probability of embryo implanting and resulting in delivery) and delivery rates per cycle were significantly higher in the CCS group compared to the routine care group.
2) In the CCS group, 61 of 72 treatment cycles led to delivery (84.7%) compared to 56 of 83 (67.5%) in the routine care group.
3) Use of CCS with blastocyst biopsy and rapid quantitative PCR-based screening resulted in statistically significantly improved IVF outcomes, with
This document provides a cautionary commentary on recent publications claiming that time-lapse imaging can be used to assess embryo aneuploidy risk and increase pregnancy rates. The authors believe the claims are premature and unsubstantiated. They argue that the studies are underpowered and likely confounded by maternal age rather than embryo aneuploidy alone. Larger, age-adjusted datasets or randomized controlled trials are needed to validate the findings before clinical application.
This study examined 1213 human embryos at the cleavage and blastocyst stages to assess the relationship between morphological appearance and chromosomal abnormalities. The researchers found that at the cleavage stage, many embryos with the best morphological scores were still chromosomally abnormal, indicating little effect of aneuploidy on appearance at this stage. However, at the blastocyst stage aneuploidies were less common in embryos with optimal morphology, though some chromosomally abnormal blastocysts still received high scores, particularly for clinically relevant aneuploidies like trisomy 21. While morphology provides some information about chromosomal status at the blastocyst stage, comprehensive chromosome testing remains important for accurate assessment of embryo viability
This document discusses endometrial receptivity and the need for objective biomarkers to diagnose it. While past research identified some potential molecular markers, none have proven clinically useful. Recent transcriptomic analyses using microarrays have defined a gene expression signature that can classify endometrial status, including receptivity, regardless of histological appearance. This led to the development of the Endometrial Receptivity Array (ERA) tool, which uses a customized microarray and algorithm to identify the personalized window of implantation in individual patients, improving outcomes over histological dating alone.
This document discusses the advantages of blastocyst stage embryo transfer compared to cleavage stage embryo transfer, particularly in the context of oocyte donation. Key points include:
- Blastocyst stage transfer has been shown to improve outcomes like implantation and pregnancy rates compared to cleavage stage transfer based on evidence from IVF studies.
- In oocyte donation specifically, studies have found significantly higher implantation and pregnancy rates per embryo transfer with blastocyst stage transfer compared to cleavage stage.
- The development of improved embryo culture systems has made successful blastocyst development and transfer more routine. Blastocyst transfer also allows more information about embryo developmental potential.
This document discusses preimplantation genetic screening (PGS) with fresh embryo transfer. It provides an overview of PGS using comprehensive chromosome analysis (CCA) with blastocyst biopsy and either fresh embryo transfer or frozen embryo transfer. Key advantages of CCA with blastocyst biopsy include improved implantation rates, elimination of the negative effect of maternal age on implantation, and the ability to perform embryo banking which facilitates multiple cycles for patients with poor prognosis. Controlled studies show no difference in outcomes between fresh versus frozen embryo transfer when using PGS with CCA.
1) The likelihood of abnormal embryos and non-chromosomal implantation failure increases with maternal age, ranging from 54% of embryos being abnormal for women under 35 to 82% for women 41-42.
2) A study found chromosomally abnormal embryos detected by array CGH had delayed blastulation compared to normal embryos.
3) Studies have found both positive and no effects of preimplantation genetic screening using day 3 embryo biopsy and FISH, with some finding a negative effect. A recent study found day 3 biopsy reduced implantation rates compared to blastocyst biopsy or no biopsy.
4) Data suggests preimplantation genetic testing for aneuploidies by methods like array C
This document analyzes 2,204 human oocytes and embryos from fertilization through the blastocyst stage using microarray comparative genomic hybridization to determine chromosome abnormalities. It finds that aneuploidy rates increase dramatically with female age and that complex abnormalities are common. Chromosome errors originate from failures in meiotic cell division and early mitosis. Most aneuploid embryos survive until the blastocyst stage but likely fail to implant, indicating selection against aneuploidy occurs late in preimplantation development.
1) Transferring embryos at the blastocyst stage on day 5 has a higher success rate than at earlier stages. Some doctors transfer multiple embryos on day 3 to increase pregnancy rates, but this increases the risk of multiple pregnancy.
2) Routinely performing blastocyst culture and single embryo transfer (SET) allows selection of top-quality embryos for transfer while avoiding multiple pregnancies. This achieves high pregnancy rates safely.
3) SET is recommended for patients under 35 with good prognosis or blastocyst quality. Two embryos may be transferred for those over 35 or who previously failed IVF. SET allows use of remaining high-quality embryos in subsequent cycles.
This document provides a summary of developments in reproductive medicine presented by T. Cordes and K. Diedrich from the University of Schleswig-Holstein, Campus Lübeck, Germany. It discusses milestones from 1960 to present including IVF in 1970, cryopreservation in 1980, and ICSI in 1990. New developments discussed include the use of GnRH antagonists and long acting FSH for ovarian stimulation, elective single embryo transfer to reduce multiple births, blastocyst culture, and preimplantation genetic screening. In-vitro maturation is presented as an alternative for certain patient groups. Cryopreservation methods including vitrification are also summarized.
Other potential definitions of success in art itt, et, (1)鋒博 蔡
This document discusses success rates for IVF/ICSI treatment and strategies to improve the patient experience. It notes that only 50% of couples will achieve an ongoing pregnancy within 1 year of starting treatment. Risks like ovarian hyperstimulation syndrome are discussed. The importance of patient selection, stimulation protocols, and embryo transfer techniques are covered. The document advocates for single embryo transfer to reduce multiples while maintaining pregnancy rates. It also stresses providing patients with information to manage expectations and improve the IVF experience.
This document summarizes studies comparing recombinant human chorionic gonadotropin (rhCG) and recombinant luteinizing hormone (rLH) to urinary hCG (uhCG) for triggering ovulation. Seven randomized controlled trials were included in the analysis. The studies found no significant differences in ongoing pregnancy rates, clinical pregnancy rates, incidence of ovarian hyperstimulation syndrome, or miscarriage rates between rhCG and uhCG. rLH was found to have lower pregnancy rates and is no longer being developed for triggering ovulation. rhCG was found to have fewer local site reactions compared to uhCG but one open-label study found no differences. In conclusion, rhCG and uhCG have similar clinical outcomes for triggering ovulation, and
This document compares different technologies for 24-chromosome copy number analysis in preimplantation genetic screening and diagnosis. It discusses the differences between screening and diagnostic tests, with screening tests being noninvasive, low-cost and allowing analysis of all patients to prioritize embryos, while diagnostic tests require high accuracy. It reviews technologies for copy number analysis including chromosome spreading, array comparative genomic hybridization, quantitative PCR and next generation sequencing, discussing their advantages and limitations for screening and diagnosis.
Preimplantation genetic screening (pgs) current ppt鋒博 蔡
This document summarizes preimplantation genetic testing techniques used to screen embryos for genetic disorders prior to implantation. It discusses the current status and future prospects of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). PGD determines an embryo's genotype to identify genetic disorders, while PGS assesses the embryo's chromosome number (karyotype) to screen for aneuploidies. The document outlines several techniques used for PGD and PGS, including multiplex PCR, fluorescence in-situ hybridization (FISH), whole genome amplification via multiple displacement amplification, and intracytoplasmic sperm injection (ICSI). It also discusses milestones in the development of
This document discusses endometrial receptivity and the Endometrial Receptivity Array (ERA) test. The ERA test analyzes the endometrial transcriptome using microarrays to determine if a patient's window of receptivity is receptive or non-receptive. For patients found to have a non-receptive window, personalizing the timing of embryo transfer based on the ERA results can improve pregnancy rates compared to using a standard transfer schedule. The ERA test is currently being clinically validated in an international randomized controlled trial.
This document discusses several potential technologies for identifying viable oocytes, including polar body biopsy, spindle imaging, and zona pellucida birefringence. Polar body biopsy and array comparative genomic hybridization can be used to assess chromosomal disorders in oocytes. Spindle imaging using polarization microscopy can identify the meiotic stage of an oocyte. Zona pellucida birefringence imaging using polarization microscopy provides information on cytoplasmic maturity, with more structured zonae correlating with better developmental potential. These technologies, especially polar body biopsy, spindle imaging, and zona imaging, may help select the most implantation-competent embryos.
Chromosomal abnormalities are a major cause of IVF failure, with only a 20% success rate. During embryo development, errors can occur that lead to an abnormal number or structure of chromosomes. As a woman's age increases, so does the risk of chromosomal issues in embryos. Preimplantation genetic diagnosis (PGD) allows testing of embryos for chromosomal or genetic disorders before implantation, improving IVF outcomes. It involves removing a cell from 8-cell stage embryos and analyzing the DNA or chromosomes to identify healthy embryos for transfer. PGD is recommended for advanced maternal age, recurrent miscarriages, infertility or prior pregnancies with abnormalities.
This document discusses invitro fertilization (IVF) and pre-implantation genetic diagnosis (PGD). PGD involves testing embryos for genetic diseases prior to implantation. It can reduce miscarriage rates and allow parents to select embryos without diseases. However, it also enables selection based on non-medical traits and discarding of embryos, raising ethical issues. Views on the morality of embryo research and genetic selection vary between utilitarian, rights-based ethics and different religious perspectives. International policies also differ in their regulation of PGD and genetic selection.
This short document promotes creating presentations using Haiku Deck, a tool for making slideshows. It encourages the reader to get started making their own Haiku Deck presentation and sharing it on SlideShare. In a single sentence, it pitches presentation creation software.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document discusses methods to identify patients who may benefit from LH supplementation before and during controlled ovarian stimulation (COS) for IVF. Before COS, patients such as those with hypogonadotropic hypogonadism, poor responders over 35 years old, or a high basal FSH/LH ratio may benefit. During COS with a GnRH agonist, patients with a "steady response" or LH levels over 1.99 on day 8 may benefit. During COS with a GnRH antagonist, patients with progesterone over 1-1.2 on the day of hCG administration may benefit from LH supplementation.
This document discusses various methods for preimplantation genetic diagnosis (PGD) using embryo biopsy and genetic analysis. It finds that a high percentage (over 50%) of morphologically normal embryos are chromosomally abnormal, and this percentage increases with maternal age. New methods like array comparative genomic hybridization (aCGH) allow analysis of all 24 chromosomes with a low error rate (<2%) and without need for parental samples. Clinical trials show improved pregnancy and implantation rates using aCGH with day 3 or day 5 embryo biopsy compared to no PGD. Blastocyst biopsy provides more DNA for analysis and may reduce mosaicism effects. Overall, the document evaluates different PGD methods and finds aCGH analysis after blast
This study analyzed the timing of early cell divisions in 180 human embryos using time-lapse imaging. Embryos with uniform timing of cleavages and interphases were more likely to develop into high-quality blastocysts and result in pregnancies, while abnormalities in timing predicted poor development and implantation failure. Specifically, embryos with shortened or prolonged cell cycles showed higher rates of morphological anomalies, lower blastocyst formation rates, and zero implantation, even when blastocyst formation occurred. The study demonstrates that time-lapse imaging can identify viable embryos with high specificity by analyzing cleavage uniformity and rule out non-viable embryos with 100% specificity.
This document provides a cautionary commentary on recent publications claiming that time-lapse imaging can be used to assess embryo aneuploidy risk and increase pregnancy rates. The authors believe the claims are premature and unsubstantiated. They argue that the studies are underpowered and likely confounded by maternal age rather than embryo aneuploidy alone. Larger, age-adjusted datasets or randomized controlled trials are needed to validate the findings before clinical application.
This document describes the development of a rapid and low-cost next-generation sequencing (NGS) protocol for diagnosing aneuploidy in single cells from human preimplantation embryos. The researchers optimized an NGS protocol that took less than 15 hours and had consumable costs two-thirds lower than existing methods. They validated the method on 54 cells with 100% sensitivity and specificity for detecting aneuploidies. The method was then successfully used to select euploid embryos for transfer in two IVF cycles that resulted in healthy pregnancies.
This document describes the development of a rapid and low-cost next-generation sequencing (NGS) protocol for diagnosing aneuploidy in single cells from human preimplantation embryos. The authors optimized an NGS method that takes less than 15 hours and has consumable costs that are only two-thirds of existing methods. They validated the method on 54 cells with 100% sensitivity and specificity for detecting aneuploidy. The method was then applied clinically in two IVF cycles that resulted in healthy pregnancies. The NGS approach could also detect specified mutations and found an association between elevated mitochondrial DNA and aneuploidy.
The document describes the development of a rapid and low-cost next-generation sequencing (NGS) protocol for detecting aneuploidy in single cells from human preimplantation embryos. The method was validated on single cells from cell lines with known karyotypes, correctly identifying chromosomal abnormalities in all samples tested. The NGS approach was then applied to single cells from human embryos, detecting several cases of aneuploidy. Initial clinical application in two in vitro fertilization cycles resulted in healthy pregnancies, demonstrating the potential clinical utility of low-cost NGS-based screening to improve IVF outcomes.
The document describes the development of a rapid and low-cost next-generation sequencing (NGS) protocol for detecting aneuploidy in single cells from human preimplantation embryos. The method was validated on single cells from cell lines with known karyotypes, correctly identifying chromosomal abnormalities in all samples tested. The NGS approach was then applied to single cells from human embryos, detecting several cases of aneuploidy. Initial clinical application in two in vitro fertilization cycles resulted in healthy pregnancies, demonstrating the potential clinical utility of low-cost NGS-based screening to improve IVF outcomes.
This randomized controlled trial compared outcomes of in vitro fertilization (IVF) when comprehensive chromosome screening (CCS) of blastocysts was used versus the standard of care. They found that using CCS resulted in significantly higher sustained implantation rates (66.4% vs 47.9%) and delivery rates per cycle (84.7% vs 67.5%) compared to the control group. CCS improved IVF outcomes by enabling selection of euploid embryos for transfer, leading to meaningful increases in the likelihood of successful implantation and delivery.
This study compared two methods for screening embryo cells for chromosomal abnormalities: fluorescence in situ hybridization (FISH) and single-nucleotide polymorphism (SNP) microarray analysis. Thirteen arrested embryos were each biopsied into individual cells, with 160 cells total randomized into the two screening methods. Microarray analysis provided interpretable results for more cells (96% vs 83% for FISH) and detected mosaicism (differences between cells of the same embryo) significantly less often than FISH (31% vs 100%). Direct comparison found FISH detected more unique genetic diagnoses per embryo on average. This is the first study to directly compare these two screening methods using paired cells from the same embryos, suggesting FISH may
This document summarizes several adjunct techniques used in IVF laboratories including sperm DNA fragmentation testing, advanced sperm selection methods like IMSI and pICSI, embryo selection techniques like time-lapse imaging and PGS, and mitochondrial DNA load measurement. It reviews the current evidence for each technique, noting that while some like TL imaging show promise, the evidence is still limited and inconclusive for many techniques to recommend their routine use to improve IVF outcomes. Larger randomized controlled trials are still needed to prove effectiveness.
This study evaluated the use of blastocyst biopsy and array comparative genomic hybridization (aCGH) for preimplantation genetic diagnosis in 12 patients with chromosomal translocations. The diagnostic efficiency was 90.2% and euploidy rate was 32.7%. Ten cycles of thawed embryo transfer resulted in three live births and three ongoing pregnancies, for an ongoing pregnancy rate of 60% per transfer cycle. Prenatal diagnoses confirmed the PGD/aCGH results. The strategy demonstrates promising outcomes and may provide a more effective approach than traditional methods like fluorescence in situ hybridization. Larger studies are still needed to verify the results.
The document describes a pilot study that investigated the presence of DNA in blastocyst fluids (BFs) and whether the chromosomal status predicted by analyzing this DNA corresponds to the status in trophectoderm (TE) cells and the whole embryo. The study found that:
1) DNA was detected in the BFs of 76.5% of blastocysts tested, allowing chromosomal analysis of these samples.
2) In 97.4% of cases, the ploidy condition (euploid vs. aneuploid) predicted by BF analysis matched the condition in TE cells.
3) BF analysis predicted the ploidy condition of the whole embryo with 100% accuracy
This study examined how often comprehensive chromosome screening (CCS) would alter the selection of embryos for transfer compared to traditional day 5 morphology-based selection. Out of 100 consecutive cycles:
- 22% of embryos selected based on day 5 morphology alone would have been aneuploid according to CCS results. This was lower than the 32% aneuploidy rate of all biopsied embryos.
- Patients aged 35 or older had a higher risk (31%) of an aneuploid best quality day 5 embryo being selected than younger patients (14%).
- Among cycles where CCS altered selection, 74% resulted in delivery including 77% for elective single embryo transfer cycles. Most patients
First mitotic division: criterion for selection of potential IVF embryo – A ...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
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First mitotic division: criterion for selection of potential IVF embryo – A S...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
This study examined 1213 human embryos at the cleavage and blastocyst stages to assess the relationship between embryo morphology and chromosomal abnormalities. At the cleavage stage, 84% of embryos were found to be chromosomally abnormal, even among those with the best morphological grades. However, at the blastocyst stage, chromosomal abnormalities were significantly less common in embryos with optimal morphology and more common in poor-quality embryos. Nonetheless, many chromosomally abnormal blastocysts still received the highest morphological scores, particularly for trisomy 21 which is sometimes compatible with live birth. In summary, chromosomal abnormalities had little effect on cleavage stage morphology but began to impact blastocyst appearance, though the effects were often subtle
Preimplantation genetic screening (pgs) current ppt鋒博 蔡
This document summarizes preimplantation genetic testing techniques used to screen embryos for genetic disorders prior to implantation. It discusses the current status and future prospects of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). PGD determines an embryo's genotype to test for specific genetic disorders, while PGS assesses the embryo's chromosome number (karyotype) to screen for chromosomal abnormalities. The document outlines several techniques used for PGD and PGS, including multiplex PCR, fluorescence in situ hybridization (FISH), and whole genome amplification from single cells. It provides examples of how these techniques are applied to test for conditions like spinal muscular atrophy, sickle cell an
This document discusses preimplantation genetic testing (PGT), which includes preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). PGD determines an embryo's genotype to test for genetic disorders, while PGS assesses the embryo's chromosome number. The document outlines the history and development of PGT, including key milestones. It also describes current technologies used for PGT, such as fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR). The document provides an example of how one clinic uses PGT to screen for chromosomal abnormalities and genetic disorders.
This document discusses preimplantation genetic testing (PGT), which includes preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). PGD determines an embryo's genotype to test for genetic disorders, while PGS assesses the embryo's chromosome number. The document outlines the history and development of PGT, including key milestones. It also describes current technologies used for PGT, such as fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR). The document provides an example of how one clinic uses PGT to screen for chromosomal abnormalities with FISH and test for genetic disorders and HLA matching.
This document summarizes preimplantation genetic testing technologies used to screen embryos for genetic disorders prior to implantation. It discusses the current status and applications of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS), which allow couples at risk of passing on genetic disorders to have unaffected children. Key technologies that enable and support PGD/PGS are also described, including intracytoplasmic sperm injection, laser-assisted embryo biopsy, sperm sorting, and cryopreservation of biopsied embryos. Current methods for PGD/PGS involving multiplex PCR, fluorescence in situ hybridization, and whole genome amplification from single cells are also summarized.
This document discusses innovations and breakthroughs in in vitro fertilization (IVF). It covers the following topics in 3 sentences or less:
Genetic screening techniques like preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) are discussed to select embryos without genetic disorders or the highest chance of implantation. Time-lapse monitoring is presented as a way to continuously monitor embryo development in real-time without disruptions. Stem cell therapy and its potential role in inducing ovarian regeneration and sustained ovarian function is briefly covered.
This document summarizes research comparing outcomes of fresh embryo transfers versus frozen embryo transfers (FET). Key points include:
- FET outcomes were found to equal or exceed fresh outcomes, suggesting endometrial asynchrony with fresh cycles due to ovarian stimulation effects.
- Slower developing day 6 blastocysts showed lower implantation rates than day 5 blastocysts with fresh but not FET transfers, again indicating endometrial asynchrony issues with fresh cycles.
- Studies directly comparing matched fresh and FET cycles found significantly higher pregnancy and implantation rates with FET, demonstrating cryopreservation can overcome negative endometrial effects of ovarian stimulation.
This document summarizes research comparing outcomes of fresh embryo transfers versus frozen embryo transfers (FET). It finds that FET results in better pregnancy and implantation rates than fresh transfers, likely due to ovarian stimulation negatively impacting endometrial receptivity in fresh cycles. Specifically, FET cycles have higher success rates for slower developing embryos and embryos transferred in cycles with premature progesterone elevation. FET outcomes in young patients can rival fresh donor egg cycles. Randomized trials show significantly higher pregnancy rates with FET compared to fresh transfer in normal responders.
This study analyzed aneuploidy rates, apoptotic markers, and DNA fragmentation in sperm samples from normozoospermic men with unexplained infertility. Samples underwent density gradient centrifugation and then magnetic activated cell sorting (MACS). MACS significantly reduced the percentage of aneuploid, apoptotic, and DNA-damaged sperm. A positive correlation was found between reduced aneuploidy and lower DNA damage after MACS, but no correlation with apoptotic markers. The interactions between apoptotic markers, DNA integrity, and aneuploidy, as well as the effects of MACS on these parameters, require further investigation.
This document discusses the impact of fetal fraction, the percentage of cell-free DNA in maternal plasma that is of fetal origin, on the performance of next generation sequencing tests for detecting common fetal aneuploidies such as Down syndrome. It finds that test performance is better with higher fetal fractions. Specifically, the distribution of test results for Down syndrome pregnancies improves and separates more from normal pregnancies as fetal fraction increases. Additionally, false negative rates and rates of low fetal fractions are highest for women with high maternal weights. When a fetus has mosaicism for a trisomy, the degree of mosaicism affects the effective fetal fraction and thus impacts test performance.
This document describes a new statistical method called FetalQuant that can deduce the fractional fetal DNA concentration directly from massively parallel sequencing (MPS) data of DNA in maternal plasma, without requiring prior genotype information. FetalQuant implements a binomial mixture model to estimate the fractional fetal DNA concentration by maximum likelihood using only the allelic count data from targeted MPS. This allows improved determination of the fetal DNA fraction without additional laboratory steps. The authors believe FetalQuant can help expand the applications of MPS-based non-invasive prenatal diagnosis.
This document discusses how exome sequencing is revolutionizing the identification of genes that cause Mendelian diseases. It provides three main points:
1) Exome sequencing has identified over 30 new disease genes since 2009, improving clinical diagnosis, genotype-phenotype correlations, and understanding of rare genetic variation.
2) Our view of Mendelian diseases is changing as exome sequencing is less biased than previous methods and is identifying disease genes in cases where the genetic cause was unclear.
3) Exome sequencing is now the primary tool for studying Mendelian diseases as it can sequence hundreds of patient exomes per year more efficiently than whole genome sequencing.
1) Genome-wide gene expression analysis identified immune response and lymphangiogenesis pathways as implicated in the pathogenesis of fetal chylothorax (FC). Genes involved in immune response were universally up-regulated, while genes related to lymphangiogenesis were down-regulated in fetal pleural fluids of FC cases.
2) Expression of the ITGA9 gene, which is important for lymphangiogenesis, was concordant with trends in the lymphangiogenesis pathway. ITGA9 mutations have previously been associated with FC.
3) For one fetus (Ind) carrying an ITGA9 mutation, immune response pathways decreased after successful treatment of FC with OK-432 pleurodesis, while lymphangiogenesis pathways
- The study analyzed 22,384 maternal plasma samples to determine the effects of gestational age and maternal weight on the percentage of fetal cell-free DNA (cfDNA) in maternal plasma.
- They found that the percentage of fetal cfDNA increases with gestational age, rising 0.1% per week between 10-21 weeks and 1% per week after 21 weeks. Fetal cfDNA percentage decreases with increasing maternal weight.
- Of samples that were redrawn due to initially low fetal cfDNA, 56% of second draws had over 4% fetal cfDNA, showing that fetal percentage often improves with redraws, especially at later gestational ages.
This method accurately detected sex chromosome aneuploidies (45,X, 47,XXY, 47,XYY) in cell-free DNA isolated from maternal plasma. It analyzed 201 pregnancies including 16 with sex chromosome aneuploidies and 185 normal controls. The method involved massively multiplexed PCR and sequencing of 19,488 SNPs across chromosomes 13, 18, 21, X and Y. Using a statistical algorithm to analyze the SNP data, it correctly identified the copy number at all five chromosomes in 93% of samples, detecting sex chromosome aneuploidies with high sensitivity and specificity.
This document describes a new noninvasive method for sequencing the entire fetal genome using cell-free DNA found in a pregnant woman's blood. The method works by counting parental haplotypes - combinations of maternal and paternal chromosomes passed to the fetus. Since a small percentage of cell-free DNA comes from the fetus, haplotypes inherited by the fetus can be identified by which have a higher count. Researchers tested this method on two pregnancies and were able to determine the fetal genomes without any invasive procedures. This noninvasive prenatal testing could allow comprehensive screening for genetic diseases.
This document describes a study that used massively parallel sequencing of cell-free DNA in maternal blood to assess zygosity and detect fetal aneuploidies in twin pregnancies. The study determined zygosity by analyzing apparent fractional fetal DNA concentrations across genomic regions. It then calculated individual fetal DNA concentrations for dizygotic twins to assess each fetus. The study detected trisomy 21 in one twin and trisomy 18 in the other twin of two pregnancies. It demonstrated that noninvasive prenatal testing for aneuploidies can be achieved for twin pregnancies using this method.
The document compares euploidy rates between blastomere biopsies on day 3 embryos and trophectoderm biopsies on day 5-7 blastocysts. Of the 1603 embryos biopsied, 31% were euploid, 62% were aneuploid, and 7% were unanalyzable. A significantly higher proportion of embryos were euploid with trophectoderm biopsy on day 5-7 (42%) compared to blastomere biopsy on day 3 (24%). Combining blastocyst culture, trophectoderm biopsy, and aneuploidy screening using aCGH provides a more efficient means of achieving euploid pregnancies in IVF.
This document describes a case study of preimplantation genetic diagnosis (PGD) performed on a breast cancer patient carrying a novel genomic deletion in the BRCA2 gene. Researchers first used single sperm haplotyping on the patient's carrier brother to establish linkage to the mutation. They then used BLAST analysis to locate putative hairpin structures in the genome and PCR screening to identify a 2,596 bp deletion in BRCA2 involving exons 15-16. PGD was performed using both direct mutation detection and linkage analysis to avoid misdiagnosis from recombination. This identified unaffected embryos, one of which was transferred, resulting in a live birth.
This document describes a case study of preimplantation genetic diagnosis (PGD) performed on a breast cancer patient carrying a novel genomic deletion in the BRCA2 gene. Researchers first used single sperm haplotyping on the patient's carrier brother to establish linkage to the mutation. They then used BLAST analysis to locate putative hairpin structures in the genome and PCR screening to identify a 2,596 bp deletion in BRCA2 involving exons 15-16. PGD was performed using both direct mutation detection and linkage analysis to avoid misdiagnosis from recombination. This identified unaffected embryos, one of which was transferred, resulting in a live birth.
- Dr. Chang informs 37-year-old patient Niki about declining fertility with age and recommends an AMH test to evaluate her ovarian reserve since Niki wants to have children.
- Niki's test results show very low AMH levels. Dr. Goldstein, who is covering for Dr. Chang, is upset that Dr. Chang informed Niki without considering her lack of a partner and career focus.
- The commentary argues that physicians have a responsibility to provide patients information relevant to their reproductive goals and futures to allow for informed decision making, even if the news is unexpected or unwelcome.
This study compared two microarray technologies, single nucleotide polymorphism (SNP) and comparative genomic hybridization (aCGH), for preimplantation genetic diagnosis and screening (PGD/PGS) of embryos from couples where one parent has a balanced reciprocal translocation. The study found:
1) There was no significant difference in the rates of euploid embryos without translocation imbalances, euploid embryos with imbalances, or aneuploid embryos between the SNP and aCGH technologies.
2) Clinical pregnancy rates were also equivalent for SNP (60%) and aCGH (65%) microarrays.
3) Both SNP and aCGH microarrays effectively identified unbalanced translocations
This document summarizes a study that developed a new microarray platform capable of simultaneously assessing aneuploidy, mitochondrial DNA content, and single-nucleotide polymorphisms in human polar bodies and embryos. The microarray was optimized and validated using cell lines and clinical samples. Results found the microarray detected aneuploidies with 97% accuracy and could accurately determine relative mitochondrial DNA quantities and genotypes, allowing confirmation of parental origin. The microarray provides information beyond chromosomal analysis alone that could improve embryo assessment and selection.
1. Approximately 15-20% of couples in Germany experience infertility issues. New developments in reproductive medicine include GnRH-antagonists for ovarian stimulation, elective single embryo transfer (eSET) to reduce multiple pregnancies, blastocyst transfer, in-vitro maturation, and vitrification for cryopreservation.
2. Studies show eSET results in similar pregnancy rates but significantly fewer multiple pregnancies compared to double embryo transfer. Vitrification is an improved cryopreservation technique with higher post-thaw survival and pregnancy rates compared to slow freezing.
3. In-vitro maturation allows retrieval of immature eggs for fertilization, and may help avoid ovarian hyperstimulation syndrome in high-risk patients
1. Approximately 15-20% of couples in Germany experience infertility issues. New developments in reproductive medicine include GnRH-antagonists for ovarian stimulation, elective single embryo transfer (eSET) to reduce multiple pregnancies, blastocyst culture, and vitrification for improved cryopreservation outcomes.
2. Studies show eSET results in similar pregnancy rates but significantly fewer multiple pregnancies compared to double embryo transfer. The use of GnRH-antagonists results in a simplified stimulation protocol with fewer side effects and no difference in live birth rates compared to GnRH-agonists.
3. Vitrification through techniques like the Cryotop method provide significantly better embryo survival and pregnancy rates compared to slow freezing methods
1. J Assist Reprod Genet (2013) 30:1081–1090
DOI 10.1007/s10815-013-0048-4
EMBRYO BIOLOGY
Could time-lapse embryo imaging reduce the need for biopsy
and PGS?
Jason E. Swain
Received: 13 May 2013 / Accepted: 3 July 2013 / Published online: 11 July 2013
# Springer Science+Business Media New York 2013
Abstract
Purpose To review relevant studies examining the relation-ship
between embryo morpho-kinetics and aneuploidy.
Methods Search of Pubmed and Medline using relevant
keywords pertaining to morphology, morphokinetics and
embryonic aneuploidy, as well as examination of various
reference lists and conference proceedings.
Results An abundance of publications, both preliminary and
peer-reviewed, have emerged regarding the usefulness of
time-lapse imaging in tracking embryo development and
improving embryo selection. Recently, these publications
have explored ability to not only predict blastocyst formation
and implantation, but also the ability to detect embryonic
chromosomal aneuploidy. Of the two peer-reviewed retro-spective
studies on morpho-kinetics and embryonic aneu-ploidy,
one demonstrates that early cleavage timings can
indicate chromosomal complement, while the other demon-strates
that key events following the maternal-zygotic tran-sition
can be markers of aneuploidy. A recent paper also
demonstrates improved outcomes following IVF using a
selection algorithm to identify embryos at “low risk” of
chromosomal abnormalities. However, the predictive nature
of these events and timings is far from ideal. Additionally,
results may be dependent upon the day of biopsy and method
utilized for chromosomal assessment.
Conclusion With continued effort, the combination of mul-tiple
morphologic endpoint assessments and developmental
timings and refinement of modeling systems may improve
the predictive ability to determine embryonic aneuploidy.
This may help select a subset of embryos that are less likely
to carry chromosomal abnormalities and improve assisted
reproductive outcomes. However, embryo biopsy, follow-ed
by preimplantation genetic screening/comprehensive
chromosomal screening still remains the most reliable
method to assess chromosomal complement of preimplan-tation
embryos.
Keywords Time-lapse . Morphokinetics . Aneuploidy .
Embryo . Blastocyst
Introduction
While real-time video or time-lapse imaging of embryo
development is not a new concept [11, 33, 38, 46, 47, 51,
54, 61, 76, 77], only recently have commercially available
devices been developed that permit wide-spread clinical
implementation. This has resulted in an abundance of publi-cations
utilizing time-lapse imaging of human preimplanta-tion
embryos [5, 15–18, 35, 41–43, 47, 62, 82].
Imaging systems suitable for clinical use that permit a
more-or-less continuous monitoring of preimplantation em-bryo
development within the incubator environment offer
unique opportunities to non-invasively visualize time points
and aspects of embryo morphokinetics not previously feasi-ble
in the traditional IVF lab, with the intent of finding more
accurate predictors of embryo quality. This emerging ap-proach
carries the advantage of avoiding unnecessary envi-ronmental
stressors, such as pH or temperature fluctuations,
associated with removal of cells from the incubator environ-ment
for the routine static observations at discrete time
points. In addition, unique incubators used by at least one
commercially available imaging system, as well as unique
culture dishes with microwells or other approaches to permit
individual embryo tracking, may further improve the embryo
microenvironment and subsequent embryo development [66,
69]. Though concerns about the detrimental impact of light
exposure from extended microscopic imaging of oocytes and
Capsule Time-lapse imaging of embryos may provide insight into
chromosomal status.
J. E. Swain (*)
Department of Obstetrics and Gynecology, Center for Reproductive
Medicine, University of Michigan, 475 Market Place Bldg 1 Ste B,
Ann Arbor, MI 48108, USA
e-mail: swainj@med.umich.edu
2. 1082 J Assist Reprod Genet (2013) 30:1081–1090
embryos may exist, especially in rodent species [9, 19, 36,
58, 59, 70, 71, 75], these embryo-specific imaging systems
have all attempted to validate safety, and reduction in light
intensity through use of low intensity source or darkfield or
LED lighting sources, and/or brief exposure times of only a
few seconds, seem to be enough to alleviate concerns or
possible detrimental effects with human cells.
As mentioned, the true strength of time-lapse embryo
imaging is the ability to observe developmental events nor-mally
missed by current static embryo visualization ap-proaches,
as well as to determine the timing of specific
morphological occurrences and permit comparison between
embryos. These events may provide key additional informa-tion
to permit improved embryo selection, with the desire of
improving clinical outcomes while promoting single embryo
transfer. For example, recent time-lapse imaging publica-tions
focus on early mitotic events in cleavage stage embryos
and timing between the first three cell divisions with the
ability to predict blastocyst formation [17, 35, 82]. Other
studies relate early embryo mitotic division timings to im-plantation
success [53]. As will be discussed, more recent
studies have attempted to utilize real-time embryo imaging
to permit insight into the chromosomal status of individual
embryos.
Aneuploidy occurs in a surprisingly high percentage of
human preimplantation embryos, with estimates that 50–
80 % may have chromosomal abnormalities [28, 78]. This
high aneuploidy rate has obvious ramifications on limiting
success of assisted reproduction. While preimplantation ge-netic
screening (PGS), now also often referred to as compre-hensive
chromosomal screening (CCS), of all 24 chromo-somes
using new SNP or CGH arrays, qPCR or nextGen
approaches are more informative and accurate compared to
prior FISH techniques [28, 73], and these technologies may
help improve embryo selection and assisted reproductive out-comes
[26, 27, 64], embryo biopsy remains an invasive pro-cedure
that could compromise embryo quality. Additionally,
the increased cost of biopsy and PGS/CCS may be prohibi-tive.
Thus, non-invasive morphologic assessment methods to
determine embryonic aneuploidy could be extremely benefi-cial
as a means of improving embryo selection.
The idea of using embryo morphology to gain insight into
embryo chromosomal compliment is not new, but has had
limited success [80]. Various studies have utilized static
assessment at distinct time points, often during cleavage
stages, to try to show some link to embryo aneuploidy;
though correlations are weak and not overly reliable [20,
21, 34, 50, 55, 57]. It was also suggested that a sequential
embryo scoring system, utilizing information from days 1 to
3 of development, including endpoints like multi-nucleation,
symmetry and number of blastomeres may help select eu-ploid
embryos [25]. However, again, accuracy of this ap-proach
is limited. Emerging morphokinetic analysis of
embryo development offers the ability to not only compile
numerous morphological endpoints, but their specific tim-ings
as well, which may perhaps be incorporated into a
predictive algorithm to improve ability to non-invasively
determine chromosomal status.
This review explores the potential for a non-invasive
means of determining embryonic aneuploidy through exam-ination
of embryo morphology and timing of distinct mor-phologic
events. This is accomplished through the descrip-tion
of major morphologic events occurring during preim-plantation
embryo development and examination of the
existing literature on static morphologic assessment and
relation to embryonic chromosomal complement. Recent
kinetic data obtained using time-lapse imaging, much of
which is preliminary, of these major morphologic events is
then reviewed, focusing on studies that attempt to correlate
timing of these events to embryonic aneuploidy.
Methods
Pubmed and Medline databases were searched using relevant
keywords pertaining to embryo morphology, morphokinetics,
and embryonic aneuploidy. Relevant papers were examined
and included reference lists searched to locate additional stud-ies.
Published conference proceedings were also examined
and preliminary studies related to embryo morphokinetics
and aneuploidy analyzed. No time limits or other restrictive
criteria were utilized. The last date of search was April, 2013.
Data analysis focused on correlation between embryo
morphokinetics and aneuploidy, examining each major pre-implantation
embryo morphological event and relevant tim-ings,
as well as the analytical methods used to examine
chromosomal status.
Results
Pronucleii
One of the first morphologic events evident and assessed
during IVF is appearance of and assessment of pronucleii.
Identification of the correct number of pronucleii is useful in
identifying those subsequent embryos that may become an-euploid
[23]. It is well-known that 3PN embryos can contin-ue
development to the blastocyst stage, but these are likely to
be aneuploid. Similarly, 1PN embryos can also continue
development and may be aneuploid, though they could also
be the result of simply missing observation of a tran-sient
2nd pronucleii. While this fertilization assessment
can be done using a single static time point assessment
~16–18 h following insemination, use of time-lapse embryo
imaging can help ensure improved accuracy of pronucleii
3. J Assist Reprod Genet (2013) 30:1081–1090 1083
assessment, permitting visualization of transient pronucleii
that may have formed or disassembled slightly earlier or later
than “normal” and thus help ensure selection of euploid em-bryos
for transfer. However, more subtle aspects of pronuclear
morphology may be indicative of chromosomal complement.
At 16 h post-insemination following ICSI or IVF, embryos
were rolled to permit adequate visualization and static assess-ment
of pronuclear positioning (5 patterns) was assessed.
Subsequent day 3 biopsy with FISH analysis indicated that
euploid embryos were only present in two pattern groups;
those with juxtaposed pronucleii either centrally or peripher-ally
located (32 %and 41%respectively [31]. Using the same
analytic approach, location of the polar bodies in respect to the
longitudinal axis of pronucleii was also correlated to aneu-ploidy.
Of the 3 groupings, those in line with or at 90° angles
had the greatest number of euploid embryos (36 % and 33 %,
respectively); significantly greater rates than the other group
[31]. Static assessment of nuclear precursor bodies (NPBs) at
16–17 within pronucleii also seems to be related to embryonic
aneuploidy. At least seven studies, with grading systems rang-ing
from 3 to 6 grouping methods, have found some level of
correlation between NPB organization (number, size, syn-chrony,
polarity) and chromosomal complement following
day 3 embryo biopsy with FISH analysis [7, 22, 30–32, 40].
It should also be noted that incorporation of three PN mor-phologic
assessments (polar body alignment, PN positioning,
NPB scoring) into a single scoring systems with 8 categories
indicated that 4 of these categories yielded significantly higher
rates of euploid embryos compared to the remaining 4 groups
[31].
It can be appreciated that, if assessment of subtle location
or other morphologic indicators is predictive of aneuploidy,
that consistent timing of these assessments is crucial for
adequate comparisons. Time-lapse imaging offers a mean’s
to ensure these timing windows are not missed. This may be
especially true in regard to PN assessments. At least one
preliminary study indicates that timing of pronuclear appear-ance,
dissolution, or size, had no correlation to embryo ploidy
when analyzing 24 chromosomes using qPCR following
trophectoderm biopsy of resulting blastocysts [68] (Table 1).
Similarly, a recent publication also found no correlation be-tween
time of PN fading and aneuploidy with TE biopsy and
24 chromosome microarray [13, 14] (Table 1). Whether spe-cific
timing of pronuclear abuttal, or even more detailed
analysis of NPB patterns/dynamics can help improve predic-tion
of chromosomal status of resulting embryos remains
unknown. Importantly, the ability to “roll” or orient embryos
to accurately visualize PN and/or NPB positioning/alignment,
factors which static assessment studies indicate may be indic-ative
of aneuploidy, is likely not feasible, or at least not as
easily performed when using current time-lapse imaging sys-tems
that promote uninterrupted culture of cells. Also impor-tant
to note, use of ICSI or IVF would appear to important
variables to consider with regard to PN timing windows, as
the exact time of sperm penetration and signs of fertilization
will likely differ between these methods.
Upon closer examination of the above mentioned studies,
it becomes apparent that the studies that find correlation
between PN/NPB scoring systems use day 3 biopsy with
FISH analysis. No predictive ability of such PN scoring
systems is apparent with blastocyst biopsy and 24 chromo-some
analysis. This finding may be an important factor in
interpretation of older static observation data in relation to
newer studies using time-lapse imaging.
Multi-nucleation
Similar to pronucleii, static observation of blastomere multi-nucleation
on Day 2 has been associated with embryo aneu-ploidy
as confirmed by day 3/4 biopsy and FISH analysis [4,
44, 67].Using 9 probe FISH analysis, aneuploid embryoswere
present 85 % of the time when multinucleation was apparent
within blastomeres on day 2, while only 78 % aneuploidy was
apparent with mono-nucleation [4]. Similarly, 5 probe FISH
indicated day 2 multinucleation yielded 76.5 % aneuploidy,
compared to only 50.9 % of mono-nucleated control embryos
[44]. The same correlation to aneuploidy appears to be true for
multinucleation on day 3 [44, 67]. Day of multinucleation
appearance, number of nuclei per cell and number of multinu-cleated
cells per embryo did not appear to increase aneuploidy
rates [44]. Importantly, these multinucleated embryos may
continue development and still form good morphology blasto-cysts.
Thus, identifying this multinucleation appears critical to
isolate those embryos that are most likely to be euploid for
selection and transfer.
At least one study using time-lapse imaging has examined
occurrence of multinucleation and relationship to aneuploi-dy.
No significant difference was apparent in rates of aneu-ploid
versus euploid embryos with 2-cell embryo multi-nucleation
as assessed by TE biopsy and 24 chromosome
SNP array analysis [13, 14] (Table 1). Apparently in agree-ment
with this finding, another preliminary study using time-lapse
imaging found that multinucleation of 2-cell embryos
had no significant impact on subsequent implantation rates
compared to mono-nucleated embryos (47.9 % vs. 52.1 %,
respectively) [6] (Table 1).
The ability to detect multinucleation over several time
points, ensuring that this transient occurrence is not missed,
may be extremely beneficial in selection of euploid embryos.
However, while static embryo assessment using day 3 biopsy
and FISH indicates the importance of this morphologic assess-ment,
no correlative data exists from time-lapse studies using
trophectoderm biopsy. Additional studies are likely required to
validate this finding. It should also be mentioned that not all
time-lapse embryo imaging devices may be able to detect
multinucleation. While identification of multinucleation may
4. 1084 J Assist Reprod Genet (2013) 30:1081–1090
Table 1 Summary of time-lapse studies evaluating various morphokinetic events and timings and correlation to embryonic aneuploidy
Timing endpoint assessment Biopsy type Diagnosis
be feasible using brightfield imaging devices, this can only
occur if the blastomeres are in the correct focal plane, and
existing darkfield devices are limited and may not be able to
visualize these structures.
Timing of mitotic divisions
The area receiving the most recent widespread attention in
regard to finding a means of predicting embryo ploidy has
focused on the timings of early mitotic divisions. As men-tioned,
information gained from time-lapse imaging during
the first 3 mitotic divisions have clearly been shown to be
related to blastocyst formation, pregnancy and perhaps im-plantation
[17, 35, 53, 81, 82], which may infer selection of
euploid embryos.
Specifically, duration of the first mitotic division with in
14.3±6.0 min, time between first and second mitosis (2-cell
to 3-cell transition) within 11.1±2.2 h and time between the
second and third mitosis (3-cell to 4-cell transition) within
1.1±1.6 h gave the ability to predict blastocyst formation
from frozen/thawed zygotes with 94 % and 93 % sensitivity
and specificity, respectively [82]. A similar study using an-other
imaging device demonstrated that shortened timing
between the second and third mitosis related to improved
blastocyst morphologic grading [35]. This was also confirmed
by Cruz et al. [17], who, in a retrospective cohort study, also
showed that timings of early cleavage divisions correlated to
blastocyst formation and quality score [17]. As will be
discussed, there may be a relationship between blastocyst
approach
Imaging
system
Aneuploidy
correlation
Reference
morphology and ploidy, so timing of early mitotic division
may also lend insight into embryonic aneuploidy. Similarly,
time-lapse imaging revealed that division to the 5-cell stage
(48.8–56.6 h), time between the first and second mitosis
(11.9 h), time between the second and third mitosis
(<0.76 h), as well as timing to reach the 2-cell, 3-cell and 4-
cell stages correlated with implantation [53]. Again, this may
suggest selection of euploid embryos. However, blastocysts
can be aneuploid at relatively high rates, and, despite implan-tation,
aneuploidy may still be present.
Numerous preliminary publications have attempted to cor-related
timings of early cleavage cell divisions with embryo
chromosomal status with limited success. Using the Em-bryoscope
®, timings of the first mitotic division, division from
2 to 3 cells, appearance of the 4th blastomere and the third
mitotic division were recorded and resulting 76 blastocysts
biopsied and analyzed using 24 chromosome aCGH [65]
(Table 1). No significant differences were apparent between
aneuploid and euploid embryos using differences in early
cleavage timings. Another similar preliminary study using
the Embryoscope® also found no correlation between early
cleavage timing and blastocyst aneuploidy following blasto-cyst
biopsy and qPCR for all chromosomes [68] (Table 1).
Other small preliminary studies report similar non-correlation
findings of various early cleavage timings and aneuploidy
following blastocyst biopsy and various chromosomal analysis
approaches [52, 65] (Table 1). These preliminary data agree
with a recent peer-reviewed publication that examined time of
the 2nd cell division (2 to 3 cells), time of the third cell cycle
Prolonged duration of 1st cytokineses, time
between 1st and 2nd mitosis
Day 2 aCGH Eeva™ Yes [15]
1st division, 2nd division, appearance of 4th
blastomere, 3rd division
Trophectoderm aCGH Embryoscope® No [65]
PN appearance, PN disappearance, cleaving
timing, compaction, cavitation
Trophectoderm qPCR Embryoscope® No [68]
1st cytokinesis, 2nd mitotic division,
synchronicity of 3rd/4th cells
Polar body &
Trophectoderm
aCGH Eeva™ Yes [29]
Cleavage times until the 8cell stage, 2–3cell
division, 3–4cell division,
Day 3 FISH Embryoscope® No [12]
Shorter 5 to 8– cell division (3rd synchrongy
division)
Day 3 FISH Embryoscope® Yes [12]
"Optimal" timings of 2nd synchrony, time to 5-cell, 2nd cell
cycle
Day 3 FISH or aCGH Embryoscope® No [10]
Duration 1st and 2nd mitosis synchrony 2nd
& 3rd cell cycle, blastulation duration,
2cell multinucleation
Trophectoderm aCGH or SNP
array
Embryoscope® No [13]
Delayed compaction, cavitation, full blastocyst
formation
Trophectoderm aCGH or SNP
array
Embryoscope® Yes [14]
Early compaction Trophectoderm aCGH Embryoscope® Yes [52]
Syngamy, cavitation Trophectoderm aCGH Embryoscope® No [52]
First sign of fragmentation Trophectoderm aCGH Embryoscope® No [56]
5. J Assist Reprod Genet (2013) 30:1081–1090 1085
(3 to 5 cells) as well as time and synchrony of the 2nd and 3rd
cell divisions (2 to 4 cells, or, 4 to 8 cells, respectively) [13,
14]. In this study, using trophectoderm biopsy and 24 chromo-some
screening, though later morphologic timings and event
appeared to predict chromosomal status of embryos, early
cleavage timings had no correlation with aneuploidy (Table 1).
Interestingly, at least two preliminary reports and one peer-reviewed
study indicate a possible correlation between early
cleavage timings and embryo aneuploidy. Utilizing day 3
biopsy and 9 probe FISH, 122 embryos analyzed indicated
that while no difference were apparent in cleavage time to the
8-cell stage or duration or cleavage from 2 to 3-cell or 3 to 4-
cell, euploid embryos had a significant shorter time to cleavage
from the 5-cell to the 8-cell stage compared to aneuploid
embryos [12] (Table 1). Similarly, utilizing a darkfield imaging
approach and automated cell tracking system, a correlation
between timing of early mitotic events and embryo ploidy
was reported [15, 29] (Tables 1 and 2). In a preliminary study,
18 embryos were analyzed using polar body biopsy and some
using trophectoderm biopsy. Using aCGH for chromosomal
analysis, 62.5 % of embryos (5/8) that exhibited “normal”
timings of duration of first cytokinesis, time of 2nd mitosis
and synchrony of the 3rd and 4th cell appearance, were eu-ploid,
while only 40 % (4/10) with “abnormal” timings were
euploid [29]. In agreement, peer reviewed data from the same
group analyzed development of 75 human zygotes that were
monitored for 2-days with image collection at 5 min intervals.
Cleavage stage embryos were then disassembled and ploidy
determined for each blastomere via 24 chromosome aCGH. It
was determined that 75% of embryos were aneuploid. Authors
then attempted to determine if normally diagnosed embryos
displayed any unique mitotic timing characteristic compared to
the aneuploid counterparts. It was determined that aneuploid
embryos had a larger standard deviation of timings related to
the interval of the first cytokinesis, as well as time for cleavage
from the 2-cell to 3-cell and 3-cell to the 4-cell stage. It was also
determined that the degree of aneuploidy impacted cell cycle
timings. As a result, only ~30 % of aneuploid embryos fell
within the time windows of euploid embryos (14.4±4.2 min,
11.8±0.71 h, 0.96±0.84 h, respectively) (Table 2). These tim-ings
were determined to give a sensitivity and specificity of
100 % and 66 % to predict embryonic euploidy.
Importantly, though difference in imaging devices and
slight variances in cleavage timing windows due to variable
starting points or embryo sources may help explain differen-tial
outcomes between the above mentioned studies in regard
to ability to predict aneuploidy with mitotic timings, again,
an explanation may lie in the stage of the embryos biopsied
and analyzed. As with PN and multinucleation analyses,
correlations were only found in the study where cleavage
embryos were biopsied, while no correlations were found in
studies with trophectoderm biopsy.
Day 2/3 morphology
Static assessment of day 2 and day 3 fragmentation and/or
blastomere size/symmetry are common indicators used for
embryo selection for transfer. Numerous studies exist show-ing
correlation between various day 2/day 3 morphologic
parameters, such has cell number or degree of fragmentation
[8, 25, 55, 83]. However, the majority of these studies
utilized day 3 biopsy and FISH. More recent preliminary
studies have examined the correlation between morphology
and aneuploidy using 24 chromosome screening. One study
using static assessment and 46 chromosome aCGH exam-ined
452 day 3 biopsied embryos and correlated ploidy with
day 3 morphology [49]. Those embryos with less than 6 cells
at time of biopsy had higher rates of aneuploidy than those
with >6 cells (59.3 % vs. 74.35). Additionally, embryos with
>15 % fragmentation were more aneuploid that those with
<15 % (66.1 % vs. 23.6 %). Another preliminary study
examining 1915 embryos using day 3 biopsy and aCGH
found that embryos with >9cells on day 3 were more likely
to be aneuploid [45]. However, not all studies indicate an
association between cleavage morphology and aneuploidy.
One preliminary study using day 3 biopsy and 24 aCGH
found no correlation to aneuploidy with day 2 or 3 fragmen-tation
when using <10 % or 11–25 % cutoffs [79].
Complicating the association of cleavage stage morphol-ogy
to aneuploidy, it is well-known that embryo develop-ment
is a dynamic process, and cell number and degree of
fragmentation can change rapidly as fragments are extruded
or absorbed during development. Thus, if a time-lapse im-aging
system were able to refine a time window for these
Table 2 Morphokinetic data
using the Eeva™ time-lapse im-aging
system that demonstrates
early cleavage stage event tim-ings
frozen/thawed human em-bryos
may correlate to
aneuploidy
Table adapted from [15]
Chromosomal status n Duration 1st
cytokinesis (min)
Interval between 1st
& 2nd mitosis (min)
Interval between 2nd
& 3rd mitosis (min)
Normal 8 14.2±4.2 11.8±0.71 0.96±0.84
Meiotic error 9 117.2±166.5 4.0±5.2 2.0±4.3
Mitotic error 21 36.0±66.9 6.4±6.6 2.0±3.9
High mosaic 13 52.7±89.8 3.5±6.2 2.2±4.1
Low mosaic 12 17.9±16.8 9.5±5.6 1.8±3.8
6. 1086 J Assist Reprod Genet (2013) 30:1081–1090
observations and then track and incorporate these assessments
into a standardized algorithm, it may be more useful in deter-mining
embryonic aneuploidy than a subjective single time
point assessment. In fact, a recent study using the time-lapse
imaging EEVA system and day 3 biopsy to correlate early
cleavage timings with embryo ploidy indicated that embryo
fragmentation on day 2 of development may help improve
ability to detect aneuploidy embryos when used with these
mitotic timing intervals [15]. Furthermore, a large number of
aneuploid and triploid, but not euploid embryos, showed
fragmentation, though fragmentation alone offered very little
predictive ability. However, a preliminary study using the
Embryoscope® for time-lapse embryo analysis with blasto-cyst
biopsy was unable to show any correlation between the
timing of first fragmentation, appearance or degree of frag-mentation
to the chromosomal status of human blastocysts
[56] (Table 1). A similar study also using the Embryoscope®
with blastocyst biopsy and qPCR of all chromosomes also
showed no correlation between aneuploidy and blastomere
symmetry or fragmentation [68] (Table 1).
Again, similar to possible limitations previously men-tioned,
while conflicting data in the correlation of day 2/3
morphology/fragmentation may lie in the inherent variability
of the visual assessment or in the thresholds used, differing
days of biopsy (day 3 vs. blastocyst) may explain differential
findings. Additional future studies using time-lapse analysis
may attempt to determine if prior described patterns of
fragmentation [2, 3] correlate to embryonic aneuploidy, and
newly developed software that can non-subjectively track
embryo fragmentation and possibly reabsorption of frag-ments
during time-lapse imaging may further refine the
objectiveness and usefulness of this approach [15].
Compaction and blastocyst formation
In addition to the early mitotic events in embryo develop-ment
that may provide morphologic indicators of embryo
ploidy, later morphologic event may provide further insight.
Blastocyst culture is used as an additional positive selection
tool in many IVF cases. It is known that blastocysts of higher
morphological grades results in higher pregnancy and im-plantation
rates. Use of established morphological grading
standards that are known to help improve pregnancy rates
may also provide insight into chromosomal status. Indeed,
500 human blastocysts were biopsied and ploidy determined
using CGH arrays [1]. The chromosomal status was then
correlated with blastocyst morphologic grade as determined
by the Gardner grading scale. It was shown that 50 % of
hatching and hatched blastocysts (grade 5/6) were euploid
compared to only 37.5 % of grade 1/2 blastocysts. The grade
of both the ICM and TE were also correlated with aneuploi-dy,
with lower grades being more aneuploid. Various prelim-inary
reports also indicate that blastocyst development and
quality appear to be positively related to euploid status [24,
37, 39, 48, 63, 79]. These findings may help partially explain
why examination of trophectoderm biopsy and attempts to
correlate to early morphology or morphokinetic timings do
not tend to prove successful. Analysis of blastocysts may be
skewing the data by only observing a select pool of the
embryos, which tend to be more euploid. A significant
portion of aneuploid embryos may be arresting prior to
blastocyst formation. Also important to note, not all studies
indicate a correlation between blastocyst morphology and
aneuploidy and a significant portion of “poor” morphology
blastocysts can still be euploid. One preliminary study in-dicates
that blastocyst morphology had no relation to aneu-ploidy,
and that CCS resulted in 22 % of single embryo
transfer cases having an alternate embryo transferred other
than the highest graded embryo [26, 27]. As a result, these
patients had a 77 % clinical pregnancy rate.
Interestingly, a recent time-lapse publication using trophec-toderm
biopsy and CGH and SNP arrays suggests that, using
insemination as the starting point, the time to compaction
(comp) as well as time to full blastocyst formation (blast)
were significantly slower in aneuploid versus euploid embry-os
(comp: 85.1 h vs. 79.7 h; blast: 110.9 h vs. 105.9 h,
respectively). Similarly, onset of cavitation was significantly
slower in single and multiple aneuploid embryos (103.4 and
101.9 h) compared to euploid (95.1) [13, 14] (Table 3). Using
two of these variables, cavitation and blastocyst formation, a
classification model was developed with three risk categories,
with an area under the ROC curve of 0.72.
It should be noted that his delay in compaction with
aneuploidy contradicts at least one preliminary study, where
compaction was actually accelerated in aneuploid embryos
compared to euploid [52] (Table 1). No differences were
apparent when looking at rates of blastocyst expansion or
hatching between groups. Additionally conflicting data exist
regarding the ability of blastocyst formation timing to predict
aneuploidy. A preliminary report analyzing blastocysts from
53 patients were grouped into those that formed expanded
blastocyst at <110 h and those that formed >110 h [68]
(Table 1). No differences in rates of aneuploidy were appar-ent
between groups. Another study using trophectoderm
biopsy also indicated time to cavitation did not differ be-tween
aneuploid or euploid blastocysts [52] (Table 1).
Importantly, observing an adequate number of embryos,
and determining the right time window is essential in deter-mining
if timing of morphologic events offers predictive
ability with respect to aneuploidy. Additionally, reduction
in subjectivity is important, as detection of subtle differences
may be instrumental in determining aneuploidy. For exam-ple,
in determining rates of expanded blastocyst formation as
a specific time-point cutoff, more specific classification of
“expanded” may be useful, utilizing blastocoels diameter or
volume measurements to help in classification. Furthermore,
7. J Assist Reprod Genet (2013) 30:1081–1090 1087
Table 3 A. Timings from post maternal-zygotic events obtained from fresh human embryos using the Embryoscope™that that may permit prediction of
aneuploidy. B. Incorporation of collected timings and formulation of a relative risk assessment with potential predictive ability (tables adapted from [13, 14])
Chromosomal Status n Compaction (hpi) Cavitation (hpi) Blastocyst formation (hpi)
Euploid 35 79.7 (56.3–107.6) 95.1 (85.2–113.9) 105.9 (86.8–122.3)
Single aneuploid 30 80.7 103.4 (79.8–121.5) 109.2
Multiple aneuploid 28 85.1 (64.9–113.0) 101.9 (86.8–129.4) 110.9 (90.1–137.0)
Risk class n Cavitation Time (hpi) Blastocyst Formation (hpi) Incidence Probability
Low 36 <122.9 <96.2 0.36 0.37
Medium 49 <122.9 ≥96.2 0.69 0.69
High 12 ≥122.9 1.00 0.97
number of expansion/collapsing events may also prove in-sightful
if use together with other apparently predictive mor-phologic
criteria. Coupling this time of morphokinetic data
with traditional blastocyst grading may further improve any
predictive power.
Conclusion
With emerging sequencing technology and other approaches
to further reduce costs to patients, PGS/CCS may become
more affordable and easier to offer, however, the invasive
nature of biopsy still persists. It has been shown using time-lapse
imaging in mouse embryos, that removal of one blas-tomere
from a 4-cell embryo can delay blastocyst formation
and increase the number of expansion/collapse events during
blastocyst development [72, 74]. Similar effects are also
apparent following biopsy on day 3 in human embryos
[41–43]. While trophectoderm biopsy is less damaging than
biopsy on day 3, avoidance of biopsy is likely best to main-tain
embryo quality. Thus, a non-invasive means to assess
embryonic aneuploidy, such as morphokinetic timings,
would be a powerful tool.
Though a non-invasive means to assess embryonic aneu-ploidy
is appealing, conflicting data exist on the ability to use
morphologic or morphokinetic embryo grading criteria to
accurately predict chromosomal complement. This may
stem, in part, from the day of biopsy used in various studies,
as the vast majority of studies that indicate a correlation
between morphology and timing of morphologic events are
evident when using day 3 biopsy and only a few studies
indicate a correlation when utilizing trophectoderm biopsy.
With known issues of cleavage stage mosaicism and recent
data indicating improved accuracy and reliability of results
using blastocyst biopsy, the reliability of those studies using
day 3 biopsy should be examined closely.
While the advantage of determining embryonic aneuploidy
as early as possible is obvious, and use of early cleavage timings
alone would be a convenient and simplified approach,
advocating a complete move to day 3 transfer may be a bit
premature. Rather, the ability to utilize and combine multiple
morphologic endpoint assessments throughout embryo devel-opment
may further improve aneuploidy predictive ability [25].
Combining the endpoint timings from the two recent peer-reviewed
retrospective publications on morphokinetics and cor-relation
to aneuploidy, using information from both pre- and
post-MZTevents, may improve predictive ability. However, this
remains to be proven. This approach would presumably help
account for any possible chromosomal “self-correction” and
permit consideration of chromosomal contributions of the male
gamete.
Importantly, having the right time-lapse imaging system
to integrate ability to view all possible or relevant morpho-logic
parameters during fertilization and cleavage develop-ment,
while also then being able to incorporate traditional
blastocyst morphology scoring, would undoubtedly be use-ful
in refining this selection process; though confirmation of
this cumulative approach and efficacy/accuracy remains to
be demonstrated. Certainly, automated tracking and algo-rithms
would be extremely useful to be able to integrate
multiple endpoint assessments while also reducing subjec-tivity,
though this may not be an easy task.
It should be mentioned, that while these visual observation
and morphokinetics may help select euploid embryos, the accu-racy
of this approach at the moment is far from ideal. Sequenc-ing
approaches still remain the most reliable method of
assessing embryo chromosomal complement. Thus, PGS/CCS
will still undoubtedly have clinical applications. However, with
the right combination of key morphologic events and timings,
non-invasive visual observations may be accurate enough to
identify “at risk” embryos and aid in selection of those more
likely to be chromosomally normal. This may be a useful tool in
perhaps avoiding biopsy and PGS/CCS in select younger pa-tients,
who are less susceptible to rates of aneuploidy, or at least
reducing the number of embryos to be biopsied and analyzed for
all patients. Supporting this approach, a recent submission used
an aneuploidy risk model based on morphokinetic timings and
demonstrated a significant improvement in fetal heart beats and
hpi hours post-insemination
8. 1088 J Assist Reprod Genet (2013) 30:1081–1090
live-birth in the “low risk” group compared to “medium risk”
[13, 14]. Ideally, the strengths of both approaches would be
utilized, with the chromosomal status of this subset of “select”
embryos identified from time-lapse being validated using
PGS/CCS, with genetic material at the blastocyst stage, either
from trophectoderm biopsy, or perhaps with a less invasive
approach to obtain genetic material, such blastocoel fluid sam-pling
[60].
Acknowledgments The authors would like to thank Thomas “Rusty”
Pool for his critical review of this manuscript.
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