Yona Barak - Academia.edu (original) (raw)
Papers by Yona Barak
Human Reproduction, Sep 1, 1994
The erbium-yttrium-aluminium-garnet (Er:YAG) laser has been applied to micromanipulation in human... more The erbium-yttrium-aluminium-garnet (Er:YAG) laser has been applied to micromanipulation in humans. It was used in the fertilization process for both subzonal insemination (SUZI) and for partial zona dissection (PZD). Laser-assisted micromanipulation achieved significantly higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), but use of the laser did not improve the PZD results (laser 14.8% versus mechanical 14%). The Er:YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80 versus 29.3%) 110 h after administration of human chorionic gonadotrophin. This technique was applied in two different centres to patients with previous invitro fertilization (IVF) failures. The implantation rate per embryo (14.4% laser-assisted hatching versus 6% control group) and the pregnancy rate per transfer (40 versus 16.2%) were improved.
Fertility and Sterility, Dec 1, 1988
Andrologia, Mar 1, 1999
The membranes of human spermatozoa contain an extremely high concentration of polyunsaturated fat... more The membranes of human spermatozoa contain an extremely high concentration of polyunsaturated fatty acids and are therefore susceptible to lipid peroxidation damage. The aim of this study was to retrospectively determine the association between the lipid peroxidation levels of washed spermatozoa, as indicated by thiobarbituric-acid-reactive substance concentration, and: (a) semen quality evaluated by basic routine, biochemical, cytological and quantitative ultramorphological analyses; (b) IVF fertilization rate. Semen samples from 45 male partners of couples who had been referred for IVF treatment due to a female infertility factor were evaluated for quality as well as for thiobarbituric-acid-reactive substance concentrations. The latter were found to have a negative correlation with total sperm count, semen volume, zinc/fructose ratio, and the integrity of sperm acrosome and axonema. It was suggested that lipid peroxidation has a deleterious effect on the ultramorphological status of the sperm cells and, thereby, on the male fertilization potential. The content of the seminal fluid, about 30% of which is produced by the prostate, may protect spermatozoa from this destructive process. A negatixre correlation was also found between thiobarbituric-acid-reactive substance concentrations and rvF fertilization rate. When the patients were subdivided into fertilizing (fertilization rate > 0%) and nonfertilizing (fertilization rate = 0%) subgroups (n = 33 and n = 12, respectively), the former exhibited significantly lower thiobarbituric-acid-reactive substance concen
Springer eBooks, 1990
The cumulus oophorus oocyte complex (OCC) is a unique structure in the mammalian female fertility... more The cumulus oophorus oocyte complex (OCC) is a unique structure in the mammalian female fertility system. The physiological role of the cumulus is to form the appropriate environment for the oocyte to develop, mature and prepare it for fertilization by the sperm. In the preovulatory stage, the cumulus exists as a compact-intact coat surrounding the oocyte. After maturation, the cumulus oophorus is expanded and transformed into a suspension of dissociated cells in a huge soft droplet of mucus, resulting in sperm-penetratable OCC.1–3
![Research paper thumbnail of Innovations In Assisted Reproduction Technology [Working Title]](https://attachments.academia-assets.com/106612918/thumbnails/1.jpg)
](IntechOpen eBooks, May 6, 2020
From 1998 to 2003, she was a member of the Faculty Scientific Advisory Board and lecturer of the ... more From 1998 to 2003, she was a member of the Faculty Scientific Advisory Board and lecturer of the MSc course for Clinical Embryology at Danube University , Krems Austria, an international program of clinical embryology in cooperation with Bourn Hall, UK and Alpha Scientists in Reproductive Medicine. In 1996, she was elected by the members of Alpha Scientists in Reproductive Medicine as an executive board member. In 1999, she became a vice president of Alpha, and in 2001, she became president and served until 2004' and is an honorary member until today. Honorary member of embryologists in Mexico, Argentina, and Italy, and a member of the Israeli National Advisory Committee of Gynecology, Embryology and Neonatology. Dr. Barak is an active scientist who has published research in the field of assisted reproductive technologies. She is a pioneer for Hyaluronate as a replacement for polyvinylpyrrolidone (PVP) in intracytoplasmic sperm injection (ICSI); intracytoplasmic morphologically selected sperm injection (IMSI) (Breakthrough paper; 2002); in vivo maturation (IVM); human oocyte vitrification in closed systems; and more. She is owner and director of Dr. Yona Barak Laboratories for fertility services, and specializes in IMSI.
Fertility and Sterility, Jun 1, 1992
Retrieval of immature oocytes from non-stimulated ovaries, followed by in vitro maturation (IVM),... more Retrieval of immature oocytes from non-stimulated ovaries, followed by in vitro maturation (IVM), was initially proposed in order to avoid side effects of gonadotropin administration. The goal is to eradicate or significantly decrease the risk of ovarian hyperstimulation syndrome (OHSS) in patients with polycystic ovary syndrome (PCOS) and to reduce drug cost and burden of patients. This technology was also proposed for treatment of normal ovulatory women, fertility preservation, or infrequent conditions as failure of oocyte to mature or repeated development of poor-quality embryos. There is no downregulation, and only a small amount of hormones are injected if at all. In vitro maturation of the oocyte procedure obtained up to 35% clinical pregnancy rate in young women, compared with in vitro fertilization (IVF) in many programs. The obstetric and perinatal outcomes of IVM cycles are comparable with IVF/ICSI cycles; therefore it may gradually substitute IVF in certain cases, as the technique continues to develop and pregnancy rates continue to increase. IVM holds great promises as an alternative to assisted reproductive technologies and may be the procedure of choice not only for infertile patients but also for obtaining oocytes for donation or fertility preservation.
Journal of in vitro fertilization and embryo transfer, Aug 1, 1991
Gamete Research, 1982
ABSTRACT The effects of luteinizing hormone (NIH-bovine LH) and progesterone on maturation in vit... more ABSTRACT The effects of luteinizing hormone (NIH-bovine LH) and progesterone on maturation in vitro of oocyte-cumulus complexes from adult proestrous rats were studied by comparing proportions of oocytes showing germinal vesicle breakdown, mucification of the cumulus oophorus, and fertilizability. Addition of either or both of the hormones to the medium in concentrations between 1.25 and 10 μg/ml during maturation had no discernible effect on germinal vesicle breakdown or on fertilization. Mucification was stimulated by LH and even more by LH plus progesterone. It was concluded that maturation in vivo is the result of concerted action of the two hormones. However, addition of LH + progesterone had no effect on the fertilizability of these oocytes. We attribute this to a relative insensitivity of the system for fertilization in vitro to subtle changes in the oocyte.
Reproductive Biomedicine Online, Feb 1, 2012
Nino Guy Cassuto is the head of the Drouot laboratory. Since 1995 he has also led the assisted re... more Nino Guy Cassuto is the head of the Drouot laboratory. Since 1995 he has also led the assisted reproduction units of two hospitals in Paris. His research fields are embryo development and male infertility. He has published national and international articles, particularly concerning sperm morphology. He continues to pursue his interests in early embryo development with a particular emphasis on the role of spermatozoa.
Fertility and Sterility, Sep 1, 2009
correlation with peak estradiol level (r¼-0.2, p¼0.04). Donors' BMI had a positive correlation wi... more correlation with peak estradiol level (r¼-0.2, p¼0.04). Donors' BMI had a positive correlation with the recipients' BMI (r¼0.26, p<0.01) and the number of embryos transferred (r¼0.37, p<0.01). Donors' BMI had no effect on the length of stimulation, gonadotropin use, number of oocytes retrieved, embryo quality, pregnancy rate, and birth weight. CONCLUSIONS: Oocyte donor BMI demonstrates no negative impact on live birth rates in donor-recipient IVF cycles. However, it is noted that overweight and obese donors are older, which may result in an increase in the number of embryos transferred to the recipients.
InTech eBooks, Jun 13, 2018
Routine sperm parameters are used to evaluate fertility potential of the male partner. Since the ... more Routine sperm parameters are used to evaluate fertility potential of the male partner. Since the introduction of intracytoplasmic sperm injection (ICSI), it seems that the importance of routine parameters of sperm morphology has decreased in the field of assisted reproduction. ICSI has facilitated to achieve fertilization, embryo development, and pregnancies, from the treatment of males with poor-quality spermatozoa. Morphology is the only criteria for sperm aspiration during ICSI. Routine criteria are based on the raw ejaculatestained sperm cells. Thus, it is important to score and aspirate a good-quality motile spermatozoon, which will contribute to the quality of the developing embryo after ICSI, in real time of the procedure. In ICSI, assessment of sperm morphology is limited due to the low magnification (200 × 400×) and concomitant low resolution. By using intracytoplasmic morphologically selected sperm injection (IMSI), it was demonstrated that a spermatozoon with normal morphology, and more precisely normal nucleus, might affect the incidence of pregnancy. Although the usage of IMSI is currently wider, it is necessary to standardize which sperm to aspirate, due to criteria based on accumulating data. Correlation to DNA integrity, embryo development in vitro, female age, male age, or the routine use of IMSI for all cases are raised in order to maximize the efficiency of IMSI technology.
Fertility and Sterility, Nov 1, 2009
Objective: To understand the correlation between normalcy of the sperm, fertilization, and early ... more Objective: To understand the correlation between normalcy of the sperm, fertilization, and early embryo development, and to establish a detailed classification scoring scale for the individual spermatozoon with the highest predictive fertilizing potential in real time during intracytoplasmic sperm injection (ICSI). Design: A retrospective and analysis. Setting: Laboratory Drouot. Patient(s): 27 couples with male factor infertility referred for ICSI treatment. Intervention(s): Before ICSI, motile spermatozoa were scored after aspiration. Main Outcome Measure(s): Oocyte fertilization, embryo development and morphology, outcome of scored motile injected spermatozoa. Result(s): Our suggested formula is (Normal head score ¼ 2) þ (Lack of vacuole score ¼ 3) þ (Normal base score ¼ 1) ¼ (Total score ¼ 6) for a morphologic ''normal top'' spermatozoon, calculated with the major criteria affecting the outcome of ICSI. We take into account the normalcy of head size and shape, the base of the head, and the lack of vacuoles. Our scoring of three classes of injected spermatozoa revealed a statistically significant difference in fertilization rate: 39 out of 46 (84%), 94 out of 128 (73%), and 27 out of 44 (61%), respectively. Our examination of the contribution of maternal age in correlation to sperm score revealed a distinction between oocytes originating from women younger than 30 years and oocytes from women aged 30 years and older. Conclusion(s): Our suggested classification provides allows the best spermatozoon to be chosen for ICSI, particularly for oocytes from women aged 30 years and older.
Fertility and Sterility, Sep 1, 2008
Fertility and Sterility, Sep 1, 2001
The technique of intracytoplasmic sperm injection (ICSI) requires mechanical immobilization of th... more The technique of intracytoplasmic sperm injection (ICSI) requires mechanical immobilization of the sperm that are to be injected; damage thus caused to the sperm membrane is considered to be necessary to activate the sperm for fertilization. Mechanical immobilization and the injection procedure are facilitated by introducing the sperm into a viscous medium that will hinder motility: a solution of polyvinylpyrrolidone (PVP) has been used successfully for this purpose. PVP is an artificial polymer, which has been regarded as chemically inert, although adverse effects have been reported as a result of its use both in vivo and in vitro. Therefore, the use of hyaluronate, the natural component of the extracellular matrix of the cumulus-oocyte complex, was investigated as a replacement for PVP during ICSI. A solution of hyaluronate was found to be as effective as PVP in facilitating the injection procedure, its effect on sperm motility was readily reversible, and its use did not affect the outcome of the treatment cycles in terms of fertilization, pregnancy and live birth rates. Every attempt should be made to eliminate artificial factors in assisted reproductive procedures. Hyaluronate, a natural and readily degradable glycosaminoglycan can be used as a substitute for the artificial PVP polymer without jeopardising the outcome of the treatment cycle.
Intra-Cytoplasmic Sperm Injection (ICSI) in humans was first introduced in 1992. ICSI enabled to ... more Intra-Cytoplasmic Sperm Injection (ICSI) in humans was first introduced in 1992. ICSI enabled to achieve fertilization, embryo development and pregnancies. It seemed that the importance of routine parameters of sperm morphology decreased in the field of assisted reproduction. However, one of the main concerns in ICSI is the aspiration of good-quality spermatozoa for microinjection into an oocyte. Practically, the injected spermatozoa are randomly chosen and their selection is based on rough morphologic aspects and motility. Sperm morphology is the only criteria for sperm aspiration during ICSI. Routine sperm criteria are based on the raw ejaculate stained sperm cells. Thus, it is important to score and aspirate a good quality motile spermatozoon, which will contribute to the quality of the developing embryo after ICSI, in real time of the procedure. In ICSI, assessment of sperm morphology is limited due to the low magnification (200 X-400 X) and concomitant low resolution. It has been demonstrated that by using intra-cytoplasmic morphologically selected sperm injected, a spermatozoon with normal morphology, and more precisely normal nucleus, might affect the incidence of pregnancy. Although the usage of Intracytoplasmic Morphologically selected Sperm Injection (IMSI) is currently wider, it is necessary to standardize which sperm to aspirate, due to criteria based on accumulating data. Moreover, the benefits of IMSI could be noticeable in cases of patients with repeated implantation failures, severe male factor infertility and advanced paternal and maternal age. The magnified on screen image obtained in IMSI, is a combination of the magnification of the objective, the camera adapter, ratio between the diagonal screen size in mm, diagonal of the camera chip size in mm and internal magnification of the microscope. Final values obtained (up to X 6000 and more) is the amplification of the surface of the sperm cell image, not observed by the routine X 200400 in ICSI, due to objective limitations of the human eyes. IMSI is still considered as a controversy technical and laboratory procedure, however, it seems to become a promising procedure in terms of improving the outcome of ICSI treatments.
Reproductive Biomedicine Online, May 1, 2014
Posters S5 tulation and implantation and therefore should be used as a de-selection criteria. How... more Posters S5 tulation and implantation and therefore should be used as a de-selection criteria. However, there is no evidence from this data for de-selecting D2+ embryos.
Human Reproduction, Sep 1, 1994
The erbium-yttrium-aluminium-garnet (Er:YAG) laser has been applied to micromanipulation in human... more The erbium-yttrium-aluminium-garnet (Er:YAG) laser has been applied to micromanipulation in humans. It was used in the fertilization process for both subzonal insemination (SUZI) and for partial zona dissection (PZD). Laser-assisted micromanipulation achieved significantly higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), but use of the laser did not improve the PZD results (laser 14.8% versus mechanical 14%). The Er:YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80 versus 29.3%) 110 h after administration of human chorionic gonadotrophin. This technique was applied in two different centres to patients with previous invitro fertilization (IVF) failures. The implantation rate per embryo (14.4% laser-assisted hatching versus 6% control group) and the pregnancy rate per transfer (40 versus 16.2%) were improved.
Fertility and Sterility, Dec 1, 1988
Andrologia, Mar 1, 1999
The membranes of human spermatozoa contain an extremely high concentration of polyunsaturated fat... more The membranes of human spermatozoa contain an extremely high concentration of polyunsaturated fatty acids and are therefore susceptible to lipid peroxidation damage. The aim of this study was to retrospectively determine the association between the lipid peroxidation levels of washed spermatozoa, as indicated by thiobarbituric-acid-reactive substance concentration, and: (a) semen quality evaluated by basic routine, biochemical, cytological and quantitative ultramorphological analyses; (b) IVF fertilization rate. Semen samples from 45 male partners of couples who had been referred for IVF treatment due to a female infertility factor were evaluated for quality as well as for thiobarbituric-acid-reactive substance concentrations. The latter were found to have a negative correlation with total sperm count, semen volume, zinc/fructose ratio, and the integrity of sperm acrosome and axonema. It was suggested that lipid peroxidation has a deleterious effect on the ultramorphological status of the sperm cells and, thereby, on the male fertilization potential. The content of the seminal fluid, about 30% of which is produced by the prostate, may protect spermatozoa from this destructive process. A negatixre correlation was also found between thiobarbituric-acid-reactive substance concentrations and rvF fertilization rate. When the patients were subdivided into fertilizing (fertilization rate > 0%) and nonfertilizing (fertilization rate = 0%) subgroups (n = 33 and n = 12, respectively), the former exhibited significantly lower thiobarbituric-acid-reactive substance concen
Springer eBooks, 1990
The cumulus oophorus oocyte complex (OCC) is a unique structure in the mammalian female fertility... more The cumulus oophorus oocyte complex (OCC) is a unique structure in the mammalian female fertility system. The physiological role of the cumulus is to form the appropriate environment for the oocyte to develop, mature and prepare it for fertilization by the sperm. In the preovulatory stage, the cumulus exists as a compact-intact coat surrounding the oocyte. After maturation, the cumulus oophorus is expanded and transformed into a suspension of dissociated cells in a huge soft droplet of mucus, resulting in sperm-penetratable OCC.1–3
IntechOpen eBooks, May 6, 2020
From 1998 to 2003, she was a member of the Faculty Scientific Advisory Board and lecturer of the ... more From 1998 to 2003, she was a member of the Faculty Scientific Advisory Board and lecturer of the MSc course for Clinical Embryology at Danube University , Krems Austria, an international program of clinical embryology in cooperation with Bourn Hall, UK and Alpha Scientists in Reproductive Medicine. In 1996, she was elected by the members of Alpha Scientists in Reproductive Medicine as an executive board member. In 1999, she became a vice president of Alpha, and in 2001, she became president and served until 2004' and is an honorary member until today. Honorary member of embryologists in Mexico, Argentina, and Italy, and a member of the Israeli National Advisory Committee of Gynecology, Embryology and Neonatology. Dr. Barak is an active scientist who has published research in the field of assisted reproductive technologies. She is a pioneer for Hyaluronate as a replacement for polyvinylpyrrolidone (PVP) in intracytoplasmic sperm injection (ICSI); intracytoplasmic morphologically selected sperm injection (IMSI) (Breakthrough paper; 2002); in vivo maturation (IVM); human oocyte vitrification in closed systems; and more. She is owner and director of Dr. Yona Barak Laboratories for fertility services, and specializes in IMSI.
Fertility and Sterility, Jun 1, 1992
Retrieval of immature oocytes from non-stimulated ovaries, followed by in vitro maturation (IVM),... more Retrieval of immature oocytes from non-stimulated ovaries, followed by in vitro maturation (IVM), was initially proposed in order to avoid side effects of gonadotropin administration. The goal is to eradicate or significantly decrease the risk of ovarian hyperstimulation syndrome (OHSS) in patients with polycystic ovary syndrome (PCOS) and to reduce drug cost and burden of patients. This technology was also proposed for treatment of normal ovulatory women, fertility preservation, or infrequent conditions as failure of oocyte to mature or repeated development of poor-quality embryos. There is no downregulation, and only a small amount of hormones are injected if at all. In vitro maturation of the oocyte procedure obtained up to 35% clinical pregnancy rate in young women, compared with in vitro fertilization (IVF) in many programs. The obstetric and perinatal outcomes of IVM cycles are comparable with IVF/ICSI cycles; therefore it may gradually substitute IVF in certain cases, as the technique continues to develop and pregnancy rates continue to increase. IVM holds great promises as an alternative to assisted reproductive technologies and may be the procedure of choice not only for infertile patients but also for obtaining oocytes for donation or fertility preservation.
Journal of in vitro fertilization and embryo transfer, Aug 1, 1991
Gamete Research, 1982
ABSTRACT The effects of luteinizing hormone (NIH-bovine LH) and progesterone on maturation in vit... more ABSTRACT The effects of luteinizing hormone (NIH-bovine LH) and progesterone on maturation in vitro of oocyte-cumulus complexes from adult proestrous rats were studied by comparing proportions of oocytes showing germinal vesicle breakdown, mucification of the cumulus oophorus, and fertilizability. Addition of either or both of the hormones to the medium in concentrations between 1.25 and 10 μg/ml during maturation had no discernible effect on germinal vesicle breakdown or on fertilization. Mucification was stimulated by LH and even more by LH plus progesterone. It was concluded that maturation in vivo is the result of concerted action of the two hormones. However, addition of LH + progesterone had no effect on the fertilizability of these oocytes. We attribute this to a relative insensitivity of the system for fertilization in vitro to subtle changes in the oocyte.
Reproductive Biomedicine Online, Feb 1, 2012
Nino Guy Cassuto is the head of the Drouot laboratory. Since 1995 he has also led the assisted re... more Nino Guy Cassuto is the head of the Drouot laboratory. Since 1995 he has also led the assisted reproduction units of two hospitals in Paris. His research fields are embryo development and male infertility. He has published national and international articles, particularly concerning sperm morphology. He continues to pursue his interests in early embryo development with a particular emphasis on the role of spermatozoa.
Fertility and Sterility, Sep 1, 2009
correlation with peak estradiol level (r¼-0.2, p¼0.04). Donors' BMI had a positive correlation wi... more correlation with peak estradiol level (r¼-0.2, p¼0.04). Donors' BMI had a positive correlation with the recipients' BMI (r¼0.26, p<0.01) and the number of embryos transferred (r¼0.37, p<0.01). Donors' BMI had no effect on the length of stimulation, gonadotropin use, number of oocytes retrieved, embryo quality, pregnancy rate, and birth weight. CONCLUSIONS: Oocyte donor BMI demonstrates no negative impact on live birth rates in donor-recipient IVF cycles. However, it is noted that overweight and obese donors are older, which may result in an increase in the number of embryos transferred to the recipients.
InTech eBooks, Jun 13, 2018
Routine sperm parameters are used to evaluate fertility potential of the male partner. Since the ... more Routine sperm parameters are used to evaluate fertility potential of the male partner. Since the introduction of intracytoplasmic sperm injection (ICSI), it seems that the importance of routine parameters of sperm morphology has decreased in the field of assisted reproduction. ICSI has facilitated to achieve fertilization, embryo development, and pregnancies, from the treatment of males with poor-quality spermatozoa. Morphology is the only criteria for sperm aspiration during ICSI. Routine criteria are based on the raw ejaculatestained sperm cells. Thus, it is important to score and aspirate a good-quality motile spermatozoon, which will contribute to the quality of the developing embryo after ICSI, in real time of the procedure. In ICSI, assessment of sperm morphology is limited due to the low magnification (200 × 400×) and concomitant low resolution. By using intracytoplasmic morphologically selected sperm injection (IMSI), it was demonstrated that a spermatozoon with normal morphology, and more precisely normal nucleus, might affect the incidence of pregnancy. Although the usage of IMSI is currently wider, it is necessary to standardize which sperm to aspirate, due to criteria based on accumulating data. Correlation to DNA integrity, embryo development in vitro, female age, male age, or the routine use of IMSI for all cases are raised in order to maximize the efficiency of IMSI technology.
Fertility and Sterility, Nov 1, 2009
Objective: To understand the correlation between normalcy of the sperm, fertilization, and early ... more Objective: To understand the correlation between normalcy of the sperm, fertilization, and early embryo development, and to establish a detailed classification scoring scale for the individual spermatozoon with the highest predictive fertilizing potential in real time during intracytoplasmic sperm injection (ICSI). Design: A retrospective and analysis. Setting: Laboratory Drouot. Patient(s): 27 couples with male factor infertility referred for ICSI treatment. Intervention(s): Before ICSI, motile spermatozoa were scored after aspiration. Main Outcome Measure(s): Oocyte fertilization, embryo development and morphology, outcome of scored motile injected spermatozoa. Result(s): Our suggested formula is (Normal head score ¼ 2) þ (Lack of vacuole score ¼ 3) þ (Normal base score ¼ 1) ¼ (Total score ¼ 6) for a morphologic ''normal top'' spermatozoon, calculated with the major criteria affecting the outcome of ICSI. We take into account the normalcy of head size and shape, the base of the head, and the lack of vacuoles. Our scoring of three classes of injected spermatozoa revealed a statistically significant difference in fertilization rate: 39 out of 46 (84%), 94 out of 128 (73%), and 27 out of 44 (61%), respectively. Our examination of the contribution of maternal age in correlation to sperm score revealed a distinction between oocytes originating from women younger than 30 years and oocytes from women aged 30 years and older. Conclusion(s): Our suggested classification provides allows the best spermatozoon to be chosen for ICSI, particularly for oocytes from women aged 30 years and older.
Fertility and Sterility, Sep 1, 2008
Fertility and Sterility, Sep 1, 2001
The technique of intracytoplasmic sperm injection (ICSI) requires mechanical immobilization of th... more The technique of intracytoplasmic sperm injection (ICSI) requires mechanical immobilization of the sperm that are to be injected; damage thus caused to the sperm membrane is considered to be necessary to activate the sperm for fertilization. Mechanical immobilization and the injection procedure are facilitated by introducing the sperm into a viscous medium that will hinder motility: a solution of polyvinylpyrrolidone (PVP) has been used successfully for this purpose. PVP is an artificial polymer, which has been regarded as chemically inert, although adverse effects have been reported as a result of its use both in vivo and in vitro. Therefore, the use of hyaluronate, the natural component of the extracellular matrix of the cumulus-oocyte complex, was investigated as a replacement for PVP during ICSI. A solution of hyaluronate was found to be as effective as PVP in facilitating the injection procedure, its effect on sperm motility was readily reversible, and its use did not affect the outcome of the treatment cycles in terms of fertilization, pregnancy and live birth rates. Every attempt should be made to eliminate artificial factors in assisted reproductive procedures. Hyaluronate, a natural and readily degradable glycosaminoglycan can be used as a substitute for the artificial PVP polymer without jeopardising the outcome of the treatment cycle.
Intra-Cytoplasmic Sperm Injection (ICSI) in humans was first introduced in 1992. ICSI enabled to ... more Intra-Cytoplasmic Sperm Injection (ICSI) in humans was first introduced in 1992. ICSI enabled to achieve fertilization, embryo development and pregnancies. It seemed that the importance of routine parameters of sperm morphology decreased in the field of assisted reproduction. However, one of the main concerns in ICSI is the aspiration of good-quality spermatozoa for microinjection into an oocyte. Practically, the injected spermatozoa are randomly chosen and their selection is based on rough morphologic aspects and motility. Sperm morphology is the only criteria for sperm aspiration during ICSI. Routine sperm criteria are based on the raw ejaculate stained sperm cells. Thus, it is important to score and aspirate a good quality motile spermatozoon, which will contribute to the quality of the developing embryo after ICSI, in real time of the procedure. In ICSI, assessment of sperm morphology is limited due to the low magnification (200 X-400 X) and concomitant low resolution. It has been demonstrated that by using intra-cytoplasmic morphologically selected sperm injected, a spermatozoon with normal morphology, and more precisely normal nucleus, might affect the incidence of pregnancy. Although the usage of Intracytoplasmic Morphologically selected Sperm Injection (IMSI) is currently wider, it is necessary to standardize which sperm to aspirate, due to criteria based on accumulating data. Moreover, the benefits of IMSI could be noticeable in cases of patients with repeated implantation failures, severe male factor infertility and advanced paternal and maternal age. The magnified on screen image obtained in IMSI, is a combination of the magnification of the objective, the camera adapter, ratio between the diagonal screen size in mm, diagonal of the camera chip size in mm and internal magnification of the microscope. Final values obtained (up to X 6000 and more) is the amplification of the surface of the sperm cell image, not observed by the routine X 200400 in ICSI, due to objective limitations of the human eyes. IMSI is still considered as a controversy technical and laboratory procedure, however, it seems to become a promising procedure in terms of improving the outcome of ICSI treatments.
Reproductive Biomedicine Online, May 1, 2014
Posters S5 tulation and implantation and therefore should be used as a de-selection criteria. How... more Posters S5 tulation and implantation and therefore should be used as a de-selection criteria. However, there is no evidence from this data for de-selecting D2+ embryos.