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Marc Dhont - One of the best experts on this subject based on the ideXlab platform.

  • single embryo transfer and multiple pregnancy rate reduction in ivf icsi a 5 year appraisal
    Reproductive Biomedicine Online, 2003
    Co-Authors: Petra De Sutter, J Van Der Elst, T Coetsier, Marc Dhont
    Abstract:

    One of the most problematic issues of assisted reproduction is the high incidence of multiple pregnancies, resulting from the transfer of more than one embryo. Particularly at risk are young women who have good quality embryos. The only strategy to reduce the incidence of multiple pregnancies, including twin pregnancies, after assisted reproduction is single embryo transfer (SET). In 1997, the present authors therefore introduced elective SET (eSET) in this particular target group. The proportion of eSET increased from 1.5 (1997–1998) to 17.5% (1999–2002) of all transfers. In 2002, 20% of all transfers were SET. Comparing these two periods, an overall pregnancy rate of 35 and 34% per transfer, respectively, was obtained, while the overall twinning rate dropped from 30 to 21%. The twinning rate dropped to 14% in 2002, and in the eSET group there was only one monozygotic twin. These results demonstrate that a decline in the twinning rate is feasible without a drop in overall pregnancy rates. Comparing eSET with elective double embryo transfer (eDET), it was found that ongoing pregnancy and implantation rates were the same in both groups, but the proportion of twins was clearly different. It was further observed that the mean birthweight of singleton children born after eSET was significantly higher than that after DET. This could reflect a better developmental or implantation potential of these embryos, but this finding remains to be confirmed.

  • a health economic decision analytic model comparing double with single embryo transfer in ivf icsi
    Human Reproduction, 2002
    Co-Authors: Petra De Sutter, Jan Gerris, Marc Dhont
    Abstract:

    BACKGROUND Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. METHODS A decision-analytic model comparing SET with DET was developed. Estimates were obtained from literature, national pregnancy registers and local hospital records. A sensitivity analysis was performed, using pregnancy rates from four published studies. The outcome measure was the cost per child born, calculated from IVF procedure-related, pregnancy-related and neonatal care costs. Neonatal mortality and long-term morbidity costs were not taken into account. RESULTS Independently of the pregnancy rates used, the SET cost per child born was in all instances the same as with DET, varying from EURO= 9520 (SET) versus EURO= 9511 (DET) to EURO= 12254 (SET) versus EURO= 12934 (DET). CONCLUSIONS More ART cycles are required to obtain the same numbers of children born following SET compared with DET. Because SET allows the avoidance of twins and thus diminishes pregnancy-related and neonatal care costs, there is no difference in the cost per child born between SET and DET. The real advantage of SET is the avoidance of the very high long-term costs resulting from the increased morbidity of twins after birth.

  • a health economic decision analytic model comparing double with single embryo transfer in ivf icsi
    Human Reproduction, 2002
    Co-Authors: Petra De Sutter, Jan Gerris, Marc Dhont
    Abstract:

    BACKGROUND: Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. METHODS: A decision-analytic model comparing SET with DET was developed. Estimates were obtained from literature, national pregnancy registers and local hospital records. A sensitivity analysis was performed, using pregnancy rates from four published studies. The outcome measure was the cost per child born, calculated from IVF procedure-related, pregnancy-related and neonatal care costs. Neonatal mortality and long-term morbidity costs were not taken into account. RESULTS: Independently of the pregnancy rates used, the SET cost per child born was in all instances the same as with DET, varying from C 9 520 (SET) versus C 9 511 (DET) to C 12 254 (SET) versus C 12 934 (DET). CONCLUSIONS: More ART cycles are required to obtain the same numbers of children born following SET compared with DET. Because SET allows the avoidance of twins and thus diminishes pregnancy-related and neonatal care costs, there is no difference in the cost per child born between SET and DET. The real advantage of SET is the avoidance of the very high long-term costs resulting from the increased morbidity of twins after birth.

Hannu Martikainen - One of the best experts on this subject based on the ideXlab platform.

  • elective single embryo transfer with cryopreservation improves the outcome and diminishes the costs of ivf icsi
    Human Reproduction, 2009
    Co-Authors: Zdravka Veleva, Petri Karinen, Candido Tomas, Juha S Tapanainen, Hannu Martikainen
    Abstract:

    BACKGROUND: Although elective single embryo transfer (eSET) minimizes the multiple birth rate after in vitro fertilization (IVF)/intra cytoplasmic sperm injection (ICSI), there remain concerns in many countries that it is less effective and more expensive than conventional double embryo transfer (DET). METHODS: We compared the clinical outcome achieved in the years 1995-1999, in which eSET was rarely used (4.2% of women, DET period) with that of the years 2000-2004, in which eSET was more widely used (46.2%, eSET period). In the DET period, 826 women had 1359 fresh embryo cycles followed by 589 frozen-thawed embryo transfer (FET) cycles. In the eSET period, 684 women had 1027 fresh and 683 FET cycles. The cumulative term live birth rate/woman was the primary clinical outcome measure. An incremental cost-effectiveness ratio of a term live birth was also calculated based on hospital charges and medication prices of IVF/ICSI treatment. RESULTS: The cumulative pregnancy rate/oocytes pickup (38.2 versus 33.1%, P = 0.01), cumulative live birth rate/oocytes pickup (28.0 versus 22.5%, P = 0.002) and cumulative live birth rate/woman (41.7 versus 36.6%, P = 0.04) were all higher in the eSET period than in the DET period. The cumulative multiple birth rate was significantly lower in the eSET period than in the DET period (8.9 versus 19.6%, P < 0.0001). A term live birth in the eSET period was 19 889 euros less expensive than in the DET period. CONCLUSIONS: This study shows that eSET with cryopreservation is more effective and less expensive than DET and should be adopted as a treatment of choice.

  • elective single embryo transfer in women aged 36 39 years
    Human Reproduction, 2006
    Co-Authors: Zdravka Veleva, Sirpa Vilska, Aila Tiitinen, Juha S Tapanainen, Hannu Martikainen, Christel Hydengranskog
    Abstract:

    BACKGROUND: The elective single embryo transfer policy is the only effective strategy known to minimize the risk of multiple pregnancy. However, little is known about its applicability to women older than 35 years. METHODS: Analysis was carried out on 1224 fresh IVF/ICSI cycles with embryo transfer and 828 frozen embryo transfer (FET) cycles of women aged 36-39 years. In the fresh cycles, 335 elective single top quality embryo (eSET), 110 elective single non top quality embryo (nt-eSET), 194 compulsory single embryo (cSET) and 585 double embryo transfers (DET) were carried out. RESULTS: Pregnancy rate/embryo transfer (33.1 versus 29.9%) and live birth rate (26.0 versus 21.9%) in fresh cycles did not differ significantly between the eSET and the DET groups. However, women in the eSET group had a higher cumulative pregnancy rate (54.0% versus 35.0%) and a higher cumulative live birth rate (41.8% versus 26.7%, P < 0.0001) compared with those in the DET group. The cumulative multiple birth rate in the eSET group was 1.7%, whereas in the DET group it was 16.6% (P < 0.0001). CONCLUSIONS: The eSET policy can be applied also to patients aged 36-39 years, reducing the risk of multiple birth and increasing the safety of assisted reproduction technique (ART) in this age group.

Petra De Sutter - One of the best experts on this subject based on the ideXlab platform.

  • single embryo transfer and multiple pregnancy rate reduction in ivf icsi a 5 year appraisal
    Reproductive Biomedicine Online, 2003
    Co-Authors: Petra De Sutter, J Van Der Elst, T Coetsier, Marc Dhont
    Abstract:

    One of the most problematic issues of assisted reproduction is the high incidence of multiple pregnancies, resulting from the transfer of more than one embryo. Particularly at risk are young women who have good quality embryos. The only strategy to reduce the incidence of multiple pregnancies, including twin pregnancies, after assisted reproduction is single embryo transfer (SET). In 1997, the present authors therefore introduced elective SET (eSET) in this particular target group. The proportion of eSET increased from 1.5 (1997–1998) to 17.5% (1999–2002) of all transfers. In 2002, 20% of all transfers were SET. Comparing these two periods, an overall pregnancy rate of 35 and 34% per transfer, respectively, was obtained, while the overall twinning rate dropped from 30 to 21%. The twinning rate dropped to 14% in 2002, and in the eSET group there was only one monozygotic twin. These results demonstrate that a decline in the twinning rate is feasible without a drop in overall pregnancy rates. Comparing eSET with elective double embryo transfer (eDET), it was found that ongoing pregnancy and implantation rates were the same in both groups, but the proportion of twins was clearly different. It was further observed that the mean birthweight of singleton children born after eSET was significantly higher than that after DET. This could reflect a better developmental or implantation potential of these embryos, but this finding remains to be confirmed.

  • a health economic decision analytic model comparing double with single embryo transfer in ivf icsi
    Human Reproduction, 2002
    Co-Authors: Petra De Sutter, Jan Gerris, Marc Dhont
    Abstract:

    BACKGROUND Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. METHODS A decision-analytic model comparing SET with DET was developed. Estimates were obtained from literature, national pregnancy registers and local hospital records. A sensitivity analysis was performed, using pregnancy rates from four published studies. The outcome measure was the cost per child born, calculated from IVF procedure-related, pregnancy-related and neonatal care costs. Neonatal mortality and long-term morbidity costs were not taken into account. RESULTS Independently of the pregnancy rates used, the SET cost per child born was in all instances the same as with DET, varying from EURO= 9520 (SET) versus EURO= 9511 (DET) to EURO= 12254 (SET) versus EURO= 12934 (DET). CONCLUSIONS More ART cycles are required to obtain the same numbers of children born following SET compared with DET. Because SET allows the avoidance of twins and thus diminishes pregnancy-related and neonatal care costs, there is no difference in the cost per child born between SET and DET. The real advantage of SET is the avoidance of the very high long-term costs resulting from the increased morbidity of twins after birth.

  • a health economic decision analytic model comparing double with single embryo transfer in ivf icsi
    Human Reproduction, 2002
    Co-Authors: Petra De Sutter, Jan Gerris, Marc Dhont
    Abstract:

    BACKGROUND: Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. METHODS: A decision-analytic model comparing SET with DET was developed. Estimates were obtained from literature, national pregnancy registers and local hospital records. A sensitivity analysis was performed, using pregnancy rates from four published studies. The outcome measure was the cost per child born, calculated from IVF procedure-related, pregnancy-related and neonatal care costs. Neonatal mortality and long-term morbidity costs were not taken into account. RESULTS: Independently of the pregnancy rates used, the SET cost per child born was in all instances the same as with DET, varying from C 9 520 (SET) versus C 9 511 (DET) to C 12 254 (SET) versus C 12 934 (DET). CONCLUSIONS: More ART cycles are required to obtain the same numbers of children born following SET compared with DET. Because SET allows the avoidance of twins and thus diminishes pregnancy-related and neonatal care costs, there is no difference in the cost per child born between SET and DET. The real advantage of SET is the avoidance of the very high long-term costs resulting from the increased morbidity of twins after birth.

Yufeng Chen - One of the best experts on this subject based on the ideXlab platform.

  • brief paper design of a maximally permissive liveness enforcing supervisor with a compressed supervisory structure for flexible manufacturing systems
    Automatica, 2011
    Co-Authors: Yufeng Chen
    Abstract:

    In this paper, a deadlock prevention policy for flexible manufacturing systems (FMS) is proposed, which can obtain a maximally permissive liveness-enforcing Petri net supervisor while the number of control places is compressed. By using a vector covering approach, the sets of legal markings and first-met bad markings (FBM) are reduced to two small ones, i.e., the minimal covering set of legal markings and the minimal covered set of FBM. A maximally permissive control purpose can be achieved by designing control places such that all markings in the minimal covered set of FBM are forbidden and no marking in the minimal covering set of legal markings is forbidden. An integer linear programming problem is designed to minimize the number of control places under an assumption that a control place is associated with a P-semiflow. The resulting net has the minimal number of control places on the premise that the assumption holds, and possesses all permissive states of a plant. The only problem of the proposed method is its computational complexity that makes it inapplicable to large-scale Petri net models. An FMS example from the literature is presented to illustrate the proposed method.

  • design of a maximally permissive liveness enforcing petri net supervisor for flexible manufacturing systems
    IEEE Transactions on Automation Science and Engineering, 2011
    Co-Authors: Yufeng Chen, Mohamed Khalgui, Olfa Mosbahi
    Abstract:

    Deadlock prevention plays an important role in the modeling and control of flexible manufacturing systems (FMS). This paper presents a novel and computationally efficient method to design optimal control places, and an iteration approach that only computes the reachability graph of a plant Petri net model once in order to obtain a maximally permissive liveness-enforcing supervisor for an FMS. By using a vector covering approach, a minimal covering set of legal markings and a minimal covered set of first-met bad markings (FBM) are computed. At each iteration, an FBM from the minimal covered set is selected. By solving an integer linear programming problem, a place invariant is designed to prevent the FBM from being reached and no marking in the minimal covering set of legal markings is forbidden. This process is carried out until no FBM can be reached. In order to make the considered problem computationally tractable, binary decision diagrams (BDD) are used to compute the sets of legal markings and FBM, and solve the vector covering problem to get a minimal covering set of legal markings and a minimal covered set of FBM. Finally, a number of FMS examples are presented to illustrate the proposed approaches.

Jan Gerris - One of the best experts on this subject based on the ideXlab platform.

  • a health economic decision analytic model comparing double with single embryo transfer in ivf icsi
    Human Reproduction, 2002
    Co-Authors: Petra De Sutter, Jan Gerris, Marc Dhont
    Abstract:

    BACKGROUND Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. METHODS A decision-analytic model comparing SET with DET was developed. Estimates were obtained from literature, national pregnancy registers and local hospital records. A sensitivity analysis was performed, using pregnancy rates from four published studies. The outcome measure was the cost per child born, calculated from IVF procedure-related, pregnancy-related and neonatal care costs. Neonatal mortality and long-term morbidity costs were not taken into account. RESULTS Independently of the pregnancy rates used, the SET cost per child born was in all instances the same as with DET, varying from EURO= 9520 (SET) versus EURO= 9511 (DET) to EURO= 12254 (SET) versus EURO= 12934 (DET). CONCLUSIONS More ART cycles are required to obtain the same numbers of children born following SET compared with DET. Because SET allows the avoidance of twins and thus diminishes pregnancy-related and neonatal care costs, there is no difference in the cost per child born between SET and DET. The real advantage of SET is the avoidance of the very high long-term costs resulting from the increased morbidity of twins after birth.

  • a health economic decision analytic model comparing double with single embryo transfer in ivf icsi
    Human Reproduction, 2002
    Co-Authors: Petra De Sutter, Jan Gerris, Marc Dhont
    Abstract:

    BACKGROUND: Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. METHODS: A decision-analytic model comparing SET with DET was developed. Estimates were obtained from literature, national pregnancy registers and local hospital records. A sensitivity analysis was performed, using pregnancy rates from four published studies. The outcome measure was the cost per child born, calculated from IVF procedure-related, pregnancy-related and neonatal care costs. Neonatal mortality and long-term morbidity costs were not taken into account. RESULTS: Independently of the pregnancy rates used, the SET cost per child born was in all instances the same as with DET, varying from C 9 520 (SET) versus C 9 511 (DET) to C 12 254 (SET) versus C 12 934 (DET). CONCLUSIONS: More ART cycles are required to obtain the same numbers of children born following SET compared with DET. Because SET allows the avoidance of twins and thus diminishes pregnancy-related and neonatal care costs, there is no difference in the cost per child born between SET and DET. The real advantage of SET is the avoidance of the very high long-term costs resulting from the increased morbidity of twins after birth.