Embryo Transfer Strategy Research Articles

Long term costs and effects of reducing the number of twin pregnancies in IVF by single embryo transfer: the TwinSing study

BackgroundPregnancies induced by in vitro fertilisation (IVF) often result in twin gestations, which are associated with both maternal and perinatal complications. An effective way to reduce the number of IVF twin pregnancies is to decrease the number of embryos transferred from two to one. The interpretation of current studies is limited because they used live birth as outcome measure and because they applied limited time horizons. So far, research on long-term outcomes of IVF twins and singletons is scarce and inconclusive. The objective of this study is to investigate the short (1-year) and long-term (5 and 18-year) costs and health outcomes of IVF singleton and twin children and to consider these in estimating the cost-effectiveness of single embryo transfer compared with double embryo transfer, from a societal and a healthcare perspective.Methods/DesignA multi-centre cohort study will be performed, in which IVF singletons and IVF twin children born between 2003 and 2005 of whom parents received IVF treatment in one of the five participating Dutch IVF centres, will be compared. Data collection will focus on children at risk of health problems and children in whom health problems actually occurred. First year of life data will be collected in approximately 1,278 children (619 singletons and 659 twin children). Data up to the fifth year of life will be collected in approximately 488 children (200 singletons and 288 twin children). Outcome measures are health status, health-related quality of life and costs. Data will be obtained from hospital information systems, a parent questionnaire and existing registries. Furthermore, a prognostic model will be developed that reflects the short and long-term costs and health outcomes of IVF singleton and twin children. This model will be linked to a Markov model of the short-term cost-effectiveness of single embryo transfer strategies versus double embryo transfer strategies to enable the calculation of the long-term cost-effectiveness.DiscussionThis is, to our knowledge, the first study that investigates the long-term costs and health outcomes of IVF singleton and twin children and the long-term cost-effectiveness of single embryo transfer strategies versus double embryo transfer strategies.

Study of the best embryo transfer strategy in frozen-thawed embryo transfer cycle

To study the relationship of the number and quality of embryos transferred with clinical pregnancy rate and multiple pregnancy rate in frozen-thawed embryo transfer (FET) cycle. Retrospective analysis of the clinical data of 995 FET cycles. Patients were stratified as age < 35 or > or = 35, Both groups' clinical pregnancy rate and multiple pregnancy rate were compared according to the number of embryos and high-quality embryos transferred. (1) The clinical pregnancy rates were 50.0%, 56.6% and 56.5%, and twin pregnancy rates were 6.3%, 43.8% and 30.6% respectively in < 35 group when one, two or three embryos were transferred. There is not any significantly statistic difference among these subgroups (P > 0.05). However, the twin pregnancy rate in one-embryo transferred subgroup was significantly lower than that of two-embryo transferred subgroup (P < 0.05). Moreover, the clinical pregnancy rate was not different among single high-quality embryo transferred subgroup and other high-quality embryo transferred subgroups, the multiple pregnancy rate was lower than the others. (2) The clinical pregnancy rates were 0, 47.3% and 53.8%, and twin pregnancy rates were 0, 25.7% and 25.7% respectively in > or = 35 group when one, two or three embryos were transferred. The clinical pregnancy rate and twin pregnancy rate between two-embryo and three-embryo transferred subgroups were not significantly different (P > 0.05). Moreover, the clinical pregnancy rate was not different among two-embryo transferred containing one high-quality embryo subgroup and other high-quality embryo transferred subgroups, the multiple pregnancy rate was lower than the others. There is a close relationship between the number and quality of embryos transferred and clinical pregnancy rate, multiple pregnancy rate in FET cycles. For the patient aged < 35, we recommend performing single high-quality embryo transfer in order to reduce the multiple pregnancy. For the patient aged > or = 35, two-embryo transfer containing one high-quality embryo is enough to obtain a satisfied clinical pregnancy rate and an acceptable multiple pregnancy rate.

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Cost‐effectiveness analysis of different embryo transfer strategies in England

The objective of this study was to assess the cost-effectiveness of different embryo transfer strategies for a single cycle when two embryos are available, and taking the NHS cost perspective. Cost-effectiveness model. Five in vitro fertilisation (IVF) centres in England between 2003/04 and 2004/05. Women with two embryos available for transfer in three age groups (<30, 30-35 and 36-39 years). A decision analytic model was constructed using observational data collected from a sample of fertility centres in England. Costs and adverse outcomes are estimated up to 5 years after the birth. Incremental cost per live birth was calculated for different embryo transfer strategies and for three separate age groups: less than 30, 30-35 and 36-39 years. Premature birth, neonatal intensive care unit admissions and days, cerebral palsy and incremental cost-effectiveness ratios. Single fresh embryo transfer (SET) plus frozen single embryo transfer (fzSET) is the more costly in terms of IVF costs, but the lower rates of multiple births mean that in terms of total costs, it is less costly than double embryo transfer (DET). Adverse events increase when moving from SET to SET+fzSET to DET. The probability of SET+fzSET being cost-effective decreases with age. When SET is included in the analysis, SET+fzSET no longer becomes a cost-effective option at any threshold value for all age groups studied. The analyses show that the choice of embryo transfer strategy is a function of four factors: the age of the mother, the relevance of the SET option, the value placed on a live birth and the relative importance placed on adverse outcomes. For each patient group, the choice of strategy is a trade-off between the value placed on a live birth and cost.

Preferences of subfertile women regarding elective single embryo transfer: additional in vitro fertilization cycles are acceptable, lower pregnancy rates are not

With identical pregnancy rates after elective single embryo transfer (ET) and double ET strategies consisting of three cycles of IVF or intracytoplasmic sperm injection (ICSI) plus transfers of thawed/frozen embryos if available, 46% of the women undergoing IVF/ICSI favor elective single ET. If elective single ET lowers pregnancy chances with 1%, 3%, or 5%, the percentage of women preferring elective single ET drops to 34%, 24%, and 15%, respectively. If four, five, or six cycles with elective single ET are needed to match the success rate of three cycles with double ET, the percentage of women with a preference for elective single ET drops from 46% to 40%, 36%, and 35% respectively.

Five years of single embryo transfer with anonymous and non-anonymous oocyte donation

Single embryo transfer (SET) has been the main embryo transfer strategy in the oocyte donation programme at the authors' clinic since 2000. The primary aim of this study was to evaluate the effect of SET on the clinical outcome in an unselected group of oocyte recipients. A retrospective analysis of the outcome in 142 recipient cycles (116 from anonymous donors; 26 from known donors) was performed. The oocytes from each anonymous donor were shared between two recipients if at least 10 oocytes were obtained. The proportion of SET of all fresh transfers was 77.3%. The clinical pregnancy rate (CPR) was 43.2% and the delivery rate 31.1% per embryo transfer. The outcome was similar in recipients undergoing anonymous and non-anonymous donation. The delivery rates were similar after SET (30.4%) or double embryo transfer (DET) (33.3%), whereas the twin rate was 0% after SET and 40% after DET. The implantation rate was significantly better (P < 0.01) with good-quality embryos (54.7%) compared with non-optimal embryos (27.1%). Of 152 frozen–thawed embryo transfer cycles, 78.9% were SET. The CPR was 28.3% and the twin rate was 7.1%. In fresh oocyte donation cycles, elective SET can be recommended if the embryo quality is considered good, and always if there is a contraindication for twin pregnancy.

Prevention of multiple pregnancies after IVF in women 38 and older: a randomized study

The objective of this study was to answer the question of whether a double instead of triple embryo transfer strategy in patients over 38 years would substantially reduce the number of multiple pregnancies while maintaining the chance of a term live birth at an acceptable level. A randomized controlled two-centre trial was performed. Forty-five patients, 38 years or older, were randomized. Double embryo transfer over a maximum of four cycles (DET group) or triple embryo transfer over a maximum of three cycles (TET group) was performed. The cumulative term live birth rate was 47.3% after four cycles in the DET group and 40.5% after three cycles in the TET group. The difference between the DET and the TET group was 6.8% in favour of the DET group (95% CI −25 to 38). The multiple pregnancy rates in the DET and TET group were 0% (95% CI 0 to 24) and 30% (95% CI 7 to 65) respectively ( P = 0.05). In the DET patients, the mean number of treatment cycles was 2.9 compared with 2.1 in the TET group ( P = 0.01). In women of 38 years and older, double embryo transfer after IVF may result in similar cumulative term live birth rates compared with triple embryo transfer, provided that a higher number of treatment cycles is accepted.

Impact of a restriction in the number of embryos transferred on the multiple pregnancy rate

Objective To study the impact of the introduction of reimbursement of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) laboratory costs in Belgium which is linked to an embryo transfer strategy leading to prevention of multiple pregnancies. The impact on the incidence of multiple and twin pregnancy rate as well as on ongoing pregnancy rate in our centre is calculated. Study design Observational cohort study of all patients in the first year (July 1, 2003–June 30, 2004) since the implementation of the law and comparison of ongoing pregnancy rate and multiple pregnancy rate of our centre with Belgian data. Results Our results of one year of IVF/ICSI since reimbursement of laboratory costs show a total conception rate of 42.2% with 29.7% ongoing pregnancies beyond 25 weeks amenorrhea. The multiple pregnancy rate was 8.5% including five monozygotic twin pregnancies. These data show an important decline of multiple pregnancy rate when compared to Belgian data (2002) with 24.4% multiple pregnancy rate in the year prior to reimbursement. Conclusion The introduction of reimbursement of IVF/ICSI laboratory costs coupled to a restriction in the number of embryos for transfer has reached the goal of halving the multiple pregnancy rate since its introduction while maintaining an optimal ongoing pregnancy rate.

Randomized single versus double embryo transfer: obstetric and paediatric outcome and a cost-effectiveness analysis

Transfer of several embryos after IVF results in a high multiple birth rate associated with increased morbidity and high costs for the neonatal care. In a previous randomized trial we demonstrated that a single embryo transfer (SET) strategy, including one fresh single embryo transfer and, if no live birth, one additional frozen-thawed SET, resulted in a live-birth rate that was not substantially lower than after double embryo transfer (DET) but markedly reduced the multiple birth rate. We compared costs for maternal health care and productivity losses and paediatric costs for the SET and DET strategies. In addition, maternal and paediatric outcomes between the two groups were compared. The SET strategy resulted in lower average total costs from treatment until 6 months after delivery. There were a few more deliveries with at least one live-born child in the DET group. The incremental cost per extra delivery in the DET alternative was high, 71 940. The rates of prematurely born and low birthweight children were significantly lower with the SET strategy. There were also markedly fewer maternal and paediatric complications in the SET group. The SET strategy is superior to the DET strategy, when number of deliveries with at least one live-born child, incremental cost-effectiveness ratio and maternal and paediatric complications are taken into consideration. The findings do not support continuing transfers of two embryos in this group of patients.

Outcome of assisted reproductive technologies after different embryo transfer strategies

The outcomes of 1028 assisted reproductive technology cycles were studied retrospectively, considering two different periods of embryo transfer. In the first period, 262 cycles in women <36 years old were studied, in which three embryos were transferred, followed by 157 cycles in women ≥36 years, in which four embryos were transferred. In the second period, 332 cycles were evaluated in women <36 years and 277 cycles in women ≥36 years old, reducing the number of embryos transferred to two and three respectively. Embryos were only scored morphologically, and the best embryos were chosen for transfer. In the first period, in women <36 years old, a clinical pregnancy rate of 55.7% was achieved, compared with 42.5% in the second period ( P < 0.01). In women ≥36 years old, the first period of embryo transfer showed a clinical pregnancy rate of 39.5%, compared with 28.5% in the second period ( P < 0.01). The number of twin pregnancies in the three groups of patients in whom one to four embryos were transferred was not significantly different (24.2, 28.4, 24.8%). It is concluded that even with the biases induced by a retrospective study, the reduction in the number of embryos transferred, from three to two in women <36 years of age, and from four to three in women ≥36 years of age, without any selection other than pre-transfer morphological score, adversely affects the outcome of treatment, without a significant reduction in twin gestation rate. Other strategies are to be implemented in gametes and embryo selection, and patients must be aware that, even with a reduction in pregnancy rate, the goal is to achieve a high cumulative pregnancy rate, reducing the complications induced by multiple pregnancies.

Embryo development and establishment of pregnancy after embryo transfer in pigs: coping with limitations in the availability of viable embryos

Embryo transfer and pregnancy maintenance strategies in pigs were evaluated with reference to situations in which limited numbers of viable embryos or micromanipulated embryos are available, such as pig cloning. Development of embryos with compromised zona pellucida was compared with development of embryos with intact zona pellucida. Micromanipulation had no effect on blastocyst production rates after development in vivo or in vitro, but development in vivo improved the number of embryos reaching the blastocyst stage. Transfer of embryos with compromised zona pellucida resulted in live piglets. Several hormone treatments to maintain pregnancy were tested in a model in which three embryos were transferred into unmated recipient gilts, compared with transfer of three embryos into mated recipients. None of the hormonal treatments resulted in pregnancy rates of more than 25% at term and no more than 9% of transferred embryos survived, in comparison with 50% of the mated recipients successfully carrying 25% of transferred embryos. Lastly, the developmental potential of parthenogenetic embryos was assessed and 62% of transferred embryos resulted in pregnancies, none of which continued beyond day 55 of gestation. After co-transfer of three fertilized embryos with 55-60 parthenogenetic embryos into each of six recipients, two live piglets were delivered. The results from the present study indicate that transfer of zona pellucida compromised embryos can yield litters of normal piglets. In addition, it was demonstrated in a model system involving the transfer of three fertilized embryos into mature gilts that hormonal pregnancy maintenance strategies support a low proportion of embryos to term. Lastly, the present study shows for the first time a comparably effective but novel alternative for pregnancy maintenance in the pig involving the co-transfer of parthenote embryos.

Embryo development and establishment of pregnancy after embryo transfer in pigs: coping with limitations in the availability of viable embryos

Embryo transfer and pregnancy maintenance strategies in pigs were evaluated with reference to situations in which limited numbers of viable embryos or micromanipulated embryos are available, such as pig cloning. Development of embryos with compromised zona pellucida was compared with development of embryos with intact zona pellucida. Micromanipulation had no effect on blastocyst production rates after development in vivo or in vitro, but development in vivo improved the number of embryos reaching the blastocyst stage. Transfer of embryos with compromised zona pellucida resulted in live piglets. Several hormone treatments to maintain pregnancy were tested in a model in which three embryos were transferred into unmated recipient gilts, compared with transfer of three embryos into mated recipients. None of the hormonal treatments resulted in pregnancy rates of more than 25% at term and no more than 9% of transferred embryos survived, in comparison with 50% of the mated recipients successfully carrying 25% of transferred embryos. Lastly, the developmental potential of parthenogenetic embryos was assessed and 62% of transferred embryos resulted in pregnancies, none of which continued beyond day 55 of gestation. After co-transfer of three fertilized embryos with 55-60 parthenogenetic embryos into each of six recipients, two live piglets were delivered. The results from the present study indicate that transfer of zona pellucida compromised embryos can yield litters of normal piglets. In addition, it was demonstrated in a model system involving the transfer of three fertilized embryos into mature gilts that hormonal pregnancy maintenance strategies support a low proportion of embryos to term. Lastly, the present study shows for the first time a comparably effective but novel alternative for pregnancy maintenance in the pig involving the co-transfer of parthenote embryos.

P-110. Development of a model for an individualized optimal embryo transfer strategy after IVF

P-110. Development of a model for an individualized optimal embryo transfer strategy after IVF