Lisbet Landuyt - Academia.edu (original) (raw)

Papers by Lisbet Landuyt

Research paper thumbnail of Improved clinical outcomes after non-invasive oocyte selection and Day 3 eSET in ICSI patients

Reproductive Biology and Endocrinology, 2021

Background Non-invasive oocyte quality scoring, based on cumulus gene expression analysis, in com... more Background Non-invasive oocyte quality scoring, based on cumulus gene expression analysis, in combination with morphology scoring, can increase the clinical pregnancy (CPR) and live birth rates (LBR) in Day 3 eSET (elective single embryo transfer) ICSI patients. This was first investigated in a pilot study and is now confirmed in a large patient cohort of 633 patients. It was investigated whether CPR, LBR and time-to-pregnancy could be improved by analyzing the gene expression profile of three predictive genes in the cumulus cells, compared to patients with morphology-based embryo selection only. Methods A large interventional, non-randomized, assessor-blinded cohort study with 633 ICSI patients was conducted in a tertiary fertility center. Non-PCOS patients, 22–39 years old, with good ovarian reserve, were stimulated with HP-hMG using a GnRH antagonist protocol and planned for fresh Day 3 eSET. The cumulus cells from individually denuded oocytes were ranked by a lab-developed cumul...

Research paper thumbnail of Additional file 2 of Improved clinical outcomes after non-invasive oocyte selection and Day 3 eSET in ICSI patients

Additional file 2: Supplementary Table 2. Infertility indication in both arms (male, female or mi... more Additional file 2: Supplementary Table 2. Infertility indication in both arms (male, female or mixed cause of infertility). Comparisons were performed using the Chi square analysis between the different arms and revealed no statistical difference.

Research paper thumbnail of Influence of cell loss after vitrification or slow-freezing on further in vitro development and implantation of human Day 3 embryos

Human Reproduction, 2013

Is the effect of cell loss on further cleavage and implantation different for vitrified than for ... more Is the effect of cell loss on further cleavage and implantation different for vitrified than for slowly frozen Day 3 embryos? summary answer: Vitrified embryos develop better overnight than slowly frozen embryos, regardless of the number of cells lost, but have similar implantation potential if further cleavage occurs overnight. what is known already: After slow-freezing, similar implantation rates have been obtained for intact 4-cell embryos or 4-cell embryos with 1 cell damaged. For slowly frozen Day 3 embryos, lower implantation rates have been observed when at least 25% of cells were lost. Other studies reported similar implantation potential for 7-to 8-cell embryos with 0, 1 or 2 cells damaged. No data are available on further development of vitrified embryos in relation to cell damage.

Research paper thumbnail of Artificially prepared frozen embryo transfer cycles are associated with an increased risk of preeclampsia

Reproductive BioMedicine Online

Research paper thumbnail of Fresh transfer of day 5 slowly developing embryos versus postponed transfer of vitrified fully-developed day 6 blastocysts: what is the best approach?

Research paper thumbnail of Multiple Vitrification-Warming and Biopsy Procedures on Human Embryos: Clinical Outcome and Neonatal Follow-up of Children

Obstetrical & Gynecological Survey

Research paper thumbnail of Multiple vitrification-warming and biopsy procedures on human embryos: clinical outcome and neonatal follow-up of children

Human Reproduction

STUDY QUESTION Does double vitrification and warming of human blastocysts having undergone biopsy... more STUDY QUESTION Does double vitrification and warming of human blastocysts having undergone biopsy once or twice have an impact on the clinical outcome? SUMMARY ANSWER The clinical pregnancy rate obtained with double vitrification single biopsy blastocysts was comparable to that obtained with single vitrification single biopsy blastocysts in our center in the same time period (46%; 2016–2018), whereas that obtained with double-vitrified double-biopsied blastocysts seemed lower and will need further study. WHAT IS KNOWN ALREADY Genetic testing on cryopreserved unbiopsied embryos involves two cryopreservation procedures. Retesting of failed/inconclusive-diagnosed blastocysts inevitably involves a second round of biopsy and a second round of vitrification as well. To what extent this practice impacts on the developmental potential of blastocysts has been studied to a limited extent so far and holds controversy. Additionally, the obstetrical/perinatal outcome after the transfer of double...

Research paper thumbnail of The freeze-all strategy versus agonist triggering with low-dose hCG for luteal phase support in IVF/ICSI for high responders: a randomized controlled trial

Human Reproduction

STUDY QUESTION Does the freeze-all strategy in high-responders increase pregnancy rates and impro... more STUDY QUESTION Does the freeze-all strategy in high-responders increase pregnancy rates and improve safety outcomes when compared with GnRH agonist triggering followed by low-dose hCG intensified luteal support with a fresh embryo transfer? SUMMARY ANSWER Pregnancy rates after either fresh embryo transfer with intensified luteal phase support using low-dose hCG or the freeze-all strategy did not vary significantly; however, moderate-to-severe ovarian hyperstimulation syndrome (OHSS) occurred more frequently in the women who attempted a fresh embryo transfer. WHAT IS KNOWN ALREADY Two strategies following GnRH agonist triggering (the freeze-all approach and a fresh embryo transfer attempt using a low-dose of hCG for intensified luteal phase support) are safer alternatives when compared with conventional hCG triggering with similar pregnancy outcomes. However, these two strategies have never been compared head-to-head in an unrestricted predicted hyper-responder population. STUDY DESI...

Research paper thumbnail of Frozen-warmed blastocyst transfer after 6 or 7 days of progesterone administration: impact on live birth rate in hormone replacement therapy cycles

Research paper thumbnail of Birthweight of singletons born after cleavage-stage or blastocyst transfer in fresh and warming cycles

Research paper thumbnail of Vitamin D deficiency and pregnancy rates following frozen-thawed embryo transfer: a prospective cohort study

Human reproduction (Oxford, England), 2016

What is the effect of vitamin D deficiency on the pregnancy rates following frozen embryo transfe... more What is the effect of vitamin D deficiency on the pregnancy rates following frozen embryo transfer (FET)?. Vitamin D deficiency does not affect pregnancy rates in FET cycles. Although there is evidence that the potential impact of vitamin D deficiency on reproductive outcome may be mediated through a detrimental effect on oocyte or embryo quality, the rationale of our design was based on evidence derived from basic science, suggesting that vitamin D may have a key role in endometrial receptivity and implantation. Only few retrospective clinical studies have been published to date with conflicting results. This study is the first prospective observational cohort study from the Centre for Reproductive Medicine at the University Hospital of Brussels. The duration of the study was 1 year. A total of 280 consecutive patients, who had at least one blastocyst frozen and were planned for a FET, were enrolled in the study following detailed information and signing of a written informed conse...

Research paper thumbnail of Cumulative live birth rates after fresh and vitrified cleavage-stage versus blastocyst-stage embryo transfer in the first treatment cycle

Human reproduction (Oxford, England), Jan 12, 2016

Do cumulative live birth rates differ between single cleavage-stage Day 3 transfer and single bla... more Do cumulative live birth rates differ between single cleavage-stage Day 3 transfer and single blastocyst-stage Day 5 transfer? Cumulative live birth rates after Day 3 and 5 transfers were similar in young patients when the vitrified embryo transfers were also taken into account. Previous evidence has shown that the probability of live birth following IVF with a fresh embryo transfer is significantly higher after blastocyst-stage Day 5 transfer. However, because the introduction of vitrification has enhanced the survival of cryopreserved embryos and improved pregnancy rates, the optimal outcome measure for this comparison should now be cumulative live birth rates, as these include the eventual contribution of vitrified-warmed embryos. Our retrospective study included first IVF/ICSI cycles performed between January 2010 and December 2013 at a tertiary care centre. All patients were scheduled for fresh single embryo transfer, either on Day 3 (n = 377) or on Day 5 (n = 623). Both IVF an...

Research paper thumbnail of The effect of an immediate frozen embryo transfer following a freeze-all protocol: a retrospective analysis from two centres

Human Reproduction, 2016

Does the timing of the first frozen embryo transfer (FET) after gonadotropin-releasing hormone (G... more Does the timing of the first frozen embryo transfer (FET) after gonadotropin-releasing hormone (GnRH) agonist triggering with the elective cryopreservation of all embryos affect pregnancy outcome? SUMMARY ANSWER: FETs performed immediately after a freeze-all cycle did not vary significantly from delayed FETs in terms of pregnancy rates. WHAT IS KNOWN ALREADY: As interest in, and use of, the freeze-all strategy expands in the field of reproductive medicine, the optimal timing to perform the subsequent FET has become increasingly important. Thus far, all clinical trials evaluating the efficacy of the segmentation strategy have opted to electively defer the first FET for at least one menstrual cycle. However, this mere empirical approach may cause unnecessary distress to infertile patients eager to conceive as soon as possible. STUDY DESIGN, SIZE AND DURATION: This retrospective cohort study included the first FET cycle of all women who underwent a freeze-all protocol between October 2010 and October 2015 in two reproductive medicine centres (in Belgium and Vietnam, respectively). PARTICIPANTS/MATERIALS, SETTING AND METHODS: A total of 333 FET cycles were included in the analysis. Following the freeze-all cycle, the preparation of the endometrium consisted of the sequential administration of oestradiol valerate and micronized vaginal progesterone. The start of the FET was classified as either immediate (following the GnRH agonist withdrawal bleeding) or delayed (by at least one menstrual cycle). Clinical pregnancy rate (CPR) was the main outcome of our study. MAIN RESULTS AND THE ROLE OF CHANCE: Women in the immediate FET group were slightly younger on average (30.9 ± 4.1 versus 31.8 ± 4.3, P = 0.045) on the date of oocyte retrieval. Moreover, women in the immediate FET group received a blastocyst transfer more frequently (53.4% versus 41.6%, P = 0.038) and had fewer embryos transferred on average compared to the delayed FET group (1.8 ± 0.8 versus 2.0 ± 0.8, P = 0.013). CPR/FET was marginally significantly higher in the immediate FET group in our crude analysis (52.9% after immediate FET versus 41.6% after delayed FET, P = 0.046). In order to assess if CPR/FET remained unaltered after adjusting for measured confounding, we performed mixed-effects multivariable regression analysis. Timing of the FET no longer affected significantly the CPR of the first FET in the adjusted analysis (adjusted odds ratio (aOR): 0.62, 95% CI: 0.38-1.00; predicted CPR of 52.5% for immediate FET versus 41.8% for delayed FET).

Research paper thumbnail of To delay or not to delay a frozen embryo transfer after a failed fresh embryo transfer attempt?

Fertility and Sterility, 2016

Objective: To evaluate if increasing the interval between a failed fresh embryo transfer and a su... more Objective: To evaluate if increasing the interval between a failed fresh embryo transfer and a subsequent frozen embryo transfer (FET) cycle has any effect on clinical pregnancy rates (CPRs). Design: Retrospective cohort study. Setting: University-based tertiary referral center. Patient(s): Women who underwent at least one FET after ovarian stimulation for in vitro fertilization (IVF) and a failed fresh embryo transfer attempt from January 2010 to November 2014. We divided our sample according to the ''timing'' of the first FET (TF-FET), defined by the interval between oocyte retrieval and the FET cycle start date. The start of the FET was classified as either immediate (%22 days after oocyte retrieval) or delayed (>22 days after oocyte retrieval). Intervention(s): None. Main Outcome Measure(s): CPR after the first FET. Result(s): A total of 1,183 FET cycles (performed in 1,087 women) were included in our study. No significant differences were found between the immediate and delayed FET groups regarding age, number of oocytes retrieved, number of good-quality embryos produced, embryo developmental stage at FET, and number of frozen embryos transferred. Most importantly, the CPRs of the first FET did not differ significantly according to the TF-FET (32.5% after immediate FET vs. 31.7% after delayed FET), even after adjusting for potential confounding with the use of multivariable logistic regression. Conclusion(s): FETs performed immediately after fresh IVF cycles had CPRs similar to those postponed to a later time. Therefore, deferring FETs may unnecessarily prolong time to pregnancy.

Research paper thumbnail of Developmental stage on day-5 and fragmentation rate on day-3 can influence the implantation potential of top-quality blastocysts in IVF cycles with single embryo transfer

Reproductive biology and endocrinology : RB&E, Jan 26, 2007

In IVF-ICSI cycles with single embryo transfer (SET), embryo selection for transfer is of crucial... more In IVF-ICSI cycles with single embryo transfer (SET), embryo selection for transfer is of crucial importance. The present study aimed to define which embryo parameters might be related to the implantation potential of advanced blastocysts. Overall, in 203 cycles with SET, developmental characteristics of 93 implanted (group A) and 110 non-implanted (group B) advanced blastocysts of good quality were compared. The following developmental parameters were assessed in the two groups: normal fertilization, developmental stage on day 5, number of blastomeres on day 2 and on day 3, fragmentation rate on day 3, compaction on day 4 and cleavage pattern on day 2 and day 3. Expanded blastocysts compared to full blastocysts have higher implantation potential (56.5% vs. 29.3%, p < 0.05). In group B, a higher proportion of advanced blastocysts showed between 10% and 50% anucleated fragments on day 3 than in group A (23.6 vs 11.8, P = 0.03). Advanced blastocysts with >10-50% fragments on day...

Research paper thumbnail of Should a single blastocyst transfer policy be a clinical decision or should it depend on the embryological evaluation on day 3?

Background: Single blastocyst transfer has the advantage of maximizing the fresh single pregnancy... more Background: Single blastocyst transfer has the advantage of maximizing the fresh single pregnancy rate. However, in patients with a low number of good quality embryos on day 3, it remains unclear whether immediate embryo transfer or further embryo culture with blastocyst transfer is the most preferable option. Methods: A retrospective cohort study was carried out in which the outcome of 590 fresh in vitro fertilization (IVF) cycles over a 15 months period and their cryo cycles were analyzed. A total of 341 patients cycles had an elective day 5 strategy independent of intermediate embryo evaluation while another 249 patients underwent a day 5 embryo transfer only if at least four embryos were available on day 3. Blastocyst vitrification was performed using a closed high security system. Results: Demographics, stimulation parameters and embryological data were comparable in the two groups. Patients in the elective day 5 group had a lower fresh transfer rate (90.62% vs. 95.18%, p < 0.05) as compared to patients with a day 3 or day 5 embryo transfer policy. No difference was observed in the fresh live birth rate and multiple pregnancy rate per initiated cycle (32.84% vs. 28.92%; 1.17% vs 0%) The projected cumulative ongoing pregnancy rate compensating for double counting in case subjects have more than one pregnancy is not different (42.58% vs. 39.84%). Conclusions: Despite lower fresh transfer rates, elective single blastocyst transfer yields a similar projected cumulative ongoing pregnancy rate as in a policy with cleavage stage or blastocyst transfer depending on a good quality embryo count on day 3.

Research paper thumbnail of Comparison of the cryopreservation method for day 3 embryos using slow freezing or vitrification

http://isrctn.org/>, 2000

Research paper thumbnail of New Belgian embryo transfer policy leads to sharp decrease in multiple pregnancy rate

Reproductive BioMedicine Online, 2006

Since 1 July 2003, a new transfer policy aiming to reduce multiple pregnancies was brought into l... more Since 1 July 2003, a new transfer policy aiming to reduce multiple pregnancies was brought into law in Belgium. The policy restricts the number of embryos transferred, depending on the patient&#39;s age and treatment cycle. This study aimed to evaluate the effect of this policy. Two 15-month periods before and after the start of the new law were compared for the following parameters: positive human chorionic gonadotrophin (HCG), clinical pregnancy rate and multiple pregnancy rate according to the age categories defined by the policy: &lt;36, 36-39 and 40-42 years. HCG rates (34.2 and 32.8%) and clinical pregnancy rates (26.2 and 24.0%) per cycle were similar for the two periods. Overall, the multiple pregnancy rate was reduced from 29.1 to 9.5% (all patients) and from 28.9 to 6.2% in women &lt;36 years. Most twins were observed in the third cycle of patients &lt;36 years and in the first three cycles in women of 36-39 years. It can be concluded that a significant decline (P &lt; 0.001) in multiple pregnancies was mainly observed in patients &lt;36 years of age. Clinical pregnancy rates were not compromised by the new law. Elective single embryo transfer should be considered more seriously for women 36-39 years of age.

Research paper thumbnail of Pregnancy Prediction in Single Embryo Transfer Cycles after ICSI Using QPCR: Validation in Oocytes from the Same Cohort

Research paper thumbnail of In Vitro Fertilization with Single Blastocyst-Stage versus Single Cleavage-Stage Embryos

New England Journal of Medicine, 2006

Background Single-embryo transfer has been recommended to reduce the incidence of multiple gestat... more Background Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, randomized, controlled trial to determine whether there were any differences in the rates of pregnancy and delivery between women undergoing transfer of a single cleavage-stage (day 3) embryo and those undergoing transfer of a single blastocyst-stage (day 5) embryo. Methods We studied 351 infertile women under 36 years of age who were randomly assigned to undergo transfer of either a single cleavage-stage embryo (176 patients) or a single blastocyst-stage embryo (175 patients). Multifollicular ovarian stimulation was performed with a gonadotropin-releasing hormone antagonist and recombinant folliclestimulating hormone. Results The study was terminated early after a prespecified interim analysis (which included 50 percent of the planned number of patients) found a higher rate of pregnancy among women undergoing transfer of a single blastocyst-stage embryo (P = 0.02). The rate of delivery was also significantly higher in this group than in the group undergoing transfer of a single cleavage-stage embryo (32.0 percent vs. 21.6 percent; relative risk, 1.48; 95 percent confidence interval, 1.04 to 2.11). Two multiple births occurred, both of monozygotic twins, both of which were in the group undergoing transfer of a single cleavage-stage embryo. Conclusions These findings support the transfer of a single blastocyst-stage (day 5) embryo in infertile women under 36 years of age.

Research paper thumbnail of Improved clinical outcomes after non-invasive oocyte selection and Day 3 eSET in ICSI patients

Reproductive Biology and Endocrinology, 2021

Background Non-invasive oocyte quality scoring, based on cumulus gene expression analysis, in com... more Background Non-invasive oocyte quality scoring, based on cumulus gene expression analysis, in combination with morphology scoring, can increase the clinical pregnancy (CPR) and live birth rates (LBR) in Day 3 eSET (elective single embryo transfer) ICSI patients. This was first investigated in a pilot study and is now confirmed in a large patient cohort of 633 patients. It was investigated whether CPR, LBR and time-to-pregnancy could be improved by analyzing the gene expression profile of three predictive genes in the cumulus cells, compared to patients with morphology-based embryo selection only. Methods A large interventional, non-randomized, assessor-blinded cohort study with 633 ICSI patients was conducted in a tertiary fertility center. Non-PCOS patients, 22–39 years old, with good ovarian reserve, were stimulated with HP-hMG using a GnRH antagonist protocol and planned for fresh Day 3 eSET. The cumulus cells from individually denuded oocytes were ranked by a lab-developed cumul...

Research paper thumbnail of Additional file 2 of Improved clinical outcomes after non-invasive oocyte selection and Day 3 eSET in ICSI patients

Additional file 2: Supplementary Table 2. Infertility indication in both arms (male, female or mi... more Additional file 2: Supplementary Table 2. Infertility indication in both arms (male, female or mixed cause of infertility). Comparisons were performed using the Chi square analysis between the different arms and revealed no statistical difference.

Research paper thumbnail of Influence of cell loss after vitrification or slow-freezing on further in vitro development and implantation of human Day 3 embryos

Human Reproduction, 2013

Is the effect of cell loss on further cleavage and implantation different for vitrified than for ... more Is the effect of cell loss on further cleavage and implantation different for vitrified than for slowly frozen Day 3 embryos? summary answer: Vitrified embryos develop better overnight than slowly frozen embryos, regardless of the number of cells lost, but have similar implantation potential if further cleavage occurs overnight. what is known already: After slow-freezing, similar implantation rates have been obtained for intact 4-cell embryos or 4-cell embryos with 1 cell damaged. For slowly frozen Day 3 embryos, lower implantation rates have been observed when at least 25% of cells were lost. Other studies reported similar implantation potential for 7-to 8-cell embryos with 0, 1 or 2 cells damaged. No data are available on further development of vitrified embryos in relation to cell damage.

Research paper thumbnail of Artificially prepared frozen embryo transfer cycles are associated with an increased risk of preeclampsia

Reproductive BioMedicine Online

Research paper thumbnail of Fresh transfer of day 5 slowly developing embryos versus postponed transfer of vitrified fully-developed day 6 blastocysts: what is the best approach?

Research paper thumbnail of Multiple Vitrification-Warming and Biopsy Procedures on Human Embryos: Clinical Outcome and Neonatal Follow-up of Children

Obstetrical & Gynecological Survey

Research paper thumbnail of Multiple vitrification-warming and biopsy procedures on human embryos: clinical outcome and neonatal follow-up of children

Human Reproduction

STUDY QUESTION Does double vitrification and warming of human blastocysts having undergone biopsy... more STUDY QUESTION Does double vitrification and warming of human blastocysts having undergone biopsy once or twice have an impact on the clinical outcome? SUMMARY ANSWER The clinical pregnancy rate obtained with double vitrification single biopsy blastocysts was comparable to that obtained with single vitrification single biopsy blastocysts in our center in the same time period (46%; 2016–2018), whereas that obtained with double-vitrified double-biopsied blastocysts seemed lower and will need further study. WHAT IS KNOWN ALREADY Genetic testing on cryopreserved unbiopsied embryos involves two cryopreservation procedures. Retesting of failed/inconclusive-diagnosed blastocysts inevitably involves a second round of biopsy and a second round of vitrification as well. To what extent this practice impacts on the developmental potential of blastocysts has been studied to a limited extent so far and holds controversy. Additionally, the obstetrical/perinatal outcome after the transfer of double...

Research paper thumbnail of The freeze-all strategy versus agonist triggering with low-dose hCG for luteal phase support in IVF/ICSI for high responders: a randomized controlled trial

Human Reproduction

STUDY QUESTION Does the freeze-all strategy in high-responders increase pregnancy rates and impro... more STUDY QUESTION Does the freeze-all strategy in high-responders increase pregnancy rates and improve safety outcomes when compared with GnRH agonist triggering followed by low-dose hCG intensified luteal support with a fresh embryo transfer? SUMMARY ANSWER Pregnancy rates after either fresh embryo transfer with intensified luteal phase support using low-dose hCG or the freeze-all strategy did not vary significantly; however, moderate-to-severe ovarian hyperstimulation syndrome (OHSS) occurred more frequently in the women who attempted a fresh embryo transfer. WHAT IS KNOWN ALREADY Two strategies following GnRH agonist triggering (the freeze-all approach and a fresh embryo transfer attempt using a low-dose of hCG for intensified luteal phase support) are safer alternatives when compared with conventional hCG triggering with similar pregnancy outcomes. However, these two strategies have never been compared head-to-head in an unrestricted predicted hyper-responder population. STUDY DESI...

Research paper thumbnail of Frozen-warmed blastocyst transfer after 6 or 7 days of progesterone administration: impact on live birth rate in hormone replacement therapy cycles

Research paper thumbnail of Birthweight of singletons born after cleavage-stage or blastocyst transfer in fresh and warming cycles

Research paper thumbnail of Vitamin D deficiency and pregnancy rates following frozen-thawed embryo transfer: a prospective cohort study

Human reproduction (Oxford, England), 2016

What is the effect of vitamin D deficiency on the pregnancy rates following frozen embryo transfe... more What is the effect of vitamin D deficiency on the pregnancy rates following frozen embryo transfer (FET)?. Vitamin D deficiency does not affect pregnancy rates in FET cycles. Although there is evidence that the potential impact of vitamin D deficiency on reproductive outcome may be mediated through a detrimental effect on oocyte or embryo quality, the rationale of our design was based on evidence derived from basic science, suggesting that vitamin D may have a key role in endometrial receptivity and implantation. Only few retrospective clinical studies have been published to date with conflicting results. This study is the first prospective observational cohort study from the Centre for Reproductive Medicine at the University Hospital of Brussels. The duration of the study was 1 year. A total of 280 consecutive patients, who had at least one blastocyst frozen and were planned for a FET, were enrolled in the study following detailed information and signing of a written informed conse...

Research paper thumbnail of Cumulative live birth rates after fresh and vitrified cleavage-stage versus blastocyst-stage embryo transfer in the first treatment cycle

Human reproduction (Oxford, England), Jan 12, 2016

Do cumulative live birth rates differ between single cleavage-stage Day 3 transfer and single bla... more Do cumulative live birth rates differ between single cleavage-stage Day 3 transfer and single blastocyst-stage Day 5 transfer? Cumulative live birth rates after Day 3 and 5 transfers were similar in young patients when the vitrified embryo transfers were also taken into account. Previous evidence has shown that the probability of live birth following IVF with a fresh embryo transfer is significantly higher after blastocyst-stage Day 5 transfer. However, because the introduction of vitrification has enhanced the survival of cryopreserved embryos and improved pregnancy rates, the optimal outcome measure for this comparison should now be cumulative live birth rates, as these include the eventual contribution of vitrified-warmed embryos. Our retrospective study included first IVF/ICSI cycles performed between January 2010 and December 2013 at a tertiary care centre. All patients were scheduled for fresh single embryo transfer, either on Day 3 (n = 377) or on Day 5 (n = 623). Both IVF an...

Research paper thumbnail of The effect of an immediate frozen embryo transfer following a freeze-all protocol: a retrospective analysis from two centres

Human Reproduction, 2016

Does the timing of the first frozen embryo transfer (FET) after gonadotropin-releasing hormone (G... more Does the timing of the first frozen embryo transfer (FET) after gonadotropin-releasing hormone (GnRH) agonist triggering with the elective cryopreservation of all embryos affect pregnancy outcome? SUMMARY ANSWER: FETs performed immediately after a freeze-all cycle did not vary significantly from delayed FETs in terms of pregnancy rates. WHAT IS KNOWN ALREADY: As interest in, and use of, the freeze-all strategy expands in the field of reproductive medicine, the optimal timing to perform the subsequent FET has become increasingly important. Thus far, all clinical trials evaluating the efficacy of the segmentation strategy have opted to electively defer the first FET for at least one menstrual cycle. However, this mere empirical approach may cause unnecessary distress to infertile patients eager to conceive as soon as possible. STUDY DESIGN, SIZE AND DURATION: This retrospective cohort study included the first FET cycle of all women who underwent a freeze-all protocol between October 2010 and October 2015 in two reproductive medicine centres (in Belgium and Vietnam, respectively). PARTICIPANTS/MATERIALS, SETTING AND METHODS: A total of 333 FET cycles were included in the analysis. Following the freeze-all cycle, the preparation of the endometrium consisted of the sequential administration of oestradiol valerate and micronized vaginal progesterone. The start of the FET was classified as either immediate (following the GnRH agonist withdrawal bleeding) or delayed (by at least one menstrual cycle). Clinical pregnancy rate (CPR) was the main outcome of our study. MAIN RESULTS AND THE ROLE OF CHANCE: Women in the immediate FET group were slightly younger on average (30.9 ± 4.1 versus 31.8 ± 4.3, P = 0.045) on the date of oocyte retrieval. Moreover, women in the immediate FET group received a blastocyst transfer more frequently (53.4% versus 41.6%, P = 0.038) and had fewer embryos transferred on average compared to the delayed FET group (1.8 ± 0.8 versus 2.0 ± 0.8, P = 0.013). CPR/FET was marginally significantly higher in the immediate FET group in our crude analysis (52.9% after immediate FET versus 41.6% after delayed FET, P = 0.046). In order to assess if CPR/FET remained unaltered after adjusting for measured confounding, we performed mixed-effects multivariable regression analysis. Timing of the FET no longer affected significantly the CPR of the first FET in the adjusted analysis (adjusted odds ratio (aOR): 0.62, 95% CI: 0.38-1.00; predicted CPR of 52.5% for immediate FET versus 41.8% for delayed FET).

Research paper thumbnail of To delay or not to delay a frozen embryo transfer after a failed fresh embryo transfer attempt?

Fertility and Sterility, 2016

Objective: To evaluate if increasing the interval between a failed fresh embryo transfer and a su... more Objective: To evaluate if increasing the interval between a failed fresh embryo transfer and a subsequent frozen embryo transfer (FET) cycle has any effect on clinical pregnancy rates (CPRs). Design: Retrospective cohort study. Setting: University-based tertiary referral center. Patient(s): Women who underwent at least one FET after ovarian stimulation for in vitro fertilization (IVF) and a failed fresh embryo transfer attempt from January 2010 to November 2014. We divided our sample according to the ''timing'' of the first FET (TF-FET), defined by the interval between oocyte retrieval and the FET cycle start date. The start of the FET was classified as either immediate (%22 days after oocyte retrieval) or delayed (>22 days after oocyte retrieval). Intervention(s): None. Main Outcome Measure(s): CPR after the first FET. Result(s): A total of 1,183 FET cycles (performed in 1,087 women) were included in our study. No significant differences were found between the immediate and delayed FET groups regarding age, number of oocytes retrieved, number of good-quality embryos produced, embryo developmental stage at FET, and number of frozen embryos transferred. Most importantly, the CPRs of the first FET did not differ significantly according to the TF-FET (32.5% after immediate FET vs. 31.7% after delayed FET), even after adjusting for potential confounding with the use of multivariable logistic regression. Conclusion(s): FETs performed immediately after fresh IVF cycles had CPRs similar to those postponed to a later time. Therefore, deferring FETs may unnecessarily prolong time to pregnancy.

Research paper thumbnail of Developmental stage on day-5 and fragmentation rate on day-3 can influence the implantation potential of top-quality blastocysts in IVF cycles with single embryo transfer

Reproductive biology and endocrinology : RB&E, Jan 26, 2007

In IVF-ICSI cycles with single embryo transfer (SET), embryo selection for transfer is of crucial... more In IVF-ICSI cycles with single embryo transfer (SET), embryo selection for transfer is of crucial importance. The present study aimed to define which embryo parameters might be related to the implantation potential of advanced blastocysts. Overall, in 203 cycles with SET, developmental characteristics of 93 implanted (group A) and 110 non-implanted (group B) advanced blastocysts of good quality were compared. The following developmental parameters were assessed in the two groups: normal fertilization, developmental stage on day 5, number of blastomeres on day 2 and on day 3, fragmentation rate on day 3, compaction on day 4 and cleavage pattern on day 2 and day 3. Expanded blastocysts compared to full blastocysts have higher implantation potential (56.5% vs. 29.3%, p < 0.05). In group B, a higher proportion of advanced blastocysts showed between 10% and 50% anucleated fragments on day 3 than in group A (23.6 vs 11.8, P = 0.03). Advanced blastocysts with >10-50% fragments on day...

Research paper thumbnail of Should a single blastocyst transfer policy be a clinical decision or should it depend on the embryological evaluation on day 3?

Background: Single blastocyst transfer has the advantage of maximizing the fresh single pregnancy... more Background: Single blastocyst transfer has the advantage of maximizing the fresh single pregnancy rate. However, in patients with a low number of good quality embryos on day 3, it remains unclear whether immediate embryo transfer or further embryo culture with blastocyst transfer is the most preferable option. Methods: A retrospective cohort study was carried out in which the outcome of 590 fresh in vitro fertilization (IVF) cycles over a 15 months period and their cryo cycles were analyzed. A total of 341 patients cycles had an elective day 5 strategy independent of intermediate embryo evaluation while another 249 patients underwent a day 5 embryo transfer only if at least four embryos were available on day 3. Blastocyst vitrification was performed using a closed high security system. Results: Demographics, stimulation parameters and embryological data were comparable in the two groups. Patients in the elective day 5 group had a lower fresh transfer rate (90.62% vs. 95.18%, p < 0.05) as compared to patients with a day 3 or day 5 embryo transfer policy. No difference was observed in the fresh live birth rate and multiple pregnancy rate per initiated cycle (32.84% vs. 28.92%; 1.17% vs 0%) The projected cumulative ongoing pregnancy rate compensating for double counting in case subjects have more than one pregnancy is not different (42.58% vs. 39.84%). Conclusions: Despite lower fresh transfer rates, elective single blastocyst transfer yields a similar projected cumulative ongoing pregnancy rate as in a policy with cleavage stage or blastocyst transfer depending on a good quality embryo count on day 3.

Research paper thumbnail of Comparison of the cryopreservation method for day 3 embryos using slow freezing or vitrification

http://isrctn.org/>, 2000

Research paper thumbnail of New Belgian embryo transfer policy leads to sharp decrease in multiple pregnancy rate

Reproductive BioMedicine Online, 2006

Since 1 July 2003, a new transfer policy aiming to reduce multiple pregnancies was brought into l... more Since 1 July 2003, a new transfer policy aiming to reduce multiple pregnancies was brought into law in Belgium. The policy restricts the number of embryos transferred, depending on the patient&#39;s age and treatment cycle. This study aimed to evaluate the effect of this policy. Two 15-month periods before and after the start of the new law were compared for the following parameters: positive human chorionic gonadotrophin (HCG), clinical pregnancy rate and multiple pregnancy rate according to the age categories defined by the policy: &lt;36, 36-39 and 40-42 years. HCG rates (34.2 and 32.8%) and clinical pregnancy rates (26.2 and 24.0%) per cycle were similar for the two periods. Overall, the multiple pregnancy rate was reduced from 29.1 to 9.5% (all patients) and from 28.9 to 6.2% in women &lt;36 years. Most twins were observed in the third cycle of patients &lt;36 years and in the first three cycles in women of 36-39 years. It can be concluded that a significant decline (P &lt; 0.001) in multiple pregnancies was mainly observed in patients &lt;36 years of age. Clinical pregnancy rates were not compromised by the new law. Elective single embryo transfer should be considered more seriously for women 36-39 years of age.

Research paper thumbnail of Pregnancy Prediction in Single Embryo Transfer Cycles after ICSI Using QPCR: Validation in Oocytes from the Same Cohort

Research paper thumbnail of In Vitro Fertilization with Single Blastocyst-Stage versus Single Cleavage-Stage Embryos

New England Journal of Medicine, 2006

Background Single-embryo transfer has been recommended to reduce the incidence of multiple gestat... more Background Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, randomized, controlled trial to determine whether there were any differences in the rates of pregnancy and delivery between women undergoing transfer of a single cleavage-stage (day 3) embryo and those undergoing transfer of a single blastocyst-stage (day 5) embryo. Methods We studied 351 infertile women under 36 years of age who were randomly assigned to undergo transfer of either a single cleavage-stage embryo (176 patients) or a single blastocyst-stage embryo (175 patients). Multifollicular ovarian stimulation was performed with a gonadotropin-releasing hormone antagonist and recombinant folliclestimulating hormone. Results The study was terminated early after a prespecified interim analysis (which included 50 percent of the planned number of patients) found a higher rate of pregnancy among women undergoing transfer of a single blastocyst-stage embryo (P = 0.02). The rate of delivery was also significantly higher in this group than in the group undergoing transfer of a single cleavage-stage embryo (32.0 percent vs. 21.6 percent; relative risk, 1.48; 95 percent confidence interval, 1.04 to 2.11). Two multiple births occurred, both of monozygotic twins, both of which were in the group undergoing transfer of a single cleavage-stage embryo. Conclusions These findings support the transfer of a single blastocyst-stage (day 5) embryo in infertile women under 36 years of age.