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Elective single-embryo transfer in frozen blastocyst transfer cycles
TABLE 2.
Starting Temp.
% survival
% re-expansion
IR
-6.5 degrees C 20 degrees C P
88.27 80.62 <0.01
37.97 33.17 0.306
0.21 0.16 0.241
Supported by: None. P-293 ELECTIVE SINGLE-EMBRYO TRANSFER IN FROZEN BLASTOCYST TRANSFER CYCLES. Y. Shu, J. Watt, J. Gebhardt, Q. Zhao, A. Milki, B. Behr. IVF Program, Dept of Obstetrics & Gynecology, Stanford University Medical Center, Palo Alto, CA. OBJECTIVE: The number of embryos transferred has been shown to be the most important factor for IVF-associated multiple pregnancies. Although several reports have suggested the value of single fresh embryo transfer in good prognostic patients, very few data is available with regard to the feasibility of single frozen embryo transfer. In this study, we evaluated single-embryo transfer in our frozen blastocyst program. DESIGN: Retrospective study performed in an academic assisted reproduction program. MATERIALS AND METHODS: Day 5 and day 6 blastocysts graded as 3BB or better were frozen and thawed between January 2004 and December 2007. A frozen-thawed blastocyst with good blastomere survival (>80%) and blastocoele re-expansion was defined as a good-quality embryo. A single good quality frozen-thawed blastocyst was transferred in 39 patients who had good prognosis of pregnancy establishment following the fresh IVF. To compare the outcome between single- and double-embryo transfers, double-embryo transfers were divided into 2 groups, those with only 1 good quality blastocyst and those with 2 good-quality blastocysts. Double-embryo transfers without good-quality embryos were excluded from this study. The rates of pregnancy and implantation were compared among groups. RESULTS: As shown in Table1, no difference exists in patient age at blastocyst freezing among groups. A similar rate of clinical pregnancy was obtained for selective single-embryo transfer when compared to double-embryo transfer containing only 1 good embryo (30.8% vs 34.8%). No twins were observed in the selective single-embryo transfer group. Although there was a significant trend towards higher clinical pregnancy rate in double-embryo transfers with 2 good-quality blastocysts, 28.8% of the pregnancies were twins. TABLE 1. Double transfers Double transfers with 2 with 1 good-quality good-quality Selective embryos embryo single transfer No. of transfers Age at freezing (mean SD) No. of positive HCG [n (%)] No. of clinical pregnancy [n (%)] No. of implantation [n (%)] No. of twins [n (%)]
P Value
39 33.8 3.6
66 34.5 3.8
140 34.2 3.8
0. 8422
14 (35.9)*
28 (35.1)
75 (53.7)*
0.0886, *,* 0.0509
12 (30.8)
23 (34.8)
59 (42.1)
0.3427
12 (30.8) *
25 (18.9)*
76 (27.1)
0.0952, *,* 0.034
0
2 (8.7)
17 (28.8)
0.0004
CONCLUSIONS: Single-embryo transfer in selected patients with a goodquality frozen-thawed blastocyst yields acceptable clinical pregnancy rate without multiple pregnancies. Supported by: Institutional. P-294 TECHNIQUE SAFETY: OOCYTE VITRIFICATION. LIVE-BIRTHS’ LONG-TERM FOLLOW-UP. A. Chavez-Badiola, L. A. Ruvalcaba-Castellon, J. Zhang, M. I. Garcia-Amador. Instituto Mexicano de Infertilidad, Mexico, Mexico; New Hope Fertility Center, New York, NY. OBJECTIVE: To report psychomotor development and follow-up of children born from cryopreserved oocytes using the Cryotop method of vitrification.
FERTILITY & STERILITYÒ
DESIGN: Analysis of prospectively recorded data. MATERIALS AND METHODS: Data from children born from vitrified oocytes in the largest IVF centre in Western Mexico from 2005-2008 under same pediatrician’s care, was assessed for newborn’s weight, size and Apgar scores, as well as for congenital and genetic malformations. Psychomotor and neurologic assessment was evaluated from birth up to May 2008 using Gesell’s scale. Oocytes were cryopreserved with the Cryotop method of vitrification as described by Kuwayama (2005). RESULTS: A total of 52 live births were followed from birth up to May 2008 (mean follow-up 18.4 months), all of them born after cesarean section. One congenital malformation was reported (interventricular communication) in a child born to a mother who developed gestational diabetes. No other malformations were reported for this or any other children. Newborn’s mean weigh was 2,600 grams, and mean height was 48cms. All children were reported as normally developing according to Gesell’s scale up to the time of this study. CONCLUSIONS: Although oocyte cryopreservation has long been considered as an investigational technique, oocyte cryopreservation with the Cryotop method of vitrification is, according to our results, a viable alternative to patients who have to undergo oocyte freezing. These initial results suggest that congenital malformations and developmental problems in children born after cryopreserved oocytes are no greater that those reported in literature for other assisted reproductive technologies (i.e. ICSI). Results might still be scarce to conclude on safety for any of the available cryopreserving methods and an international registry, reporting on live-births and long-term follow-up of these newborns, should be started aiming to conclude on this issue. Supported by: Private medical practice.
P-295 VIABLE PREGNANCIES FOLLOWING FRESH VERSUS FROZEN EMBRYO TRANSFER: IS THERE A DIFFERENCE IN THE RATE OF SERUM HUMAN CHORIONIC GONADOTROPIN (HCG) RISE? S. Kansal Kalra, T. A. Molinaro, M. D. Sammel. Reproductive Endocrinology & Infertility, University of Pennsylvania, Philadelphia, PA; University of Pennsylvania, Center for Clinical Epidemiology and Biostatistics, Philadelphia, PA. OBJECTIVE: To characterize if there is a difference in rate of hCG rise with viable IVF pregnancies following transfer of fresh vs frozen embryos. DESIGN: Retrospective cohort. MATERIALS AND METHODS: All pregnancies following a transfer of fresh embryos, in cycles in which 2:PN supernumerary embryos were also available for cryopreservation, and all pregnancies conceived following transfer of 2:PN frozen-thawed embryos at a single university center between January 1998 - June 2006. The rate of increase in log transformed hCG for each type of transfer cycle (fresh/frozen) was compared using general linear mixed effects regression which were extended to address data having 2 levels of correlation (time within each cycle, and multiple cycles/patient). Observed data included values taken from cycle days 20 to 40. A linear association with log transformed hCG was assumed and models were adjusted for multiple pregnancy. The rate of hCG rise, i.e. the slope of the curve, in fresh versus frozen embryo transfers, was analyzed for each group separately and 1 day and 2 day relative increases in hCG were estimated. RESULTS: The final sample included 218 conceptions with 595 hCG values. There were 153 conceptions which contributed 373 hCG determinations following fresh embryo transfer (70% of total conceptions), and 81 (30%) conceptions with 222 hCG measurements contributed by frozen embryo transfers. There were 29 women (10%) who contributed data from multiple pregnancies. The rate of rise in log hCG was significantly higher for conception cycles where frozen embryos had been transferred compared to fresh embryos (Frozen: slope¼0.44, 99% CI 0 .416, 0.471; Fresh: slope¼0.39, 99%CI 0.373, 0.415, p<0.0001). This association remained after adjustment for multiple pregnancy. The median rate of hCG rise was significantly higher after transfer of frozen versus fresh embryos; 60% vs 51% over 1 day and 157% vs 128% over 2 days. The minimal rise over 2 days following transfer of frozen embryos was 63% compared to 45% following transfer of fresh embryos. CONCLUSIONS: The rate of hCG rise following transfer of frozen embryos is significantly greater than that seen with transfer of fresh embryos. This difference may reflect that the most healthy embryos survive the freeze-thaw process or may be secondary to the more physiologic endocrine environment at the time of implantation. Future study with a larger sample size may confirm that the standard curve for rate of hCG rise is not applicable to pregnancies following frozen embryo transfer. Supported by: None.
S205
Starting Temp.
% survival
% re-expansion
IR
-6.5 degrees C 20 degrees C P
88.27 80.62 <0.01
37.97 33.17 0.306
0.21 0.16 0.241
Supported by: None. P-293 ELECTIVE SINGLE-EMBRYO TRANSFER IN FROZEN BLASTOCYST TRANSFER CYCLES. Y. Shu, J. Watt, J. Gebhardt, Q. Zhao, A. Milki, B. Behr. IVF Program, Dept of Obstetrics & Gynecology, Stanford University Medical Center, Palo Alto, CA. OBJECTIVE: The number of embryos transferred has been shown to be the most important factor for IVF-associated multiple pregnancies. Although several reports have suggested the value of single fresh embryo transfer in good prognostic patients, very few data is available with regard to the feasibility of single frozen embryo transfer. In this study, we evaluated single-embryo transfer in our frozen blastocyst program. DESIGN: Retrospective study performed in an academic assisted reproduction program. MATERIALS AND METHODS: Day 5 and day 6 blastocysts graded as 3BB or better were frozen and thawed between January 2004 and December 2007. A frozen-thawed blastocyst with good blastomere survival (>80%) and blastocoele re-expansion was defined as a good-quality embryo. A single good quality frozen-thawed blastocyst was transferred in 39 patients who had good prognosis of pregnancy establishment following the fresh IVF. To compare the outcome between single- and double-embryo transfers, double-embryo transfers were divided into 2 groups, those with only 1 good quality blastocyst and those with 2 good-quality blastocysts. Double-embryo transfers without good-quality embryos were excluded from this study. The rates of pregnancy and implantation were compared among groups. RESULTS: As shown in Table1, no difference exists in patient age at blastocyst freezing among groups. A similar rate of clinical pregnancy was obtained for selective single-embryo transfer when compared to double-embryo transfer containing only 1 good embryo (30.8% vs 34.8%). No twins were observed in the selective single-embryo transfer group. Although there was a significant trend towards higher clinical pregnancy rate in double-embryo transfers with 2 good-quality blastocysts, 28.8% of the pregnancies were twins. TABLE 1. Double transfers Double transfers with 2 with 1 good-quality good-quality Selective embryos embryo single transfer No. of transfers Age at freezing (mean SD) No. of positive HCG [n (%)] No. of clinical pregnancy [n (%)] No. of implantation [n (%)] No. of twins [n (%)]
P Value
39 33.8 3.6
66 34.5 3.8
140 34.2 3.8
0. 8422
14 (35.9)*
28 (35.1)
75 (53.7)*
0.0886, *,* 0.0509
12 (30.8)
23 (34.8)
59 (42.1)
0.3427
12 (30.8) *
25 (18.9)*
76 (27.1)
0.0952, *,* 0.034
0
2 (8.7)
17 (28.8)
0.0004
CONCLUSIONS: Single-embryo transfer in selected patients with a goodquality frozen-thawed blastocyst yields acceptable clinical pregnancy rate without multiple pregnancies. Supported by: Institutional. P-294 TECHNIQUE SAFETY: OOCYTE VITRIFICATION. LIVE-BIRTHS’ LONG-TERM FOLLOW-UP. A. Chavez-Badiola, L. A. Ruvalcaba-Castellon, J. Zhang, M. I. Garcia-Amador. Instituto Mexicano de Infertilidad, Mexico, Mexico; New Hope Fertility Center, New York, NY. OBJECTIVE: To report psychomotor development and follow-up of children born from cryopreserved oocytes using the Cryotop method of vitrification.
FERTILITY & STERILITYÒ
DESIGN: Analysis of prospectively recorded data. MATERIALS AND METHODS: Data from children born from vitrified oocytes in the largest IVF centre in Western Mexico from 2005-2008 under same pediatrician’s care, was assessed for newborn’s weight, size and Apgar scores, as well as for congenital and genetic malformations. Psychomotor and neurologic assessment was evaluated from birth up to May 2008 using Gesell’s scale. Oocytes were cryopreserved with the Cryotop method of vitrification as described by Kuwayama (2005). RESULTS: A total of 52 live births were followed from birth up to May 2008 (mean follow-up 18.4 months), all of them born after cesarean section. One congenital malformation was reported (interventricular communication) in a child born to a mother who developed gestational diabetes. No other malformations were reported for this or any other children. Newborn’s mean weigh was 2,600 grams, and mean height was 48cms. All children were reported as normally developing according to Gesell’s scale up to the time of this study. CONCLUSIONS: Although oocyte cryopreservation has long been considered as an investigational technique, oocyte cryopreservation with the Cryotop method of vitrification is, according to our results, a viable alternative to patients who have to undergo oocyte freezing. These initial results suggest that congenital malformations and developmental problems in children born after cryopreserved oocytes are no greater that those reported in literature for other assisted reproductive technologies (i.e. ICSI). Results might still be scarce to conclude on safety for any of the available cryopreserving methods and an international registry, reporting on live-births and long-term follow-up of these newborns, should be started aiming to conclude on this issue. Supported by: Private medical practice.
P-295 VIABLE PREGNANCIES FOLLOWING FRESH VERSUS FROZEN EMBRYO TRANSFER: IS THERE A DIFFERENCE IN THE RATE OF SERUM HUMAN CHORIONIC GONADOTROPIN (HCG) RISE? S. Kansal Kalra, T. A. Molinaro, M. D. Sammel. Reproductive Endocrinology & Infertility, University of Pennsylvania, Philadelphia, PA; University of Pennsylvania, Center for Clinical Epidemiology and Biostatistics, Philadelphia, PA. OBJECTIVE: To characterize if there is a difference in rate of hCG rise with viable IVF pregnancies following transfer of fresh vs frozen embryos. DESIGN: Retrospective cohort. MATERIALS AND METHODS: All pregnancies following a transfer of fresh embryos, in cycles in which 2:PN supernumerary embryos were also available for cryopreservation, and all pregnancies conceived following transfer of 2:PN frozen-thawed embryos at a single university center between January 1998 - June 2006. The rate of increase in log transformed hCG for each type of transfer cycle (fresh/frozen) was compared using general linear mixed effects regression which were extended to address data having 2 levels of correlation (time within each cycle, and multiple cycles/patient). Observed data included values taken from cycle days 20 to 40. A linear association with log transformed hCG was assumed and models were adjusted for multiple pregnancy. The rate of hCG rise, i.e. the slope of the curve, in fresh versus frozen embryo transfers, was analyzed for each group separately and 1 day and 2 day relative increases in hCG were estimated. RESULTS: The final sample included 218 conceptions with 595 hCG values. There were 153 conceptions which contributed 373 hCG determinations following fresh embryo transfer (70% of total conceptions), and 81 (30%) conceptions with 222 hCG measurements contributed by frozen embryo transfers. There were 29 women (10%) who contributed data from multiple pregnancies. The rate of rise in log hCG was significantly higher for conception cycles where frozen embryos had been transferred compared to fresh embryos (Frozen: slope¼0.44, 99% CI 0 .416, 0.471; Fresh: slope¼0.39, 99%CI 0.373, 0.415, p<0.0001). This association remained after adjustment for multiple pregnancy. The median rate of hCG rise was significantly higher after transfer of frozen versus fresh embryos; 60% vs 51% over 1 day and 157% vs 128% over 2 days. The minimal rise over 2 days following transfer of frozen embryos was 63% compared to 45% following transfer of fresh embryos. CONCLUSIONS: The rate of hCG rise following transfer of frozen embryos is significantly greater than that seen with transfer of fresh embryos. This difference may reflect that the most healthy embryos survive the freeze-thaw process or may be secondary to the more physiologic endocrine environment at the time of implantation. Future study with a larger sample size may confirm that the standard curve for rate of hCG rise is not applicable to pregnancies following frozen embryo transfer. Supported by: None.
S205