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Blastomere survival during cryopreservation is directly related to pregnancy rate following FET
number were excluded. Mean cell number and mean ETS were calculated. Clinical (CLN) pregnancy and implantation rates were defined via ultrasonic detection of gestational sac(s). Ongoing was defined as fetal cardiac activity. Statistical analysis was performed using the Mann-Whitney rank sum and chi squared tests as indicated with p ⬍0.05 considered statistically significant. Retrospective power analysis was performed to ensure that appropriate conclusions were drawn from embryo cell number and quality scores Results: Mean evaluation of age, cell number on D3,and mean ETS, yielded no significant differences. Clinical and OG pregnancies per transfer, CLN implantation rates, as analyzed by chi square resulted no significant differences, potentially due to a limited number of FET cycles. Table 1 Total FET cycles/Total of Embryo Transferred Mean Age ⫾ SD* Mean cell # on D3 ⫾ SD* Mean ETS ⫾ SD* CLN Pregnancies/transfer (%) OG Pregnancies/transfer (%) CLN Implantation (%) Singleton Twins Triplets
34/68
24/72
33 ⫾ 3 7.5 ⫾ 1.5 3.4 ⫾ 0.5 16/34 (47.1) 15/34 (44.1) 22/68 (32.4) 12/15 3/15 0/15
34 ⫾ 4 7.0 ⫾ 1.7 3.5 ⫾ 0.5 12/24 (50.0) 11/24 (45.8) 19/72 (26.4) 6/11 4/11 1/11
* NS (p 0.05) Conclusions: An additional embryo was not significantly different in both the mean cell number and most importantly, the mean ETS; which was the main parameter used to determine whether the criteria for fresh cycles can be applied to FET cycles. Although there were not enough cycles included in the data set in order to determine significance in clinical parameters, there did not seem to be an alteration in the overall pregnancies as well as implantation rates. Risk of multiples appears to increase with the additional embryo. Transfer of 2 embryos on day 3 also appeared to establish a pregnancy at a similar rate compared with 3 embryos, with a benefit of decreasing multiple pregnancy risk Supported by: None.
P-36 Assisted hatching and cryopreservation: Impact on pregnancy rates in frozen embryo transfers. Eva Johnson, Wayne Caswell, Michael Tucker, Gabriel SanRoman, Kristen Cain, James Stelling. Reproductive Science Assoc, Mineola, NY. Objective: This analysis was designed to assess the Clinical Pregnancy Rate following Assisted Hatching versus Non-Assisted Hatching performed in cleavage stage Frozen Embryo Transfers. Design: A Retrospective Study over a one year period from January 2001-December 2001. Inclusion Criteria for this study were: 1) Cleavage Stage Frozen Embryo Transfer 2)Maternal Age ⬍39 years of age 3) Assisted Hatching versus Non-Assisted Hatching performed on all-thawed embryos prior to transfer. The average age did not differ significantly between the control group (Non-Assisted Hatching) and test group (Assisted Hatching). Materials/Methods: A total of 370 patients undergoing Frozen Embryo Transfers were studied for this analysis. The embryos were frozen and thawed using a standard cleavage stage Propandiol/Sucrose Slow Freeze/ Rapid Thaw protocol using 0.25uL cryostraws. All Thawed embryos were transferred later the same day and usually withing 3–5 hours. The Assisted Hatching was performed using Acid Tyrode’s (pH 2.4) to drill approximately 18 –20 um holes in the Zona Pellucida. Results: A clinical pregnancy was determined by the presence of an intrauterine gestational sac. The clinical pregnancy rate(CPR) per transfer for Non-Assisted Hatching cycles was 22% CPR. The CPR for cycles having Assisted Hatching performed was 37% (P⬍0.05). Conclusions: Clinical Pregnancy Rates for Frozen Embryo Transfers where Assisted Hatching was performed were significantly higher than for those cycles where it was not performed. We are continuing to collect data
FERTILITY & STERILITY威
to evaluate this apparent benefit of assisted hatching for thawed embryos. The basis for this improvement in implantation is most likely due to the hardening of the zona pellucida during the cryopreservation process, which can be alleviated by the opening of the zona. Supported by: Reproductive Science Associates, Mineola, NY.
P-37 Blastomere survival during cryopreservation is directly related to pregnancy rate following FET. Peter Kovacs, Lubna Pal, Barry R. Witt, David H. Barad. Albert Einstein Coll of Medicine, Bronx, NY. Objective: The freeze/thaw process may adversely impact embryo survival and pregnancy rate in frozen embryo transfer (FET) cycles. Day three cryopreserved embryos are composed of 4 to 8 blastomeres each. After thaw it is common to observe that some blastomeres are injured by cryopreservation. In this report we investigate the relationship of percentage blastomere survival to pregnancy outcomes after FET. Design: A retrospective cohort analysis of all day 3 cryopreserved embryo FET cycles reaching the stage of embryo transfer between 1/1/1999 and 12/31/2000. Materials/Methods: Embryo cryopreservation and thaw was per standard protocol. Data collected included blastomere number at freezing and after thawing, number of embryos transferred (ET) and cycle outcome. Exclusion criteria: donor oocytes/ incomplete information/ blastocyst transfer. For patients undergoing more than one FET cycle from a single in vitro fertilization (IVF) attempt, only the first FET cycle was included in our analysis. Blastomere survival per cycle was calculated by dividing the average postthaw blastomere count by the average prefreeze blastomere count among the thawed embryos. Based on blastomere survival, the data was divided into tertiles (high, mid, low). We developed logistic regression models with pregnancy rate (⫹ [BetaHCG, PR), clinical pregnancy rate (⫹ fetal heart, CPR) and implantation rate (gestational sac/ # of embryos transferred, IR) as dependent variables; blastomere survival (high, mid, low) as the independent variable and prefreeze blastomere count and number of embryos transferred as covariates. Results: Of the 137 FET cycles identified, 102 met inclusion criteria. Data on blastomere survival is reported in Table I. PR and CPR were significantly decreased in the low compared to the high blastomere survival group. IR in the low survival group was significantly lower when compared to the mid ⫹ high groups (p ⫽ 0.009). Table I. Pre-freeze and post-thaw blastomere number, blastomere survival, PR and CPR in the low, mid, high blastomere survival groups
Blastomere survival Prefreeze blastomere number (⫾ SD) Postthaw blastomere number (⫾ SD) survival (%) PR (95% CI) CPR (95% CI)
Low (N ⫽ 34)
Mid (N ⫽ 34)
High (N ⫽ 34)
4.09 ⫾ 1.08
4.69 ⫾ 1.12
3.8 ⫾ 1.32
2.62 ⫾ 1.06
4.19 ⫾ 1.02
3.85 ⫾ 1.19
64 ⫾ 18 89 ⫾ 4 0.22 (0.08–0.64)a 0.52 (0.19–1.45)c 0.22 (0.07–0.67)b 0.45 (0.16–1.28)c
99 ⫾ 2 1 1
low vs high p ⫽ 0.006 low vs high p ⫽ 0.008 c. mid vs high p ⫽ NS a.
b.
Conclusions: We demonstrate that low blastomere survival is associated with lower pregnancy rate and poorer outcome following FET cycles. This information would aid in decision-making regarding the number of embryos to thaw and transfer in future FET cycles. Supported by: None.
P-38 Are elevated estradiol levels detrimental to embryonic development? Steven David Spandorfer, Richard Bodine, Robert Clarke, Lucinda Veeck, Zev Rosenwaks. The New York Presbyterian Hospital/Cornell Medical Ctr, New York, NY.
S127
34/68
24/72
33 ⫾ 3 7.5 ⫾ 1.5 3.4 ⫾ 0.5 16/34 (47.1) 15/34 (44.1) 22/68 (32.4) 12/15 3/15 0/15
34 ⫾ 4 7.0 ⫾ 1.7 3.5 ⫾ 0.5 12/24 (50.0) 11/24 (45.8) 19/72 (26.4) 6/11 4/11 1/11
* NS (p 0.05) Conclusions: An additional embryo was not significantly different in both the mean cell number and most importantly, the mean ETS; which was the main parameter used to determine whether the criteria for fresh cycles can be applied to FET cycles. Although there were not enough cycles included in the data set in order to determine significance in clinical parameters, there did not seem to be an alteration in the overall pregnancies as well as implantation rates. Risk of multiples appears to increase with the additional embryo. Transfer of 2 embryos on day 3 also appeared to establish a pregnancy at a similar rate compared with 3 embryos, with a benefit of decreasing multiple pregnancy risk Supported by: None.
P-36 Assisted hatching and cryopreservation: Impact on pregnancy rates in frozen embryo transfers. Eva Johnson, Wayne Caswell, Michael Tucker, Gabriel SanRoman, Kristen Cain, James Stelling. Reproductive Science Assoc, Mineola, NY. Objective: This analysis was designed to assess the Clinical Pregnancy Rate following Assisted Hatching versus Non-Assisted Hatching performed in cleavage stage Frozen Embryo Transfers. Design: A Retrospective Study over a one year period from January 2001-December 2001. Inclusion Criteria for this study were: 1) Cleavage Stage Frozen Embryo Transfer 2)Maternal Age ⬍39 years of age 3) Assisted Hatching versus Non-Assisted Hatching performed on all-thawed embryos prior to transfer. The average age did not differ significantly between the control group (Non-Assisted Hatching) and test group (Assisted Hatching). Materials/Methods: A total of 370 patients undergoing Frozen Embryo Transfers were studied for this analysis. The embryos were frozen and thawed using a standard cleavage stage Propandiol/Sucrose Slow Freeze/ Rapid Thaw protocol using 0.25uL cryostraws. All Thawed embryos were transferred later the same day and usually withing 3–5 hours. The Assisted Hatching was performed using Acid Tyrode’s (pH 2.4) to drill approximately 18 –20 um holes in the Zona Pellucida. Results: A clinical pregnancy was determined by the presence of an intrauterine gestational sac. The clinical pregnancy rate(CPR) per transfer for Non-Assisted Hatching cycles was 22% CPR. The CPR for cycles having Assisted Hatching performed was 37% (P⬍0.05). Conclusions: Clinical Pregnancy Rates for Frozen Embryo Transfers where Assisted Hatching was performed were significantly higher than for those cycles where it was not performed. We are continuing to collect data
FERTILITY & STERILITY威
to evaluate this apparent benefit of assisted hatching for thawed embryos. The basis for this improvement in implantation is most likely due to the hardening of the zona pellucida during the cryopreservation process, which can be alleviated by the opening of the zona. Supported by: Reproductive Science Associates, Mineola, NY.
P-37 Blastomere survival during cryopreservation is directly related to pregnancy rate following FET. Peter Kovacs, Lubna Pal, Barry R. Witt, David H. Barad. Albert Einstein Coll of Medicine, Bronx, NY. Objective: The freeze/thaw process may adversely impact embryo survival and pregnancy rate in frozen embryo transfer (FET) cycles. Day three cryopreserved embryos are composed of 4 to 8 blastomeres each. After thaw it is common to observe that some blastomeres are injured by cryopreservation. In this report we investigate the relationship of percentage blastomere survival to pregnancy outcomes after FET. Design: A retrospective cohort analysis of all day 3 cryopreserved embryo FET cycles reaching the stage of embryo transfer between 1/1/1999 and 12/31/2000. Materials/Methods: Embryo cryopreservation and thaw was per standard protocol. Data collected included blastomere number at freezing and after thawing, number of embryos transferred (ET) and cycle outcome. Exclusion criteria: donor oocytes/ incomplete information/ blastocyst transfer. For patients undergoing more than one FET cycle from a single in vitro fertilization (IVF) attempt, only the first FET cycle was included in our analysis. Blastomere survival per cycle was calculated by dividing the average postthaw blastomere count by the average prefreeze blastomere count among the thawed embryos. Based on blastomere survival, the data was divided into tertiles (high, mid, low). We developed logistic regression models with pregnancy rate (⫹ [BetaHCG, PR), clinical pregnancy rate (⫹ fetal heart, CPR) and implantation rate (gestational sac/ # of embryos transferred, IR) as dependent variables; blastomere survival (high, mid, low) as the independent variable and prefreeze blastomere count and number of embryos transferred as covariates. Results: Of the 137 FET cycles identified, 102 met inclusion criteria. Data on blastomere survival is reported in Table I. PR and CPR were significantly decreased in the low compared to the high blastomere survival group. IR in the low survival group was significantly lower when compared to the mid ⫹ high groups (p ⫽ 0.009). Table I. Pre-freeze and post-thaw blastomere number, blastomere survival, PR and CPR in the low, mid, high blastomere survival groups
Blastomere survival Prefreeze blastomere number (⫾ SD) Postthaw blastomere number (⫾ SD) survival (%) PR (95% CI) CPR (95% CI)
Low (N ⫽ 34)
Mid (N ⫽ 34)
High (N ⫽ 34)
4.09 ⫾ 1.08
4.69 ⫾ 1.12
3.8 ⫾ 1.32
2.62 ⫾ 1.06
4.19 ⫾ 1.02
3.85 ⫾ 1.19
64 ⫾ 18 89 ⫾ 4 0.22 (0.08–0.64)a 0.52 (0.19–1.45)c 0.22 (0.07–0.67)b 0.45 (0.16–1.28)c
99 ⫾ 2 1 1
low vs high p ⫽ 0.006 low vs high p ⫽ 0.008 c. mid vs high p ⫽ NS a.
b.
Conclusions: We demonstrate that low blastomere survival is associated with lower pregnancy rate and poorer outcome following FET cycles. This information would aid in decision-making regarding the number of embryos to thaw and transfer in future FET cycles. Supported by: None.
P-38 Are elevated estradiol levels detrimental to embryonic development? Steven David Spandorfer, Richard Bodine, Robert Clarke, Lucinda Veeck, Zev Rosenwaks. The New York Presbyterian Hospital/Cornell Medical Ctr, New York, NY.
S127