Effects of laser-assisted removal of necrotic blastomeres from partially damaged embryos in frozen-thawed embryo transfer cycles

laparoscopic detorsion, followed by successful embryo transfer on day five of the same IVF cycle. Similarly, a 32 y.o woman had ovarian torsion three days after egg retrieval, and was treated by a prompt laparoscopic ovarian detorsion with subsequent successful embryo transfer on day five of the same IVF cycle. RESULTS: In addition to maintaining viable ovaries after laparoscopic ovarian detorsion in the two cases, there was a successful embryo transfer on day five of the same IVF cycle for both patients, with subsequent successful pregnancies. Both patients had minimal postoperative pain and were discharged home a few hours after the laparoscopy. CONCLUSION: Ovarian torsion is a potential complication of ovarian hyperstimulation. Its early diagnosis and treatment is important for preservation of ovarian function. After a prompt laparoscopic ovarian detorsion of a torsed ovary that occurred following egg retrieval, a patient should not automatically be assigned to cryopreservation of all embryos with delayed frozen embryo transfer in a subsequent cycle; rather, embryo transfer can be performed successfully, as scheduled, during the same cycle. P-475 Wednesday, October 16, 2013 CUMULATIVE PREGNANCY RATE PER OOCYTE RETRIEVAL BY CONTROL OVARIAN STIMULATION. H. Ohno,a,b F. Noritaka,a,b,c K. Nakayama,a,b M. Takeuchi,a,b K. Yasue,a,b Y. Asada.a,b,c aAsada Ladies Nagoya Clinic, Nagoya, Aichi, Japan; bAsada Ladies Kachigawa Clinic, Nagoya, Aichi, Japan; cThe Asada Institute for Reproductive Medicine, Nagoya, Aichi, Japan. OBJECTIVE: Assisted reproductive technology (ART) imposes mental and economic burdens on the patient, in addition to physical stress caused by oocyte retrieval; improved pregnancy rates per oocyte retrieval would reduce such burdens. DESIGN: Retrospective study. MATERIALS AND METHODS: We undertook a retrospective analysis of all patients (1617 patients, 1966 transfers) who underwent controlled ovarian stimulation at our clinic between January 2009 and December 2011. The above-mentioned target cases were compared among three age groups: Group A, %35 years; Group B, 36-38 years; and Group C, R39 years. We then examined cumulative pregnancy rates per oocyte retrieval. RESULTS: Cumulative pregnancy rates were determined by five attempts, showing rates of 43.3-69.8% in Group A, 29.3-53.2% in Group B, and 18.230.2% in Group C. Cumulative rate of pregnancy per oocyte retrieval

the cumulative rate(%) Age(years)

1stET 2ndET 3rdET 4thET 5thET

Group A (age &35 years) Group B (age 36-38 years) Group C (age S39 years)

43.3 29.3 18.2

60.9 43.0 26.6

67.5 50.0 28.9

69.1 52.6 30.2

69.8 53.2 30.2

In each age group, pregnancy rate increased significantly with the second transplant. Conversely, the increase in cumulative pregnancy rate for the third transplant was %7% in all age groups. In addition, cumulative pregnancy rate plateaued from the fourth transplant. CONCLUSION: To increase cumulative pregnancy rates, securing embryos for more than two transplantations per oocyte retrieval is important.

R50% intact; 306 embryos). The necrotic blastomeres removal was performed in 118 partially damaged embryos (n¼34). 188 partially damaged embryos (n¼56, control group) were cultured directly, without the necrotic blastomeres removal. Embryos in two groups were cultured until day 6 and then transferred. Effects of necrotic blastomeres removal on developmental changes and clinical outcomes were investigated. Statistical analyses were preformed by using the Student’s t-test or c2 test. RESULTS: Removal of necrotic blastomeres from partially damaged embryos significantly increased the post-thaw cleavage rates (61% vs. 32.4%, P<0.05), blastocyst formation rates (39% vs. 13.3%, P<0.05) and the percentage of good quality blastocyst of day 6 (22% vs. 3.7%, P<0.05) compared with the control group. Implantation and pregnancy rates of necrotic blastomere removed embryos were 18.1% and 38.2%, whereas the rates of control group embryos were 10.3% and 19.6%, respectively. There was no statistical significance between the two groups. CONCLUSION: The removal of necrotic blastomeres significantly improves viability of partially damaged frozen-thawed embryos and may be beneficial for neighboring blastomeres by eliminating potentially toxic substances released from the dead blastomeres. These results indicate that developmental potential of partially damaged frozen-thawed embryos can be equivalent to fully survived embryos by removing necrotic blastomeres. P-477 Wednesday, October 16, 2013 COMPARISON OF PREGNANT OUTCOMES OF THAWING BLASTOCYST ONE DAY BEFORE TRANSFER OR NOT. T. Li, X. Wang, C. Yue, C. Fang. Center for Reproductive Medicine, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China. OBJECTIVE: To discuss the impact on pregnant outcomes of two different thawing time of blastocyst, thawing on the day before transfer and thawing on the day of transfer. DESIGN: Retrospectively analyze whether thawing time of blastocysts influence pregnant outcomes. MATERIALS AND METHODS: Patients underwent first IVF-ET cycle in October, 2010 to March, 2013, and got their embryos transfer once or twice, with age below 40 years old, are involved. Analyze the 739 cycles of thawed blastocyst transfer, all with good quality blastocysts. All the cycles are divided into 4 groups based on different thawing time and different development days: Day 5 blastocyst thawed on the day of transfer (Group A, n¼140), Day 5 blastocyst thawed one day before transfer and cultured overnight (Group B, n¼299), Day 6 blastocyst thawed on the day of transfer (Group C, n¼96) and Day 6 blastocyst thawed one day before transfer and cultured overnight (Group D, n¼204). The pregnant outcomes are compared among four groups. RESULTS: There are no significant differences found in age, BMI, basal FSH level, endometrium thickness and number of transferred blastocysts among the four groups. And clinical pregnancy rate of each group and statistic analysis are shown in Table. Comparison of pregnancy rates among four groups

Day 5 Day 6 p

Thawed on the day of transfer

Thawed one day before transfer and cultured overnight

66.4%(group A) 50%(group C) 0.012

64.5%(group B) 45.6%(group D) <0.01

p NS NS

P-476 Wednesday, October 16, 2013

Data are defined as pregnency rates, and statistically analyzed by Chi-square test.

EFFECTS OF LASER-ASSISTED REMOVAL OF NECROTIC BLASTOMERES FROM PARTIALLY DAMAGED EMBRYOS IN FROZEN-THAWED EMBRYO TRANSFER CYCLES. J. H. Jang, J. S. Kim, E. H. Kwak, A. R. Lee, M. S. Shin, E. H. Kang. IR Center, Seoul Women’s Hospital, Incheon, Republic of Korea.

CONCLUSION: In the cycles of thawed blastocyst transfer, the pregnancy rate of Day 5 blastocyst is significantly higher than Day 6 blastocyst. And thawing good quality blastocyst one day before transfer does not impair pregnancy rate, which can provide bases of proper opportunity for arrangement of work in embryonic laboratory.

OBJECTIVE: In general, the implantation potential of partially damaged frozen-thawed embryos is significantly lower than that obtained with use of fully intact embryos. The aim of this study is to examine whether the developmental potential of partially damaged frozen-thawed embryos can be improved by removal of necrotic blastomeres before embryo transfer. DESIGN: A retrospective study. MATERIALS AND METHODS: From 2009 to 2012 eighty-one patients (90 cycles) undergoing frozen embryo transfer were participated in the present study. 576 day 3 embryos were thawed (100% intact; 270 embryos,

S286

ASRM Abstracts

P-478 Wednesday, October 16, 2013 THE IMPACT OF OVERNIGHT CULTURE FOR PREGNANCY OUTCOMES IN THAWED - FROZEN BLASTOCYST TRANSFER CYCLES. C. Yue,a C. Fang,a X. Gong,b L. Li,a T. Li,a X. Liang.a aReproductive Center, Sixth Affiliated Hospital of Sun Yan-Sen University, Guangzhou, Guangdong, China; bMedical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong, China.

Vol. 100, No. 3, Supplement, September 2013