Single Embryo Transfer as Strategy to Decrease of Twins After Assisted Reproduction Techniques

ment. Monozygotic twinning rates of the overall clinical pregnancy rates were assessed for all these parameters as well as the morphologic stage and quality of these embryos. Recipients of donor oocytes and IVF patients were included as were ICSI and conventional insemination. Most day 3 ETs had assisted hatching prior to ET. RESULTS: Overall there were 74 cases of monozygotic (MZ) twinning in 4093 clinical pregnancies (1.8%). When MS was used to supplement HTF in day 3 ETs, there were 8 MZT out of 1085 clinical pregnancies (0.7%). During the same time period, 1of 410 pregnancies (0.2%) were observed when plasmanate was used. However, from 2000-2004, the MZT rate with plasmanate and HTF for day 3 ET was 7 of 402 (1.7%). When sequential media supplemented with plasmanate was used from 2000-2004, the MZT rate was 58 of 2196 (2.6%); the rate for day 3 ET was significantly lower than for day 5 ET (7 of 561, 1.2% vs 51 of 1638, 3.1%, respectively, p⬍ 0.05). MZTs were observed in IVF patients ranging in age from 23-42 years; there was no age difference between day 3 and day 5 groups. For day3 ET, 16 of the 23 MZTs were observed following assisted hatching. CONCLUSION: It is difficult to make conclusions about relationships between media/supplements and MZT because over the years marked variations in MZT rate often occur as was the case for day 3 ETs. These variations may reflect changes in the patients’ clinical profiles including the need for assisted hatching. However, when sequential media was used the MZT rate was significantly higher day 5 ET was performed. Most MZT arising from day 5 ET were from good quality and most advanced stage blastocysts. Supported by: None

OBJECTIVE: The objective of this study was to evaluate the rates of maturation of germinal vesicle and metaphase I oocytes in G1 version 2 and G1 version 3. DESIGN: A retrospective analysis of 1256 immature oocytes cultured for 56 to 58 hours post hCG administration in either G1 version 2 from January 1, 2001 to January 19, 2002 or in G1 version 3 from November 20, 2002 to March 31, 2004. MATERIALS AND METHODS: Patients underwent Antagon® (Organon) or Cetrotide® (Serono) antagonist protocols, Lupron® (TAP) agonist protocols, or flare protocols prior to controlled ovarian hyper-stimulation with Follistim® (Organon) or Gonal-F® (Serono). Oocyte retrieval occurred 36-39 hours post Human Chorionic Gonadotropin (hCG) administration. Intracytoplasmic sperm injection (ICSI) was performed 38-42 hours post hCG. Oocytes were individually placed in 50-100␮l micro-drops of sequential media (G1.2, G1.3, IVF Science, Vitrolife) under oil (Squibb, Sigma) and cultured overnight. Degree of maturation was evaluated 16-18 hours after ICSI was performed. If applicable, maturation ICSI was performed on metaphase II oocytes and evaluated for fertilization the following day. RESULTS: See tables.

P-615 Single Embryo Transfer as Strategy to Decrease of Twins After Assisted Reproduction Techniques. M. Nicolas, I. Pe´rez-Cano, V. Villalobos, E. Go´mez, L. Ferna´ndez, J. Landeras. IVI-MURCIA, Murcia, Spain. OBJECTIVE: The aim of the present study is analyze the results of single embryo transfer in IVF/ICSI in our clinic and its impact on decreasing of twin pregnancy rate. DESIGN: A retrospective analysis of the results in FIV/ICSI between January 1, 1996 and December 31, 2004 MATERIALS AND METHODS: The study groups were: elective single embryo transfer (eSET): a top quality embryo was selected on each cohort of embryos. compulsory single embryo transfer (cSET): we transfer the only available embryo with good quality (top or non top). elective double embryo transfer (eDET): two top quality embryo was selected on each cohort of embryos compulsory double embryo transfer (cDET): we transfer the only two available embryos with good quality (top or non top). RESULTS: CONCLUSION: These findings suggest the ability of maturing cumulus free oocytes in culture in both G1 version 2 and G1 version 3. Similar numbers have been reported by N. Cekleniak (Fertility and Sterility, Vol. 75, No. 6, June 2001) where 59.7% of GV and MI oocytes reached MII stage by 24 hours when cultured in P1-S (Irvine Scientific). Of those GV/MI oocytes that reach metaphase II and were injected, 29.1% fertilized. Although fertilization can be achieved from these immature oocytes, only 7.1% of maturation ICSI 2PN oocytes reached blastocyst and were either transferred or cryopreserved. Supported by: None. *,**,*** : statistically significant

CONCLUSION: Though we have few cases we believe that SET is a very good tool to minimize the multiple pregnancy rate in good prognosis cases in which select a top quality embryo supporting good pregnancy rates. Supported by: None

P-616 In Vitro Maturation of Immature Oocytes in G1.2 and G1.3. M. Langley, A. Nackley, K. M. Doody, K. J. Doody. Center for Assisted Reproduction, Bedford, TX.

FERTILITY & STERILITY威

P-617 EmbryoGlue® and its Impact on Pregnancy and Implantation Rates in Normal and Low Responding IVF Patients. W. D. Hazlett, L. Meyer, T. Nasta, P. Mangan, V. C. Karande. Karande and Associates, S.C., Hoffman Estates, IL. OBJECTIVE: Determine if EmbryoGlue® has an impact on pregnancy and implantation rates if used for ET in non-donor, normal and low responding IVF patients. DESIGN: Prospective randomized IRB approved study. MATERIALS AND METHODS: Two hundred and nine non-donor IVF patients underwent controlled ovarian hyper-stimulation using a gonadotropinreleasing hormone agonist (Lupron; TAP Pharmaceutical, Waukegan, IL) or antagonist (Ganerelix, Organon Inc., West Orange, NJ) and recombinant follicle-stimulating hormone (FSH) (Follistim, Organon; Gonal-F, Serono Labora-

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