CONCLUSIONS: Although the clinical pregnancy rates were similar be-tween slow freeze and vitirified blastocysts our data suggests that vitirifiedblastocysts have greater potential.

Supported by: None.

A-131

CRYOPRESERVATION OF PRONUCLEAR (PN) ZYGOTES IN-CREASES CUMULATIVE PREGNANCY RATES IN PRIMARY IN-FERTILITY PATIENTS HAVING LESS THAN TEN ZYGOTES.M. K. Kim, D.-W. Park, K. H. Bang, S. Choi, I. O. Song, C. K. Lim. Labo-ratory of Reproductive Biology and Infertility, Cheil General Hosp. &Women’s Healthcare Ctr., Seoul, Republic of Korea; Department of Obstet-rics and Gynecology, Cheil General Hosp. & Women’s Healthcare Ctr.,Seoul, Republic of Korea.

OBJECTIVE: It is well known that cryopreservation of supernumeraryembryos could increase the cumulative pregnancy rates. However, there isno consensus regarding cryopreservation at the PN stages to improve preg-nancy outcomes in IVF cycles with small number of zygotes. This studywas carried out to see whether cryopreservation of PN zygotes could increasethe cumulative pregnancy rates in the patients having less than 10 zygotes.

DESIGN: Retrospective data analysis.MATERIALS AND METHODS: We retrospectively analyzed 344 em-

bryo transfer (ET) cycles with less than ten embryos. Total ET cycles weredivided into two groups: group A (n¼107), some of the sibling embryoswere cryopreserved at the PN stages and the others were cultured on day3; group B (n¼237), all embryos were cultured to transfer on 3 day. Inboth groups, remained good quality embryos after ET were also cryopre-served. And each groups were subdivided by the causes of infertility (primaryA-1, B-1; secondary A-2, B-2). Clinical pregnancy outcomes were comparedamong them in fresh ET cycles and cumulative ongoing pregnancy were es-timated after fresh ET and subsequent frozen-thawed ET.

RESULTS: Mean age, mean scores and top score transferred embryoswere similar among four groups. Number of transferred embryos was signif-icantly lower in group A (3.0 � 0.8) compared with group B (3.6 � 0.6)(p<0.05). The number of beta-hCG positives, clinical pregnancy rates andongoing pregnancy rates were similar in all groups after fresh ET. Implanta-tion rates of group B were significantly higher (20.2% vs 15.3%, p < 0.05)than group A. There were no significantly differences in cumulative preg-nancy rates between group A (53.3%) and B (45.6%). However, the cumula-tive ongoing pregnancy rates were significantly higher in group A-1 (62.8%)compared with group B-1 (39.2% P< 0.01).

CONCLUSIONS: Our results suggested that cryopreservation of embryosat the PN stages could increase cumulative pregnancy rates in primary infer-tility patients even though the patients had less than ten embryos.

Supported by: None.

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DAY 7 BLASTOCYSTS, SHOULD THEY BE DISCARDED OR CRY-OPRESERVED? M. Li, F. Miller, M. Zhang, A. Kumar, G. Hubert,R. Buyalos. Fertility & Surgical Associates of CA, Thousand Oaks, CA.

OBJECTIVE: This is a case report of a frozen-thawed day 7 blastocysttransfer resulting in an ongoing twin pregnancy.

DESIGN: Private IVF clinic.MATERIALS AND METHODS: The patient is a 30 year old nulligravida

female with two years of primary infertility whose husband has male factorinfertility. Semen parameters on the day of ova retrieval revealed a spermdensity of 2 million per ml with 20% progressive motility. In January2008, she received a total of 2025 IU of gonadotropins using a GnRH antag-onist protocol, 18 oocytes were retrieved. 12 metaphase-II oocytes were in-jected via intracytoplasmic injection (ICSI) using her husband’s sperm. AfterICSI, oocytes were cultured in Life Global (LG) medium supplemented withSerum Substitute Supplement (SSS, Irvine Scientific, Cat #99193) and 3%Human Serum Albumin (HSA, Irvine Scientific, Cat#9988). Eleven two-pro-nuclear stage embryos were observed 18h after ICSI. On day 3, embryoswere transferred into fresh LG medium for continuous culture. On day 5,one early blastocyst and two morula stage embryos were selected for embryotransfer (ET). On day 6 of culture, the leading embryos had reached the earlyblastocyst stage and were not deemed suitable for cryopreservation. There-fore, the remaining embryos were cultured until Day 7. On Day 7, three ex-panded blastocysts were cryopreserved using blastocyst freezing media F1and F2 (Irvine Scientific, Cat#90108) and a slow freezing protocol.

FERTILITY & STERILITY�

RESULTS: The patient did not conceive in the fresh cycle. Forty one dayslater she completed a frozen embryo transfer cycle following endometrialpriming with I.M. estradiol valerate and I.M. progesterone. Three, day 7 blas-tocysts were thawed on the morning of transfer using blastocyst thawing so-lution T1 and T2 (Irvine Scientific, Cat#90110). All three blastocystssurvived and re-expanded prior to ET. Assisted hatching was performedone hour prior to ET on all embryos using acid Tyrode’s solution. 12 days af-ter ET, the patient’s serum hCG level was 772 mIU/ml. Thirty-four days afterET, two gestational sacs with fetal cardiac activity were observed via trans-vaginal ultrasound. Forty-five days after ET, at 10 and 4/7 weeks gestation,a viable diamniotic dizygotic twin gestation was confirmed. The patientwas then referred for obstetrical care.

CONCLUSIONS: An ongoing clinical diamniotic dizygotic twin gestationwas established using cryopreserved-thawed day 7 blastocysts. Day 7 blasto-cysts may be considered for cryopreservation, especially from patients ofyoung reproductive age.

Supported by: None.

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FREEZING THE BIOLOGICAL CLOCK: DEMOGRAPHICS OF ANOOCYTE CRYOPRESERVATION PROGRAM. J. M. Knopman,A. E. Reh, N. Noyes, J. A. Grifo, L. C. Krey, L. Kump. OB/GYN, NYU Med-ical Center, New York, NY.

OBJECTIVE: To report oocyte cryopreservation patient demographicsand medical information.

DESIGN: Retrospective cohort review of women undergoing oocyte cryo-preservation at a large university-based IVF center.

MATERIALS AND METHODS: Demographic information for patientscompleting oocyte cryopreservation cycles from 2005 to 2007 was analyzedincluding age, marital status, day 2 FSH and estradiol (E2) levels, occupa-tion, and relevant medical, infertility, and/or obstetrical history.

RESULTS: Of 81 patients (mean age 38.6� 3 y, range 19-44 y) presentingto discuss oocyte cryopreservation and consenting to IRB-approved registryparticipation, 62 (77%) completed at least one treatment cycle. Of 19 (23%)who did not complete a cycle, 7 were cancelled for poor response, 6 providedno information for not proceeding with their treatment, 2 did not begin ovar-ian stimulation due to an elevated day 2 FSH level, 2 elected alternatively toproceed with embryo cryopreservation, 1 developed a cancer recurrenceprior to initiating the cycle and 1 stopped her treatment after developing cel-lulitis at an injection site. A total of 62 women completed freezing cycles.Their mean day 2 FSH was 7.9 � 6.6 IU/L and E2 was 38 � 19 pg/ml.Fifty-three (85%; mean age 39 � 3 y) cited elective reasons for undergoingtreatment while 9 (15%; mean age 35.7 � 5 y) gave medical indications, allrelated to a cancer diagnosis: breast, endometrial, ovarian, cervical, colonand vaginal cancer, spinal cord tumor and Ewing’s Sarcoma. Relationshipstatus of the women revealed 42 (68%) were single, 8 (13%) were di-vorced/separated, 7 (11%) had significant others (but not-married) and 5(8%) were married. Forty-two patients (68%) were nulliparous. Of thoseever pregnant (n ¼ 20), 17 (85%) had terminated, 2 (10%) miscarried and1 delivered a full-term live born. Ten (16%) women had a concurrent diagno-sis of infertility. Fifty (81%) women were employed in positions that requiredprofessional degrees.

CONCLUSIONS: Despite the experimental and newly emerging technol-ogy of oocyte cryopreservation, well informed counseled patients remainpassionate in pursuing this treatment. While little is currently known aboutthe women undergoing this procedure, our data indicates that the majorityare older, single and employed in positions with professional degrees. Al-though initially available only to cancer patients who, without preservationmethods, would be left potentially infertile by treatment modalities, oocytecryopreservation is also being embraced electively.

Supported by: None.

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IMPROVED PREGNANCY RATES FOLLOWING THE INTRODUC-TION OF VITRIFICATION FOR CRYOPRESERVATION. M. J. Angle,A. Shanti, C. Smikle, L. Kao. Laurel Fertility Care, San Francisco, CA; Ob-stetrics and Gynecology, UAMS, Little Rock, AR.

OBJECTIVE: After two years practice with mouse embryos and discardedspecimens prior to disposal (with patient permission) the decision was made

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