GnRH agonist (GnRHa) used to trigger ovulation in patients at risk of ovarian hyperstimulation syndrome (OHSS) gives fertilization, implantation and pregnancy rates comparable to hCG

P-749 GNRH AGONIST (GNRHA) USED TO TRIGGER OVULATION IN PATIENTS AT RISK OF OVARIAN HYPERSTIMULATION SYNDROME (OHSS) GIVES FERTILIZATION, IMPLANTATION AND PREGNANCY RATES COMPARABLE TO HCG. V. Sanabria, J. Herna´ndez, E. Chinea, V. Pe~na, C. Concepcio´n, A. Palumbo. Centro de A.Reproduccio´n Humana de Canarias, La Laguna, Spain; Centro de A.Reproduccio´n Humana de Canarias, La Laguna, Spain. OBJECTIVE: The purpose of this study was to compare fertilization, implantation, pregnancy and OHSS rates after GnRHa or hCG administration to trigger ovulation in patients at risk for OHSS. DESIGN: Prospective clinical study in a private IVF clinic. MATERIALS AND METHODS: 48 patients underwent ovulation induction for IVF with an antagonist protocol and were at risk for OHSS. Ovulation induction was carried out with FSH and LH and monitored by ultrasound and estradiol levels. When at least 2 follicles reached a mean diameter of 18 mm either hCG [5.000-10.000 IU 36 hours before eggs retrieval (ER)] or leuprolide acetate (2 doses of 0.6 mg given 36 and 26 hours before ER) was administered. Patients at highest risk received the GnRHa. For luteal phase support in the hCG group (n¼26), progesterone administration was begun the night after ER and oral estradiol valerate (EV) on the day of embryo transfer. In the GnRHa group (n¼22) progesterone and EV administration began on the day of ER. Statistical analysis was performed using the SPSS. RESULTS: The two groups were comparable for age, dose of gonadotrophins and E2 level on the day of hCG (table 1). The number of follicles on the day of hCG was significantly higher in the GnRHa group. There was no statistically significant difference in fertilization, implantation and pregnancy rates. There were 4 cases of OHSS (15.38%) in the hCG group and none in the GnRHa group. TABLE 1. Results

Antagonist hCG No. Cycles Age FSH units LH units Maximum E2 level No. follicles No. oocytes % mature oocytes Fertilization rate No. transferred embryos per cycle No. frozen embryos Clinical PR Cumulative PR rate per patient (freshþfrozen cycles) IR No. miscarriages Incidence of mild to severe OHSS

Antagonist GnRH agonist

P value

26 22 32.503.56 33.903.70 1873.98617.31 1754.81661.30 517.50205.40 530.11342.70 2916.07858.30 4386.132036.16 18.384.39 26.227.80 20.125.45 30.4011.31 79.360.14 73.260.13 67.450.20 71.030.15 2.230.43 2.090.52

NS NS NS NS 0.019 NS NS NS NS

4.153.80 18/26 (69.23%) 19/25 (76.00%)

NS NS NS

41.38% 2/26 4/26

7.046.66 10/22(45.45%) 14/21(66.66%) 23.91% 2/22 0/22

NS NS NS

CONCLUSIONS: With GnRHa trigger, OHSS is eliminated while maintaining implantation and pregnancy rates similar to those obtained with hCG. Therefore, we believe that the choice of an antagonist protocol with GnRH agonist to trigger ovulation is an excellent choice for patients at risk for OHSS. Supported by: None.

P-750 ANTRAL FOLLICLE COUNT (AFC) AND OVARIAN VOLUME (OV) CORRELATE WITH OVARIAN RESPONSE TO GONADOTROPHIN STIMULATION AND PREGNANCY. R. Garcıa, J. Herna´ndez, L. Iaconianni, E. Bilancioni, R. A. Bennett, A. Palumbo. Centro de A.Reproduccio´n Humana de Canarias, La Laguna, Spain; EcoBI, Rome, Italy; Westchester Reproductive Medicine, NY, NY.

S360

Abstracts

OBJECTIVE: To determine whether AFC and OV predict ovarian response to ovulation induction for IVF and pregnancy. DESIGN: Review of 263 IVF cycles from January to December 2007 in a private fertility practice. MATERIALS AND METHODS: Ultrasounds were performed by one of 4 expert operators, after standardization of the technique, using a Voluson Pro V General Electric instrument. Antral follicles measuring 2 to 10 mm were counted in each ovary. A correlation was sought between the following variables: age, basal FSH, OV/AFC on day 2 of cycle, units of FSH and LH employed for ovulation induction, number of follicles R16 mm on day of hCG, total and MII oocytes retrieved, % MII oocytes, estradiol (E2) level on day of hCG, occurrence of pregnancy. Statistical analysis was performed using the SPSS software. RESULTS: A linear correlation was present between OV and AFC and both decreased with advancing patient age (r2, p< 0.01). A linear correlation also exists between FSH and age, but to a lesser degree (p¼0.046). There was a correlation between basal FSH and both AFC (r2, p< 0.01) and OV (r2, p< 0.05). Of the variables reflecting ovarian response to stimulation, the number of follicles R16 mm on the day of hCG had a negative correlation with FSH, and a positive correlation with AFC and OV. The E2 level on the day of hCG and the number of total oocytes retrieved showed a positive linear correlation with the AFC but not with the OV and a negative correlation with the basal FSH (r2, p< 0.01). No significant correlation was found for the % MII oocytes. There was a negative linear correlation between the units of FSH and LH administered for ovulation induction and both AFC/OV and a positive correlation with basal FSH (r2, p< 0.01). FSH and AFC, but not OV, show a linear correlation with clinical pregnancy. Age, independently from other variables, had a negative and highly significant correlation with the variables related to ovarian response to stimulation and pregnancy. CONCLUSIONS: This study suggests that AFC and basal FSH are the best predictors of ovarian response to gonadotrophin stimulation and pregnancy. Therefore, the combination of these two parameters (in addition to patient’s age) should be used to individualize ovulation induction protocols to optimize IVF results. Extending this analysis to a larger number of patients will permit a more exact identification of a ‘‘cut off’’ value for AFC and OV for the prediction of ovarian reserve, which may be useful for patients’ counselling. Supported by: None.

P-751 IS THE USE OF A GNRH ANTAGONIST STIMULATION PROTOCOL INFERIOR TO A GNRH AGONIST IN DONOR OOCYTE IVF? M. F. Costantini-Ferrando, E. R. Rauch, S. Spandorfer, O. K. Davis, I. N. Cholst, Z. Rosenwaks. Center for Reproductive Medicine and Infertility, Cornell Weill Medical College, New York, NY. OBJECTIVE: Our hypothesis was that Gonadotropin-releasing hormone antagonist (GnRHant) protocols are not inferior to Gonadotropin-releasing hormone agonist (GnRHa) protocols in terms of in vitro fertilization (IVF) outcomes using donor oocytes. GnRHa have reduced the incidence of premature LH surges and cancelled IVF cycles, while increasing pregnancy rates. They are, however, associated with an increased duration of stimulation and dosage requirement for gonadotropins. The use of GnRHant has offered an alternative strategy to reducing the incidence of premature LH surges and ovarian hyperstimulation syndrome (OHSS). However, decreased pregnancy rates of up to 15% have been reported, raising concern as to the relative efficacy of this approach. DESIGN: Retrospective cohort study with sufficient sample size to detect a 15% difference in protocols at 95% confidence with 80% power. MATERIALS AND METHODS: We reviewed 339 donor cycles (514 recipients) undergoing IVF in a ‘‘shared’’ program, between 1/05 and 2/ 08. We compared 261 IVF donor cycles using a GnRHa to 78 donor cycles using a GnRHant. Most donors donated to two separate recipients in each cycle. Outcomes of interest were: estrogen on day of HCG, total gonadotropins, oocytes retrieved and fertilized, embryos transferred, pregnancy and implantation rates. We used Pearson Chi-Square analysis for categorical variables and Mixed Model Analysis of Variance for continuous variables to account for the nesting effect of a donor donating to more than one recipient. RESULTS: Other than a higher gonadotropin dosage requirement in the GnRHant protocol, and a lower mean estradiol level on the day of

Vol. 90, Suppl 1, September 2008