P-752: Peri-ovulatory estradiol levels in poor responder IVF patients: Correlations with outcome

Abstract

Estradiol (E2) levels are utilized to determine an effective stimulation. Poor responder IVF patients typically have a limited ovarian reserve. The purpose of this study is to determine if clinical outcomes are adversely affected when there is a decline in serum E2 levels at or following human chorionic gonadotropin (hCG) administration in women with a history of a poor response undergoing an IVF cycle with an antagonist protocol. Retrospective analysis of poor responder IVF patients undergoing a subsequent attempt without down-regulation, utilizing an antagonist-based stimulation protocol. All patients who underwent an IVF cycle utilizing an antagonist protocol at a single IVF center between July 2004 and December 2004 were included in this analysis. Serum E2 levels the day before (hCG - 1), on the day of (hCG), and the day following hCG (hCG + 1) administration were collected in 252 cycles. Number of oocytes retrieved, number of mature oocytes, number of normally-fertilized oocytes, implantation rate, positive pregnancy rate, and clinical pregnancy rate were analyzed. The results are summarized in the tables. A decline in E2 levels from the day before (hCG - 1) to the day of hCG administration occurred in 4.4% of cycles (11 cycles) and did not significantly affect any clinical outcome measured. E2 levels fell from the hCG day to the day after (hCG + 1) in 15 cycles (6.0%). These women had fewer oocytes retrieved, fewer mature oocytes, fewer normally-fertilized oocytes, and fewer embryos transferred when compared to women in whom the E2 levels rose. However, comparing cycles in which the E2 levels fell after hCG administration with cycles in which E2 rose, there was no statistically significant difference in the implantation rate, positive pregnancy rate, or clinical pregnancy rate.Tabled 1Tabled 1 Clinical outcomes in antagonist cycles are not affected when E2 levels are lower on the day of hCG as compared with the day prior to hCG administration. However, in these poor responder patients, a decline in E2 level on the day after hCG administration is associated with fewer oocytes retrieved, fewer mature oocytes, fewer normally-fertilized oocytes, and fewer embryos transferred. Implantation rate, positive pregnancy rate, and clinical pregnancy rate are not affected by a fall in serum E2 level following hCG administration. This work suggests that the decline in estradiol levels after hCG administration seen in some poor responder patients is a reflection of a delicate ovarian reserve.