Purposes: To evaluate the role of peak E2 level and its ratio to mid-luteal E2 level on implantation and clinical pregnancy rates in patients undergoing IVF cycles.
Methods: A retrospective study was designed covering 106 patients who were admitted to IVF Unit between June and October 2008. The patients were divided into two groups with respect to peak E2 levels. Ovulation induction has been done via standard long agonist protocol. Blood samples were drawn on the day of (hCG) administration and 8 days after embryo transfer for serum E2, progesterone measurements.
Results: The mean peak E2 level was 2,697.4 ± 1,453 pg/ml (range 684-4,983 pg/ml. The number of retrieved oocytes, luteal E2 level, peak E2 level and E2 ratio were significantly higher in E2 >2,500 group, however, the implantation rate was significantly lower in this group. There were statistically significant differences in peak E2 levels, luteal E2 levels, retrieved oocytes, E2 ratios; of the women who got pregnant and did not get pregnant, all the above parameters were significantly higher in non-pregnant group. According to E2 ratios, the clinical pregnancy rate was highest in group 1 and significantly lowest in group 3.
Conclusion: This study has shown that the high E2 level and mid-luteal decline of E2 which were defined as peak E2 level/mid-luteal E2 level were predictive for implantation rate in IVF cycles.