Elevated E-2: Oocyte ratio in women undergoing IVF and tubal ET - Correlation with a decrease in the implantation rate

OBJECTIVE: To investigate the influence of various estradiol (E-2):oocyte r atios on reproductive outcome in women undergoing in vitro fertilization an d tubal embryo transfer (IVF-TET). STUDY DESIGN: Two hundred seven women undergoing 251 IVF-TET cycles were re cruited in this retrospective study. All the women received a flare-up gona dotropin releasing hormone agonist (GnRHa) protocol to achieve ovarian hype rstimulation. Oocyte retrieval was performed 34-36 hours after human chorio nic gonadotropin (hCG) injection, followed by TET two days later. RESULTS: An E-2:oocyte ratio greater than or equal to 350 pg/mL had a highe r E-2 level (2,213 +/- 2,258 vs. 1,553 +/- 972 pg/mL, P < .05) and fertiliz ation rate (77 +/- 23 vs. 64 +/- 23%, P < .001) but a lower oocyte number ( 4.8 +/- 4.7 vs. 7.6 +/- 4.8, P < .001) than in those with a ratio < 350 pg/ mL, The pregnancy (17.9% vs. 32.8%, P = .03) and implantation (5.3% vs. 12. 9%, P = .008) rates were significantly decreased in cycles with an E-2:oocy te ratio greater than or equal to 350 pg/mL ns compared to those with a unt ie < 350 pg/mL. CONCLUSION: IVF-TET cycles with nn elevated E-2: oocyte ratio correlated wi th lower pregnancy and implantation rates. The poor reproductive outcome po ssibly was due to the relatively high E-2 concentration, which might have a detrimental effect on endometrial receptivity.