Association of serum estradiol levels on the day of hCG administration with pregnancy rates and embryo scores in fresh ICSI/ET cycles down regulated with either GnRH agonists or GnRH antagonists.

Purpose: To investigate the interrelation between serum E2 level on hCG day, score of transferred embryos and pregnancy achievement. Methods: Records of 350 women aged 18-40 years who underwent ovarian hyperstimulation in fresh cycles down regulated either with GnRH agonist ( n = 70) or GnRH antagonist ( n = 280) followed by oocyte pick-up, ICSI and embryo transfer are retrospectively analyzed. Results: Median E2 levels on hCG day of cycles ending with and without pregnancy were similar ( p = 0.308). ROC curve for AUC of E2 on hCG day with dependent variable pregnancy rate also demonstrated that the E2 level on hCG day cannot be used to predict pregnancy in IVF/ICSI cycles (AUC 0.532, 95 % confidence interval: 0.471-0.593). Grouping cycles according to their E2 levels on hCG day also did not demonstrate any detrimental effect of either low or high E2 levels on hCG day both in agonist and antagonist cycles. Pregnancy rates are strongly correlated with mean and total score of transferred embryos. Interrelation of E2 on hCG day and pregnancy rate is independent from score of transferred embryos. Conclusions: E2 on hCG day is not correlated with pregnancy rates and cannot be used to predict pregnancy in neither agonist nor antagonist cycles, no matter its level or percentile is used. [ABSTRACT FROM AUTHOR]