The impact of supraphysiologic serum estradiol levels on peri-implantation embryo development and early pregnancy outcome following in vitro fertilization cycles

Abstract

To determine the impact of elevated serum estradiol levels (EE2-defined as levels > 90th percentile) on the day of hCG administration during IVF on oocyte fertilization, embryo development, implantation, clinical pregnancy and miscarriage rates. A total of 2,995 consecutive IVF cycles in 1,889 patients with non-donor oocyte retrieval resulting in fresh embryo transfer between 1/1/2005 and 12/31/2011 were analyzed. Cycles were stratified by serum E2 level on the day of hCG administration into those with levels >90th percentile and ≤ 90th percentile. Rates of normal fertilization, embryo development, positive pregnancy test, implantation, clinical pregnancy and spontaneous miscarriage were compared. Serum estradiol above the 90th percentile on the day of hCG administration was associated with a significantly lower rate of normal fertilization (68.6 ± 20 vs. 71.6 ± 21, p = 0.02) when compared with patients with a lower serum estradiol threshold. The proportion of embryos that progressed from 2PN to 6-8 cell on day 3 was not different between the two groups. Although rates of positive pregnancy test (55.2% vs. 57%), implantation (26.4% vs. 28.5%) and clinical pregnancy (45.5% vs. 49.4%) were lower in patients with a higher estradiol threshold, these differences were not statistically significant. Similarly, there was no difference in the spontaneous miscarriage rates between the two groups (8.4% vs. 7.1%). Serum estradiol levels above the 90th percentile on the day of hCG administration is associated with lower oocyte fertilization rate; however, such levels do not impact embryo development, implantation, clinical pregnancy or spontaneous miscarriage rates.