Association between serum estradiol level on the hCG administration day and IVF-ICSI outcome

Estradiol (E2) is required for follicular development and play an important role in embryo implantation.

The aim of this study was to assess the impact of serum E2 levels on the day of hCG administration in IVF-ICSI patients who are performed controlled ovarian hyperstimulation (COH).

A total of 203 women who were undergone one time IVF cyclus were evaluated in this cross sectional study. All the patients were treated either with long protocol or with microdose flare protocol. The patients were categorized into five groups according to the serum E2 levels on the day of hCG administration.

The mean number of the retrieved oocytes was (NRO) 10.6±6.7, mean fertilization rate was 55.7±24.8, and implantation rate was 9.0±19.2. Of 203 patients, 43 (21%) patients were pregnant. When the overall results are examined, the number of the retrieved oocytes and the number of transferred embryos were better in patients with serum E2 levels >4000 pg/ml and these values were statistically significant. There were no statistical difference in patients 37 years or older. In women ≤36 years old, the IVF-ICSI outcomes were better in patients with serum E2 levels >4000 pg/ml.

In spite of the lack of high quality evidence to support a positive association between serum E2 levels and IVF-ICSI outcomes, this study shows that high E2 levels during COH might be associated with an increased potential of pregnancy depending on better ovarian response. When the overall results are examined, the best scores were in patients with serum E2 levels >4000 pg/ml.