Related Experiment Video
Updated: Oct 5, 2026

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Can we abandon routine evaluation of serum estradiol levels during controlled ovarian hyperstimulation for assisted
I Ben-Shlomo1, J Geslevich, E Shalev
1Division of Reproductive Endocrinology and Assisted Reproduction Technology, Department of Obstetrics and Gynecology, Ha'Emek Medical Center, Haifa, Israel.
Objective:
To assess whether abandoning measurement of serum estradiol (E2) and spacing ultrasound evaluations at greater intervals had an effect on the results of assisted reproduction technology (ART).
Design:
A retrospective comparison of two consecutive periods.
Setting:
Division of Assisted Reproduction Technology, Department of Obstetrics and Gynecology, Ha'Emek Medical Center, Afula, Israel.
Patient(S):
One thousand nine hundred and eighty-five controlled ovarian hyperstimulation (COH) cycles for ART were initiated during the years 1996 to 1999.
Intervention(S):
During the first 2 years an intensive follow-up protocol was used that included E2 blood levels measurements. In the next 2 years a less intensive protocol was adopted that did not use E2 measurements.
Main Outcome Measure(S):
ART results and the rate of ovarian hyperstimulation syndrome (OHSS).
Result(S):
The patients' background characteristics did not differ between the two periods. The cancellation rate was not different (9.8% vs. 7.2%). There was no difference in the duration of stimulation or the amount of gonadotropins used. The number of oocytes retrieved (12.1 +/- 9.3 vs. 9.6 +/- 6.3), fertilization rates (74% vs. 75%), and clinical pregnancy rates (26.2% vs. 27.9%) did not differ. The incidence of severe ovarian hyperstimulation syndrome was not significantly different between the two periods.
Conclusion(S):
Controlled ovarian hyperstimulation for ART can be done reliably without routine, serial serum E2 measurements without compromising the treatment results.