Related Experiment Video
Updated: Aug 18, 2026
Collection of Human Follicular Fluid, Follicle Somatic Cells, and Immature Oocytes from Individuals Undergoing In Vitro Fertilization
Published on: October 24, 2025
A prospective, randomized, double-blind study to compare two doses of recombinant human chorionic gonadotropin in
Carina C W Chan1, Ernest H Y Ng, O S Tang
1Department of Obstetrics and Gynecology, University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong SAR, China. cwcchan@graduate.hku.hk
Context:
Different doses of human chorionic gonadotropin (hCG) have been used in various in vitro fertilization (IVF) treatment protocols to achieve final oocyte maturation. There is as yet no agreement on the optimum dose required.
Objectives:
The objective of this study was to compare the effectiveness of 250 and 500 microg recombinant hCG (r-hCG), which represented the lower and upper limits of the dose range, in inducing final oocyte maturation during IVF and intracytoplasmic sperm injection cycles.
Design:
This was a prospective, randomized, double-blind study.
Setting:
This study was performed at an IVF clinic in a teaching hospital.
Patients:
Sixty patients with an indication for intracytoplasmic sperm injection were studied.
Intervention:
The treatment dose used was 250 or 500 microg r-hCG.
Main Outcome Measures:
The percentage of metaphase II oocytes retrieved per patient, as an indicator of oocyte maturation, and the hormone profiles of the treatment cycle starting from the day of hCG up to hCG+10 d were the main outcome measures.
Results:
The percentage of metaphase II oocytes was similar in the two groups (89.3% vs. 86.0%; P = 0.326) despite higher serum and follicular fluid hCG levels on hCG+2 and hCG+4 d, as was the follicular fluid to serum hCG ratio in the 500-microg r-hCG group. Serum estradiol and progesterone levels were comparable initially, but became significantly higher in the 500-microg r-hCG group on hCG+10 d.
Conclusion:
The two doses of r-hCG were equally effective in inducing final oocyte maturation. It remains unclear whether the higher midluteal estradiol and progesterone levels in the 500-microg r-hCG group confer any benefit.
