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Updated: Sep 6, 2025

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Ovarian stimulation with GnRH analogues
Ivan S Montenegro1,2, Mariana Faller2, Isabel C A de Almeida2
1Gynecology and Obstetrics Service of the Hospital de Clínicas de Porto Alegre, Assisted Reproductive Sector, Federal University of Rio Grande do Sul.
Objective:
Analysis and compare data between two induction protocols (long agonist and flexible antagonist) in patients submitted an assisted reproduction technique in Porto Alegre.
Methods:
Cross-sectional study comparing the intermediate results with the use of two different ovarian stimulation protocols with gonadotropin-releasing hormone agonist versus antagonist to assisted reproductive techniques. The statistical analysis of the retrieved data (age, body mass index, number of oocytes recovered, number of fertilized oocytes, number of oocytes cleaved, total dose of FSH used and ovarian hyperstimulation syndrome) was performed by Student's t-test for parametric data and analysis of covariance for the dependent variables.
Results:
A total of 50 patients, 25 in each group, met the criteria for inclusion in the study between January and March in the year 2010. There was statistically significant difference only in the middle ages between the groups (P = 0.031). There was no statistical difference for the remaining data analyzed (body mass index, number of oocytes recovered, number of fertilized oocytes, number of oocytes cleaved and dose of FSH utilized). There were no cases of ovarian hyperstimulation syndrome.
Conclusion:
Both protocols are equal in terms of results. The agonist has advantages about scheduling of the procedure, but it takes too long to start the stimulation and have possibility to start medication in a pregnant patient. Added to this, we have the possibility of getting the ovarian hyperstimulation syndrome as complication. In the antagonist group, is clear the ease-of-use of the medication and the fastest start of stimulation.
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