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Updated: Jun 14, 2026

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Comparison of GnRH antagonist with long GnRH agonist protocol after OCP pretreatment in PCOs patients
Ensieh Shahrokh Tehraninejad1, Roya Nasiri, Batool Rashidi
1Vali-e-Asr Reproductive Health Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Purpose:
To evaluate the efficacy of GnRH antagonist in comparison with the GnRH agonist protocol in OCP pretreated polycystic ovary syndrome (PCOs) patients undergoing their first ART cycle.
Materials And Methods:
Prospective randomized controlled trial. University-based tertiary fertility center. Ninety-five PCOs patients under 35 years of age, with primary infertility were randomized to an ovarian stimulation protocol consisting of either. GnRh antagonist (study group) or GnRH agonist (control group) after pretreatment with OCP. Coasting or GnRH agonist Trigger was used when estradiol level > or =3,000 pgr/ml in the control and study group, respectively. Both groups received 800 mg vaginal progesterone and 4 mg oral estradiol valerate for luteal phase support.
Results:
There was no statistically significant difference in the age, body mass index, basal FSH, duration of infertility, the number of oocytes retrieved, the number of embryos transferred, Serum E2 levels on day of trigger, fertilization rate, chemical and clinical pregnancy rates between the two groups. None of the patients in the study group developed ovarian hyperstimulation syndrome (OHSS) compared with 22.2% of patients in the control group. Total duration of treatment and the number of HMG ampoules used were lower in the study group.
Conclusion:
Antagonist protocol and GnRH agonist trigger for ovulation whenever necessary has a similar cycle outcome to the GnRH-agonist protocol in OCP pretreated PCOs patients, with significantly reduced risk of OHSS.
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