ELOGA-IVF STUD: Comparative Effectiveness of Oral Elagolix Once Daily, Oral Elagolix Twice Daily, and Injectable Cetrorelix During Controlled Ovarian Stimulation in GnRH Antagonist IVF Cycles: A Retrospective Cohort Study

Abstract

Dr. Saurav Prakash Maity and Dr. Apurba Pailan

Background GnRH antagonists are routinely used during controlled ovarian stimulation (COS) to prevent premature luteinizing hormone (LH) surge. Injectable Cetrorelix is the conventional antagonist; however, oral elagolix has emerged as a potential alternative because of easier administration and lower treatment burden. Comparative real-world evidence remains limited.

Objective To compare ovarian stimulation, embryological, and clinical outcomes among women receiving injectable Cetrorelix, oral elagolix 200 mg twice daily, and oral elagolix 200 mg once daily during antagonist IVF cycles.

Methods A retrospective observational cohort study was conducted at Rashmika Fertility, Kolkata, India. Medical records of women undergoing antagonist IVF cycles between January 2024 and December 2025 were reviewed. Patients were categorized according to antagonist received during ovarian stimulation:

• Group A: Injectable Cetrorelix 0.25 mg once daily

• Group B: Oral Elagolix 200 mg twice daily

• Group C: Oral Elagolix 200 mg once daily

Selection of antagonist was based solely on physician preference and routine clinical practice.

Primary outcome:

• Number of mature (MII) oocytes retrieved.

Secondary outcomes:

• Total oocyte yield

• Fertilization rate

• Blastocyst formation rate

• Clinical pregnancy rate

• Trigger-day estradiol level

• Premature LH surge

• Cycle cancellation

• Medication cost

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