NCT07088952

Triggering Ovulation at Follicle Size Smaller or Larger Than 17mm in a Modified Natural Cycle

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 572 (estimated)
• Sponsor: Vida Recoletas Sevilla · Academic / Other
• Sex: Female
• Age: 18 Years – 50 Years
• Healthy volunteers: Not accepted

Summary

The rise in frozen embryo transfer (FET) cycles within assisted reproductive technology (ART) has sparked the need to refine endometrial preparation protocols. The switch from hormone replacement cycles (HRT) to natural cycles, poses scheduling challenges onto laboratories, doctors and patients. The modified natural cycle (mNC), offering more precision for scheduling, shows promise but lacks comprehensive data on the potential flexibility of triggering criteria that may allow to control timing in a wider range. This prospective randomized study seeks to address this knowledge gap by evaluating the non-inferiority of triggering ovulation in mNC with follicle diameters of 13-16.9mm compared to the conventional 17-22mm. The study aims to enhance the understanding of the impact of follicle size at ovulation in reproductive outcomes, optimize FET treatments providing a more flexible mNC protocol, and improve patient care in ART clinics.

Conditions

• Embryo Transfer

Interventions

Type	Name	Description
PROCEDURE	Trigger at smaller folicular size	Trigger indicated at folicular diameter smaller than standard clinical practice, from 13mm to 16.9mm

Timeline

• Start date: 2025-10-22
• Primary completion: 2027-07-30
• Completion: 2028-05-30
• First posted: 2025-07-28
• Last updated: 2026-01-13

Locations

1 site across 1 country: Spain