NCT06433518

BEst Size for Ovulation Triggering in Poseidon 4 Patients (BEST 4 Study)

What Should Be The Optimal Ovulation Triggering Size in Poseidon Group 4 Patients Undergoing Ovarian Stimulation?

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 200 (estimated)
• Sponsor: Centrum Clinic IVF Center · Academic / Other
• Sex: Female
• Age: 35 Years – 44 Years
• Healthy volunteers: Not accepted

Summary

This observational clinical study aims to determine the optimal timing of ovulation triggering in women aged 35 and above with poor ovarian reserve. For this purpose, cases undergoing ovarian stimulation for assisted reproductive treatment and planned final oocyte triggering will be evaluated in two separate groups: 1. \*\*Experimental Group\*\*: Final oocyte triggering will be performed when the follicle or follicles measure between 13-16 mm. 2. \*\*Control Group\*\*: Final oocyte triggering will be performed when the follicle or follicles measure greater than 17 mm. All triggers will be administered uniformly with 6500 units of recombinant hCG and 0,2 mg triptorelin injections. The primary outcome of the study will be the number of mature oocytes. Secondary outcomes will include fertilization rates, embryo counts, and implantation rates. Primary and secondary outcomes will be compared between the two groups.

Detailed description

The timing of final oocyte maturation in assisted reproductive techniques is critically important. If serum steroid hormone levels are appropriate during the late follicular phase, ovulation triggering can be performed using various agents. There are numerous comparative studies in the literature on this topic. However, a key issue is determining the most optimal timing for this trigger. In standard practice, the final triggering is performed when the follicle size reaches 17 mm or more. The purpose of this is to obtain mature eggs from these follicles during the oocyte aspiration process. However, in some special cases, to maximize the desired yield, this size threshold may be adjusted. A prime example of this is in older patients with poor ovarian reserve, as the expected egg yield may not be achieved with standard practices. During the oocyte collection process, fewer mature oocytes (M2) may be retrieved, or no oocytes may be retrieved at all, despite proper ovarian stimulation. Therefore, the optimal follicle size for these cases has not been definitively established in the literature. Thus, there is a need to determine other follicular thresholds specifically for older women with poor ovarian reserves to enhance egg and mature egg yields. For this purpose, cases undergoing ovarian stimulation for assisted reproductive treatment and planned final oocyte triggering will be evaluated in two separate groups: 1. \*\*Experimental Group\*\*: Final oocyte triggering will be performed when the follicle or follicles measure between 13-16 mm. 2. \*\*Control Group\*\*: Final oocyte triggering will be performed when the follicle or follicles measure greater than 17 mm. All triggers will be administered uniformly with 6500 units of recombinant hCG and 0,2 mg triptorelin injections. The primary outcome of the study will be the number of mature oocytes. Secondary outcomes will include fertilization rates, embryo counts, and implantation rates. Primary and secondary outcomes will be compared between the two groups.

Conditions

• Fertilization
• Fertilization in Vitro

Interventions

Type	Name	Description
OTHER	Ovulation Trigger Timing Based on Leading Follicle Size in POSEIDON Group 4 IVF Patients	In this study, ovulation trigger timing is determined according to the diameter of the leading follicle measured by transvaginal ultrasound during ovarian stimulation in women classified as POSEIDON group 4. Patients undergoing controlled ovarian stimulation are monitored with serial ultrasound examinations and serum hormone measurements. Ovulation triggering is performed when the leading follicle reaches predefined size categories. The study evaluates the association between the diameter of the leading follicle at the time of trigger and reproductive outcomes. The primary outcome measure is the number of metaphase II (MII) oocytes retrieved, while secondary outcomes include blastocyst formation and pregnancy outcomes.

Timeline

• Start date: 2026-03-15
• Primary completion: 2026-12-01
• Completion: 2026-12-30
• First posted: 2024-05-29
• Last updated: 2026-03-19

Locations

1 site across 1 country: Turkey (Türkiye)