Long versus short Clomid protocols for ovarian stimulation in IVF

Evaluation of a Long Versus Short Clomid Protocol for Controlled Ovarian Stimulation in Patients With Diminished Ovarian Reserve Undergoing In-vitro Fertilization: a Randomized Controlled Trial

Phase 4 Interventional University of Southern California · NCT06701071

This test compares taking Clomid throughout an IVF stimulation cycle versus the usual five-day Clomid course (with a GnRH antagonist) to see which approach yields more mature eggs for people with diminished ovarian reserve.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment120 (estimated)
Ages18 Years to 45 Years
SexFemale
SponsorUniversity of Southern California Academic / other
Locations1 site (Pasadena, California)
Trial IDNCT06701071 on ClinicalTrials.gov

What this trial studies

People with diminished ovarian reserve undergoing IVF will be randomized to either a "long" Clomid protocol (Clomid given throughout stimulation) or the standard approach of Clomid for five days with a later GnRH antagonist. The long protocol aims to boost FSH exposure, potentially increase ovarian response, and eliminate the need for an injectable antagonist. The trial's primary outcome is the number of mature (MII) eggs retrieved at oocyte pickup. The design targets patients planning a freeze-all cycle or those eligible for a fresh transfer if randomized to the short Clomid arm.

Who should consider this trial

Good fit: Ideal candidates are people undergoing IVF with diminished ovarian reserve by POSEIDON criteria, antral follicle count ≥2, age under 45 at stimulation start, a non-azoospermic sperm source, and who are planning a freeze-all cycle or are eligible for fresh transfer in the short-Clomid arm.

Not a fit: Patients with normal ovarian reserve or good response, those on minimal stimulation protocols, individuals with prior premature ovulation, or anyone allergic to Clomid are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the long Clomid approach could produce more mature eggs while reducing injections and medication costs.

How similar studies have performed: Some clinics and observational reports have suggested benefit from extended Clomid use, but randomized data on a full-cycle "long Clomid" approach are limited, making this a relatively novel comparison.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Undergoing IVF
* Must meet POSEIDON criteria based on clinic evaluation
* Female partner: Antral follicle count of 2 or more and age \<45 at time of stimulation start
* Male partner/sperm source: Cannot be azoospermic
* Planning freeze-all cycle (regardless of blastocyst or cleavage stage culture) or fresh transfer if randomized to short Clomid group
* Planning 36-hour trigger window

Exclusion Criteria:

* Normal ovarian reserve or good response
* Allergy or adverse reaction to Clomid
* Minimal stimulation protocols
* History of prior premature ovulation

Where this trial is running

Pasadena, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Infertility, Female
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.