Evaluation of a Long Versus Short Clomid Protocol for Controlled Ovarian Stimulation

June 1, 2026 updated by: Richard Paulson, University of Southern California

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

The goal of this clinical trial is to evaluate a long Clomid protocol as compared to a 5-day Clomid protocol for ovarian stimulation in patients with diminished ovarian reserve undergoing ovarian stimulation for in-vitro fertilization. The aim of the long Clomid protocol is to intensify stimulation of the ovaries and reduce both cost and injection burden for patients. Participants will be randomized to receive the long Clomid protocol vs. the typical protocol involving Clomid only for 5 days followed by growth hormone-releasing hormone (GnRH) antagonist. The primary outcome the investigators will evaluate will be the number of mature eggs retrieved.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Clomiphene citrate (Clomid) is often used for assisted reproductive technologies and may be used to augment ovarian stimulation with exogenous gonadotropins by stimulating pituitary follicle-stimulating hormone (FSH) release in addition. The mechanism of action of Clomid is antagonism at the estrogen receptor, and this stimulates FSH release from the pituitary. The typical Clomid-based protocol has involved clomid only given for the first five days of stimulation to allow for endometrial development later in the cycle for a fresh embryo transfer following the oocyte retrieval. This protocol involves the addition of a GnRH antagonist medication later in the cycle to prevent premature ovulation. Recent national trends in IVF, however, have moved towards frozen embryo transfers and use of preimplantation genetic testing, which obviates any concerns regarding the endometrium. Recent experience in our clinic has suggested that Clomid may also prevent premature ovulation by antagonizing the positive feedback that is responsible for the luteinizing hormone (LH) surge and ovulation. Given in this manner, Clomid can be given throughout the duration of an ovarian stimulation cycle, achieve higher FSH levels and degree of ovarian stimulation in patients with diminished ovarian reserve, and obviate the need for GnRH antagonist medication (another expensive subcutaneous injection). The objective of this study is to compare a "long Clomid protocol" (i.e. using Clomid throughout the entire duration of the IVF cycle) as compared to the typical 5-day clomid protocol. The investigators hypothesize that the long Clomid protocol will be non-inferior to the typical five-day course and obviate the need for GnRH antagonist by preventing premature ovulation. Patients with diminished ovarian reserve and anticipated poor response to ovarian stimulation will be randomized to the long Clomid protocol vs. a 5-day Clomid with GnRH antagonist protocol. The primary outcome will be oocyte yield. Secondary outcome will be premature ovulation, embryo development, and pregnancy outcomes.

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Long Clomid
Clomid with gonadotropins throughout the entire duration of ovarian stimulation without addition of GnRH antagonist
Clomiphene citrate is an estrogen receptor antagonist that leads to pituitary FSH release and prevention of the LH surge.
Active Comparator: 5-day Clomid
Clomid only for 5 days at beginning of ovarian stimulation with gonadotropins, with GnRH antagonist added when the lead follicle reaches ~14mm.
Clomiphene citrate is an estrogen receptor antagonist that leads to pituitary FSH release and prevention of the LH surge.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of mature oocytes
Time Frame: Up to 1 month after study completion
The number of mature oocytes retrieved at oocyte retrieval
Up to 1 month after study completion

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of participants that experience premature ovulation
Time Frame: Up to 1 month after study completion
Premature LH surge, progesterone rise and estradiol decrease, or evidence of premature ovulation (no oocytes on retrieval or free fluid and follicular collapse on ultrasound)
Up to 1 month after study completion
Number of oocytes that get fertilized and grow to the blastocyst stage
Time Frame: Up to 1 month after study completion
Fertilization rate and blastulation
Up to 1 month after study completion
Pregnancy outcomes
Time Frame: Up to 3 years after study completion
Clinical pregnancy rate, ongoing pregnancy rate, live birth rate
Up to 3 years after study completion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Richard Paulson, paulsonivf@havingbabies.com

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2025

Primary Completion (Estimated)

June 1, 2028

Study Completion (Estimated)

June 1, 2028

Study Registration Dates

First Submitted

June 13, 2024

First Submitted That Met QC Criteria

November 19, 2024

First Posted (Actual)

November 22, 2024

Study Record Updates

Last Update Posted (Actual)

June 3, 2026

Last Update Submitted That Met QC Criteria

June 1, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Infertility, Female

Clinical Trials on Clomiphene Citrate

Subscribe