Letrozole plus clomiphene versus letrozole alone to help ovulate
Official title: The Combination of Letrozole (LE) and Clomiphene Citrate (CC) or LE Alone for Ovulation Induction in Women With WHO Group II/IV Ovulatory Disorders: A Randomized Controlled Trial
Run by Mỹ Đức Hospital · NCT06934785 · Data updated 2026-11-12
This trial will test whether adding clomiphene citrate to letrozole helps women with WHO II/IV ovulatory disorders have more live births after ovulation induction.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 40 Years |
| Sex | Women only |
| Enrollment | 600 (estimated) |
| Sponsor | Mỹ Đức Hospital Academic / other |
| Locations | 1 site (Ho Chi Minh City, Ho Chi Minh City) |
| Status | Recruiting |
| Started | April 28, 2025 |
| Main results expected | June 30, 2027 |
| Study ends | June 30, 2027 |
| Registry record updated | October 20, 2026 |
| Trial ID | NCT06934785 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Women aged 18–40 with WHO II/IV ovulatory disorders, adequate partner semen parameters (progressive motility ≥32% and sperm concentration ≥5 million/ml), no untreated thyroid or prolactin disorders, no tubal blockage, and who can give informed consent are ideal candidates.
✕Probably not a fit
Patients with untreated endocrine disorders, confirmed unilateral or bilateral tubal blockage, severe male factor infertility outside the entry criteria, or allergy/contraindication to letrozole or clomiphene are unlikely to benefit from this intervention.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This is an open-label, multicenter randomized controlled trial conducted across six fertility clinics in Vietnam that randomizes participants to letrozole plus clomiphene citrate versus letrozole alone. Eligible women with WHO II/IV ovulatory disorders will receive one cycle of ovulation induction with either the combination or letrozole alone, with intercourse or IUI as the method of conception. The primary outcome is live birth rate after one treatment cycle, and the study plans to enroll approximately 600 participants to detect a clinically meaningful difference. Secondary and safety outcomes, and prior smaller trials on ovulation rates, will be considered in the analysis.
Why it matters
Potential benefit: If successful, the combination could raise live birth rates for women undergoing ovulation induction for WHO II/IV ovulatory disorders.
How similar studies have gone: Previous small randomized trials have reported higher ovulation rates with the combination but results for live birth have been mixed and not consistently significant.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Women 18-40 years of age * Having ovulation disorder (length of cycle \< 21 or \> 35 days or having \< 8 cycles per year) * FSH ≥5 IU/L and ≤25 IU/L, or LH ≥5 IU/L and AMH ≥1.2 ng/mL * Progressive motility (PR) ≥ 32% OR total progressive motility sperm count \> 5 million; and sperm concentration ≥ 5 million/ml, (World Health Organization, 2021) * Agreeing to take part in study. * Not participating in other studies. Exclusion Criteria: * Untreated thyroid disease; Thyroid disease is suspected if patients have one of these (Bednarczuk et al., 2021); TSH ≥4 mIU/L or TSH ≥2.5mIU/L and TPOAb (+) or TSH \<0.1mIU/L * Untreated hyper-prolactinemia; Hyperprolactinemia is suspected if patients have prolactinemia concentration \>50 ng/mL (The sample is collected after an overnight fast, at least 2 hours after waking up, ensuring that venipuncture does not cause excessive stress.) * Allergy or having contraindications to LE or CC; * Unilateral or Bilateral fallopian tube blockage (HSG, HyFoSy or surgery confirmation) * Untreated endometrial abnormalities include endometrial hyperplasia, intrauterine adhesions, endometrial polyp, or chronic endometritis. * Uterine abnormalities include leiomyomas L0, L1, or L2; severe adenomyosis; congenital uterine abnormalities, include didelphus, arcuate, unicornuate, bicornuate, septate.
Where it's running
-
My Duc Hospital
Ho Chi Minh City, Ho Chi Minh City, Vietnam Recruiting
Study contacts
- Principal investigator: Lan N Vuong, PhD,MD — University of Medicine and Pharmacy at Ho Chi Minh City
- Study coordinator: Van TT Tran, MD
- Email: bsvan.ttt@myduchospital.vn
- Phone: +84353345020
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.