LetrozoleCOLANCT06934785
LE + CC vs. LE for Ovulation Induction
A study testing IUI or intercourse in people with Letrozole and Clomiphene Citrate, run by Mỹ Đức Hospital at 1 site in Vietnam.
Trial summary
This randomized controlled trial (RCT) aims to evaluate whether, in infertile women with WHO II/IV ovulatory disorders, a combination of letrozole (LE) and clomiphene citrate (CC) compared to LE alone, result in higher live birth rates. Read more about this study
- Who is it for?
- Ages 18 to 40 years, women only
- Conditions the study is for
- Letrozole, Clomiphene Citrate, Ovulation Disorder
- What is being tested?
- IUI or intercourse
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 600 participants
- Where
- 1 siteVietnam
- Study dates
- 28 Apr 2025to 30 Jun 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Vinh Q Dang, MSc,MD contact
Vietnam1 site, 1 recruiting
- Recruiting
My Duc Hospital
Ho Chi Minh City, Ho Chi Minh City, 70000
Tuong M Ho, MSc,MD, +84 90 3633377, tuongho.ivfmd@gmail.com
About this study
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
This randomized controlled trial (RCT) aims to evaluate whether, in infertile women with WHO II/IV ovulatory disorders, a combination of letrozole (LE) and clomiphene citrate (CC) compared to LE alone, result in higher live birth rates.
The study is designed as an open-label, multicenter RCT across six fertility clinics in Vietnam. Participants will be randomized into two groups: (1) LE + CC , (2) LE alone. The primary outcome measure is the live birth rate after one treatment cycle. Based on prior data, the live birth rate for IUI in letrozole cycles is estimated at 12%. To detect a 10% increase in live birth rates with CC, 436 couples are needed (α = 0.05, power = 80%). Additionally, the live birth rate after IUI with LE-induced ovulation is approximately 18.7% (Diamond et al., 2015). To detect a 10% increase with CC, 560 couples are required (α = 0.05, power = 80%). Considering a 5% loss to follow-up and protocol deviations, the study plans to recruit 600 participants (150 per arm).
Read the detailed description
Letrozole (LE) has been suggested as a first-line treatment for ovulation induction in PCOS. Clomiphene citrate (CC) is another widely used drug to induce ovulation in women with PCOS. Due to the different mechanisms of action of CC and letrozole, it is possible that taking these drugs together may increase the ovulation rate by having a synergistic effect with their own mechanisms and resulting to increase the pregnancy outcome of patients undergoing ovulation induction (OI).
Mejia et al. conducted a randomized controlled trial (RCT) and reported the ovulation rate was significantly higher in the combination group than in the LE-alone group (N=70, 77% vs. 42.9%, respectively; RR 1.80 95%. CI. 1.18 to 2.75, P=0.007). This finding is confirmed by another RCT but not in a third more recent RCT, with larger sample size. Live birth rate was only reported as secondary endpoint in two studies, with a non-significant difference between the two groups [12% vs. 7%, RR 1.68, 95% CI 0.19 to 14.66) and 16.4% vs. 18.6%, RR 0.92, 95% CI 0.57 to 1.50)]. Therefore, the investigators plan an RCT to evaluate whether a combination of LE and CC results in higher live birth rates than LE alone in women with WHO II/IV ovulatory disorders.
This is a open-label, multicenter, randomized controlled trial across six fertility clinics in Vietnam. Potentially eligible participants will be given a study information sheet during their first consultation, at least 2 weeks before the start of the menstrual cycle, whether spontaneous or induced. In case the women present to the clinic during their menstrual cycle and wish to start treatment straightaway, they will be given the information sheet to read while waiting for the clinicians. Screening for eligibility will be performed by treating physicians on the day OI starts. Eligible participants will be invited to a full discussion with investigators about the study. Women who fulfil the eligibility criteria and who have been counselled before will be formally invited to participate in the study. If the women agree to participate, they will be asked to sign the informed consent form. After informed consent, a fasting blood sample will be obtained for hormone and biochemical analysis.
Participants will be randomized in a 1:1 ratio to receive the combination of LE and CC (LE+CC) and LE alone. The computer-generated random list will be prepared by an independent statistician who has no other involvement in the study. Assignment to treatment allocation will be done via a web portal hosted by HOPE Research Center, Vietnam. The randomization schedule will be computer-generated at HOPE Research Center, with a permuted random block size of 4 and 8.
Combination of LE and CC group: 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) and 50 milligrams CC (Duinum 50 milligrams, Medochemie, Cyprus) per day, starting on the second to the fourth day of the cycle, for five consecutive days.
LE alone group: 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland), starting on the second to the fourth day of cycle, for five consecutive days.
IUI or natural intercourse will be indicated based on the physicians and patients.
The primary endpoint will be live birth after one treatment cycle.
- Conditions
- Letrozole, Clomiphene Citrate, Ovulation Disorder, Ovulation Induction
- Being tested
- IUI or intercourse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
IUI or intercourseProcedure or surgery
5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) and 50 milligrams CC (Duinum 50 milligrams, Medochemie, Cyprus) or 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) will be started on the second to the fourth day of the cycle, for five consecutive days. An ultrasound will be carried out three days after the last dose of medicine (day 8 of OI) to evaluate ovarian follicles' growth and the endometrium's thickness. If the follicular diameter reach ≥14 millimetres, check-up will be planned every two days until it reaches 18 millimetres. If there is the appearance of at least one follicle reaching 18 millimetres or more, a human chorionic gonadotropin (hCG) injection (IVF-C 5000 IU, LG Life Science, Korea) will be administered on the same day of the ultrasound in order to induce ovulation. IUI will be scheduled 36 - 38 hours after hCG injection or intercourse will be scheduled in the next day.
| Study group | Role | What they receive |
|---|---|---|
| Combination of LE and CC group | Active comparator | 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) and 50 milligrams CC (Duinum 50 milligrams, Medochemie, Cyprus) per day, starting on the second to the fourth day of the cycle, for five consecutive days. Receives: Procedure: IUI or intercourse |
| LE alone group | Active comparator | 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland), starting on the second to the fourth day of cycle, for five consecutive days. Receives: Procedure: IUI or intercourse |
What is being measured
The primary outcome is the main question the study is designed to answer.
Live birth after one treatment cycle
Live birth will be defined as the complete expulsion or extraction from a woman of a product of fertilization, after 22 completed weeks of gestational age; which, after such separation, breathes or shows any other evidence of life, such as heart beat, umbilical cord pulsation or definite movement of voluntary muscles, irrespective of whether the umbilical cord has been cut or the placenta is attached.
Measured: At 22 weeks of gestation
Secondary outcomes (31)
Duration of stimulation
Duration of stimulation
Measured: During the intervention
Number of follicles ≥14mm on day of hCG
Number of follicles ≥14mm on day of hCG
Measured: During the intervention
Endometrial thickness on day of hCG
Endometrial thickness on day of hCG
Measured: During the intervention
Cycle cancellation
The cycle will be cancelled if (1) there is no follicle reaches ≥18 millimetres) on day 21 of the OI; (2) there are ≥ 3 follicles with diameter ≥16 millimetres or (3) ≥ 4 ovarian follicles with diameter ≥10 millimetres
Measured: At 21 day of the ovulation induction cycle
Ovulation
A serum midluteal progesterone (17-OH-progesterone) will be measured on day 7 after the hCG injection. A level of >3 ng/mL (>9.5 nmol/L) will be used as evidence of ovulation.
Measured: At day 7 after the hCG injection
Positive pregnancy test
Serum human chorionic gonadotropin level greater than 25 mIU/mL at day 15 after IUI or timed intercourse
Measured: At day 15 after IUI or timed intercourse
Clinical pregnancy
Diagnosed by ultrasonographic visualization of one or more gestational sacs or definitive clinical signs of pregnancy at 6 weeks or more. In addition to intra-uterine pregnancy, it includes a clinically documented ectopic pregnancy
Measured: After 6 weeks of gestation
Ongoing pregnancy
Pregnancy with a detectable heart rate at 12 weeks gestation or beyond
Measured: After 12 weeks of gestation
Multiple pregnancies
The presence of more than one sac at early pregnancy ultrasound (6-9 weeks gestation)
Measured: At 6-9 weeks of gestation
Multiple birth
The complete expulsion or extraction from a woman of more than one fetus, after 22 completed weeks of gestational age, irrespective of whether it is a live birth or stillbirth
Measured: At 22 weeks of gestation
Ectopic pregnancy
A pregnancy outside the uterine cavity, diagnosed by ultrasound, surgical visualization or histopathology
Measured: At 7 weeks of gestation
Miscarriage <22 weeks
Spontaneous loss of pregnancy up to 22 weeks of gestation
Measured: Before 22 completed weeks of gestation
Gestational age at delivery
Gestational age at delivery
Measured: At the time of delivery
Growth restriction
a birth weight < 10th percentile
Measured: At the time of delivery
Stillbirth
The death of a fetus prior to the complete expulsion or extraction from its mother after 20 completed weeks of gestational age. The death is determined by the fact that, after such separation, the fetus does not breathe or show any other.
Measured: After 20 completed weeks of gestational age
Premature birth
Multiple definitions, defined as delivery at <24, <28, <32, <37 completed weeks
Measured: At 22, 28, 32 weeks and 37 weeks of gestation
Onset of labour
Onset of labour
Measured: At the time of delivery
Mode of delivery
Mode of delivery
Measured: At the time of delivery
Birth weight
Weight of singletons and twins
Measured: At the time of delivery
Low birth weight
Weight < 2500 gm at birth
Measured: At the time of delivery
Very low birth weight
Weight < 1500 gm at birth
Measured: At the time of delivery
High birth weight
Weight 4000 gm or 4500 gm at birth
Measured: At the time of delivery
Very high birth weight
Weight over than 4.500 g for women with diabetes, and a threshold of 5000 g for women without diabetes
Measured: At the time of delivery
Gestational diabetes mellitus
GDM is diagnosed using a 75g oral glucose tolerance test
Measured: At 24 to 28 weeks of gestation
Hypertension in pregnancy
Pregnancy-induced hypertension, pre-eclampsia, eclampsia and HELLP syndrome
Measured: after 20 weeks of gestation or beyond
Congenital abnormalities
Structural or functional disorders that occur during intra-uterine life and can be identified prenatally, at birth or later in life. Congenital anomalies can be caused by single gene defects, chromosomal disorders, multifactorial inheritance, environmental teratogens, and micronutrient deficiencies. The time of identification should be reported
Measured: At birth
Neonatal mortality
Death of a live-born baby within 28 days of birth
Measured: within 28 days of birth
NICU admission
The admittance of the newborn to NICU
Measured: At birth
Reported side-effects
included headache, hot flashes, abdominal bloating, abdominal pain including cramps, nausea, mood changes, fatigue, back pain, dizziness, breast discomfort, diarrhoea, night sweats, sleep disturbances
Measured: During the intervention
Hospitalized or seek any additional care during the ovulation induction cycle
Hospitalized or seek any additional care during the ovulation induction cycle
Measured: During the intervention
Incidence of Ovarian hyperstimulation syndrome (OHSS)
A potentially lethal iatrogenic complication of the early luteal phase or/and early pregnancy after OI or ovarian stimulation. OHSS was evaluated if symptoms were reported by the patient. OHSS was classified using the flow diagram
Measured: 10 days after the intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2025
- Study start28 Apr 2025
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for LetrozoleStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 600 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mỹ Đức Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Lan N Vuong, PhD,MD, Principal investigator, University of Medicine and Pharmacy at Ho Chi Minh City
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06934785
- Sponsor's protocol ID
- 02/25/DD/BVMD
- Acronym
- COLA
- Status last verified
- Oct 2026
- First submitted
- 7 Apr 2025
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Publications
Teede HJ, Tay CT, Laven JJE, Dokras A, Moran LJ, Piltonen TT, Costello MF, Boivin J, Redman LM, Boyle JA, Norman RJ, Mousa A, Joham AE. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab. 2023 Sep 18;108(10):2447-2469. doi: 10.1210/clinem/dgad463.
PubMed 37580314Weiss NS, Nahuis MJ, Bordewijk E, Oosterhuis JE, Smeenk JM, Hoek A, Broekmans FJ, Fleischer K, de Bruin JP, Kaaijk EM, Laven JS, Hendriks DJ, Gerards MH, van Rooij IA, Bourdrez P, Gianotten J, Koks C, Lambalk CB, Hompes PG, van der Veen F, Mol BWJ, van Wely M. Gonadotrophins versus clomifene citrate with or without intrauterine insemination in women with normogonadotropic anovulation and clomifene failure (M-OVIN): a randomised, two-by-two factorial trial. Lancet. 2018 Feb 24;391(10122):758-765. doi: 10.1016/S0140-6736(17)33308-1. Epub 2017 Dec 19.
PubMed 29273245Mejia RB, Summers KM, Kresowik JD, Van Voorhis BJ. A randomized controlled trial of combination letrozole and clomiphene citrate or letrozole alone for ovulation induction in women with polycystic ovary syndrome. Fertil Steril. 2019 Mar;111(3):571-578.e1. doi: 10.1016/j.fertnstert.2018.11.030. Epub 2019 Jan 22.
PubMed 30683591Diamond MP, Legro RS, Coutifaris C, Alvero R, Robinson RD, Casson P, Christman GM, Ager J, Huang H, Hansen KR, Baker V, Usadi R, Seungdamrong A, Bates GW, Rosen RM, Haisenleder D, Krawetz SA, Barnhart K, Trussell JC, Ohl D, Jin Y, Santoro N, Eisenberg E, Zhang H; NICHD Reproductive Medicine Network. Letrozole, Gonadotropin, or Clomiphene for Unexplained Infertility. N Engl J Med. 2015 Sep 24;373(13):1230-40. doi: 10.1056/NEJMoa1414827.
PubMed 26398071
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT06934785
- Acronym / sponsor ID
- COLA / 02/25/DD/BVMD
- Conditions
- Letrozole, Clomiphene Citrate, Ovulation Disorder, Ovulation Induction
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 600 participants (estimated)
- Lead sponsor
- Mỹ Đức HospitalUniversity, hospital or other
- Study start
- 28 Apr 2025 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 18 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized controlled trial (RCT) aims to evaluate whether, in infertile women with WHO II/IV ovulatory disorders, a combination of letrozole (LE) and clomiphene citrate (CC) compared to LE alone, result in higher live birth rates.
The study is designed as an open-label, multicenter RCT across six fertility clinics in Vietnam. Participants will be randomized into two groups: (1) LE + CC , (2) LE alone. The primary outcome measure is the live birth rate after one treatment cycle. Based on prior data, the live birth rate for IUI in letrozole cycles is estimated at 12%. To detect a 10% increase in live birth rates with CC, 436 couples are needed (α = 0.05, power = 80%). Additionally, the live birth rate after IUI with LE-induced ovulation is approximately 18.7% (Diamond et al., 2015). To detect a 10% increase with CC, 560 couples are required (α = 0.05, power = 80%). Considering a 5% loss to follow-up and protocol deviations, the study plans to recruit 600 participants (150 per arm).
Detailed description
Letrozole (LE) has been suggested as a first-line treatment for ovulation induction in PCOS. Clomiphene citrate (CC) is another widely used drug to induce ovulation in women with PCOS. Due to the different mechanisms of action of CC and letrozole, it is possible that taking these drugs together may increase the ovulation rate by having a synergistic effect with their own mechanisms and resulting to increase the pregnancy outcome of patients undergoing ovulation induction (OI).
Mejia et al. conducted a randomized controlled trial (RCT) and reported the ovulation rate was significantly higher in the combination group than in the LE-alone group (N=70, 77% vs. 42.9%, respectively; RR 1.80 95%. CI. 1.18 to 2.75, P=0.007). This finding is confirmed by another RCT but not in a third more recent RCT, with larger sample size. Live birth rate was only reported as secondary endpoint in two studies, with a non-significant difference between the two groups [12% vs. 7%, RR 1.68, 95% CI 0.19 to 14.66) and 16.4% vs. 18.6%, RR 0.92, 95% CI 0.57 to 1.50)]. Therefore, the investigators plan an RCT to evaluate whether a combination of LE and CC results in higher live birth rates than LE alone in women with WHO II/IV ovulatory disorders.
This is a open-label, multicenter, randomized controlled trial across six fertility clinics in Vietnam. Potentially eligible participants will be given a study information sheet during their first consultation, at least 2 weeks before the start of the menstrual cycle, whether spontaneous or induced. In case the women present to the clinic during their menstrual cycle and wish to start treatment straightaway, they will be given the information sheet to read while waiting for the clinicians. Screening for eligibility will be performed by treating physicians on the day OI starts. Eligible participants will be invited to a full discussion with investigators about the study. Women who fulfil the eligibility criteria and who have been counselled before will be formally invited to participate in the study. If the women agree to participate, they will be asked to sign the informed consent form. After informed consent, a fasting blood sample will be obtained for hormone and biochemical analysis.
Participants will be randomized in a 1:1 ratio to receive the combination of LE and CC (LE+CC) and LE alone. The computer-generated random list will be prepared by an independent statistician who has no other involvement in the study. Assignment to treatment allocation will be done via a web portal hosted by HOPE Research Center, Vietnam. The randomization schedule will be computer-generated at HOPE Research Center, with a permuted random block size of 4 and 8.
Combination of LE and CC group: 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) and 50 milligrams CC (Duinum 50 milligrams, Medochemie, Cyprus) per day, starting on the second to the fourth day of the cycle, for five consecutive days.
LE alone group: 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland), starting on the second to the fourth day of cycle, for five consecutive days.
IUI or natural intercourse will be indicated based on the physicians and patients.
The primary endpoint will be live birth after one treatment cycle.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Combination of LE and CC group | Active comparator | Procedure: IUI or intercourse5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) and 50 milligrams CC (Duinum 50 milligrams, Medochemie, Cyprus) per day, starting on the second to the fourth day of the cycle, for five consecutive days. |
| LE alone group | Active comparator | Procedure: IUI or intercourse5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland), starting on the second to the fourth day of cycle, for five consecutive days. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (6 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| IUI or intercourse5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) and 50 milligrams CC (Duinum 50 milligrams, Medochemie, Cyprus) or 5 milligrams LE per day (Femara® 2.5 milligrams, Novartis, Switzerland) will be started on the second to the fourth day of the cycle, for five consecutive days. An ultrasound will be carried out three days after the last dose of medicine (day 8 of OI) to evaluate ovarian follicles' growth and the endometrium's thickness. If the follicular diameter reach ≥14 millimetres, check-up will be planned every two days until it reaches 18 millimetres. If there is the appearance of at least one follicle reaching 18 millimetres or more, a human chorionic gonadotropin (hCG) injection (IVF-C 5000 IU, LG Life Science, Korea) will be administered on the same day of the ultrasound in order to induce ovulation. IUI will be scheduled 36 - 38 hours after hCG injection or intercourse will be scheduled in the next day. | Procedure or surgery | Combination of LE and CC group, LE alone group |
Primary outcome
Live birth after one treatment cycle
Time frame: At 22 weeks of gestation
Live birth will be defined as the complete expulsion or extraction from a woman of a product of fertilization, after 22 completed weeks of gestational age; which, after such separation, breathes or shows any other evidence of life, such as heart beat, umbilical cord pulsation or definite movement of voluntary muscles, irrespective of whether the umbilical cord has been cut or the placenta is attached.
31 secondary outcomes
Duration of stimulation
Time frame: During the intervention
Number of follicles ≥14mm on day of hCG
Time frame: During the intervention
Endometrial thickness on day of hCG
Time frame: During the intervention
Cycle cancellation
Time frame: At 21 day of the ovulation induction cycle
Ovulation
Time frame: At day 7 after the hCG injection
Positive pregnancy test
Time frame: At day 15 after IUI or timed intercourse
Clinical pregnancy
Time frame: After 6 weeks of gestation
Ongoing pregnancy
Time frame: After 12 weeks of gestation
Multiple pregnancies
Time frame: At 6-9 weeks of gestation
Multiple birth
Time frame: At 22 weeks of gestation
Ectopic pregnancy
Time frame: At 7 weeks of gestation
Miscarriage <22 weeks
Time frame: Before 22 completed weeks of gestation
Gestational age at delivery
Time frame: At the time of delivery
Growth restriction
Time frame: At the time of delivery
Stillbirth
Time frame: After 20 completed weeks of gestational age
Premature birth
Time frame: At 22, 28, 32 weeks and 37 weeks of gestation
Onset of labour
Time frame: At the time of delivery
Mode of delivery
Time frame: At the time of delivery
Birth weight
Time frame: At the time of delivery
Low birth weight
Time frame: At the time of delivery
Very low birth weight
Time frame: At the time of delivery
High birth weight
Time frame: At the time of delivery
Very high birth weight
Time frame: At the time of delivery
Gestational diabetes mellitus
Time frame: At 24 to 28 weeks of gestation
Hypertension in pregnancy
Time frame: after 20 weeks of gestation or beyond
Congenital abnormalities
Time frame: At birth
Neonatal mortality
Time frame: within 28 days of birth
NICU admission
Time frame: At birth
Reported side-effects
Time frame: During the intervention
Hospitalized or seek any additional care during the ovulation induction cycle
Time frame: During the intervention
Incidence of Ovarian hyperstimulation syndrome (OHSS)
Time frame: 10 days after the intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2026.
- Background: PubMed 37580314Teede HJ, Tay CT, Laven JJE, Dokras A, Moran LJ, Piltonen TT, Costello MF, Boivin J, Redman LM, Boyle JA, Norman RJ, Mousa A, Joham AE. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab. 2023 Sep 18;108(10):2447-2469. doi: 10.1210/clinem/dgad463.
- Background: PubMed 29273245Weiss NS, Nahuis MJ, Bordewijk E, Oosterhuis JE, Smeenk JM, Hoek A, Broekmans FJ, Fleischer K, de Bruin JP, Kaaijk EM, Laven JS, Hendriks DJ, Gerards MH, van Rooij IA, Bourdrez P, Gianotten J, Koks C, Lambalk CB, Hompes PG, van der Veen F, Mol BWJ, van Wely M. Gonadotrophins versus clomifene citrate with or without intrauterine insemination in women with normogonadotropic anovulation and clomifene failure (M-OVIN): a randomised, two-by-two factorial trial. Lancet. 2018 Feb 24;391(10122):758-765. doi: 10.1016/S0140-6736(17)33308-1. Epub 2017 Dec 19.
- Background: PubMed 30683591Mejia RB, Summers KM, Kresowik JD, Van Voorhis BJ. A randomized controlled trial of combination letrozole and clomiphene citrate or letrozole alone for ovulation induction in women with polycystic ovary syndrome. Fertil Steril. 2019 Mar;111(3):571-578.e1. doi: 10.1016/j.fertnstert.2018.11.030. Epub 2019 Jan 22.
- Background: PubMed 26398071Diamond MP, Legro RS, Coutifaris C, Alvero R, Robinson RD, Casson P, Christman GM, Ager J, Huang H, Hansen KR, Baker V, Usadi R, Seungdamrong A, Bates GW, Rosen RM, Haisenleder D, Krawetz SA, Barnhart K, Trussell JC, Ohl D, Jin Y, Santoro N, Eisenberg E, Zhang H; NICHD Reproductive Medicine Network. Letrozole, Gonadotropin, or Clomiphene for Unexplained Infertility. N Engl J Med. 2015 Sep 24;373(13):1230-40. doi: 10.1056/NEJMoa1414827.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Vinh Q Dang, MSc,MD contact
Lan N Vuong, PhD,MD principal investigator
University of Medicine and Pharmacy at Ho Chi Minh City
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing IUI or intercourse in people with Letrozole and Clomiphene Citrate, run by Mỹ Đức Hospital at 1 site in Vietnam.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Vietnam. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Van TT Tran, MD (+84353345020, bsvan.ttt@myduchospital.vn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Live birth after one treatment cycle (time frame: At 22 weeks of gestation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06934785, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026; AzTrials last refreshed its copy on 27 Oct 2026.