An interventional study of Traditional Letrozole Therapy and Extended Letrozole Therapy in PCOS (Polycystic Ovary Syndrome), Infertility and Anovulation, sponsored by GABRIEL MONTEIRO PINHEIRO. Recruiting at 1 site in Brazil. Open to female participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-28.
Sponsored by GABRIEL MONTEIRO PINHEIRO · Not applicable, Interventional, and Treatment
This randomized clinical trial aims to compare the efficacy and safety of extended letrozole therapy (5 mg/day for 10 days) versus standard letrozole therapy (5 mg/day for 5 days) for ovulation induction in women with polycystic ovary syndrome (PCOS). A total of 84 women aged 18-40 years will be randomized into two groups. Ovulation will be monitored by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum presence. The primary outcome is ovulation rate, while secondary outcomes include number and size of mature follicles, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate, number of cycles until pregnancy, and incidence of ovarian hyperstimulation syndrome (OHSS).
Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and one of the leading causes of anovulatory infertility worldwide. Letrozole, an aromatase inhibitor, has emerged as the preferred first-line pharmacological agent for ovulation induction in women with PCOS. Despite its widespread use, there is ongoing debate regarding the optimal duration of therapy to maximize ovulatory and pregnancy outcomes.
This randomized clinical trial is designed to evaluate whether an extended regimen of letrozole provides superior reproductive outcomes compared with the standard regimen. The extended protocol consists of daily administration of 5 mg letrozole from cycle day 2 through day 12, whereas the standard regimen involves 5 mg daily from cycle day 2 through day 6. Ovulatory response will be monitored through serial transvaginal ultrasound and biochemical markers of ovulation.
The trial aims to generate high-quality evidence on the efficacy and safety of extended letrozole therapy. The findings may inform future clinical guidelines on ovulation induction strategies in women with PCOS and contribute to optimizing treatment protocols for anovulatory infertility.
956 studies on the registry are indexed under Polycystic Ovary Syndrome; 176 are open to participants now.
This study's planned enrollment of 20 is below the median of 70 across 697 interventional studies indexed under Polycystic Ovary Syndrome.
Browse Polycystic Ovary Syndrome studies →This is the only study on the registry with GABRIEL MONTEIRO PINHEIRO as lead sponsor.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group will receive standard letrozole therapy for ovulation induction. Letrozole will be administered orally at a dose of 5 mg/day from cycle day 2 through cycle day 6 (5 consecutive days). Ovulation monitoring will be performed by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum visualization. This arm serves as the active comparator against the extended regimen for evaluating efficacy and safety outcomes.
Drug: Traditional Letrozole Therapy
Participants in this group will receive extended letrozole therapy for ovulation induction. Letrozole will be administered orally at a dose of 5 mg/day from cycle day 2 through cycle day 12 (10 consecutive days). Ovulation monitoring will be performed by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum visualization. This arm will be compared with the standard regimen to assess differences in ovulation rate, follicular development, pregnancy outcomes, and safety.
Drug: Extended Letrozole Therapy
Traditional therapy group: 5 mg/day of letrozole for 5 days (cycle days 2-6).
Extended therapy group: 5 mg/day of letrozole for 10 days (cycle days 2-12)
Ovulation rate
Proportion of participants achieving ovulation, defined as the presence of a dominant follicle ≥18 mm on transvaginal ultrasound with confirmation by urinary LH surge and/or visualization of corpus luteum.
Time frame: Assessed within one treatment cycle (up to 6 weeks from the start of medication).
Clinical Pregnancy Rate
Proportion of participants achieving clinical pregnancy, defined as visualization of a gestational sac by transvaginal ultrasound.
Time frame: Assessed within 8 weeks after the start of treatment.
Number of Mature Follicles
Number of follicles ≥18 mm observed by transvaginal ultrasound in the stimulated cycle.
Time frame: Assessed during one treatment cycle (up to 6 weeks).
Follicular Size
Maximum diameter (in millimeters) of the leading follicle(s) observed by transvaginal ultrasound.
Time frame: Assessed during one treatment cycle (up to 6 weeks).
Miscarriage Rate
Proportion of participants with spontaneous pregnancy loss within the first trimester (\<12 weeks of gestation).
Time frame: Assessed up to 12 weeks of gestation.
Multiple Pregnancy Rate
Proportion of participants with multiple gestations, confirmed by transvaginal ultrasound.
Time frame: Assessed within 8 weeks after the start of treatment.
Incidence of Ovarian Hyperstimulation Syndrome (OHSS)
Proportion of participants presenting clinical or ultrasound signs of OHSS during treatment.
Time frame: Assessed within one treatment cycle (up to 6 weeks).
Plan to share: Yes — Data obtained through this study may be shared with qualified researchers with academic interest in polycystic ovary syndrome (PCOS), ovulation induction, or related reproductive medicine topics. Any shared data will be de-identified and coded, with no personal health information (PHI) included. Approval of the request by the principal investigator and execution of all applicable agreements (e.g., data use agreement or material transfer agreement) will be required prior to data sharing.
Supporting information: Informed consent form
Time frame: Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.
Access criteria: Access to trial IPD can be requested by qualified researchers engaging in independent scientific research, and will be provided only in accordance with participants' informed consent (ICF). For more information or to submit a request, please contact katherinereimao000@gmail.com
No publications or documents are linked to this record.
Started Sep 2025 (actual). Primary completion is estimated for Jul 2026, 10 months after the start.
Of 202 non-industry interventional studies with no phase under Polycystic Ovary Syndrome, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 39. This study's planned 10 months is below that.
Counting every sponsor, half of 217 studies reached it within 18 months; a quarter within 7 and three quarters within 39.
How these figures are worked out, and which studies are left out of them.
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