Best Treatment for Women With Both (Polycystic Ovary Syndrome) PCOS and Subclinical Hypothyroidism

August 30, 2025 updated by: Muhamed Ahmed Abdelmoaty Muhamed Alhagrasy

Letrozole Alone vs. Letrozole Plus Levothyroxine for Ovulation Induction in Infertile Women With Both (Polycystic Ovary Syndrome) PCOS and Sub-clinical Hypothyroidism.

The goal of this randomized controlled trial is to compare letrozole alone versus letrozole plus levothyroxine for ovulation induction in infertile women with both PCOS and subclinical hypothyroidism. The main questions it aims to answer are:

Is letrozole plus levothyroxine superior to letrozole alone in achieving ovulation in these patients? Does combining levothyroxine with letrozole lead to higher pregnancy and live birth rates compared to letrozole alone?

Participants will be randomized into two groups:

Group 1 will receive letrozole only, starting at 2.5 mg daily from day 3 to 7 of the menstrual cycle. The dose will be increased up to 7.5 mg if no ovulation occurs, for a maximum treatment period of 6 months or until pregnancy is achieved.

Group 2 will receive letrozole at the same doses as group 1 plus 25 mcg levothyroxine daily.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Not Applicable

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 Locations

  • Egypt
      • Cairo, Egypt, 11633

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:

Age between 20-40 years

BMI between 18-35 kg/m2

Meet diagnostic criteria for PCOS based on the Rotterdam consensus criteria and ESHRE/ASRM modifications (2018):

Oligo- and/or anovulation Clinical and/or biochemical signs of hyperandrogenism Polycystic ovaries on ultrasound

Subclinical hypothyroidism defined as TSH level between 5-10 mIU/L with normal free T4

Infertility duration ≥ 1 year

Intact ovaries and uterus, confirmed by physical exam and imaging

Normal semen analysis in male partner

No tubal or peritoneal factor contributing to infertility

Effective contraception if not attempting conception

Willing and able to provide informed consent

Exclusion Criteria:

Known thyroid disease or on thyroid medications

Abnormal thyroid function tests other than subclinical hypothyroidism

Hyperprolactinemia

Presence of other causes of infertility such as:

Moderate to severe male factor infertility Bilateral tubal occlusion or peritoneal factors Stage III-IV endometriosis Ovarian failure or insufficiency (high FSH or low AMH)

Previous diagnosis of any type of congenital adrenal hyperplasia

Uncontrolled diabetes (HbA1C >8%)

History of deep vein thrombosis or thromboembolic events

Any contraindication to letrozole or levothyroxine

Previous use of letrozole or levothyroxine in past 6 months

Current or suspected pregnancy

Breastfeeding

Inability to comply with treatment and follow-up procedures

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Letrozole Group
Participants randomized to letrozole group will take 5mg tablets orally daily for 5 days starting on day 3 of cycle. Dose can be adjusted up to 7.5mg based on ovulation response, maintained for subsequent cycles. Treatment continues for up to 6 ovulatory cycles or until pregnancy occurs. Ovulation assessed by follicular monitoring and progesterone. Compliance monitored by pill counts and diary. Routine antenatal care if pregnant. Adverse effects monitored per guidelines. Participants followed for multiple pregnancies. Tablets taken at same time each day. Maximum treatment period is 6 months.
Drug: Letrozole 2.5mg
Participants will receive 2.5mg letrozole tablets orally daily for 5 days starting on day 3 of menstrual cycle. The 2.5mg dose will be maintained for at least the first 3 cycles. If no ovulation after 3 cycles, dose cautiously increased up to 7.5mg maximum. Once minimum ovulation dose determined, it will be continued for up to 6 cycles total or until pregnancy occurs. Compliance monitored by pill counts and diary. Ovulation assessed by follicular monitoring and progesterone levels. Routine antenatal care if pregnant. Adverse effects monitored and managed per guidelines. Participants followed for multiple pregnancies. Maximum treatment duration is 6 ovulatory cycles or 6 months. Tablets taken at same time each day.
Experimental: Letrozole plus levothyroxine
Participants randomized to this group will take letrozole tablets at same dose and schedule as letrozole only group. In addition, they will take levothyroxine tablets orally once daily. Levothyroxine dose will start at 25mcg and be titrated based on TSH level, with a target TSH in the normal range. Participants will take levothyroxine at approximately same time each day. Letrozole dosing and schedule as described for other group. Treatment continues for up to 6 ovulatory cycles or until pregnancy occurs. Ovulation assessed by follicular monitoring and progesterone. Compliance monitored by pill counts, TSH levels and diary. Routine antenatal care if pregnant. Adverse effects monitored per guidelines. Participants followed for multiple pregnancies. Maximum treatment period is 6 months.
Drug: Letrozole 2.5mg
Participants will receive 2.5mg letrozole tablets orally daily for 5 days starting on day 3 of menstrual cycle. The 2.5mg dose will be maintained for at least the first 3 cycles. If no ovulation after 3 cycles, dose cautiously increased up to 7.5mg maximum. Once minimum ovulation dose determined, it will be continued for up to 6 cycles total or until pregnancy occurs. Compliance monitored by pill counts and diary. Ovulation assessed by follicular monitoring and progesterone levels. Routine antenatal care if pregnant. Adverse effects monitored and managed per guidelines. Participants followed for multiple pregnancies. Maximum treatment duration is 6 ovulatory cycles or 6 months. Tablets taken at same time each day.
Drug: Levothyroxine 25 Mcg (0.025 Mg) Oral Tablet
Participants will take letrozole at same doses as letrozole only group. Also receive levothyroxine starting at 25mcg orally once daily, titrated by 25mcg every 4 weeks to reach normal TSH, maximum 100mcg daily. Once appropriate dose determined to normalize TSH, it is maintained throughout treatment period. Compliance monitored by pill counts, TSH levels, and diary. Treatment continues for up to 6 ovulatory cycles or until pregnancy, whichever is first, maximum 6 months. Ovulation assessed by monitoring and progesterone. Routine antenatal care if pregnant. Adverse effects monitored and managed per guidelines. Participants followed for multiple pregnancies. Letrozole and levothyroxine taken daily at same time. All other procedures same as letrozole only group.
Other Names:
  • levothyroxine 25

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pregnancy rate
Time Frame: Assessed at the end of each cycle. the cycles are 6. Each cycle is 28 days.
Biochemical evidence of pregnancy by positive urine or serum β-hCG test.
Assessed at the end of each cycle. the cycles are 6. Each cycle is 28 days.
Live birth rate
Time Frame: Through study completion average 1 year.
The number of deliveries that resulted in a live born baby, documented by hospital delivery records.
Through study completion average 1 year.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ovulation rate
Time Frame: Assessed at the end of each cycle. the cycles are 6. Each cycle is 28 days.
Evidence of ovulation by ultrasound monitoring of dominant follicle development and serum progesterone level > 3 ng/mL in mid-luteal phase.
Assessed at the end of each cycle. the cycles are 6. Each cycle is 28 days.
Miscarriage rate
Time Frame: Through study completion average 1 year.
Loss of clinical pregnancy before 20 weeks gestation, confirmed by ultrasound or histopathology.
Through study completion average 1 year.
Menstrual regularity
Time Frame: Through study completion average 1 year.
Normal ovulatory menstrual cycles defined as cycle length 21-35 days.
Through study completion average 1 year.
Side effects
Time Frame: Through study completion average 1 year.
Participant reports of adverse effects of letrozole or levothyroxine, graded per standard criteria.
Through study completion average 1 year.

Collaborators and Investigators

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

Sponsor

Muhamed Ahmed Abdelmoaty Muhamed Alhagrasy

Investigators

  • Principal Investigator: Muhamed Alhagrasy, M.D., Al-Azhar University

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)

May 6, 2021

Primary Completion (Estimated)

May 30, 2026

Study Completion (Estimated)

June 28, 2026

Study Registration Dates

First Submitted

September 5, 2023

First Submitted That Met QC Criteria

September 11, 2023

First Posted (Actual)

September 18, 2023

Study Record Updates

Last Update Posted (Estimated)

September 3, 2025

Last Update Submitted That Met QC Criteria

August 30, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Gyne2021

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

To protect participant confidentiality, individual-level data from this study will not be made publicly available. However, de-identified aggregated data and results can be shared with other researchers upon request after publication. Any data provided will be limited, non-identifiable, and subject to a data use agreement to ensure participant privacy. Only select excerpts needed to validate findings will be shared under approved research objectives. The investigators reserve the right to reject requests that may compromise anonymity. We aim to promote transparency through controlled data access rather than public availability of the full dataset due to re-identification risks for participants.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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.

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