A Comparison of Letrozole and Clomifene Citrate

October 26, 2016 updated by: The University of Hong Kong

A Comparison of Hormonal Profile and the Follicular Development Between Letrozole and Clomifene Citrate in Anovulatory Women With Polycystic Ovary Syndrome and Ovulatory Women

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies, affecting 5% to 10% of women of reproductive age. Women with PCOS suffer from anovulatory infertility. Following lifestyle modification with weight reduction in obese PCOS women, clomifene citrate (CC) is considered the first line treatment for ovulation induction (OI) in these women. 75-80% of women will ovulate after CC administration. However, there is a discrepancy between the ovulation rate and pregnancy rate, which was reported to be 22% per each ovulating cycles after CC. Other alternatives, including gonadotropin injections and laparoscopic ovarian drilling, carried different disadvantages, such as costly treatment and risks of ovarian hyperstimulation syndrome and multiple pregnancy rate in gonadotrophin therapy and surgical risks and risk of ovarian failure in surgical treatment.

The use of aromatase inhibitor, letrozole (LTZ), in reproductive medicine started in 2001. After this publication, there have been many groups of investigators studying the use of LTZ either in OI or ovarian stimulation in IVF cycles. A large multicentre randomized trial reported a significantly higher ovulation rate and live-birth rate comparing LTZ with CC. In majority of the publications, the multiple pregnancy rate was lower in LTZ group than in CC group. This can be attributed to the higher chance of monofollicular development after LTZ compared with CC. However, there is no information comparing the hormonal profile and follicular development after letrozole and CC.

Mild ovarian stimulation using LTZ or CC in conjunction with intrauterine insemination is commonly offered to ovulatory women with unexplained infertility, minimal endometriosis or mild factor to improve the pregnancy rate. There is again no information comparing the hormonal profile and follicular development after letrozole and CC in ovulatory women.

The aim of this study is to compare the hormonal profile after the use of LTZ and CC in anovulatory PCOS women and ovulatory women with unexplained subfertility. The hypothesis is that the FSH risk after LTZ is shorter than that of CC.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies, affecting 5% to 10% of women of reproductive age. Women with PCOS suffer from anovulatory infertility. Following lifestyle modification with weight reduction in obese PCOS women, clomifene citrate (CC) is considered the first line treatment for ovulation induction (OI) in these women. 75-80% of women will ovulate after CC administration. However, there is a discrepancy between the ovulation rate and pregnancy rate, which was reported to be 22% per each ovulating cycles after CC. Other alternatives, including gonadotropin injections and laparoscopic ovarian drilling, carried different disadvantages, such as costly treatment and risks of ovarian hyperstimulation syndrome and multiple pregnancy rate in gonadotrophin therapy and surgical risks and risk of ovarian failure in surgical treatment.

The use of aromatase inhibitor, letrozole (LTZ), in reproductive medicine started in 2001. After this publication, there have been many groups of investigators studying the use of LTZ either in OI or ovarian stimulation in IVF cycles. A large multicentre randomized trial reported a significantly higher ovulation rate and live-birth rate comparing LTZ with CC. In majority of the publications, the multiple pregnancy rate was lower in LTZ group than in CC group. This can be attributed to the higher chance of monofollicular development after LTZ compared with CC. However, there is no information comparing the hormonal profile and follicular development after letrozole and CC.

Mild ovarian stimulation using LTZ or CC in conjunction with intrauterine insemination is commonly offered to ovulatory women with unexplained infertility, minimal endometriosis or mild factor to improve the pregnancy rate. There is again no information comparing the hormonal profile and follicular development after letrozole and CC in ovulatory women.

The aim of this study is to compare the hormonal profile after the use of LTZ and CC in anovulatory PCOS women and ovulatory women with unexplained subfertility. The hypothesis is that the FSH risk after LTZ is shorter than that of CC.

Study Type

Interventional

Enrollment (Anticipated)

40

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

  • Name: Vivian Lee, MBBS, MRCOG
  • Phone Number: 22553400
  • Email: v200lee@hku.hk

Study Locations

  • Hong Kong
      • Hong Kong, Hong Kong, 852
        • Recruiting
        • Queen Mary Hospital
        • Contact:
          • Vivian CY Lee, MBBS
          • Phone Number: 852-22553400
          • Email: v200lee@hku.hk
        • Principal Investigator:
          • Vivian Lee
        • Sub-Investigator:
          • Ernest HY Ng, MD

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

16 years to 37 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion criteria:

  • Age of women 18-39 years
  • Irregular menstrual cycles with anovulation (cycle >35 days) together with polycystic ovaries on pelvic scanning or laboratory/clinical hyperandrogenism (in PCOS group)
  • Regular cycle of 25-35 days cycle for the ovulatory women group
  • Body mass index </= 30 kg/m2

Exclusion criteria:

  • Couples undergoing ART treatment cycles
  • History of ovarian surgery
  • Drug allergy to CC or LTZ
  • History of diabetes mellitus or other severe medical diseases
  • Refusal to join the study

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: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: PCOS group
PCOS women with anovulation
Drug: Letrozole
Letrozole 2.5 mg daily from Day 2 to 6
Other Names:
  • Letrozole group
Drug: Clomiphene
After one month of washout period, clomiphene 50 mg daily from day 2 to day 6 given
Other Names:
  • Clomiphene group
Other: Ovulatory group
Ovulatory group planned for intra-uterine insemination
Drug: Letrozole
Letrozole 2.5 mg daily from Day 2 to 6
Other Names:
  • Letrozole group
Drug: Clomiphene
After one month of washout period, clomiphene 50 mg daily from day 2 to day 6 given
Other Names:
  • Clomiphene group

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
FSH concentrations
Time Frame: Alternative day during ovulation induction cycle (for about 3 month)
Alternative day during ovulation induction cycle (for about 3 month)

Secondary Outcome Measures

Outcome Measure
Time Frame
LHconcentration
Time Frame: Alternative day during ovulation induction cycles (for about 3 month)
Alternative day during ovulation induction cycles (for about 3 month)
Endometrial Thickness
Time Frame: Monitoring during ovulation induction cycle (for about 3 month)
Monitoring during ovulation induction cycle (for about 3 month)
Oestradiol concentration
Time Frame: Alternative day during ovulation induction cycles (for about 3 month)
Alternative day during ovulation induction cycles (for about 3 month)
Progesterone concentration
Time Frame: Alternative day during ovulation induction cycles (for about 3 month)
Alternative day during ovulation induction cycles (for about 3 month)
Number of growing follicles
Time Frame: Monitoring during OI cycles (for about 3 month)
Monitoring during OI cycles (for about 3 month)

Collaborators and Investigators

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

Sponsor

The University of Hong Kong

Investigators

  • Principal Investigator: Vivian Lee, MBBS, MRCOG, Queen Mary Hospital / University of Hong Kong.

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

December 1, 2015

Primary Completion (Anticipated)

December 1, 2017

Study Completion (Anticipated)

December 1, 2017

Study Registration Dates

First Submitted

December 29, 2015

First Submitted That Met QC Criteria

January 5, 2016

First Posted (Estimate)

January 6, 2016

Study Record Updates

Last Update Posted (Estimate)

October 27, 2016

Last Update Submitted That Met QC Criteria

October 26, 2016

Last Verified

October 1, 2016

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HKU-VL-LCC

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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