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A Comparison of Letrozole and Clomifene Citrate

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

Status
UNKNOWN
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02647424
Enrollment
40
Registered
2016-01-06
Start date
2015-12-31
Completion date
2017-12-31
Last updated
2016-10-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Polycystic Ovarian Syndrome, Subfertility

Brief summary

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.

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.

Interventions

DRUGLetrozole

Letrozole 2.5 mg daily from Day 2 to 6

DRUGClomiphene

After one month of washout period, clomiphene 50 mg daily from day 2 to day 6 given

Sponsors

The University of Hong Kong
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 39 Years
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frame
FSH concentrationsAlternative day during ovulation induction cycle (for about 3 month)

Secondary

MeasureTime frame
LHconcentrationAlternative day during ovulation induction cycles (for about 3 month)
Endometrial ThicknessMonitoring during ovulation induction cycle (for about 3 month)
Oestradiol concentrationAlternative day during ovulation induction cycles (for about 3 month)
Progesterone concentrationAlternative day during ovulation induction cycles (for about 3 month)
Number of growing folliclesMonitoring during OI cycles (for about 3 month)

Countries

Hong Kong

Contacts

Primary ContactVivian Lee, MBBS, MRCOG
v200lee@hku.hk22553400

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026