Letrozole Versus Clomifene Citrate for Ovulation Induction

Double Blind Cross-over Randomized Controlled Trial Comparing Letrozole Versus Clomifene Citrate for Ovulation Induction in Women With Polycystic Ovarian Syndrome

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00478504

Enrollment

159

Registered

2007-05-24

Start date

2007-05-31

Completion date

2014-09-30

Last updated

2016-10-28

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

Conditions

Infertility, Polycystic Ovarian Syndrome

Keywords

anovulation, ovulation induction,, polycystic ovarian syndrome, clomifene citrate, letrozole

Brief summary

The primary aim of the study is to assess the efficacy of letrozole as an ovulation induction agent and to test the hypothesis that letrozole will generate better pregnancy rates with fewer multiple pregnancies and higher live birth rate than the current standard agent, clomifene citrate in anovular infertile women with polycystic ovarian syndrome.

Interventions

DRUGLetrozole

Starting daily dose 2.5 mg on menstrual cycles days 2 to 6, to be increased to 5 mg daily if there is no response to 2.5 mg

DRUGClomifene citrate

Starting daily dose 50 mg on menstrual cycles days 2 to 6, to be increased to 100 mg daily if there is no response to 50 mg

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

FEMALE

Age

18 Years to 39 Years

Healthy volunteers

Inclusion criteria

1. Age: 18 - 39 2. BMI \< 36 3. Infertility due to anovulation 4. PCOS: At least two of the following diagnostic criteria of: 1. Oligo/amenorrhoea 2. Hyperandrogenaemia: biochemical (testosterone ≥2.5 nmol/l or free androgen index (FAI) ≥ 5) or clinical (acne/hirsutism) evidence 3. USS evidence of PCO (either ≥12 follicles measuring 2-9 mm in diameter, or an ovarian volume of \> 10 ml) 5. No recent (within 6 months) treatment for induction of ovulation 6. Normal semen analysis (WHO 1999) 7. Proven patency of at least one Fallopian tube

Exclusion criteria

1. Inability to give informed consent 2. Contraindication to letrozole or clomifene citrate 3. Absence of any inclusion criteria

Design outcomes

Primary

Measure	Time frame
Pregnancy rate	14 moths

Secondary

Measure	Time frame
1. Ovulation rate 2. Number of growing and mature follicles during treatment 3. Miscarriage rate 4. Live-birth rate 5. Multiple pregnancy rate 6. Endometrial thickness	14 months

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 9, 2026