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Study On The Effects of Letrozole And Clomiphene Citrate For Induction of Ovulation In Polycystic Ovarian Syndrome(PCOS)


Phase 3
19 Years
39 Years
Not Enrolling
Female
Polycystic Ovarian Syndrome

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Trial Information

Study On The Effects of Letrozole And Clomiphene Citrate For Induction of Ovulation In Polycystic Ovarian Syndrome(PCOS)


Polycystic Ovarian Syndrome (PCOS) is the most common endocrinopathy among women of
reproductive age group and is one of the leading causes of infertility. It is characterized
by chronic anovulation and hyperandrogenism with variable clinical manifestations that
include oligomenorrhea, infertility, hirsutism, and acne (Ehrmann DA 2005).

Several methods have been described to induce ovulation in PCOS patients- weight reduction,
laparoscopic ovarian drilling and the use of various induction ovulation agents like
clomiphene citrate (CC), aromatase inhibitors (AIs) and gonadotrophins.

Clomiphene citrate (CC) has been most widely used and standard drug for the treatment of
infertility. It is known that clomiphene citrate results in an ovulation rate of 60-85%, but
a conception rate of only around 20% (Bayar et al 2006, Sohrabvand et al 2006). About 20-25%
of women are resistant to CC and do not ovulate. Discrepancy between ovulation and pregnancy
rate is related to anti-estrogenic activity on endometrium and cervical mucus is due to CC
has a long half life of 5 to 7 days.

In view of disappointing result of CC treatment with many adverse effect and cost and
possible complication of gonadotrophin, the concept of aromatase inhibition was proposed as
a new method of ovulation that are easy to use, less expensive and more effective drugs.

Letrozole is an oral, potent, reversible, and highly selective aromatase inhobitor that
prevent androgen-to-estrogen (E) conversion. These aromatase inhibitors have a short half
life (45 hours), hence is rapidly eliminated from the body. No adverse effect on E target
tissues is seen with letrozole due to this short half life; furthermore, it does not down
regulate the ER compare to CC.

The main impetus for the development of aromatase inhibitor as ovulation induction agents
was to avoid the peripheral antiestrogenic effects of CC, especially the frequent occurrence
of a thin endometrial lining (Sohrabvand et al 2006).

Rationale of performing the study As both medications i.e. CC and letrozole have been shown
to be effective in inducing ovulation in PCOS patients, this study was performed in order to
evaluate which regime (whether CC or letrozole) is the best to be used as the first line
treatment for PCOS patients with infertility for local population. The best regime will
therefore could be included in the protocol of management of infertility patients with PCOS
so that the quality of patients' care could be improved.

HYPOTHESIS

Letrozole is more effective than clomiphene citrate as ovulation agent in PCOS patients.

General Objective To compare the effectiveness of letrozole and clomiphene citrate as
ovulation agent in PCOS.

Specific Objectives

i. To identify the ovulation percentage between letrozole and CC ii. To compare the
endometrial thickness between letrozole and CC iii. To determine the pregnancy outcome
between letrozole and CC iv. To study the associated factors that can affect the
effectiveness of the treatment e.g. age, body weight, smoking, duration of marriage,
duration of infertility and types of infertility either primary or secondary)

Methodology

1.0 Study design

Prospective, multicenter, randomized control trial.

2.0 Population and sample

Reference population

The reference population will be the female patient diagnosed to have polycystic ovarian
syndrome at infertility clinic HSB, Kedah and infertility clinic HUSM, Kelantan and
infertility Clinic, Hospital Tengku Ampuan Afzan (HTAA), Kuantan, Pahang.

3.0 Selection criteria 3.1 Inclusion criteria i. Age > 18 years but < 40 years old ii.
Was diagnosed PCOS iii. Patient is not illiterate. iv. Normal husband's seminal fluid
analysis (SFA) - (Count > 20 million/ml, Motility > 40% and normal morphology > 30%) 3.2
Exclusion criteria : i. Having medical problem eg- renal disease, tyhroid disorder,
hyperprolactinemia, liver disease.

ii. Other causes of anovulatory infertility

4.0 Sampling and Sample size

4.1 Sample size

Sample size calculation:

1. Ovulation percentage

From Hananel Holzer 2006

Proportion of ovulation rate by using Clomiphene citrate (Po) = 0.60 Proportion of
ovualtion rate by using Letrozole (P1) = 0.84

P = P1 + Po = 0.83 + 0.64 = 0.72 zα = 1.96 zβ = 0.84 for 80% power 2
2 Significance level (α) = 5% (0.05) Power of study ( 1 - β )= 80% β =20% ( 0.2 ) n
= (zα√2P(1-P) + zβ√P1(1-P1)+Po(1-Po))2 (P1-Po)2 n = ( 1.96√2(0.72)(1-0.72) +
0.84√0.83(1-0.84) + 0.60(1-0.60))2 (0.75 - 0.50 )2 n = 54 Therefore sample size = 108
+ 20 % drop out = 130 By using PS software - sample size : 130

2. Endomterial thickness between letrozole and CC From Mosammat Rhasid et al 2008
Letrozole 2.5 mg, mean ± SD ratio -10.37 ± 1.2 CC 100mg, mean ± SD ratio -
9.03 ± 0.89

- - 0.5 n = 2 α2 (zα + zβ)2

- 2 = 2 (1.2)2 ( 1.96 + 0.84) 2 (0.5)2 = 49 per group Therefore sample size = 98 +
20 % drop out Total n = 117 By using software, n = 51 per group, total n = 122

3. Pregnancy rate between letrozole and CC From Mosammat Rashida Begum 2008 Letrozole
2.5mg - pregnancy rate - 40.6% CC 100mg - pregnancy rate - 18.7% ( Po ) =
0.18 (P1) = 0.41 P = P1 + Po = 0.41 + 0.18 = 0.30 zα = 1.96 zβ = 0.84 for 80% power 2
2 Significance level (α) = 5% (0.05) Power of study ( 1 - β )= 80% β
=20% ( 0.2 ) n = (zα√2P(1-P) + zβ√P1(1-P1)+Po(1-Po))2 (P1-Po)2 n = (
1.96√2(0.30)(1-0.30) + 0.84√0.41(1-0.41) + 0.18(1-0.18))2 (0.41-0.18 )2 n = 61
Therefore sample size = 120 + 20 % drop out n= 146

- The maximun sample size that were calculated for this study is 146. Therefore
sample size that were decided for the the study = 150 patients

4.2 Sampling frame All PCOS patients attending Infertility Clinic Hospital Sultanah Bahiyah
(HSB), Kedah, Infertility Clinic Hospital Universiti Sains Malaysia (HUSM), Kelantan and
Infertility Clinic Hospital Tengku Ampuan Afzan (HTAA), Kuantan, Pahang who fulfill
inclusion and exclusion criteria will be recruited in the study.

5.0 Methods of data collection

The study will be conducted after the approval from Hospital Sultanah Bahiyah, Kedah, USM
and HTAA, Pahang ethical committee.

All PCOS patients, age more than 18 years old at Gynecology Clinic, HUSM were given
information form regarding the study conducted. When the participants agree to involve in
this study, the consent form will be given to them. Participants are required to fill the
social demographic data which includes age, address, occupation, monthly family income,
education status, and duration of marriage, number of parity and year of last child birth.
Measurement such as waist circumference, weight, height and blood pressure reading will be
recorded. Then patients will be randomized into two groups

Randomization PCOS women who are eligible and fulfilling the criteria of the study will
recruit. After they had given inform consent, they will assigned to one of the groups of
sealed opaque envelope labelled as C and L. Women in group C will assigned CC 100mg and
those in L assigned Letrozole 2.5 mg. The randomization will be done by computer- generated
randomization using http://www.randomization.com according to the random sequence.

Group 1- Letrozole group

- The patients will be given letrozole 2.5 mg from D5-D9 of menses.

- Base line TVS at D2 will be done, following spontaneous menses/induction with MPA 10 mg
Daily for 1 week.

- Transvaginal scan was done to document the evidence of ovulation only if patient having
menses (D8 -10 onwards ).

- If dominant follicle (DF) present (DF> 12mm), repeat TVS every 2 days,

- ovulation is diagnosed when the mature DF is about 18 to 22 mm and then evidence of
ruptured about 3 to 4 days later

o If dominant follicle (DF) absent (DF<12mm), repeat TVS every 3-4 days later.

- Measure Endometrial thickness (ET) for every follow-up.

- If absent of Dominant follicle (DF<12mm up to Days 20), consider failed or
anovulation.

Group 2 Clomiphene Citrate Group

- The patients will be given CC 100 mg from D5-D9 of menses.

- Base line TVS at D2 will be done, following spontaneous menses /induction with MPA 10
mg Daily for 1 week.

- Transvaginal scan was done to document the evidence of ovulation only if patient having
menses (D8 -10 onwards).

- If dominant follicle (DF) present (DF> 12mm), repeat TVS every 2 days,

- ovulation is diagnosed when the mature DF is about 18 to 22 mm and then evidence of
ruptured about 3 to 4 days later

- If dominant follicle (DF) absent (DF<12mm), repeat TVS every 3-4 days later.

- Measure Endometrial thickness (ET) for every follow-up.

- If absent of dominant follicle (DF<12mm up to Days 20), consider failed or
anovulation.

In all groups a urine pregnancy test was done 3 weeks after documented ovulation and the
patient remained amenorrheic. All study medications will be discontinued when there was a
positive pregnancy test. Pregnant patients were then will be followed up until an ultrasound
could document the viability of pregnancy. Copies of patients' obstetric records, including
delivery records, were reviewed by the investigators to obtain obstetrics outcomes e.g:
miscarriage, ectopic pregnancy, molar pregnancy, preterm delivery etc).

Research tool

- General Questionnaire

- Weighing scale using Seca weighing machine

- Measuring tape

- Ultrasound machine

- BP set Investigations Urine pregnancy test Hormonal and biochemical profiles

Inclusion Criteria


Inclusion criteria

- Age > 18 years but < 40 years old

- Was diagnosed PCOS

- Normal husband's seminal fluid analysis (SFA)

Exclusion criteria :

- Not having medical problems eg- renal disease, tyhroid disorder, hyperprolactinemia,
liver disease.

- Other causes of anovulatory infertility

Type of Study:

Interventional

Study Design:

Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Outcome Measure:

To evaluate the effectiveness of ovulation induction among PCOS patients

Outcome Description:

To evaluate the effectiveness of letrozole and clomiphene citrate for induction of ovulation in PCOS patients.

Outcome Time Frame:

6 weeks

Safety Issue:

Yes

Authority:

Malaysia: Ministry of Health

Study ID:

PCOS- Letrozole vs Clomid

NCT ID:

NCT01577017

Start Date:

May 2008

Completion Date:

March 2012

Related Keywords:

  • Polycystic Ovarian Syndrome
  • ovulation induction, clomiphene citrate, letrozole
  • Polycystic Ovary Syndrome

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