The primary research hypothesis is that ovulation induction with an aromatase inhibitor (letrozole) is more likely to result in live birth than ovulation induction with a selective estrogen receptor modulator (clomiphene citrate) in infertile women with PCOS. A safety hypothesis will also be incorporated into the primary research hypothesis in which we hypothesize both treatments are equally safe for mother and child. Secondary research hypotheses include: 1. Treatment with letrozole is more likely to result in singleton pregnancy compared to treatment with clomiphene citrate. Singleton pregnancy is defined as presence of a single intrauterine gestational sac with a single fetal pole and observable heart motion. 2. Treatment with letrozole will less likely result in a first trimester intrauterine fetal demise than treatment with clomiphene citrate. A first trimester IUFD is defined as a pregnancy that ends before 13 weeks gestation. 3. Treatment with letrozole is more likely to result in ovulation (increased ovulation rate) compared to treatment with clomiphene citrate. Ovulation is defined as a midluteal progesterone level ≥ 3 ng/mL. 4. The shortest time to pregnancy will be with letrozole. 5. Age, body mass index, SHBG, testosterone, LH, Anti-Mullerian Hormone (AMH), and degree of hirsutism and acne will be significant predictors of ovulation and conception regardless of treatment. 6. Improvement in SHBG, testosterone, AMH, and LH levels will be significant predictors of ovulation and conception regardless of treatment. 7. DNA polymorphisms in estrogen action genes will predict response to study drug. 8. Quality of Life will be better on letrozole than clomiphene. 9. Letrozole will be more cost effective at achieving singleton pregnancies than clomiphene.
Preliminary data are promising for the use of letrozole to induce ovulation in infertile women with PCOS. However the true magnitude of the effect of letrozole is difficult to discern from prior studies. Therefore we intend to determine the safety and efficacy of letrozole, an aromatase inhibitor, compared to clomiphene citrate, a selective estrogen receptor modulator, in achieving live birth in infertile women with PCOS. Treatment- After progestin withdrawal, 750 women will be equally randomized to two different treatment arms: A) clomiphene citrate 50 mg every day for 5 days (day 3-7 of cycle), or B) letrozole 2.5 mg every day for 5 days (day 3-7 of cycle), for a total of 5 cycles or 20 weeks. Dose will be increased in subsequent cycles in both treatment groups for non-response or poor ovulatory response up to a maximum of 150 mg of clomiphene a day (x 5 days) or 7.5 mg of letrozole a day (x 5 days). Statistical Analysis- The primary analysis will use an intent-to-treat approach to examine differences in the live birth rate in the two treatment arms. Anticipated time to completion- A total of 4 years will be required to complete the study after start up; 31 month enrollment period, 5 month treatment period, with 9 month additional observation to determine pregnancy outcomes. This will be accomplished by enrolling \~3.45 women with PCOS per center per month over the enrollment period (N = 7 RMN sites).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
750
Clomiphene citrate 50 mg every day for 5 days (day 3-7 of cycle), for a total of 5 cycles or 20 weeks
Letrozole 2.5 mg every day for 5 days (day 3-7 of cycle), for a total of 5 cycles or 20 weeks
University of Alabama Birmingham
Birmingham, Alabama, United States
Stanford University Medical Center
Stanford, California, United States
University of Colorado
Aurora, Colorado, United States
Yale University
New Haven, Connecticut, United States
University of Michigan
Ann Arbor, Michigan, United States
Wayne State University
Detroit, Michigan, United States
Carolinas Medical Center
Charlotte, North Carolina, United States
Pennsylvania State University College of Medicine
Hershey, Pennsylvania, United States
University of Pennsylvania
Philadelphia, Pennsylvania, United States
University of Texas Health Science Center at San Antonio
San Antonio, Texas, United States
...and 2 more locations
Live Birth
The primary outcome measure is the occurrence of a live birth during the study period. Safety measures will be the number and type of reported adverse events in subjects and offspring.
Time frame: as few as 5 months, up to 16 months
Number of Pregnancy
Time frame: as few as 5 months, up to 16 months
Number of Ovulations
Time frame: as few as 5 months, up to 16 months
Number of Serious Adverse Events
Time frame: as few as 5 months, up to 16 months
Neonatal Complication Rate
Time frame: September 2008 - December 2011
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