Randomized Controlled Trial of Combined Letrozole and Clomid (CLC II) Versus Letrozole Alone for Women With Anovulation

Inclusion Criteria:

1. Willing to comply with all study procedures and be available for the duration of thestudy

2. Diagnosis of infertility: Inability of couple to achieve successful pregnancy after 12 months of regular time unprotected intercourse in women less than 35 years ofage; and after 6 months of regular intercourse without use of contraception in women 35 years and older. Women that have anovulation or oligomenorrhea are alsoconsidered to meet diagnosis of infertility, without meeting the time constraintsdescribed above.

3. Diagnosis of polycystic ovary syndrome based on Revised Rotterdam criteria.

4. Ability to have regular intercourse during the ovulation induction phase of thestudy.

5. Partner with a normal sperm concentration of 15 million/mL and with normal motilityof >40% according to World Health Organization cutoff points or greater than 10million total motile sperm count OR has fathered a pregnancy in the past.

Exclusion Criteria:

1. Current pregnancy

2. Current use of hormonal contraception; use of any type of combined contraceptive ororal progestins within the past month; or use of hormonal implants or depoprogestins within the past 3 months

3. Other known cause of infertility: endometriosis, tubal factor, uterine abnormalities

4. Uncorrected thyroid disease

5. Untreated hyperprolactinemia

6. Medical conditions in which avoiding pregnancy is recommended until under improvedcontrol: poorly controlled Type 1 or Type 2 diabetes, poorly controlled hypertension

7. Contraindications to clomiphene citrate: hypersensitivity to clomiphene citrate orany of its components, history of liver disease or known liver disease, unknowncause of abnormal uterine bleeding, or intracranial lesion

8. Contraindications to letrozole: hypersensitivity to letrozole or any of itscomponents

9. Use of medications known to affect reproductive function or metabolism or that arean absolute contraindication during pregnancy within the past month

10. If patients are suspected based on clinical findings for other etiologies that mimicPCOS, work up must be completed to exclude other etiologies prior to enrollment (i.e. Cushing's syndrome, androgen-secreting tumor)