Recent findings suggest that letrozole may be a superior Clomiphene Citrate.

Women with polycystic ovary syndrome (PCOS) can suffer from infertility because they do not produce an egg each month, resulting in irregular periods. As a result, these women often need a medication called clomiphene citrate (clomiphene) to induce ovulation. A traditional 'clomiphene protocol' begins with a short course of progestin treatment to bring on a period (termed a 'withdrawal bleed') before starting the clomiphene medication. Newer evidence, however, has suggested that this progestin-induced shedding of the uterine lining (i.e., withdrawal bleed) may decrease the chances of pregnancy. The purpose of our study is to determine whether withdrawal bleeding has an impact on pregnancy rates for patients with PCOS undergoing a clomiphene cycle.

It is hypothesized that patients who undergo ovulation induction with clomiphene citrate without prior endometrial shedding will have higher clinical pregnancy rates than those who begin with a progestin-induced withdrawal bleed.

Inclusion Criteria:

• Polycystic ovary syndrome (Rotterdam 2003 Consensus Criteria) and a diagnosis of anovulatory infertility
• Age 18-38 years
• At least 1 patent fallopian tube (as demonstrated by hysterosalpingogram, hydrotubation or hysterosonogram within the last year)
• Normal semen analysis (total motile sperm count >20million/ml)
• Normal uterine cavity (as demonstrated by hysterosalpingogram, hydrotubation or hysterosonogram within the last year)
• Undergoing ovulation-induction with clomiphene citrate without intra-uterine insemination (IUI)

Exclusion Criteria:

• Body mass index (BMI) < 17 kg/m2 or > 40 kg/m2
• Prior treatment with clomiphene citrate
• Presence of a hydrosalpinx (as seen on ultrasound, hysterosalpingogram, hydrotubation or hysterosonogram)
• Those with systemic disease such as diabetes mellitus, uncontrolled thyroid disease, systemic lupus erythematosus and antiphospholipid antibody syndrome
• Any other cause of infertility other than anovulation